{"title":"Hydrogen Sulfide (H2S) Detectors","description":"\u003c!-- gas-type subcollection: hydrogen-sulfide-detectors | smart tag = h2s-detector --\u003e\n\n\u003ch2\u003eWhich hydrogen sulfide (H2S) detector should you buy in 2026?\u003c\/h2\u003e\n\n\u003cp\u003e\u003cstrong\u003eShort answer:\u003c\/strong\u003e For hydrogen sulfide, choose a single-gas clip like the \u003ca href=\"\/products\/honeywell-bw-clip-h2s-monitor-bwc2-h\" title=\"Honeywell BW Clip H2S\"\u003eHoneywell BW Clip H2S\u003c\/a\u003e when H2S is the only hazard, or a \u003ca href=\"\/products\/forensics-detectors-4-gas-meter-confined-space\" title=\"4-gas monitor\"\u003e4-gas monitor\u003c\/a\u003e when you also need O2, LEL and CO for confined-space entry.\u003c\/p\u003e\n\n\u003cp\u003eHydrogen sulfide (H2S) is a colorless, highly toxic gas with a rotten-egg odor that deadens your sense of smell at dangerous levels. It is the signature hazard of oil and gas, wastewater, sewers, and pulp and paper. H2S is detected by electrochemical sensors in both single-gas clips and 4-gas monitors.\u003c\/p\u003e\n\n\u003cp\u003eThis is a gas-type collection under the \u003ca href=\"\/collections\/gas-detectors\" title=\"Gas Detectors\"\u003eGas Detectors\u003c\/a\u003e hub. Match the gas to the right form factor: \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"Portable Gas Detectors\"\u003ePortable Gas Detectors\u003c\/a\u003e for carried checks, \u003ca href=\"\/collections\/personal-gas-detectors\" title=\"Personal \u0026amp; Wearable Gas Detectors\"\u003ePersonal \u0026amp; Wearable Gas Detectors\u003c\/a\u003e for single-worker exposure, \u003ca href=\"\/collections\/fixed-gas-detection-systems\" title=\"Fixed Gas Detection Systems\"\u003eFixed Gas Detection Systems\u003c\/a\u003e for continuous plant monitoring, \u003ca href=\"\/collections\/area-gas-monitors\" title=\"Area \u0026amp; Transportable Gas Monitors\"\u003eArea \u0026amp; Transportable Gas Monitors\u003c\/a\u003e for job-site zones, and \u003ca href=\"\/collections\/gas-leak-detectors\" title=\"Gas Leak Detectors\"\u003eGas Leak Detectors\u003c\/a\u003e to pinpoint a leak source.\u003c\/p\u003e\n\n\u003ch2\u003eDetectors in this collection\u003c\/h2\u003e\n\n\u003cp\u003eThis collection gathers every H2S-capable instrument we stock — dedicated single-gas clips (\u003ca href=\"\/products\/honeywell-bw-clip-h2s-monitor-bwc2-h\" title=\"BW Clip H2S\"\u003eBW Clip H2S\u003c\/a\u003e, \u003ca href=\"\/products\/bw-gasalertclip-extreme-h2s-monitor\" title=\"BW GasAlertClip Extreme\"\u003eBW GasAlertClip Extreme\u003c\/a\u003e, \u003ca href=\"\/products\/toptes-guard-633-h2s-detector\" title=\"TopTes Guard-633\"\u003eTopTes Guard-633\u003c\/a\u003e) and the full range of \u003ca href=\"\/products\/forensics-detectors-4-gas-meter-confined-space\" title=\"4-gas monitors\"\u003e4-gas monitors\u003c\/a\u003e that include an H2S channel. Browse by form factor in \u003ca href=\"\/collections\/personal-gas-detectors\" title=\"Personal \u0026amp; Wearable\"\u003ePersonal \u0026amp; Wearable\u003c\/a\u003e and \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"Portable\"\u003ePortable\u003c\/a\u003e.\u003c\/p\u003e\n\n\u003cblockquote style=\"background:#1a1a1a;border-left:4px solid #ff9800;padding:14px 18px;margin:18px 0;color:#f5e6d3;\"\u003e\n\u003cstrong style=\"color:#ffb74d;\"\u003eEditor’s pick — a single-gas H2S clip or a 4-gas monitor\u003c\/strong\u003e\u003cbr\u003eFor H2S-only work the maintenance-free \u003ca href=\"\/products\/honeywell-bw-clip-h2s-monitor-bwc2-h\" title=\"Honeywell BW Clip H2S\"\u003eHoneywell BW Clip H2S\u003c\/a\u003e is the lowest cost per worker; for confined-space entry a \u003ca href=\"\/products\/forensics-detectors-4-gas-meter-confined-space\" title=\"4-gas monitor\"\u003e4-gas monitor\u003c\/a\u003e adds O2, LEL and CO. \u003cspan style=\"display:block;margin-top:6px;font-size:0.82em;color:#bdae9d;\"\u003eAs an Amazon Associate, WC Safety earns from qualifying purchases.\u003c\/span\u003e\u003cp style=\"margin-top:12px;\"\u003e\u003ca href=\"https:\/\/www.amazon.com\/s?k=hydrogen+sulfide+h2s+gas+detector\u0026amp;tag=wcsafety04-20\" rel=\"sponsored nofollow noopener\" target=\"_blank\" style=\"display:inline-block;background:#FFD814;color:#0F1111;padding:12px 22px;text-decoration:none;font-weight:bold;border-radius:4px;border:1px solid #FCD200;\"\u003eCHECK PRICES ON AMAZON →\u003c\/a\u003e\u003c\/p\u003e\n\u003c\/blockquote\u003e\n\n\u003ch2\u003eHow to choose a hydrogen sulfide detector\u003c\/h2\u003e\n\n\u003ch3\u003eSingle-gas or multi-gas?\u003c\/h3\u003e\u003cp\u003eIf H2S is the only hazard, a single-gas clip worn in the breathing zone is simplest. For confined-space entry, a 4-gas monitor covers H2S plus oxygen, combustibles and CO.\u003c\/p\u003e\u003ch3\u003eWatch the odor trap\u003c\/h3\u003e\u003cp\u003eH2S deadens your sense of smell at higher concentrations, so never rely on odor — a calibrated detector is essential.\u003c\/p\u003e\u003ch3\u003ePlacement\u003c\/h3\u003e\u003cp\u003eH2S is heavier than air and collects in low and enclosed areas like sumps, vaults and tank bottoms.\u003c\/p\u003e\n\n\u003ch2\u003eHydrogen Sulfide (H2S) hazard, exposure limits \u0026amp; placement\u003c\/h2\u003e\n\n\u003cp\u003eOSHA sets a ceiling of 20 ppm for hydrogen sulfide in general industry, and ACGIH lists a 1 ppm TWA with a 5 ppm short-term limit. H2S is heavier than air and lethal at high concentrations. Set low alarm points and bump-test daily. Confirm current limits with \u003ca href=\"https:\/\/www.osha.gov\/annotated-pels\" rel=\"noopener\" target=\"_blank\" style=\"color:#4fc3f7;\"\u003eOSHA's annotated PEL tables\u003c\/a\u003e.\u003c\/p\u003e\n\n\u003ch2 id=\"faq\"\u003eFrequently asked questions\u003c\/h2\u003e\n\u003ch3\u003eWhat detects hydrogen sulfide?\u003c\/h3\u003e\u003cp\u003eAn electrochemical H2S sensor in a single-gas clip or a 4-gas monitor. For H2S-only work use a clip like the \u003ca href=\"\/products\/honeywell-bw-clip-h2s-monitor-bwc2-h\" title=\"BW Clip H2S\"\u003eBW Clip H2S\u003c\/a\u003e; for confined space a \u003ca href=\"\/products\/forensics-detectors-4-gas-meter-confined-space\" title=\"4-gas monitor\"\u003e4-gas monitor\u003c\/a\u003e.\u003c\/p\u003e\n\u003ch3\u003eWhat is the OSHA limit for H2S?\u003c\/h3\u003e\u003cp\u003eA 20 ppm ceiling in general industry per the \u003ca href=\"https:\/\/www.osha.gov\/annotated-pels\" rel=\"noopener\" target=\"_blank\" style=\"color:#4fc3f7;\"\u003eOSHA PEL\u003c\/a\u003e; ACGIH lists a 1 ppm TWA and 5 ppm STEL.\u003c\/p\u003e\n\u003ch3\u003eWhy can't I rely on the rotten-egg smell?\u003c\/h3\u003e\u003cp\u003eH2S deadens your sense of smell at dangerous concentrations, so the odor disappears just when the hazard is greatest. Always use a calibrated detector.\u003c\/p\u003e\n\u003ch3\u003eSingle-gas H2S clip or 4-gas monitor?\u003c\/h3\u003e\u003cp\u003eUse a single-gas clip when H2S is the only hazard; use a \u003ca href=\"\/products\/forensics-detectors-4-gas-meter-confined-space\" title=\"4-gas monitor\"\u003e4-gas monitor\u003c\/a\u003e for confined-space entry where O2, combustibles and CO also matter.\u003c\/p\u003e\n\u003ch3\u003eWhere does H2S collect?\u003c\/h3\u003e\u003cp\u003eH2S is heavier than air and accumulates in low, enclosed spaces — sumps, vaults, manholes and tank bottoms — so test those areas first.\u003c\/p\u003e\n\u003ch3\u003eWhere is H2S detection needed?\u003c\/h3\u003e\u003cp\u003eOil and gas, wastewater and sewers, pulp and paper, tanning and agriculture. Browse \u003ca href=\"\/collections\/personal-gas-detectors\" title=\"wearable clips\"\u003ewearable clips\u003c\/a\u003e and \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"portable monitors\"\u003eportable monitors\u003c\/a\u003e.\u003c\/p\u003e\n\u003ch3\u003eDo H2S sensors need calibration?\u003c\/h3\u003e\u003cp\u003eYes — bump-test before each day of use with H2S calibration gas and calibrate on schedule; electrochemical H2S sensors are consumables.\u003c\/p\u003e\n\u003ch3\u003eCan I use it for confined-space entry?\u003c\/h3\u003e\u003cp\u003eFor entry use a \u003ca href=\"\/products\/forensics-detectors-4-gas-meter-confined-space\" title=\"4-gas monitor\"\u003e4-gas monitor\u003c\/a\u003e (often with a pump) so you cover oxygen and combustibles as well as H2S.\u003c\/p\u003e\n\u003ch3\u003eHow long do H2S sensors last?\u003c\/h3\u003e\u003cp\u003eTypically two to three years; plan for sensor replacement and calibration gas as ongoing costs.\u003c\/p\u003e\n\u003ch3\u003eWhat's the difference between a clip and a 4-gas monitor for H2S?\u003c\/h3\u003e\u003cp\u003eA clip monitors H2S only and is the cheapest per worker; a \u003ca href=\"\/products\/forensics-detectors-4-gas-meter-confined-space\" title=\"4-gas monitor\"\u003e4-gas monitor\u003c\/a\u003e adds O2, LEL and CO for full confined-space coverage.\u003c\/p\u003e\n\n\u003cdiv style=\"background:#1a2733;border:1px dashed #4fc3f7;padding:16px 20px;margin:30px 0 18px 0;color:#cfd8dc;font-size:0.92em;\"\u003e\n\u003cstrong style=\"color:#4fc3f7;\"\u003eWhy trust this hydrogen sulfide detector collection?\u003c\/strong\u003e WC Safety is an independent industrial safety-equipment retailer. This collection is curated on detection principle, gas coverage and certification, grounded in published OSHA standards and manufacturer data — not paid placement. Disclosed: we earn Amazon affiliate commissions on outbound links; that does not influence what we recommend.\u003c\/div\u003e\n\u003cdiv style=\"background:#1a2733;border-left:4px solid #4fc3f7;padding:18px 22px;margin:18px 0;color:#cfd8dc;font-size:0.92em;\"\u003e\n\u003cstrong style=\"color:#4fc3f7;\"\u003eCurated by Steven Eaton, WC Safety Editorial\u003c\/strong\u003e — Industrial safety-equipment desk · atmospheric monitoring and chemical-specific gas detection.\u003cbr\u003e\n\u003cstrong\u003eLast reviewed:\u003c\/strong\u003e \u003ctime datetime=\"2026-06-22\"\u003eJune 22, 2026\u003c\/time\u003e · \u003cstrong\u003eSources:\u003c\/strong\u003e OSHA Annotated PEL tables, OSHA 29 CFR 1910, ACGIH Threshold Limit Values, manufacturer data sheets.\u003c\/div\u003e\n\u003cdiv style=\"background:#2a2520;border-left:4px solid #ff9800;padding:16px 20px;margin:18px 0;color:#f5e6d3;font-size:0.92em;\"\u003e\n\u003cstrong style=\"color:#ffb74d;\"\u003eDisclosure.\u003c\/strong\u003e WC Safety participates in the Amazon Associates Program (tag wcsafety04-20). Buyer guidance only, not medical, legal or regulatory advice — confirm gas-detection requirements against the applicable OSHA standard and, for commercial programs, a Certified Industrial Hygienist (CIH).\u003c\/div\u003e\n\n\u003cscript type=\"application\/ld+json\"\u003e\n{\n \"@context\": \"https:\/\/schema.org\",\n \"@graph\": [\n  {\n   \"@type\": \"CollectionPage\",\n   \"@id\": \"https:\/\/wcsafety.com\/collections\/hydrogen-sulfide-detectors#collection\",\n   \"name\": \"Hydrogen Sulfide (H2S) Detectors\",\n   \"description\": \"Shop hydrogen sulfide (H2S) detectors for oil \u0026 gas, wastewater and confined space — single-gas clips and 4-gas monitors. Compare and choose.\",\n   \"url\": \"https:\/\/wcsafety.com\/collections\/hydrogen-sulfide-detectors\",\n   \"isPartOf\": {\n    \"@type\": \"WebSite\",\n    \"name\": \"WC Safety\",\n    \"url\": \"https:\/\/wcsafety.com\"\n   },\n   \"breadcrumb\": {\n    \"@id\": \"https:\/\/wcsafety.com\/collections\/hydrogen-sulfide-detectors#breadcrumb\"\n   }\n  },\n  {\n   \"@type\": \"FAQPage\",\n   \"mainEntity\": [\n    {\n     \"@type\": \"Question\",\n     \"name\": \"What detects hydrogen sulfide?\",\n     \"acceptedAnswer\": {\n      \"@type\": \"Answer\",\n      \"text\": \"An electrochemical H2S sensor in a single-gas clip or a 4-gas monitor. For H2S-only work use a clip like the BW Clip H2S; for confined space a 4-gas monitor.\"\n     }\n    },\n    {\n     \"@type\": \"Question\",\n     \"name\": \"What is the OSHA limit for H2S?\",\n     \"acceptedAnswer\": {\n      \"@type\": \"Answer\",\n      \"text\": \"A 20 ppm ceiling in general industry per the OSHA PEL; ACGIH lists a 1 ppm TWA and 5 ppm STEL.\"\n     }\n    },\n    {\n     \"@type\": \"Question\",\n     \"name\": \"Why can't I rely on the rotten-egg smell?\",\n     \"acceptedAnswer\": {\n      \"@type\": \"Answer\",\n      \"text\": \"H2S deadens your sense of smell at dangerous concentrations, so the odor disappears just when the hazard is greatest. Always use a calibrated detector.\"\n     }\n    },\n    {\n     \"@type\": \"Question\",\n     \"name\": \"Single-gas H2S clip or 4-gas monitor?\",\n     \"acceptedAnswer\": {\n      \"@type\": \"Answer\",\n      \"text\": \"Use a single-gas clip when H2S is the only hazard; use a 4-gas monitor for confined-space entry where O2, combustibles and CO also matter.\"\n     }\n    },\n    {\n     \"@type\": \"Question\",\n     \"name\": \"Where does H2S collect?\",\n     \"acceptedAnswer\": {\n      \"@type\": \"Answer\",\n      \"text\": \"H2S is heavier than air and accumulates in low, enclosed spaces — sumps, vaults, manholes and tank bottoms — so test those areas first.\"\n     }\n    },\n    {\n     \"@type\": \"Question\",\n     \"name\": \"Where is H2S detection needed?\",\n     \"acceptedAnswer\": {\n      \"@type\": \"Answer\",\n      \"text\": \"Oil and gas, wastewater and sewers, pulp and paper, tanning and agriculture. Browse wearable clips and portable monitors.\"\n     }\n    },\n    {\n     \"@type\": \"Question\",\n     \"name\": \"Do H2S sensors need calibration?\",\n     \"acceptedAnswer\": {\n      \"@type\": \"Answer\",\n      \"text\": \"Yes — bump-test before each day of use with H2S calibration gas and calibrate on schedule; electrochemical H2S sensors are consumables.\"\n     }\n    },\n    {\n     \"@type\": \"Question\",\n     \"name\": \"Can I use it for confined-space entry?\",\n     \"acceptedAnswer\": {\n      \"@type\": \"Answer\",\n      \"text\": \"For entry use a 4-gas monitor (often with a pump) so you cover oxygen and combustibles as well as H2S.\"\n     }\n    },\n    {\n     \"@type\": \"Question\",\n     \"name\": \"How long do H2S sensors last?\",\n     \"acceptedAnswer\": {\n      \"@type\": \"Answer\",\n      \"text\": \"Typically two to three years; plan for sensor replacement and calibration gas as ongoing costs.\"\n     }\n    },\n    {\n     \"@type\": \"Question\",\n     \"name\": \"What's the difference between a clip and a 4-gas monitor for H2S?\",\n     \"acceptedAnswer\": {\n      \"@type\": \"Answer\",\n      \"text\": \"A clip monitors H2S only and is the cheapest per worker; a 4-gas monitor adds O2, LEL and CO for full confined-space coverage.\"\n     }\n    }\n   ]\n  },\n  {\n   \"@type\": \"BreadcrumbList\",\n   \"@id\": \"https:\/\/wcsafety.com\/collections\/hydrogen-sulfide-detectors#breadcrumb\",\n   \"itemListElement\": [\n    {\n     \"@type\": \"ListItem\",\n     \"position\": 1,\n     \"name\": \"Home\",\n     \"item\": \"https:\/\/wcsafety.com\/\"\n    },\n    {\n     \"@type\": \"ListItem\",\n     \"position\": 2,\n     \"name\": \"Gas Detectors\",\n     \"item\": \"https:\/\/wcsafety.com\/collections\/gas-detectors\"\n    },\n    {\n     \"@type\": \"ListItem\",\n     \"position\": 3,\n     \"name\": \"Hydrogen Sulfide (H2S) Detectors\"\n    }\n   ]\n  }\n ]\n}\n\u003c\/script\u003e","products":[{"product_id":"forensics-detectors-4-gas-meter-confined-space","title":"Forensics Detectors 4 Gas Meter for Confined Space (O2, CO, H2S, LEL)","description":"\u003c!-- PRODUCT B0GNQ37S9C | tag portable-gas-detector | TODO: add matching Product Review + best-of guide links when those silo layers exist --\u003e\n\n\u003cdiv style=\"background:#1a1a1a;border-left:4px solid #ff9800;padding:14px 18px;margin:0 0 18px 0;color:#f5e6d3;font-size:0.95em;\"\u003e\n\u003cstrong style=\"color:#ffb74d;\"\u003eEditor’s note:\u003c\/strong\u003e the Forensics Detectors 4 gas meter is one of the portable instruments we curate in our \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"Portable Gas Detectors\"\u003ePortable Gas Detectors\u003c\/a\u003e buyer’s hub. Compare it head-to-head with the \u003ca href=\"\/products\/forensics-detectors-4-gas-monitor-usb-rechargeable\" title=\"Forensics Detectors USB 4 Gas Monitor\"\u003eForensics Detectors USB 4 Gas Monitor\u003c\/a\u003e below before you order.\u003c\/div\u003e\n\n\u003ch2 id=\"top\"\u003eForensics Detectors 4 Gas Meter — Confined-Space O2, CO, H2S \u0026amp; LEL Monitor\u003c\/h2\u003e\n\n\u003cp\u003eThe \u003cstrong\u003eForensics Detectors 4 gas meter\u003c\/strong\u003e is a NIST-calibrated, confined-space-ready monitor that reads oxygen (O2), combustible gas (LEL), carbon monoxide (CO) and hydrogen sulfide (H2S) in one pass — the four-hazard set \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"portable gas detector\"\u003eportable gas detector\u003c\/a\u003e buyers need for permit entry. At 4.8 oz with triple alarms, it is built for field crews who want documented accuracy without a fleet-management contract.\u003c\/p\u003e\n\n\u003cp style=\"font-size:0.9em;color:#bdae9d;margin:10px 0 18px 0;\"\u003eJump to: \u003ca href=\"#features\" style=\"color:#ffb74d;\"\u003eFeatures\u003c\/a\u003e · \u003ca href=\"#specs\" style=\"color:#ffb74d;\"\u003eSpecs\u003c\/a\u003e · \u003ca href=\"#compatibility\" style=\"color:#ffb74d;\"\u003eWhat it detects\u003c\/a\u003e · \u003ca href=\"#comparison\" style=\"color:#ffb74d;\"\u003eComparison\u003c\/a\u003e · \u003ca href=\"#faq\" style=\"color:#ffb74d;\"\u003eFAQ\u003c\/a\u003e\u003c\/p\u003e\n\n\u003cp\u003eThe Forensics Detectors 4 Gas Meter is a battery-powered, electrochemical four-gas monitor (O2, CO, H2S, LEL) with a NIST calibration certificate, designed for \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"portable\"\u003eportable\u003c\/a\u003e confined-space pre-entry testing.\u003c\/p\u003e\n\n\u003ch3 id=\"features\"\u003eKey features\u003c\/h3\u003e\n\n\u003cul\u003e\n\u003cli\u003eReads all four confined-space hazards — oxygen (O2), combustible gas (LEL), carbon monoxide (CO) and hydrogen sulfide (H2S) — on one screen\u003c\/li\u003e\n\u003cli\u003eShips with a USA NIST calibration certificate so you can document instrument accuracy from day one\u003c\/li\u003e\n\u003cli\u003eTriple alarm — adjustable audible, visual LED and vibration — for noisy or low-visibility work\u003c\/li\u003e\n\u003cli\u003eElectrochemical nano sensors with zero and span calibration options for ongoing accuracy\u003c\/li\u003e\n\u003cli\u003eRugged anti-slip ABS housing that is water-resistant, dust-proof and explosion-resistant\u003c\/li\u003e\n\u003cli\u003eLight 4.8 oz body that clips to a belt or harness for pre-entry checks\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cdiv style=\"display:flex;gap:14px;flex-wrap:wrap;margin:18px 0;\"\u003e\n\u003cdiv style=\"flex:1;min-width:240px;background:#1b3a2a;border:1px solid #4caf50;border-radius:6px;padding:14px 18px;\"\u003e\n\u003cstrong style=\"color:#81c784;\"\u003ePros\u003c\/strong\u003e\u003cul style=\"margin:8px 0 0 0;\"\u003e\n\u003cli\u003eNIST calibration certificate included\u003c\/li\u003e\n\u003cli\u003eHighest customer rating in our portable lineup (4.9\/5)\u003c\/li\u003e\n\u003cli\u003eAdjustable audible, visual and vibration alarms\u003c\/li\u003e\n\u003cli\u003eVery light at 4.8 oz\u003c\/li\u003e\n\u003cli\u003eZero\/span field calibration supported\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"flex:1;min-width:240px;background:#3a1e1e;border:1px solid #ef5350;border-radius:6px;padding:14px 18px;\"\u003e\n\u003cstrong style=\"color:#e57373;\"\u003eCons\u003c\/strong\u003e\u003cul style=\"margin:8px 0 0 0;\"\u003e\n\u003cli\u003eDiffusion sampling only — no built-in pump for remote pre-entry testing\u003c\/li\u003e\n\u003cli\u003eField\/value-grade; not a managed-fleet instrument like Industrial Scientific or BW Honeywell\u003c\/li\u003e\n\u003cli\u003eElectrochemical sensors need periodic replacement (typically every 2–3 years)\u003c\/li\u003e\n\u003cli\u003eSingle unit — no docking-station bump\/cal automation\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\n\u003ch3 id=\"specs\"\u003eSpecifications\u003c\/h3\u003e\n\n\u003cdiv style=\"overflow-x:auto;\"\u003e\u003ctable style=\"width:100%;border-collapse:collapse;background:#1a1a1a;margin:14px 0;\"\u003e\n\u003cthead\u003e\u003ctr style=\"background:#2a2a2a;\"\u003e\n\u003cth style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;text-align:left;\"\u003eSpecification\u003c\/th\u003e\n\u003cth style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;text-align:left;\"\u003eDetail\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eGases detected\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eO2, CO, H2S, LEL combustibles\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eSensor type\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eElectrochemical (nano sensors)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eAlarms\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eAudible, visual (LED) \u0026amp; vibration, adjustable\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eCalibration\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eZero \u0026amp; span; NIST certificate included\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003ePower\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eRechargeable battery\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eWeight\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003e4.8 oz\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eDimensions\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003e2.6\" x 1.2\" x 5.1\"\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eBuild\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eHigh-strength ABS, water\/dust\/explosion-resistant\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eColor\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eYellow\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003c\/div\u003e\n\n\u003ch3\u003eWhere the Forensics Detectors 4 Gas Meter fits\u003c\/h3\u003e\n\n\u003cul\u003e\n\u003cli\u003eConfined-space pre-entry atmosphere checks\u003c\/li\u003e\n\u003cli\u003eSewer, vault and manhole spot tests\u003c\/li\u003e\n\u003cli\u003eTank and vessel entry monitoring\u003c\/li\u003e\n\u003cli\u003eHVAC, boiler and mechanical-room checks\u003c\/li\u003e\n\u003cli\u003eGeneral industrial walk-around monitoring\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2 id=\"compatibility\"\u003eWhat the Forensics Detectors 4 Gas Meter detects (and what it doesn’t)\u003c\/h2\u003e\n\n\u003cp\u003eThis meter measures oxygen (O2), combustible gas (LEL), carbon monoxide (CO) and hydrogen sulfide (H2S) — the standard four-gas set for confined-space entry. It does \u003cstrong\u003enot\u003c\/strong\u003e read volatile organic compounds (VOCs), CO2, or single toxics such as chlorine or ammonia; those need a dedicated PID or gas-specific sensor. It uses diffusion sampling, so it reads the air around it — to draw a remote sample from the bottom of a tank before entry, choose the \u003ca href=\"\/products\/forensics-detectors-4-gas-monitor-with-pump\" title=\"Forensics Detectors 4 Gas Monitor with Pump\"\u003eForensics Detectors 4 Gas Monitor with Pump\u003c\/a\u003e instead. Keep it accurate with zero\/span calibration and a periodic bump test using standard four-gas calibration gas. For all-shift single-worker wear, pair it with a clip from \u003ca href=\"\/collections\/personal-gas-detectors\" title=\"Personal \u0026amp; Wearable Gas Detectors\"\u003ePersonal \u0026amp; Wearable Gas Detectors\u003c\/a\u003e.\u003c\/p\u003e\n\n\u003cp\u003eCross-shopping? This unit sits in our \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"Portable Gas Detectors\"\u003ePortable Gas Detectors\u003c\/a\u003e hub alongside the \u003ca href=\"\/products\/forensics-detectors-4-gas-monitor-usb-rechargeable\" title=\"Forensics Detectors USB 4 Gas Monitor\"\u003eForensics Detectors USB 4 Gas Monitor\u003c\/a\u003e, \u003ca href=\"\/products\/toptes-guard-863pro-4-gas-monitor\" title=\"TopTes Guard-863Pro\"\u003eTopTes Guard-863Pro\u003c\/a\u003e, \u003ca href=\"\/products\/toptes-guard-101-4-gas-detector\" title=\"TopTes Guard-101\"\u003eTopTes Guard-101\u003c\/a\u003e, \u003ca href=\"\/products\/toptes-guard-156-4-gas-monitor\" title=\"TopTes Guard-156\"\u003eTopTes Guard-156\u003c\/a\u003e. If one worker needs all-shift wear instead of a carried meter, see \u003ca href=\"\/collections\/personal-gas-detectors\" title=\"Personal \u0026amp; Wearable Gas Detectors\"\u003ePersonal \u0026amp; Wearable Gas Detectors\u003c\/a\u003e; for a fixed install or a job-site perimeter, see \u003ca href=\"\/collections\/fixed-gas-detection-systems\" title=\"Fixed Gas Detection Systems\"\u003eFixed Gas Detection Systems\u003c\/a\u003e and \u003ca href=\"\/collections\/area-gas-monitors\" title=\"Area \u0026amp; Transportable Gas Monitors\"\u003eArea \u0026amp; Transportable Gas Monitors\u003c\/a\u003e.\u003c\/p\u003e\n\n\u003ch2 id=\"comparison\"\u003eForensics Detectors 4-gas family compared\u003c\/h2\u003e\n\n\u003cdiv style=\"overflow-x:auto;\"\u003e\u003ctable style=\"width:100%;border-collapse:collapse;background:#1a1a1a;margin:14px 0;\"\u003e\n\u003ccaption style=\"color:#bdae9d;font-size:0.85em;text-align:left;padding:4px 0;\"\u003eForensics Detectors portable 4-gas family (O2, CO, H2S, LEL)\u003c\/caption\u003e\n\u003cthead\u003e\u003ctr style=\"background:#2a2a2a;\"\u003e\n\u003cth style=\"color:#ffb74d;padding:9px;border:1px solid #3a3a3a;text-align:left;\"\u003eModel\u003c\/th\u003e\n\u003cth style=\"color:#ffb74d;padding:9px;border:1px solid #3a3a3a;text-align:left;\"\u003eSampling\u003c\/th\u003e\n\u003cth style=\"color:#ffb74d;padding:9px;border:1px solid #3a3a3a;text-align:left;\"\u003eNIST cert\u003c\/th\u003e\n\u003cth style=\"color:#ffb74d;padding:9px;border:1px solid #3a3a3a;text-align:left;\"\u003eRecharge\u003c\/th\u003e\n\u003cth style=\"color:#ffb74d;padding:9px;border:1px solid #3a3a3a;text-align:left;\"\u003eStreet price\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e\u003ca href=\"\/products\/forensics-detectors-4-gas-meter-confined-space\" title=\"4 Gas Meter (Confined Space)\"\u003e4 Gas Meter (Confined Space)\u003c\/a\u003e\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eDiffusion\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eYes\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eBattery\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e~$199\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e\u003ca href=\"\/products\/forensics-detectors-4-gas-monitor-usb-rechargeable\" title=\"4 Gas Monitor (USB)\"\u003e4 Gas Monitor (USB)\u003c\/a\u003e\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eDiffusion\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eYes\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eUSB rechargeable\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e~$225\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#2a2520;\"\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e\u003cstrong\u003e\u003ca href=\"\/products\/forensics-detectors-4-gas-monitor-with-pump\" title=\"4 Gas Monitor + Pump\"\u003e4 Gas Monitor + Pump\u003c\/a\u003e\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eMotorized pump + probe\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eYes\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eUSB rechargeable\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e~$299\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003c\/div\u003e\n\n\u003cul\u003e\n\u003cli\u003eChoose this \u003cstrong\u003e4 Gas Meter\u003c\/strong\u003e for the lightest, lowest-cost NIST-certified diffusion unit for routine pre-entry checks.\u003c\/li\u003e\n\u003cli\u003eStep up to the \u003ca href=\"\/products\/forensics-detectors-4-gas-monitor-usb-rechargeable\" title=\"USB-rechargeable 4 Gas Monitor\"\u003eUSB-rechargeable 4 Gas Monitor\u003c\/a\u003e if you want USB charging and a higher review count.\u003c\/li\u003e\n\u003cli\u003eMove to the \u003ca href=\"\/products\/forensics-detectors-4-gas-monitor-with-pump\" title=\"4 Gas Monitor with Pump\"\u003e4 Gas Monitor with Pump\u003c\/a\u003e if you must sample remotely before entry.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2 id=\"faq\"\u003eFrequently asked questions\u003c\/h2\u003e\n\n\u003ch3\u003eWhat gases does the Forensics Detectors 4 gas meter detect?\u003c\/h3\u003e\u003cp\u003eIt detects oxygen (O2), combustible gas (LEL), carbon monoxide (CO) and hydrogen sulfide (H2S) — the four atmospheric hazards required for confined-space entry. For VOCs you need a separate PID unit; browse the full \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"Portable Gas Detectors\"\u003ePortable Gas Detectors\u003c\/a\u003e range for options.\u003c\/p\u003e\n\u003ch3\u003eIs the Forensics Detectors 4 gas meter NIST calibrated?\u003c\/h3\u003e\u003cp\u003eYes — it ships with a USA NIST calibration certificate documenting instrument accuracy at the time of calibration. You should still bump-test before each use.\u003c\/p\u003e\n\u003ch3\u003eHow do I calibrate and bump-test this meter?\u003c\/h3\u003e\u003cp\u003eUse standard four-gas calibration gas with the zero and span calibration functions. Bump-test before each day of use to confirm the sensors and alarms respond; do a full calibration on the manufacturer's schedule.\u003c\/p\u003e\n\u003ch3\u003eCan I use this for confined-space entry?\u003c\/h3\u003e\u003cp\u003eYes — its O2\/CO\/H2S\/LEL set matches the hazards OSHA 1910.146 names for permit entry. For pre-entry sampling of a sealed space, the \u003ca href=\"\/products\/forensics-detectors-4-gas-monitor-with-pump\" title=\"pump version\"\u003epump version\u003c\/a\u003e lets you test before anyone enters.\u003c\/p\u003e\n\u003ch3\u003eDoes it have a pump or is it diffusion?\u003c\/h3\u003e\u003cp\u003eThis model is diffusion — it reads the air around it. If you need to draw a remote sample through a probe, choose the \u003ca href=\"\/products\/forensics-detectors-4-gas-monitor-with-pump\" title=\"Forensics Detectors 4 Gas Monitor with Pump\"\u003eForensics Detectors 4 Gas Monitor with Pump\u003c\/a\u003e.\u003c\/p\u003e\n\u003ch3\u003eHow is it powered and how long does it run?\u003c\/h3\u003e\u003cp\u003eIt runs on a rechargeable internal battery sized for a full work shift. Recharge between shifts so it is always ready for pre-entry checks.\u003c\/p\u003e\n\u003ch3\u003eWhat alarms does it have?\u003c\/h3\u003e\u003cp\u003eAdjustable audible, visual LED and vibration alarms trip when a gas reaches its preset level — useful in loud or low-visibility environments.\u003c\/p\u003e\n\u003ch3\u003eHow long do the sensors last?\u003c\/h3\u003e\u003cp\u003eThe electrochemical sensors typically last two to three years depending on exposure. Budget for sensor replacement and calibration gas as ongoing costs.\u003c\/p\u003e\n\u003ch3\u003eWhat does this meter NOT detect?\u003c\/h3\u003e\u003cp\u003eIt does not read VOCs, CO2, or specific toxics like chlorine or ammonia. For those, a PID or gas-specific instrument is required — see the wider \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"Portable Gas Detectors\"\u003ePortable Gas Detectors\u003c\/a\u003e hub.\u003c\/p\u003e\n\u003ch3\u003eIs it in stock and how does it ship?\u003c\/h3\u003e\u003cp\u003eStocked items ship through our Amazon fulfillment partner; use the buy button for current availability and delivery timing.\u003c\/p\u003e\n\u003ch3\u003eHow does it compare to the USB-rechargeable Forensics monitor?\u003c\/h3\u003e\u003cp\u003eBoth read the same four gases with NIST certificates; the \u003ca href=\"\/products\/forensics-detectors-4-gas-monitor-usb-rechargeable\" title=\"USB 4 Gas Monitor\"\u003eUSB 4 Gas Monitor\u003c\/a\u003e adds USB charging and has more reviews, while this meter is lighter and lower cost.\u003c\/p\u003e\n\u003ch3\u003eIs this an industrial-grade instrument?\u003c\/h3\u003e\u003cp\u003eIt is a NIST-certified field meter well suited to small crews and facilities. Large managed-fleet programs that need docking-station automation usually specify Industrial Scientific or BW Honeywell instruments.\u003c\/p\u003e\n\n\u003cdiv style=\"background:#1a1a1a;border:1px solid #3a3a3a;border-radius:6px;padding:16px 18px;margin:22px 0;\"\u003e\n\u003cp style=\"margin:0 0 10px 0;color:#f5e6d3;\"\u003eReady to order the \u003cstrong\u003eForensics Detectors 4 gas meter\u003c\/strong\u003e? Add it to your cart above, or check the current Amazon price below. Compare it against the rest of our \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"Portable Gas Detectors\"\u003ePortable Gas Detectors\u003c\/a\u003e lineup before you buy.\u003c\/p\u003e\n\u003cp style=\"display:flex;gap:10px;flex-wrap:wrap;align-items:center;margin:0;\"\u003e\u003ca href=\"https:\/\/www.amazon.com\/dp\/B0GNQ37S9C?tag=wcsafety04-20\" rel=\"sponsored nofollow noopener\" target=\"_blank\" style=\"display:inline-block;background:#FFD814;color:#0F1111;padding:13px 26px;text-decoration:none;font-weight:bold;border-radius:4px;border:1px solid #FCD200;\"\u003eCHECK PRICE ON AMAZON →\u003c\/a\u003e\u003cspan style=\"font-size:0.8em;color:#bdae9d;\"\u003eAs an Amazon Associate, WC Safety earns from qualifying purchases.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/div\u003e\n\n\u003cdiv style=\"background:#1a2733;border:1px dashed #4fc3f7;padding:16px 20px;margin:30px 0 18px 0;color:#cfd8dc;font-size:0.92em;\"\u003e\n  \u003cstrong style=\"color:#4fc3f7;\"\u003eWhy trust this Forensics Detectors page?\u003c\/strong\u003e WC Safety is an independent industrial safety-equipment retailer serving safety managers, procurement teams and field supervisors. The specifications on this page are taken from the manufacturer’s published listing for Forensics Detectors 4 Gas Meter and framed against \u003ca href=\"https:\/\/www.osha.gov\/laws-regs\/regulations\/standardnumber\/1910\/1910.146\" rel=\"noopener\" target=\"_blank\" style=\"color:#4fc3f7;\"\u003eOSHA 29 CFR 1910.146\u003c\/a\u003e for confined-space atmospheric testing. Disclosed: WC Safety earns Amazon affiliate commissions on outbound clicks; that does not influence the specs shown or where this unit sits in our lineup.\n\u003c\/div\u003e\n\u003cdiv style=\"background:#1a2733;border-left:4px solid #4fc3f7;padding:18px 22px;margin:18px 0;color:#cfd8dc;font-size:0.92em;\"\u003e\n  \u003cstrong style=\"color:#4fc3f7;\"\u003eBy Steven Eaton, WC Safety Editorial\u003c\/strong\u003e — Industrial safety-equipment desk · specialization: portable atmospheric monitoring, confined-space gas detection and instrument selection.\u003cbr\u003e\n  \u003cstrong\u003eLast updated:\u003c\/strong\u003e \u003ctime datetime=\"2026-06-22\"\u003eJune 22, 2026\u003c\/time\u003e · \u003cstrong\u003eSources reviewed:\u003c\/strong\u003e manufacturer product listing \u0026amp; specifications, OSHA 29 CFR 1910.146, OSHA Annotated PEL tables, ACGIH Threshold Limit Values.\u003cbr\u003e\n  \u003cstrong\u003eEditorial standard:\u003c\/strong\u003e \u003cem\u003eZero sponsored listings. No manufacturer input. Specs verified against the manufacturer’s published data.\u003c\/em\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"background:#1a2733;border-left:4px solid #4fc3f7;padding:16px 20px;margin:18px 0;color:#cfd8dc;font-size:0.92em;\"\u003e\n  \u003cstrong style=\"color:#4fc3f7;\"\u003eHow this page is maintained.\u003c\/strong\u003e Specifications and pricing are reviewed against the manufacturer’s current listing and re-checked whenever the lineup changes. Gas-detection guidance follows \u003ca href=\"https:\/\/www.osha.gov\/laws-regs\/regulations\/standardnumber\/1910\/1910.146\" rel=\"noopener\" target=\"_blank\" style=\"color:#4fc3f7;\"\u003eOSHA 1910.146\u003c\/a\u003e (permit-required confined spaces) and \u003ca href=\"https:\/\/www.osha.gov\/annotated-pels\" rel=\"noopener\" target=\"_blank\" style=\"color:#4fc3f7;\"\u003eOSHA Permissible Exposure Limits\u003c\/a\u003e, cross-referenced with ACGIH TLVs.\n\u003c\/div\u003e\n\u003cdiv style=\"background:#2a2520;border-left:4px solid #ff9800;padding:16px 20px;margin:18px 0;color:#f5e6d3;font-size:0.92em;\"\u003e\n  \u003cstrong style=\"color:#ffb74d;\"\u003eDisclosure.\u003c\/strong\u003e WC Safety participates in the Amazon Associates Program and earns commissions on qualifying purchases through outbound links on this page (tag wcsafety04-20). We are not sponsored by any instrument manufacturer. This page is buyer guidance, not medical, legal or regulatory advice — confirm gas-detection requirements for your site against the applicable OSHA standard and, for commercial monitoring programs, a Certified Industrial Hygienist (CIH).\n\u003c\/div\u003e\n\n\u003cscript type=\"application\/ld+json\"\u003e\n{\"@context\": \"https:\/\/schema.org\", \"@graph\": [{\"@type\": \"Product\", \"@id\": \"https:\/\/wcsafety.com\/products\/forensics-detectors-4-gas-meter-confined-space#product\", \"name\": \"Forensics Detectors 4 Gas Meter for Confined Space (O2, CO, H2S, LEL)\", \"description\": \"Forensics Detectors 4 gas meter for confined space — O2, CO, H2S \u0026 LEL, NIST-calibrated with triple alarm. Order this pre-entry monitor at WC Safety.\", \"sku\": \"B0GNQ37S9C\", \"mpn\": \"FD-4Gas\", \"image\": [\"https:\/\/wcsafety.com\/cdn\/shop\/products\/forensics-detectors-4-gas-meter-confined-space.jpg\"], \"brand\": {\"@type\": \"Brand\", \"name\": \"Forensics Detectors\"}, \"category\": \"Portable Gas Detector\", \"isPartOf\": {\"@type\": \"CollectionPage\", \"@id\": \"https:\/\/wcsafety.com\/collections\/portable-gas-detectors#collection\", \"name\": \"Portable Gas Detectors\", \"url\": \"https:\/\/wcsafety.com\/collections\/portable-gas-detectors\"}, \"isRelatedTo\": [{\"@type\": \"Product\", \"name\": \"Forensics Detectors 4 Gas Monitor (USB Rechargeable)\", \"url\": \"https:\/\/wcsafety.com\/products\/forensics-detectors-4-gas-monitor-usb-rechargeable\"}, {\"@type\": \"Product\", \"name\": \"TopTes Guard-863Pro 4 Gas Monitor\", \"url\": \"https:\/\/wcsafety.com\/products\/toptes-guard-863pro-4-gas-monitor\"}, {\"@type\": \"Product\", \"name\": \"TopTes Guard-101 4 Gas Detector\", \"url\": \"https:\/\/wcsafety.com\/products\/toptes-guard-101-4-gas-detector\"}, {\"@type\": \"Product\", \"name\": \"TopTes Guard-156 4 Gas Monitor\", \"url\": \"https:\/\/wcsafety.com\/products\/toptes-guard-156-4-gas-monitor\"}, {\"@type\": \"Product\", \"name\": \"Forensics Detectors 4 Gas Monitor with Pump\", \"url\": \"https:\/\/wcsafety.com\/products\/forensics-detectors-4-gas-monitor-with-pump\"}, {\"@type\": \"Product\", \"name\": \"Forsensal 4 Gas Detector with Pump\", \"url\": \"https:\/\/wcsafety.com\/products\/forsensal-4-gas-detector-with-pump\"}], \"offers\": {\"@type\": \"Offer\", \"url\": \"https:\/\/wcsafety.com\/products\/forensics-detectors-4-gas-meter-confined-space\", \"priceCurrency\": \"USD\", \"price\": \"199.00\", \"availability\": \"https:\/\/schema.org\/InStock\", \"seller\": {\"@type\": \"Organization\", \"name\": \"WC Safety\"}}}, {\"@type\": \"BreadcrumbList\", \"@id\": \"https:\/\/wcsafety.com\/products\/forensics-detectors-4-gas-meter-confined-space#breadcrumb\", \"itemListElement\": [{\"@type\": \"ListItem\", \"position\": 1, \"name\": \"Home\", \"item\": \"https:\/\/wcsafety.com\/\"}, {\"@type\": \"ListItem\", \"position\": 2, \"name\": \"Gas Detectors\", \"item\": \"https:\/\/wcsafety.com\/collections\/gas-detectors\"}, {\"@type\": \"ListItem\", \"position\": 3, \"name\": \"Portable Gas Detectors\", \"item\": \"https:\/\/wcsafety.com\/collections\/portable-gas-detectors\"}, {\"@type\": \"ListItem\", \"position\": 4, \"name\": \"Forensics Detectors 4 Gas Meter for Confined Space (O2, CO, H2S, LEL)\"}]}, {\"@type\": \"FAQPage\", \"mainEntity\": [{\"@type\": \"Question\", \"name\": \"What gases does the Forensics Detectors 4 gas meter detect?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"It detects oxygen (O2), combustible gas (LEL), carbon monoxide (CO) and hydrogen sulfide (H2S) — the four atmospheric hazards required for confined-space entry. For VOCs you need a separate PID unit; browse the full Portable Gas Detectors range for options.\"}}, {\"@type\": \"Question\", \"name\": \"Is the Forensics Detectors 4 gas meter NIST calibrated?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Yes — it ships with a USA NIST calibration certificate documenting instrument accuracy at the time of calibration. You should still bump-test before each use.\"}}, {\"@type\": \"Question\", \"name\": \"How do I calibrate and bump-test this meter?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Use standard four-gas calibration gas with the zero and span calibration functions. Bump-test before each day of use to confirm the sensors and alarms respond; do a full calibration on the manufacturer's schedule.\"}}, {\"@type\": \"Question\", \"name\": \"Can I use this for confined-space entry?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Yes — its O2\/CO\/H2S\/LEL set matches the hazards OSHA 1910.146 names for permit entry. For pre-entry sampling of a sealed space, the pump version lets you test before anyone enters.\"}}, {\"@type\": \"Question\", \"name\": \"Does it have a pump or is it diffusion?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"This model is diffusion — it reads the air around it. If you need to draw a remote sample through a probe, choose the Forensics Detectors 4 Gas Monitor with Pump.\"}}, {\"@type\": \"Question\", \"name\": \"How is it powered and how long does it run?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"It runs on a rechargeable internal battery sized for a full work shift. Recharge between shifts so it is always ready for pre-entry checks.\"}}, {\"@type\": \"Question\", \"name\": \"What alarms does it have?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Adjustable audible, visual LED and vibration alarms trip when a gas reaches its preset level — useful in loud or low-visibility environments.\"}}, {\"@type\": \"Question\", \"name\": \"How long do the sensors last?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"The electrochemical sensors typically last two to three years depending on exposure. Budget for sensor replacement and calibration gas as ongoing costs.\"}}, {\"@type\": \"Question\", \"name\": \"What does this meter NOT detect?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"It does not read VOCs, CO2, or specific toxics like chlorine or ammonia. For those, a PID or gas-specific instrument is required — see the wider Portable Gas Detectors hub.\"}}, {\"@type\": \"Question\", \"name\": \"Is it in stock and how does it ship?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Stocked items ship through our Amazon fulfillment partner; use the buy button for current availability and delivery timing.\"}}, {\"@type\": \"Question\", \"name\": \"How does it compare to the USB-rechargeable Forensics monitor?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Both read the same four gases with NIST certificates; the USB 4 Gas Monitor adds USB charging and has more reviews, while this meter is lighter and lower cost.\"}}, {\"@type\": \"Question\", \"name\": \"Is this an industrial-grade instrument?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"It is a NIST-certified field meter well suited to small crews and facilities. Large managed-fleet programs that need docking-station automation usually specify Industrial Scientific or BW Honeywell instruments.\"}}]}, {\"@type\": \"Organization\", \"@id\": \"https:\/\/wcsafety.com\/#org\", \"name\": \"WC Safety\", \"url\": \"https:\/\/wcsafety.com\", \"logo\": \"https:\/\/wcsafety.com\/cdn\/shop\/files\/logo.png\"}, {\"@type\": \"Person\", \"@id\": \"https:\/\/wcsafety.com\/#editor\", \"name\": \"Steven Eaton\", \"jobTitle\": \"Editorial Lead\", \"worksFor\": {\"@id\": \"https:\/\/wcsafety.com\/#org\"}, \"knowsAbout\": [\"industrial gas detection\", \"confined-space atmospheric monitoring\", \"personal protective equipment\"]}, {\"@type\": \"Brand\", \"name\": \"Forensics Detectors\"}]}\n\u003c\/script\u003e","brand":"Forensics Detectors","offers":[{"title":"Default Title","offer_id":44266356965464,"sku":"B0GNQ37S9C","price":199.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0594\/1900\/0920\/files\/81tiqJGnDsL._AC_SL1500.jpg?v=1782119866"},{"product_id":"forensics-detectors-4-gas-monitor-usb-rechargeable","title":"Forensics Detectors 4 Gas Monitor (USB Rechargeable, NIST Calibrated)","description":"\u003c!-- PRODUCT B07J1WQST5 | tag portable-gas-detector | TODO: add matching Product Review + best-of guide links when those silo layers exist --\u003e\n\n\u003cdiv style=\"background:#1a1a1a;border-left:4px solid #ff9800;padding:14px 18px;margin:0 0 18px 0;color:#f5e6d3;font-size:0.95em;\"\u003e\n\u003cstrong style=\"color:#ffb74d;\"\u003eEditor’s note:\u003c\/strong\u003e the Forensics Detectors 4 gas monitor is one of the portable instruments we curate in our \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"Portable Gas Detectors\"\u003ePortable Gas Detectors\u003c\/a\u003e buyer’s hub. Compare it head-to-head with the \u003ca href=\"\/products\/forensics-detectors-4-gas-meter-confined-space\" title=\"Forensics Detectors 4 Gas Meter\"\u003eForensics Detectors 4 Gas Meter\u003c\/a\u003e below before you order.\u003c\/div\u003e\n\n\u003ch2 id=\"top\"\u003eForensics Detectors 4 Gas Monitor — USB-Rechargeable O2, CO, H2S \u0026amp; LEL\u003c\/h2\u003e\n\n\u003cp\u003eThe \u003cstrong\u003eForensics Detectors 4 gas monitor\u003c\/strong\u003e is the USB-rechargeable member of the Forensics family, reading oxygen (O2), combustible gas (LEL), carbon monoxide (CO) and hydrogen sulfide (H2S) with a NIST certificate and triple alarms. It is the \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"portable gas detector\"\u003eportable gas detector\u003c\/a\u003e to pick when you want simple USB charging and a long, well-reviewed track record.\u003c\/p\u003e\n\n\u003cp style=\"font-size:0.9em;color:#bdae9d;margin:10px 0 18px 0;\"\u003eJump to: \u003ca href=\"#features\" style=\"color:#ffb74d;\"\u003eFeatures\u003c\/a\u003e · \u003ca href=\"#specs\" style=\"color:#ffb74d;\"\u003eSpecs\u003c\/a\u003e · \u003ca href=\"#compatibility\" style=\"color:#ffb74d;\"\u003eWhat it detects\u003c\/a\u003e · \u003ca href=\"#comparison\" style=\"color:#ffb74d;\"\u003eComparison\u003c\/a\u003e · \u003ca href=\"#faq\" style=\"color:#ffb74d;\"\u003eFAQ\u003c\/a\u003e\u003c\/p\u003e\n\n\u003cp\u003eThe Forensics Detectors 4 Gas Monitor is a USB-rechargeable, electrochemical four-gas instrument (O2, CO, H2S, LEL) with a NIST certificate, built for \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"portable\"\u003eportable\u003c\/a\u003e confined-space and field monitoring.\u003c\/p\u003e\n\n\u003ch3 id=\"features\"\u003eKey features\u003c\/h3\u003e\n\n\u003cul\u003e\n\u003cli\u003eMonitors oxygen (O2), combustible gas (LEL), carbon monoxide (CO) and hydrogen sulfide (H2S) on a single backlit display\u003c\/li\u003e\n\u003cli\u003eUSB-rechargeable — top it up from a laptop, power bank or wall adapter between shifts\u003c\/li\u003e\n\u003cli\u003eIncludes a USA NIST calibration certificate for documented accuracy\u003c\/li\u003e\n\u003cli\u003eAudible, vibration and visual alarms for multi-environment alerting\u003c\/li\u003e\n\u003cli\u003eElectrochemical sensors with zero\/span calibration for field accuracy\u003c\/li\u003e\n\u003cli\u003eMost-reviewed Forensics four-gas unit we stock (123 ratings)\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cdiv style=\"display:flex;gap:14px;flex-wrap:wrap;margin:18px 0;\"\u003e\n\u003cdiv style=\"flex:1;min-width:240px;background:#1b3a2a;border:1px solid #4caf50;border-radius:6px;padding:14px 18px;\"\u003e\n\u003cstrong style=\"color:#81c784;\"\u003ePros\u003c\/strong\u003e\u003cul style=\"margin:8px 0 0 0;\"\u003e\n\u003cli\u003eUSB-rechargeable convenience\u003c\/li\u003e\n\u003cli\u003eNIST calibration certificate included\u003c\/li\u003e\n\u003cli\u003eStrong, well-reviewed track record (123 ratings)\u003c\/li\u003e\n\u003cli\u003eTriple alarm modes\u003c\/li\u003e\n\u003cli\u003ePocketable confined-space form factor\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"flex:1;min-width:240px;background:#3a1e1e;border:1px solid #ef5350;border-radius:6px;padding:14px 18px;\"\u003e\n\u003cstrong style=\"color:#e57373;\"\u003eCons\u003c\/strong\u003e\u003cul style=\"margin:8px 0 0 0;\"\u003e\n\u003cli\u003eDiffusion sampling only — no pump for remote sampling\u003c\/li\u003e\n\u003cli\u003eHeavier (9.6 oz) than the lightweight 4 Gas Meter\u003c\/li\u003e\n\u003cli\u003eElectrochemical sensors need periodic replacement\u003c\/li\u003e\n\u003cli\u003eField-grade; not a docking-station fleet instrument\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\n\u003ch3 id=\"specs\"\u003eSpecifications\u003c\/h3\u003e\n\n\u003cdiv style=\"overflow-x:auto;\"\u003e\u003ctable style=\"width:100%;border-collapse:collapse;background:#1a1a1a;margin:14px 0;\"\u003e\n\u003cthead\u003e\u003ctr style=\"background:#2a2a2a;\"\u003e\n\u003cth style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;text-align:left;\"\u003eSpecification\u003c\/th\u003e\n\u003cth style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;text-align:left;\"\u003eDetail\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eGases detected\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eO2, CO, H2S, LEL combustibles\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eSensor type\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eElectrochemical\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eAlarms\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eAudible, vibration \u0026amp; visual\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eCalibration\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eZero \u0026amp; span; NIST certificate included\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003ePower\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eUSB-rechargeable battery\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eWeight\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003e9.6 oz\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eDimensions\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003e1.18\" x 2.64\" x 5.12\"\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eColor\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eBlack \/ yellow\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003c\/div\u003e\n\n\u003ch3\u003eWhere the Forensics Detectors USB 4 Gas Monitor fits\u003c\/h3\u003e\n\n\u003cul\u003e\n\u003cli\u003eConfined-space pre-entry checks\u003c\/li\u003e\n\u003cli\u003eUtility, sewer and water-treatment work\u003c\/li\u003e\n\u003cli\u003eOil-and-gas field spot monitoring\u003c\/li\u003e\n\u003cli\u003eFacilities and maintenance rounds\u003c\/li\u003e\n\u003cli\u003eFire-overhaul and rescue support checks\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2 id=\"compatibility\"\u003eWhat the Forensics Detectors USB 4 Gas Monitor detects (and what it doesn’t)\u003c\/h2\u003e\n\n\u003cp\u003eIt measures oxygen (O2), combustible gas (LEL), carbon monoxide (CO) and hydrogen sulfide (H2S) and ships NIST-calibrated. Like most compact four-gas units it uses diffusion sampling, so for remote pre-entry sampling step up to the \u003ca href=\"\/products\/forensics-detectors-4-gas-monitor-with-pump\" title=\"pump version\"\u003epump version\u003c\/a\u003e. It does not detect VOCs, CO2 or single toxic gases such as chlorine — those require a PID or dedicated sensor. Recharge over USB, bump-test daily with four-gas calibration gas, and for all-shift single-worker coverage add a clip from \u003ca href=\"\/collections\/personal-gas-detectors\" title=\"Personal \u0026amp; Wearable Gas Detectors\"\u003ePersonal \u0026amp; Wearable Gas Detectors\u003c\/a\u003e.\u003c\/p\u003e\n\n\u003cp\u003eCross-shopping? This unit sits in our \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"Portable Gas Detectors\"\u003ePortable Gas Detectors\u003c\/a\u003e hub alongside the \u003ca href=\"\/products\/forensics-detectors-4-gas-meter-confined-space\" title=\"Forensics Detectors 4 Gas Meter\"\u003eForensics Detectors 4 Gas Meter\u003c\/a\u003e, \u003ca href=\"\/products\/toptes-guard-863pro-4-gas-monitor\" title=\"TopTes Guard-863Pro\"\u003eTopTes Guard-863Pro\u003c\/a\u003e, \u003ca href=\"\/products\/toptes-guard-101-4-gas-detector\" title=\"TopTes Guard-101\"\u003eTopTes Guard-101\u003c\/a\u003e, \u003ca href=\"\/products\/toptes-guard-156-4-gas-monitor\" title=\"TopTes Guard-156\"\u003eTopTes Guard-156\u003c\/a\u003e. If one worker needs all-shift wear instead of a carried meter, see \u003ca href=\"\/collections\/personal-gas-detectors\" title=\"Personal \u0026amp; Wearable Gas Detectors\"\u003ePersonal \u0026amp; Wearable Gas Detectors\u003c\/a\u003e; for a fixed install or a job-site perimeter, see \u003ca href=\"\/collections\/fixed-gas-detection-systems\" title=\"Fixed Gas Detection Systems\"\u003eFixed Gas Detection Systems\u003c\/a\u003e and \u003ca href=\"\/collections\/area-gas-monitors\" title=\"Area \u0026amp; Transportable Gas Monitors\"\u003eArea \u0026amp; Transportable Gas Monitors\u003c\/a\u003e.\u003c\/p\u003e\n\n\u003ch2 id=\"comparison\"\u003eForensics Detectors 4-gas family compared\u003c\/h2\u003e\n\n\u003cdiv style=\"overflow-x:auto;\"\u003e\u003ctable style=\"width:100%;border-collapse:collapse;background:#1a1a1a;margin:14px 0;\"\u003e\n\u003ccaption style=\"color:#bdae9d;font-size:0.85em;text-align:left;padding:4px 0;\"\u003eForensics Detectors portable 4-gas family (O2, CO, H2S, LEL)\u003c\/caption\u003e\n\u003cthead\u003e\u003ctr style=\"background:#2a2a2a;\"\u003e\n\u003cth style=\"color:#ffb74d;padding:9px;border:1px solid #3a3a3a;text-align:left;\"\u003eModel\u003c\/th\u003e\n\u003cth style=\"color:#ffb74d;padding:9px;border:1px solid #3a3a3a;text-align:left;\"\u003eSampling\u003c\/th\u003e\n\u003cth style=\"color:#ffb74d;padding:9px;border:1px solid #3a3a3a;text-align:left;\"\u003eNIST cert\u003c\/th\u003e\n\u003cth style=\"color:#ffb74d;padding:9px;border:1px solid #3a3a3a;text-align:left;\"\u003eRecharge\u003c\/th\u003e\n\u003cth style=\"color:#ffb74d;padding:9px;border:1px solid #3a3a3a;text-align:left;\"\u003eStreet price\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e\u003ca href=\"\/products\/forensics-detectors-4-gas-meter-confined-space\" title=\"4 Gas Meter (Confined Space)\"\u003e4 Gas Meter (Confined Space)\u003c\/a\u003e\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eDiffusion\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eYes\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eBattery\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e~$199\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e\u003ca href=\"\/products\/forensics-detectors-4-gas-monitor-usb-rechargeable\" title=\"4 Gas Monitor (USB)\"\u003e4 Gas Monitor (USB)\u003c\/a\u003e\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eDiffusion\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eYes\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eUSB rechargeable\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e~$225\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#2a2520;\"\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e\u003cstrong\u003e\u003ca href=\"\/products\/forensics-detectors-4-gas-monitor-with-pump\" title=\"4 Gas Monitor + Pump\"\u003e4 Gas Monitor + Pump\u003c\/a\u003e\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eMotorized pump + probe\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eYes\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eUSB rechargeable\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e~$299\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003c\/div\u003e\n\n\u003cul\u003e\n\u003cli\u003eChoose this \u003cstrong\u003eUSB 4 Gas Monitor\u003c\/strong\u003e for USB charging and the most-reviewed Forensics option.\u003c\/li\u003e\n\u003cli\u003ePick the lighter \u003ca href=\"\/products\/forensics-detectors-4-gas-meter-confined-space\" title=\"4 Gas Meter\"\u003e4 Gas Meter\u003c\/a\u003e if minimum weight and price matter most.\u003c\/li\u003e\n\u003cli\u003eChoose the \u003ca href=\"\/products\/forensics-detectors-4-gas-monitor-with-pump\" title=\"4 Gas Monitor with Pump\"\u003e4 Gas Monitor with Pump\u003c\/a\u003e when remote sampling is required.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2 id=\"faq\"\u003eFrequently asked questions\u003c\/h2\u003e\n\n\u003ch3\u003eWhat gases does the Forensics Detectors 4 gas monitor detect?\u003c\/h3\u003e\u003cp\u003eIt reads oxygen (O2), combustible gas (LEL), carbon monoxide (CO) and hydrogen sulfide (H2S) — the standard confined-space set. VOCs require a separate PID; see the \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"Portable Gas Detectors\"\u003ePortable Gas Detectors\u003c\/a\u003e hub.\u003c\/p\u003e\n\u003ch3\u003eHow is the Forensics 4 gas monitor recharged?\u003c\/h3\u003e\u003cp\u003eOver USB — from a laptop, power bank or wall adapter. A full charge covers a typical work shift.\u003c\/p\u003e\n\u003ch3\u003eDoes it come NIST calibrated?\u003c\/h3\u003e\u003cp\u003eYes, it ships with a USA NIST calibration certificate. Bump-test before each use and calibrate on schedule to maintain accuracy.\u003c\/p\u003e\n\u003ch3\u003eIs this monitor good for confined-space entry?\u003c\/h3\u003e\u003cp\u003eYes for ongoing monitoring; its O2\/CO\/H2S\/LEL set matches OSHA 1910.146 hazards. For sampling a space before entry, use the \u003ca href=\"\/products\/forensics-detectors-4-gas-monitor-with-pump\" title=\"pump model\"\u003epump model\u003c\/a\u003e.\u003c\/p\u003e\n\u003ch3\u003eHow heavy is it compared to the 4 Gas Meter?\u003c\/h3\u003e\u003cp\u003eAt 9.6 oz it is heavier than the \u003ca href=\"\/products\/forensics-detectors-4-gas-meter-confined-space\" title=\"4.8 oz 4 Gas Meter\"\u003e4.8 oz 4 Gas Meter\u003c\/a\u003e; the trade-off is USB charging and a larger review base.\u003c\/p\u003e\n\u003ch3\u003eWhat alarms does it use?\u003c\/h3\u003e\u003cp\u003eAudible, vibration and visual alarms trigger when a gas crosses its set point, so alerts register in loud or bright conditions.\u003c\/p\u003e\n\u003ch3\u003eHow often should I bump-test and calibrate it?\u003c\/h3\u003e\u003cp\u003eBump-test before each day of use; perform a full zero\/span calibration on the manufacturer's schedule or after any failed bump test.\u003c\/p\u003e\n\u003ch3\u003eHow long do the sensors last?\u003c\/h3\u003e\u003cp\u003eElectrochemical sensors generally last two to three years. Plan for replacement sensors and calibration gas as recurring costs.\u003c\/p\u003e\n\u003ch3\u003eWhat does it not detect?\u003c\/h3\u003e\u003cp\u003eNo VOCs, CO2 or specific toxics like ammonia or chlorine. For VOC work you need a PID; explore options across the \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"Portable Gas Detectors\"\u003ePortable Gas Detectors\u003c\/a\u003e hub.\u003c\/p\u003e\n\u003ch3\u003eCan one monitor cover a whole crew?\u003c\/h3\u003e\u003cp\u003eNo — it monitors the air where it is. For per-worker exposure, issue wearable clips from \u003ca href=\"\/collections\/personal-gas-detectors\" title=\"Personal \u0026amp; Wearable Gas Detectors\"\u003ePersonal \u0026amp; Wearable Gas Detectors\u003c\/a\u003e; for a perimeter use \u003ca href=\"\/collections\/area-gas-monitors\" title=\"Area \u0026amp; Transportable Gas Monitors\"\u003eArea \u0026amp; Transportable Gas Monitors\u003c\/a\u003e.\u003c\/p\u003e\n\u003ch3\u003eIs it in stock?\u003c\/h3\u003e\u003cp\u003eUse the Amazon buy button for live availability and delivery timing through our fulfillment partner.\u003c\/p\u003e\n\u003ch3\u003eIs this a fleet-management instrument?\u003c\/h3\u003e\u003cp\u003eIt is a capable field monitor. Sites needing automated docking-station bump\/cal across large fleets typically specify Industrial Scientific or BW Honeywell.\u003c\/p\u003e\n\n\u003cdiv style=\"background:#1a1a1a;border:1px solid #3a3a3a;border-radius:6px;padding:16px 18px;margin:22px 0;\"\u003e\n\u003cp style=\"margin:0 0 10px 0;color:#f5e6d3;\"\u003eReady to order the \u003cstrong\u003eForensics Detectors 4 gas monitor\u003c\/strong\u003e? Add it to your cart above, or check the current Amazon price below. Compare it against the rest of our \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"Portable Gas Detectors\"\u003ePortable Gas Detectors\u003c\/a\u003e lineup before you buy.\u003c\/p\u003e\n\u003cp style=\"display:flex;gap:10px;flex-wrap:wrap;align-items:center;margin:0;\"\u003e\u003ca href=\"https:\/\/www.amazon.com\/dp\/B07J1WQST5?tag=wcsafety04-20\" rel=\"sponsored nofollow noopener\" target=\"_blank\" style=\"display:inline-block;background:#FFD814;color:#0F1111;padding:13px 26px;text-decoration:none;font-weight:bold;border-radius:4px;border:1px solid #FCD200;\"\u003eCHECK PRICE ON AMAZON →\u003c\/a\u003e\u003cspan style=\"font-size:0.8em;color:#bdae9d;\"\u003eAs an Amazon Associate, WC Safety earns from qualifying purchases.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/div\u003e\n\n\u003cdiv style=\"background:#1a2733;border:1px dashed #4fc3f7;padding:16px 20px;margin:30px 0 18px 0;color:#cfd8dc;font-size:0.92em;\"\u003e\n  \u003cstrong style=\"color:#4fc3f7;\"\u003eWhy trust this Forensics Detectors page?\u003c\/strong\u003e WC Safety is an independent industrial safety-equipment retailer serving safety managers, procurement teams and field supervisors. The specifications on this page are taken from the manufacturer’s published listing for Forensics Detectors USB 4 Gas Monitor and framed against \u003ca href=\"https:\/\/www.osha.gov\/laws-regs\/regulations\/standardnumber\/1910\/1910.146\" rel=\"noopener\" target=\"_blank\" style=\"color:#4fc3f7;\"\u003eOSHA 29 CFR 1910.146\u003c\/a\u003e for confined-space atmospheric testing. Disclosed: WC Safety earns Amazon affiliate commissions on outbound clicks; that does not influence the specs shown or where this unit sits in our lineup.\n\u003c\/div\u003e\n\u003cdiv style=\"background:#1a2733;border-left:4px solid #4fc3f7;padding:18px 22px;margin:18px 0;color:#cfd8dc;font-size:0.92em;\"\u003e\n  \u003cstrong style=\"color:#4fc3f7;\"\u003eBy Steven Eaton, WC Safety Editorial\u003c\/strong\u003e — Industrial safety-equipment desk · specialization: portable atmospheric monitoring, confined-space gas detection and instrument selection.\u003cbr\u003e\n  \u003cstrong\u003eLast updated:\u003c\/strong\u003e \u003ctime datetime=\"2026-06-22\"\u003eJune 22, 2026\u003c\/time\u003e · \u003cstrong\u003eSources reviewed:\u003c\/strong\u003e manufacturer product listing \u0026amp; specifications, OSHA 29 CFR 1910.146, OSHA Annotated PEL tables, ACGIH Threshold Limit Values.\u003cbr\u003e\n  \u003cstrong\u003eEditorial standard:\u003c\/strong\u003e \u003cem\u003eZero sponsored listings. No manufacturer input. Specs verified against the manufacturer’s published data.\u003c\/em\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"background:#1a2733;border-left:4px solid #4fc3f7;padding:16px 20px;margin:18px 0;color:#cfd8dc;font-size:0.92em;\"\u003e\n  \u003cstrong style=\"color:#4fc3f7;\"\u003eHow this page is maintained.\u003c\/strong\u003e Specifications and pricing are reviewed against the manufacturer’s current listing and re-checked whenever the lineup changes. Gas-detection guidance follows \u003ca href=\"https:\/\/www.osha.gov\/laws-regs\/regulations\/standardnumber\/1910\/1910.146\" rel=\"noopener\" target=\"_blank\" style=\"color:#4fc3f7;\"\u003eOSHA 1910.146\u003c\/a\u003e (permit-required confined spaces) and \u003ca href=\"https:\/\/www.osha.gov\/annotated-pels\" rel=\"noopener\" target=\"_blank\" style=\"color:#4fc3f7;\"\u003eOSHA Permissible Exposure Limits\u003c\/a\u003e, cross-referenced with ACGIH TLVs.\n\u003c\/div\u003e\n\u003cdiv style=\"background:#2a2520;border-left:4px solid #ff9800;padding:16px 20px;margin:18px 0;color:#f5e6d3;font-size:0.92em;\"\u003e\n  \u003cstrong style=\"color:#ffb74d;\"\u003eDisclosure.\u003c\/strong\u003e WC Safety participates in the Amazon Associates Program and earns commissions on qualifying purchases through outbound links on this page (tag wcsafety04-20). We are not sponsored by any instrument manufacturer. This page is buyer guidance, not medical, legal or regulatory advice — confirm gas-detection requirements for your site against the applicable OSHA standard and, for commercial monitoring programs, a Certified Industrial Hygienist (CIH).\n\u003c\/div\u003e\n\n\u003cscript type=\"application\/ld+json\"\u003e\n{\"@context\": \"https:\/\/schema.org\", \"@graph\": [{\"@type\": \"Product\", \"@id\": \"https:\/\/wcsafety.com\/products\/forensics-detectors-4-gas-monitor-usb-rechargeable#product\", \"name\": \"Forensics Detectors 4 Gas Monitor (USB Rechargeable, NIST Calibrated)\", \"description\": \"Forensics Detectors 4 gas monitor — USB-rechargeable, NIST-calibrated O2, CO, H2S \u0026 LEL detector with triple alarm. Order at WC Safety.\", \"sku\": \"B07J1WQST5\", \"mpn\": \"FD-90A\", \"image\": [\"https:\/\/wcsafety.com\/cdn\/shop\/products\/forensics-detectors-4-gas-monitor-usb-rechargeable.jpg\"], \"brand\": {\"@type\": \"Brand\", \"name\": \"Forensics Detectors\"}, \"category\": \"Portable Gas Detector\", \"isPartOf\": {\"@type\": \"CollectionPage\", \"@id\": \"https:\/\/wcsafety.com\/collections\/portable-gas-detectors#collection\", \"name\": \"Portable Gas Detectors\", \"url\": \"https:\/\/wcsafety.com\/collections\/portable-gas-detectors\"}, \"isRelatedTo\": [{\"@type\": \"Product\", \"name\": \"Forensics Detectors 4 Gas Meter for Confined Space\", \"url\": \"https:\/\/wcsafety.com\/products\/forensics-detectors-4-gas-meter-confined-space\"}, {\"@type\": \"Product\", \"name\": \"TopTes Guard-863Pro 4 Gas Monitor\", \"url\": \"https:\/\/wcsafety.com\/products\/toptes-guard-863pro-4-gas-monitor\"}, {\"@type\": \"Product\", \"name\": \"TopTes Guard-101 4 Gas Detector\", \"url\": \"https:\/\/wcsafety.com\/products\/toptes-guard-101-4-gas-detector\"}, {\"@type\": \"Product\", \"name\": \"TopTes Guard-156 4 Gas Monitor\", \"url\": \"https:\/\/wcsafety.com\/products\/toptes-guard-156-4-gas-monitor\"}, {\"@type\": \"Product\", \"name\": \"Forensics Detectors 4 Gas Monitor with Pump\", \"url\": \"https:\/\/wcsafety.com\/products\/forensics-detectors-4-gas-monitor-with-pump\"}, {\"@type\": \"Product\", \"name\": \"Forsensal 4 Gas Detector with Pump\", \"url\": \"https:\/\/wcsafety.com\/products\/forsensal-4-gas-detector-with-pump\"}], \"offers\": {\"@type\": \"Offer\", \"url\": \"https:\/\/wcsafety.com\/products\/forensics-detectors-4-gas-monitor-usb-rechargeable\", \"priceCurrency\": \"USD\", \"price\": \"225.45\", \"availability\": \"https:\/\/schema.org\/InStock\", \"seller\": {\"@type\": \"Organization\", \"name\": \"WC Safety\"}}}, {\"@type\": \"BreadcrumbList\", \"@id\": \"https:\/\/wcsafety.com\/products\/forensics-detectors-4-gas-monitor-usb-rechargeable#breadcrumb\", \"itemListElement\": [{\"@type\": \"ListItem\", \"position\": 1, \"name\": \"Home\", \"item\": \"https:\/\/wcsafety.com\/\"}, {\"@type\": \"ListItem\", \"position\": 2, \"name\": \"Gas Detectors\", \"item\": \"https:\/\/wcsafety.com\/collections\/gas-detectors\"}, {\"@type\": \"ListItem\", \"position\": 3, \"name\": \"Portable Gas Detectors\", \"item\": \"https:\/\/wcsafety.com\/collections\/portable-gas-detectors\"}, {\"@type\": \"ListItem\", \"position\": 4, \"name\": \"Forensics Detectors 4 Gas Monitor (USB Rechargeable, NIST Calibrated)\"}]}, {\"@type\": \"FAQPage\", \"mainEntity\": [{\"@type\": \"Question\", \"name\": \"What gases does the Forensics Detectors 4 gas monitor detect?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"It reads oxygen (O2), combustible gas (LEL), carbon monoxide (CO) and hydrogen sulfide (H2S) — the standard confined-space set. VOCs require a separate PID; see the Portable Gas Detectors hub.\"}}, {\"@type\": \"Question\", \"name\": \"How is the Forensics 4 gas monitor recharged?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Over USB — from a laptop, power bank or wall adapter. A full charge covers a typical work shift.\"}}, {\"@type\": \"Question\", \"name\": \"Does it come NIST calibrated?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Yes, it ships with a USA NIST calibration certificate. Bump-test before each use and calibrate on schedule to maintain accuracy.\"}}, {\"@type\": \"Question\", \"name\": \"Is this monitor good for confined-space entry?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Yes for ongoing monitoring; its O2\/CO\/H2S\/LEL set matches OSHA 1910.146 hazards. For sampling a space before entry, use the pump model.\"}}, {\"@type\": \"Question\", \"name\": \"How heavy is it compared to the 4 Gas Meter?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"At 9.6 oz it is heavier than the 4.8 oz 4 Gas Meter; the trade-off is USB charging and a larger review base.\"}}, {\"@type\": \"Question\", \"name\": \"What alarms does it use?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Audible, vibration and visual alarms trigger when a gas crosses its set point, so alerts register in loud or bright conditions.\"}}, {\"@type\": \"Question\", \"name\": \"How often should I bump-test and calibrate it?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Bump-test before each day of use; perform a full zero\/span calibration on the manufacturer's schedule or after any failed bump test.\"}}, {\"@type\": \"Question\", \"name\": \"How long do the sensors last?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Electrochemical sensors generally last two to three years. Plan for replacement sensors and calibration gas as recurring costs.\"}}, {\"@type\": \"Question\", \"name\": \"What does it not detect?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"No VOCs, CO2 or specific toxics like ammonia or chlorine. For VOC work you need a PID; explore options across the Portable Gas Detectors hub.\"}}, {\"@type\": \"Question\", \"name\": \"Can one monitor cover a whole crew?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"No — it monitors the air where it is. For per-worker exposure, issue wearable clips from Personal \u0026 Wearable Gas Detectors; for a perimeter use Area \u0026 Transportable Gas Monitors.\"}}, {\"@type\": \"Question\", \"name\": \"Is it in stock?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Use the Amazon buy button for live availability and delivery timing through our fulfillment partner.\"}}, {\"@type\": \"Question\", \"name\": \"Is this a fleet-management instrument?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"It is a capable field monitor. Sites needing automated docking-station bump\/cal across large fleets typically specify Industrial Scientific or BW Honeywell.\"}}]}, {\"@type\": \"Organization\", \"@id\": \"https:\/\/wcsafety.com\/#org\", \"name\": \"WC Safety\", \"url\": \"https:\/\/wcsafety.com\", \"logo\": \"https:\/\/wcsafety.com\/cdn\/shop\/files\/logo.png\"}, {\"@type\": \"Person\", \"@id\": \"https:\/\/wcsafety.com\/#editor\", \"name\": \"Steven Eaton\", \"jobTitle\": \"Editorial Lead\", \"worksFor\": {\"@id\": \"https:\/\/wcsafety.com\/#org\"}, \"knowsAbout\": [\"industrial gas detection\", \"confined-space atmospheric monitoring\", \"personal protective equipment\"]}, {\"@type\": \"Brand\", \"name\": \"Forensics Detectors\"}]}\n\u003c\/script\u003e","brand":"Forensics Detectors","offers":[{"title":"Default Title","offer_id":44266357031000,"sku":"B07J1WQST5","price":225.45,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0594\/1900\/0920\/files\/615YDnPc4_L._AC_SL1500.jpg?v=1782119869"},{"product_id":"toptes-guard-863pro-4-gas-monitor","title":"TopTes Guard-863Pro 4 Gas Monitor (O2, CO, H2S, LEL, Color Screen)","description":"\u003c!-- PRODUCT B0GFV373JJ | tag portable-gas-detector | TODO: add matching Product Review + best-of guide links when those silo layers exist --\u003e\n\n\u003cdiv style=\"background:#1a1a1a;border-left:4px solid #ff9800;padding:14px 18px;margin:0 0 18px 0;color:#f5e6d3;font-size:0.95em;\"\u003e\n\u003cstrong style=\"color:#ffb74d;\"\u003eEditor’s note:\u003c\/strong\u003e the TopTes Guard-863Pro is one of the portable instruments we curate in our \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"Portable Gas Detectors\"\u003ePortable Gas Detectors\u003c\/a\u003e buyer’s hub. Compare it head-to-head with the \u003ca href=\"\/products\/forensics-detectors-4-gas-meter-confined-space\" title=\"Forensics Detectors 4 Gas Meter\"\u003eForensics Detectors 4 Gas Meter\u003c\/a\u003e below before you order.\u003c\/div\u003e\n\n\u003ch2 id=\"top\"\u003eTopTes Guard-863Pro 4 Gas Monitor — Color-Screen O2, CO, H2S \u0026amp; LEL\u003c\/h2\u003e\n\n\u003cp\u003eThe \u003cstrong\u003eTopTes Guard-863Pro\u003c\/strong\u003e is the feature leader of the TopTes line — a \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"portable gas detector\"\u003eportable gas detector\u003c\/a\u003e that reads oxygen (O2), combustible gas (LEL), carbon monoxide (CO) and hydrogen sulfide (H2S) on a color screen, runs up to 18 hours, exports data over USB, and uses a 5-year oxygen sensor to cut long-term cost.\u003c\/p\u003e\n\n\u003cp style=\"font-size:0.9em;color:#bdae9d;margin:10px 0 18px 0;\"\u003eJump to: \u003ca href=\"#features\" style=\"color:#ffb74d;\"\u003eFeatures\u003c\/a\u003e · \u003ca href=\"#specs\" style=\"color:#ffb74d;\"\u003eSpecs\u003c\/a\u003e · \u003ca href=\"#compatibility\" style=\"color:#ffb74d;\"\u003eWhat it detects\u003c\/a\u003e · \u003ca href=\"#comparison\" style=\"color:#ffb74d;\"\u003eComparison\u003c\/a\u003e · \u003ca href=\"#faq\" style=\"color:#ffb74d;\"\u003eFAQ\u003c\/a\u003e\u003c\/p\u003e\n\n\u003cp\u003eThe TopTes Guard-863Pro is a rechargeable four-gas monitor (O2, CO, H2S, LEL) with a TFT color screen, an upgraded 5-year O2 sensor, 18-hour battery and USB data export.\u003c\/p\u003e\n\n\u003ch3 id=\"features\"\u003eKey features\u003c\/h3\u003e\n\n\u003cul\u003e\n\u003cli\u003eReads oxygen (O2), combustible gas (LEL), carbon monoxide (CO) and hydrogen sulfide (H2S) on a bright TFT color screen that is easy to see in the field\u003c\/li\u003e\n\u003cli\u003eUpgraded oxygen sensor rated for a 5-year lifespan — longer than typical electrochemical O2 cells\u003c\/li\u003e\n\u003cli\u003eUp to 18 hours of battery life for long shifts and back-to-back entries\u003c\/li\u003e\n\u003cli\u003eUSB data export for logging and record-keeping\u003c\/li\u003e\n\u003cli\u003eAudible, visual and vibration alarms for multi-condition alerting\u003c\/li\u003e\n\u003cli\u003eTop of the TopTes line, balancing features and price\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cdiv style=\"display:flex;gap:14px;flex-wrap:wrap;margin:18px 0;\"\u003e\n\u003cdiv style=\"flex:1;min-width:240px;background:#1b3a2a;border:1px solid #4caf50;border-radius:6px;padding:14px 18px;\"\u003e\n\u003cstrong style=\"color:#81c784;\"\u003ePros\u003c\/strong\u003e\u003cul style=\"margin:8px 0 0 0;\"\u003e\n\u003cli\u003eTFT color display for fast reading\u003c\/li\u003e\n\u003cli\u003e5-year O2 sensor reduces replacement cost\u003c\/li\u003e\n\u003cli\u003eLong 18-hour battery life\u003c\/li\u003e\n\u003cli\u003eUSB data export for records\u003c\/li\u003e\n\u003cli\u003eFeature leader of the TopTes line\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"flex:1;min-width:240px;background:#3a1e1e;border:1px solid #ef5350;border-radius:6px;padding:14px 18px;\"\u003e\n\u003cstrong style=\"color:#e57373;\"\u003eCons\u003c\/strong\u003e\u003cul style=\"margin:8px 0 0 0;\"\u003e\n\u003cli\u003eDiffusion sampling only — no pump\u003c\/li\u003e\n\u003cli\u003eValue brand, not a managed-fleet platform\u003c\/li\u003e\n\u003cli\u003eCombustible and toxic sensors still need periodic replacement\u003c\/li\u003e\n\u003cli\u003eNo NIST certificate included as standard\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\n\u003ch3 id=\"specs\"\u003eSpecifications\u003c\/h3\u003e\n\n\u003cdiv style=\"overflow-x:auto;\"\u003e\u003ctable style=\"width:100%;border-collapse:collapse;background:#1a1a1a;margin:14px 0;\"\u003e\n\u003cthead\u003e\u003ctr style=\"background:#2a2a2a;\"\u003e\n\u003cth style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;text-align:left;\"\u003eSpecification\u003c\/th\u003e\n\u003cth style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;text-align:left;\"\u003eDetail\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eGases detected\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eO2, CO, H2S, LEL combustibles\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eDisplay\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eTFT color screen\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eO2 sensor life\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eUpgraded, 5-year lifespan\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eBattery life\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eUp to 18 hours\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eData\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eUSB data export\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eAlarms\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eAudible, visual \u0026amp; vibration\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003ePower\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eRechargeable battery\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eColor\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eOrange\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003c\/div\u003e\n\n\u003ch3\u003eWhere the TopTes Guard-863Pro fits\u003c\/h3\u003e\n\n\u003cul\u003e\n\u003cli\u003eConfined-space and pre-entry checks\u003c\/li\u003e\n\u003cli\u003eLong-shift utility and municipal work\u003c\/li\u003e\n\u003cli\u003eFacilities and maintenance monitoring\u003c\/li\u003e\n\u003cli\u003eSewer and water-treatment rounds\u003c\/li\u003e\n\u003cli\u003eJobs needing exportable gas logs\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2 id=\"compatibility\"\u003eWhat the TopTes Guard-863Pro detects (and what it doesn’t)\u003c\/h2\u003e\n\n\u003cp\u003eThe Guard-863Pro detects oxygen (O2), combustible gas (LEL), carbon monoxide (CO) and hydrogen sulfide (H2S). It does not read VOCs, CO2 or single toxics like chlorine or ammonia — those need a PID or dedicated sensor. It is a diffusion instrument; for remote pre-entry sampling choose a pump unit such as the \u003ca href=\"\/products\/forensics-detectors-4-gas-monitor-with-pump\" title=\"Forensics Detectors 4 Gas Monitor with Pump\"\u003eForensics Detectors 4 Gas Monitor with Pump\u003c\/a\u003e. Bump-test with standard four-gas calibration gas before use; the 5-year O2 cell reduces sensor swaps. For single-worker all-shift wear, add a clip from \u003ca href=\"\/collections\/personal-gas-detectors\" title=\"Personal \u0026amp; Wearable Gas Detectors\"\u003ePersonal \u0026amp; Wearable Gas Detectors\u003c\/a\u003e.\u003c\/p\u003e\n\n\u003cp\u003eCross-shopping? This unit sits in our \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"Portable Gas Detectors\"\u003ePortable Gas Detectors\u003c\/a\u003e hub alongside the \u003ca href=\"\/products\/forensics-detectors-4-gas-meter-confined-space\" title=\"Forensics Detectors 4 Gas Meter\"\u003eForensics Detectors 4 Gas Meter\u003c\/a\u003e, \u003ca href=\"\/products\/forensics-detectors-4-gas-monitor-usb-rechargeable\" title=\"Forensics Detectors USB 4 Gas Monitor\"\u003eForensics Detectors USB 4 Gas Monitor\u003c\/a\u003e, \u003ca href=\"\/products\/toptes-guard-101-4-gas-detector\" title=\"TopTes Guard-101\"\u003eTopTes Guard-101\u003c\/a\u003e, \u003ca href=\"\/products\/toptes-guard-156-4-gas-monitor\" title=\"TopTes Guard-156\"\u003eTopTes Guard-156\u003c\/a\u003e. If one worker needs all-shift wear instead of a carried meter, see \u003ca href=\"\/collections\/personal-gas-detectors\" title=\"Personal \u0026amp; Wearable Gas Detectors\"\u003ePersonal \u0026amp; Wearable Gas Detectors\u003c\/a\u003e; for a fixed install or a job-site perimeter, see \u003ca href=\"\/collections\/fixed-gas-detection-systems\" title=\"Fixed Gas Detection Systems\"\u003eFixed Gas Detection Systems\u003c\/a\u003e and \u003ca href=\"\/collections\/area-gas-monitors\" title=\"Area \u0026amp; Transportable Gas Monitors\"\u003eArea \u0026amp; Transportable Gas Monitors\u003c\/a\u003e.\u003c\/p\u003e\n\n\u003ch2 id=\"comparison\"\u003eTopTes 4-gas family compared\u003c\/h2\u003e\n\n\u003cdiv style=\"overflow-x:auto;\"\u003e\u003ctable style=\"width:100%;border-collapse:collapse;background:#1a1a1a;margin:14px 0;\"\u003e\n\u003ccaption style=\"color:#bdae9d;font-size:0.85em;text-align:left;padding:4px 0;\"\u003eTopTes portable 4-gas family (O2, CO, H2S, LEL)\u003c\/caption\u003e\n\u003cthead\u003e\u003ctr style=\"background:#2a2a2a;\"\u003e\n\u003cth style=\"color:#ffb74d;padding:9px;border:1px solid #3a3a3a;text-align:left;\"\u003eModel\u003c\/th\u003e\n\u003cth style=\"color:#ffb74d;padding:9px;border:1px solid #3a3a3a;text-align:left;\"\u003eDisplay\u003c\/th\u003e\n\u003cth style=\"color:#ffb74d;padding:9px;border:1px solid #3a3a3a;text-align:left;\"\u003eBattery\u003c\/th\u003e\n\u003cth style=\"color:#ffb74d;padding:9px;border:1px solid #3a3a3a;text-align:left;\"\u003eNotable\u003c\/th\u003e\n\u003cth style=\"color:#ffb74d;padding:9px;border:1px solid #3a3a3a;text-align:left;\"\u003eStreet price\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e\u003ca href=\"\/products\/toptes-guard-101-4-gas-detector\" title=\"Guard-101\"\u003eGuard-101\u003c\/a\u003e\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eLCD\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e14 h\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eBest value\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e~$106\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e\u003ca href=\"\/products\/toptes-guard-156-4-gas-monitor\" title=\"Guard-156\"\u003eGuard-156\u003c\/a\u003e\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eLCD\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eLong-life\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e0.5 s response\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e~$127\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#2a2520;\"\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e\u003cstrong\u003e\u003ca href=\"\/products\/toptes-guard-863pro-4-gas-monitor\" title=\"Guard-863Pro\"\u003eGuard-863Pro\u003c\/a\u003e\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eTFT color\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e18 h\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e5-yr O2 sensor, USB data export\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e~$170\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003c\/div\u003e\n\n\u003cul\u003e\n\u003cli\u003eChoose the \u003cstrong\u003eGuard-863Pro\u003c\/strong\u003e for the color screen, 18-hour battery, USB export and 5-year O2 sensor.\u003c\/li\u003e\n\u003cli\u003ePick the \u003ca href=\"\/products\/toptes-guard-101-4-gas-detector\" title=\"Guard-101\"\u003eGuard-101\u003c\/a\u003e to save money on a straightforward LCD unit.\u003c\/li\u003e\n\u003cli\u003ePick the \u003ca href=\"\/products\/toptes-guard-156-4-gas-monitor\" title=\"Guard-156\"\u003eGuard-156\u003c\/a\u003e for fast 0.5-second response in a mid-priced body.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2 id=\"faq\"\u003eFrequently asked questions\u003c\/h2\u003e\n\n\u003ch3\u003eWhat gases does the TopTes Guard-863Pro detect?\u003c\/h3\u003e\u003cp\u003eIt reads oxygen (O2), combustible gas (LEL), carbon monoxide (CO) and hydrogen sulfide (H2S). For VOCs you need a separate PID; see the \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"Portable Gas Detectors\"\u003ePortable Gas Detectors\u003c\/a\u003e hub for other instrument types.\u003c\/p\u003e\n\u003ch3\u003eHow long does the Guard-863Pro O2 sensor last?\u003c\/h3\u003e\u003cp\u003eIts upgraded oxygen sensor is rated for a 5-year lifespan — longer than typical electrochemical O2 cells, which lowers replacement cost over time.\u003c\/p\u003e\n\u003ch3\u003eHow long is the battery life?\u003c\/h3\u003e\u003cp\u003eUp to 18 hours per charge, enough for long shifts and multiple confined-space entries before recharging.\u003c\/p\u003e\n\u003ch3\u003eCan I export data from the Guard-863Pro?\u003c\/h3\u003e\u003cp\u003eYes — it supports USB data export for logging gas readings and keeping compliance records.\u003c\/p\u003e\n\u003ch3\u003eIs the Guard-863Pro good for confined-space entry?\u003c\/h3\u003e\u003cp\u003eYes for ongoing monitoring of the O2\/CO\/H2S\/LEL hazards. For sampling a sealed space before entry, use a \u003ca href=\"\/products\/forensics-detectors-4-gas-monitor-with-pump\" title=\"pump-equipped monitor\"\u003epump-equipped monitor\u003c\/a\u003e.\u003c\/p\u003e\n\u003ch3\u003eDoes it have a color screen?\u003c\/h3\u003e\u003cp\u003eYes — a TFT color display that is easier to read at a glance than a monochrome LCD, especially in bright or dim conditions.\u003c\/p\u003e\n\u003ch3\u003eHow does the Guard-863Pro compare to the Guard-101?\u003c\/h3\u003e\u003cp\u003eThe 863Pro adds a color screen, longer battery, USB export and a 5-year O2 sensor; the \u003ca href=\"\/products\/toptes-guard-101-4-gas-detector\" title=\"Guard-101\"\u003eGuard-101\u003c\/a\u003e is a simpler, lower-cost LCD unit.\u003c\/p\u003e\n\u003ch3\u003eDoes it come calibrated?\u003c\/h3\u003e\u003cp\u003eIt is factory-calibrated; bump-test with four-gas calibration gas before use and calibrate on the manufacturer's schedule to keep readings accurate.\u003c\/p\u003e\n\u003ch3\u003eWhat alarms does it have?\u003c\/h3\u003e\u003cp\u003eAudible, visual and vibration alarms trigger when any gas exceeds its preset threshold.\u003c\/p\u003e\n\u003ch3\u003eWhat does it not detect?\u003c\/h3\u003e\u003cp\u003eNo VOCs, CO2, or specific toxics such as ammonia or chlorine. For VOC monitoring use a PID; browse the \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"Portable Gas Detectors\"\u003ePortable Gas Detectors\u003c\/a\u003e hub.\u003c\/p\u003e\n\u003ch3\u003eIs it in stock and how does it ship?\u003c\/h3\u003e\u003cp\u003eUse the Amazon buy button for current availability and delivery timing through our fulfillment partner.\u003c\/p\u003e\n\u003ch3\u003eIs the Guard-863Pro industrial grade?\u003c\/h3\u003e\u003cp\u003eIt is a strong value-tier monitor for crews and facilities. Large managed-fleet programs usually specify Industrial Scientific or BW Honeywell instruments with docking automation.\u003c\/p\u003e\n\n\u003cdiv style=\"background:#1a1a1a;border:1px solid #3a3a3a;border-radius:6px;padding:16px 18px;margin:22px 0;\"\u003e\n\u003cp style=\"margin:0 0 10px 0;color:#f5e6d3;\"\u003eReady to order the \u003cstrong\u003eTopTes Guard-863Pro\u003c\/strong\u003e? Add it to your cart above, or check the current Amazon price below. Compare it against the rest of our \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"Portable Gas Detectors\"\u003ePortable Gas Detectors\u003c\/a\u003e lineup before you buy.\u003c\/p\u003e\n\u003cp style=\"display:flex;gap:10px;flex-wrap:wrap;align-items:center;margin:0;\"\u003e\u003ca href=\"https:\/\/www.amazon.com\/dp\/B0GFV373JJ?tag=wcsafety04-20\" rel=\"sponsored nofollow noopener\" target=\"_blank\" style=\"display:inline-block;background:#FFD814;color:#0F1111;padding:13px 26px;text-decoration:none;font-weight:bold;border-radius:4px;border:1px solid #FCD200;\"\u003eCHECK PRICE ON AMAZON →\u003c\/a\u003e\u003cspan style=\"font-size:0.8em;color:#bdae9d;\"\u003eAs an Amazon Associate, WC Safety earns from qualifying purchases.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/div\u003e\n\n\u003cdiv style=\"background:#1a2733;border:1px dashed #4fc3f7;padding:16px 20px;margin:30px 0 18px 0;color:#cfd8dc;font-size:0.92em;\"\u003e\n  \u003cstrong style=\"color:#4fc3f7;\"\u003eWhy trust this TopTes page?\u003c\/strong\u003e WC Safety is an independent industrial safety-equipment retailer serving safety managers, procurement teams and field supervisors. The specifications on this page are taken from the manufacturer’s published listing for TopTes Guard-863Pro and framed against \u003ca href=\"https:\/\/www.osha.gov\/laws-regs\/regulations\/standardnumber\/1910\/1910.146\" rel=\"noopener\" target=\"_blank\" style=\"color:#4fc3f7;\"\u003eOSHA 29 CFR 1910.146\u003c\/a\u003e for confined-space atmospheric testing. Disclosed: WC Safety earns Amazon affiliate commissions on outbound clicks; that does not influence the specs shown or where this unit sits in our lineup.\n\u003c\/div\u003e\n\u003cdiv style=\"background:#1a2733;border-left:4px solid #4fc3f7;padding:18px 22px;margin:18px 0;color:#cfd8dc;font-size:0.92em;\"\u003e\n  \u003cstrong style=\"color:#4fc3f7;\"\u003eBy Steven Eaton, WC Safety Editorial\u003c\/strong\u003e — Industrial safety-equipment desk · specialization: portable atmospheric monitoring, confined-space gas detection and instrument selection.\u003cbr\u003e\n  \u003cstrong\u003eLast updated:\u003c\/strong\u003e \u003ctime datetime=\"2026-06-22\"\u003eJune 22, 2026\u003c\/time\u003e · \u003cstrong\u003eSources reviewed:\u003c\/strong\u003e manufacturer product listing \u0026amp; specifications, OSHA 29 CFR 1910.146, OSHA Annotated PEL tables, ACGIH Threshold Limit Values.\u003cbr\u003e\n  \u003cstrong\u003eEditorial standard:\u003c\/strong\u003e \u003cem\u003eZero sponsored listings. No manufacturer input. Specs verified against the manufacturer’s published data.\u003c\/em\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"background:#1a2733;border-left:4px solid #4fc3f7;padding:16px 20px;margin:18px 0;color:#cfd8dc;font-size:0.92em;\"\u003e\n  \u003cstrong style=\"color:#4fc3f7;\"\u003eHow this page is maintained.\u003c\/strong\u003e Specifications and pricing are reviewed against the manufacturer’s current listing and re-checked whenever the lineup changes. Gas-detection guidance follows \u003ca href=\"https:\/\/www.osha.gov\/laws-regs\/regulations\/standardnumber\/1910\/1910.146\" rel=\"noopener\" target=\"_blank\" style=\"color:#4fc3f7;\"\u003eOSHA 1910.146\u003c\/a\u003e (permit-required confined spaces) and \u003ca href=\"https:\/\/www.osha.gov\/annotated-pels\" rel=\"noopener\" target=\"_blank\" style=\"color:#4fc3f7;\"\u003eOSHA Permissible Exposure Limits\u003c\/a\u003e, cross-referenced with ACGIH TLVs.\n\u003c\/div\u003e\n\u003cdiv style=\"background:#2a2520;border-left:4px solid #ff9800;padding:16px 20px;margin:18px 0;color:#f5e6d3;font-size:0.92em;\"\u003e\n  \u003cstrong style=\"color:#ffb74d;\"\u003eDisclosure.\u003c\/strong\u003e WC Safety participates in the Amazon Associates Program and earns commissions on qualifying purchases through outbound links on this page (tag wcsafety04-20). We are not sponsored by any instrument manufacturer. This page is buyer guidance, not medical, legal or regulatory advice — confirm gas-detection requirements for your site against the applicable OSHA standard and, for commercial monitoring programs, a Certified Industrial Hygienist (CIH).\n\u003c\/div\u003e\n\n\u003cscript type=\"application\/ld+json\"\u003e\n{\"@context\": \"https:\/\/schema.org\", \"@graph\": [{\"@type\": \"Product\", \"@id\": \"https:\/\/wcsafety.com\/products\/toptes-guard-863pro-4-gas-monitor#product\", \"name\": \"TopTes Guard-863Pro 4 Gas Monitor (O2, CO, H2S, LEL, Color Screen)\", \"description\": \"TopTes Guard-863Pro 4 gas monitor — O2, CO, H2S \u0026 LEL with TFT color screen, 5-year O2 sensor, 18h battery and USB data export. Order at WC Safety.\", \"sku\": \"B0GFV373JJ\", \"mpn\": \"Guard-863Pro\", \"image\": [\"https:\/\/wcsafety.com\/cdn\/shop\/products\/toptes-guard-863pro-4-gas-monitor.jpg\"], \"brand\": {\"@type\": \"Brand\", \"name\": \"TopTes\"}, \"category\": \"Portable Gas Detector\", \"isPartOf\": {\"@type\": \"CollectionPage\", \"@id\": \"https:\/\/wcsafety.com\/collections\/portable-gas-detectors#collection\", \"name\": \"Portable Gas Detectors\", \"url\": \"https:\/\/wcsafety.com\/collections\/portable-gas-detectors\"}, \"isRelatedTo\": [{\"@type\": \"Product\", \"name\": \"Forensics Detectors 4 Gas Meter for Confined Space\", \"url\": \"https:\/\/wcsafety.com\/products\/forensics-detectors-4-gas-meter-confined-space\"}, {\"@type\": \"Product\", \"name\": \"Forensics Detectors 4 Gas Monitor (USB Rechargeable)\", \"url\": \"https:\/\/wcsafety.com\/products\/forensics-detectors-4-gas-monitor-usb-rechargeable\"}, {\"@type\": \"Product\", \"name\": \"TopTes Guard-101 4 Gas Detector\", \"url\": \"https:\/\/wcsafety.com\/products\/toptes-guard-101-4-gas-detector\"}, {\"@type\": \"Product\", \"name\": \"TopTes Guard-156 4 Gas Monitor\", \"url\": \"https:\/\/wcsafety.com\/products\/toptes-guard-156-4-gas-monitor\"}, {\"@type\": \"Product\", \"name\": \"Forensics Detectors 4 Gas Monitor with Pump\", \"url\": \"https:\/\/wcsafety.com\/products\/forensics-detectors-4-gas-monitor-with-pump\"}, {\"@type\": \"Product\", \"name\": \"Forsensal 4 Gas Detector with Pump\", \"url\": \"https:\/\/wcsafety.com\/products\/forsensal-4-gas-detector-with-pump\"}], \"offers\": {\"@type\": \"Offer\", \"url\": \"https:\/\/wcsafety.com\/products\/toptes-guard-863pro-4-gas-monitor\", \"priceCurrency\": \"USD\", \"price\": \"169.99\", \"availability\": \"https:\/\/schema.org\/InStock\", \"seller\": {\"@type\": \"Organization\", \"name\": \"WC Safety\"}}}, {\"@type\": \"BreadcrumbList\", \"@id\": \"https:\/\/wcsafety.com\/products\/toptes-guard-863pro-4-gas-monitor#breadcrumb\", \"itemListElement\": [{\"@type\": \"ListItem\", \"position\": 1, \"name\": \"Home\", \"item\": \"https:\/\/wcsafety.com\/\"}, {\"@type\": \"ListItem\", \"position\": 2, \"name\": \"Gas Detectors\", \"item\": \"https:\/\/wcsafety.com\/collections\/gas-detectors\"}, {\"@type\": \"ListItem\", \"position\": 3, \"name\": \"Portable Gas Detectors\", \"item\": \"https:\/\/wcsafety.com\/collections\/portable-gas-detectors\"}, {\"@type\": \"ListItem\", \"position\": 4, \"name\": \"TopTes Guard-863Pro 4 Gas Monitor (O2, CO, H2S, LEL, Color Screen)\"}]}, {\"@type\": \"FAQPage\", \"mainEntity\": [{\"@type\": \"Question\", \"name\": \"What gases does the TopTes Guard-863Pro detect?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"It reads oxygen (O2), combustible gas (LEL), carbon monoxide (CO) and hydrogen sulfide (H2S). For VOCs you need a separate PID; see the Portable Gas Detectors hub for other instrument types.\"}}, {\"@type\": \"Question\", \"name\": \"How long does the Guard-863Pro O2 sensor last?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Its upgraded oxygen sensor is rated for a 5-year lifespan — longer than typical electrochemical O2 cells, which lowers replacement cost over time.\"}}, {\"@type\": \"Question\", \"name\": \"How long is the battery life?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Up to 18 hours per charge, enough for long shifts and multiple confined-space entries before recharging.\"}}, {\"@type\": \"Question\", \"name\": \"Can I export data from the Guard-863Pro?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Yes — it supports USB data export for logging gas readings and keeping compliance records.\"}}, {\"@type\": \"Question\", \"name\": \"Is the Guard-863Pro good for confined-space entry?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Yes for ongoing monitoring of the O2\/CO\/H2S\/LEL hazards. For sampling a sealed space before entry, use a pump-equipped monitor.\"}}, {\"@type\": \"Question\", \"name\": \"Does it have a color screen?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Yes — a TFT color display that is easier to read at a glance than a monochrome LCD, especially in bright or dim conditions.\"}}, {\"@type\": \"Question\", \"name\": \"How does the Guard-863Pro compare to the Guard-101?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"The 863Pro adds a color screen, longer battery, USB export and a 5-year O2 sensor; the Guard-101 is a simpler, lower-cost LCD unit.\"}}, {\"@type\": \"Question\", \"name\": \"Does it come calibrated?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"It is factory-calibrated; bump-test with four-gas calibration gas before use and calibrate on the manufacturer's schedule to keep readings accurate.\"}}, {\"@type\": \"Question\", \"name\": \"What alarms does it have?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Audible, visual and vibration alarms trigger when any gas exceeds its preset threshold.\"}}, {\"@type\": \"Question\", \"name\": \"What does it not detect?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"No VOCs, CO2, or specific toxics such as ammonia or chlorine. For VOC monitoring use a PID; browse the Portable Gas Detectors hub.\"}}, {\"@type\": \"Question\", \"name\": \"Is it in stock and how does it ship?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Use the Amazon buy button for current availability and delivery timing through our fulfillment partner.\"}}, {\"@type\": \"Question\", \"name\": \"Is the Guard-863Pro industrial grade?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"It is a strong value-tier monitor for crews and facilities. Large managed-fleet programs usually specify Industrial Scientific or BW Honeywell instruments with docking automation.\"}}]}, {\"@type\": \"Organization\", \"@id\": \"https:\/\/wcsafety.com\/#org\", \"name\": \"WC Safety\", \"url\": \"https:\/\/wcsafety.com\", \"logo\": \"https:\/\/wcsafety.com\/cdn\/shop\/files\/logo.png\"}, {\"@type\": \"Person\", \"@id\": \"https:\/\/wcsafety.com\/#editor\", \"name\": \"Steven Eaton\", \"jobTitle\": \"Editorial Lead\", \"worksFor\": {\"@id\": \"https:\/\/wcsafety.com\/#org\"}, \"knowsAbout\": [\"industrial gas detection\", \"confined-space atmospheric monitoring\", \"personal protective equipment\"]}, {\"@type\": \"Brand\", \"name\": \"TopTes\"}]}\n\u003c\/script\u003e","brand":"TopTes","offers":[{"title":"Default Title","offer_id":44266357129304,"sku":"B0GFV373JJ","price":169.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0594\/1900\/0920\/files\/71eB7rf08jL._AC_SL1500.jpg?v=1782119873"},{"product_id":"toptes-guard-101-4-gas-detector","title":"TopTes Guard-101 4 Gas Detector (O2, CO, H2S, LEL, 14h Battery)","description":"\u003c!-- PRODUCT B0D7C8BJL1 | tag portable-gas-detector | TODO: add matching Product Review + best-of guide links when those silo layers exist --\u003e\n\n\u003cdiv style=\"background:#1a1a1a;border-left:4px solid #ff9800;padding:14px 18px;margin:0 0 18px 0;color:#f5e6d3;font-size:0.95em;\"\u003e\n\u003cstrong style=\"color:#ffb74d;\"\u003eEditor’s note:\u003c\/strong\u003e the TopTes Guard-101 is one of the portable instruments we curate in our \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"Portable Gas Detectors\"\u003ePortable Gas Detectors\u003c\/a\u003e buyer’s hub. Compare it head-to-head with the \u003ca href=\"\/products\/forensics-detectors-4-gas-meter-confined-space\" title=\"Forensics Detectors 4 Gas Meter\"\u003eForensics Detectors 4 Gas Meter\u003c\/a\u003e below before you order.\u003c\/div\u003e\n\n\u003ch2 id=\"top\"\u003eTopTes Guard-101 4 Gas Detector — Best-Value O2, CO, H2S \u0026amp; LEL\u003c\/h2\u003e\n\n\u003cp\u003eThe \u003cstrong\u003eTopTes Guard-101\u003c\/strong\u003e is the best-value pick in our lineup — a \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"portable gas detector\"\u003eportable gas detector\u003c\/a\u003e that reads oxygen (O2), combustible gas (LEL), carbon monoxide (CO) and hydrogen sulfide (H2S) with triple alarms, a 14-hour battery and an explosion-proof body, all at the lowest price we stock. It is the most-reviewed unit in the range.\u003c\/p\u003e\n\n\u003cp style=\"font-size:0.9em;color:#bdae9d;margin:10px 0 18px 0;\"\u003eJump to: \u003ca href=\"#features\" style=\"color:#ffb74d;\"\u003eFeatures\u003c\/a\u003e · \u003ca href=\"#specs\" style=\"color:#ffb74d;\"\u003eSpecs\u003c\/a\u003e · \u003ca href=\"#compatibility\" style=\"color:#ffb74d;\"\u003eWhat it detects\u003c\/a\u003e · \u003ca href=\"#comparison\" style=\"color:#ffb74d;\"\u003eComparison\u003c\/a\u003e · \u003ca href=\"#faq\" style=\"color:#ffb74d;\"\u003eFAQ\u003c\/a\u003e\u003c\/p\u003e\n\n\u003cp\u003eThe TopTes Guard-101 is a rechargeable four-gas detector (O2, CO, H2S, LEL) with a backlit LCD, 14-hour battery, triple alarms and an explosion-proof design, positioned as an entry-price confined-space monitor.\u003c\/p\u003e\n\n\u003ch3 id=\"features\"\u003eKey features\u003c\/h3\u003e\n\n\u003cul\u003e\n\u003cli\u003eMonitors oxygen (O2), combustible gas (LEL), carbon monoxide (CO) and hydrogen sulfide (H2S) on a clear backlit LCD\u003c\/li\u003e\n\u003cli\u003eUp to 14 hours of runtime per charge for a full work shift\u003c\/li\u003e\n\u003cli\u003eTriple alarm — audible, visual and vibration\u003c\/li\u003e\n\u003cli\u003eExplosion-proof design for flammable atmospheres\u003c\/li\u003e\n\u003cli\u003eOur most-reviewed gas detector (500+ ratings) and lowest price point\u003c\/li\u003e\n\u003cli\u003eSimple operation for crews that just need reliable four-gas readings\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cdiv style=\"display:flex;gap:14px;flex-wrap:wrap;margin:18px 0;\"\u003e\n\u003cdiv style=\"flex:1;min-width:240px;background:#1b3a2a;border:1px solid #4caf50;border-radius:6px;padding:14px 18px;\"\u003e\n\u003cstrong style=\"color:#81c784;\"\u003ePros\u003c\/strong\u003e\u003cul style=\"margin:8px 0 0 0;\"\u003e\n\u003cli\u003eLowest price in our portable lineup\u003c\/li\u003e\n\u003cli\u003eMost reviews of any unit we stock (500+)\u003c\/li\u003e\n\u003cli\u003e14-hour battery life\u003c\/li\u003e\n\u003cli\u003eTriple alarm modes\u003c\/li\u003e\n\u003cli\u003eExplosion-proof design\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"flex:1;min-width:240px;background:#3a1e1e;border:1px solid #ef5350;border-radius:6px;padding:14px 18px;\"\u003e\n\u003cstrong style=\"color:#e57373;\"\u003eCons\u003c\/strong\u003e\u003cul style=\"margin:8px 0 0 0;\"\u003e\n\u003cli\u003eDiffusion only — no pump\u003c\/li\u003e\n\u003cli\u003eMonochrome LCD (no color screen or USB export)\u003c\/li\u003e\n\u003cli\u003eValue brand, not a fleet platform\u003c\/li\u003e\n\u003cli\u003eSensors need periodic replacement\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\n\u003ch3 id=\"specs\"\u003eSpecifications\u003c\/h3\u003e\n\n\u003cdiv style=\"overflow-x:auto;\"\u003e\u003ctable style=\"width:100%;border-collapse:collapse;background:#1a1a1a;margin:14px 0;\"\u003e\n\u003cthead\u003e\u003ctr style=\"background:#2a2a2a;\"\u003e\n\u003cth style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;text-align:left;\"\u003eSpecification\u003c\/th\u003e\n\u003cth style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;text-align:left;\"\u003eDetail\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eGases detected\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eO2, CO, H2S, LEL combustibles\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eDisplay\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eBacklit LCD\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eBattery life\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eUp to 14 hours\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eAlarms\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eAudible, visual \u0026amp; vibration\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eBuild\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eExplosion-proof design\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003ePower\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eRechargeable battery\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eWeight\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003e~0.6 kg\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eColor\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eOrange\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003c\/div\u003e\n\n\u003ch3\u003eWhere the TopTes Guard-101 fits\u003c\/h3\u003e\n\n\u003cul\u003e\n\u003cli\u003eBudget-conscious confined-space checks\u003c\/li\u003e\n\u003cli\u003eFirst gas detector for small crews\u003c\/li\u003e\n\u003cli\u003eSewer, vault and manhole spot tests\u003c\/li\u003e\n\u003cli\u003eFacilities and maintenance rounds\u003c\/li\u003e\n\u003cli\u003eBackup\/spare unit for a tool crib\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2 id=\"compatibility\"\u003eWhat the TopTes Guard-101 detects (and what it doesn’t)\u003c\/h2\u003e\n\n\u003cp\u003eThe Guard-101 detects oxygen (O2), combustible gas (LEL), carbon monoxide (CO) and hydrogen sulfide (H2S) and nothing outside that set — no VOCs, CO2 or single toxics such as chlorine. It is a diffusion unit, so for remote sampling before entry pick a pump model like the \u003ca href=\"\/products\/forsensal-4-gas-detector-with-pump\" title=\"Forsensal 4 Gas Detector with Pump\"\u003eForsensal 4 Gas Detector with Pump\u003c\/a\u003e. Bump-test with four-gas calibration gas before use. Stepping up to the \u003ca href=\"\/products\/toptes-guard-863pro-4-gas-monitor\" title=\"Guard-863Pro\"\u003eGuard-863Pro\u003c\/a\u003e adds a color screen, USB export and a 5-year O2 sensor. For all-shift single-worker wear, add a clip from \u003ca href=\"\/collections\/personal-gas-detectors\" title=\"Personal \u0026amp; Wearable Gas Detectors\"\u003ePersonal \u0026amp; Wearable Gas Detectors\u003c\/a\u003e.\u003c\/p\u003e\n\n\u003cp\u003eCross-shopping? This unit sits in our \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"Portable Gas Detectors\"\u003ePortable Gas Detectors\u003c\/a\u003e hub alongside the \u003ca href=\"\/products\/forensics-detectors-4-gas-meter-confined-space\" title=\"Forensics Detectors 4 Gas Meter\"\u003eForensics Detectors 4 Gas Meter\u003c\/a\u003e, \u003ca href=\"\/products\/forensics-detectors-4-gas-monitor-usb-rechargeable\" title=\"Forensics Detectors USB 4 Gas Monitor\"\u003eForensics Detectors USB 4 Gas Monitor\u003c\/a\u003e, \u003ca href=\"\/products\/toptes-guard-863pro-4-gas-monitor\" title=\"TopTes Guard-863Pro\"\u003eTopTes Guard-863Pro\u003c\/a\u003e, \u003ca href=\"\/products\/toptes-guard-156-4-gas-monitor\" title=\"TopTes Guard-156\"\u003eTopTes Guard-156\u003c\/a\u003e. If one worker needs all-shift wear instead of a carried meter, see \u003ca href=\"\/collections\/personal-gas-detectors\" title=\"Personal \u0026amp; Wearable Gas Detectors\"\u003ePersonal \u0026amp; Wearable Gas Detectors\u003c\/a\u003e; for a fixed install or a job-site perimeter, see \u003ca href=\"\/collections\/fixed-gas-detection-systems\" title=\"Fixed Gas Detection Systems\"\u003eFixed Gas Detection Systems\u003c\/a\u003e and \u003ca href=\"\/collections\/area-gas-monitors\" title=\"Area \u0026amp; Transportable Gas Monitors\"\u003eArea \u0026amp; Transportable Gas Monitors\u003c\/a\u003e.\u003c\/p\u003e\n\n\u003ch2 id=\"comparison\"\u003eTopTes 4-gas family compared\u003c\/h2\u003e\n\n\u003cdiv style=\"overflow-x:auto;\"\u003e\u003ctable style=\"width:100%;border-collapse:collapse;background:#1a1a1a;margin:14px 0;\"\u003e\n\u003ccaption style=\"color:#bdae9d;font-size:0.85em;text-align:left;padding:4px 0;\"\u003eTopTes portable 4-gas family (O2, CO, H2S, LEL)\u003c\/caption\u003e\n\u003cthead\u003e\u003ctr style=\"background:#2a2a2a;\"\u003e\n\u003cth style=\"color:#ffb74d;padding:9px;border:1px solid #3a3a3a;text-align:left;\"\u003eModel\u003c\/th\u003e\n\u003cth style=\"color:#ffb74d;padding:9px;border:1px solid #3a3a3a;text-align:left;\"\u003eDisplay\u003c\/th\u003e\n\u003cth style=\"color:#ffb74d;padding:9px;border:1px solid #3a3a3a;text-align:left;\"\u003eBattery\u003c\/th\u003e\n\u003cth style=\"color:#ffb74d;padding:9px;border:1px solid #3a3a3a;text-align:left;\"\u003eNotable\u003c\/th\u003e\n\u003cth style=\"color:#ffb74d;padding:9px;border:1px solid #3a3a3a;text-align:left;\"\u003eStreet price\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e\u003ca href=\"\/products\/toptes-guard-101-4-gas-detector\" title=\"Guard-101\"\u003eGuard-101\u003c\/a\u003e\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eLCD\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e14 h\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eBest value\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e~$106\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e\u003ca href=\"\/products\/toptes-guard-156-4-gas-monitor\" title=\"Guard-156\"\u003eGuard-156\u003c\/a\u003e\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eLCD\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eLong-life\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e0.5 s response\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e~$127\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#2a2520;\"\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e\u003cstrong\u003e\u003ca href=\"\/products\/toptes-guard-863pro-4-gas-monitor\" title=\"Guard-863Pro\"\u003eGuard-863Pro\u003c\/a\u003e\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eTFT color\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e18 h\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e5-yr O2 sensor, USB data export\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e~$170\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003c\/div\u003e\n\n\u003cul\u003e\n\u003cli\u003eChoose the \u003cstrong\u003eGuard-101\u003c\/strong\u003e for the lowest price and the most field-proven review base.\u003c\/li\u003e\n\u003cli\u003ePick the \u003ca href=\"\/products\/toptes-guard-156-4-gas-monitor\" title=\"Guard-156\"\u003eGuard-156\u003c\/a\u003e for faster 0.5-second sensor response.\u003c\/li\u003e\n\u003cli\u003ePick the \u003ca href=\"\/products\/toptes-guard-863pro-4-gas-monitor\" title=\"Guard-863Pro\"\u003eGuard-863Pro\u003c\/a\u003e for a color screen, USB export and a 5-year O2 sensor.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2 id=\"faq\"\u003eFrequently asked questions\u003c\/h2\u003e\n\n\u003ch3\u003eWhat gases does the TopTes Guard-101 detect?\u003c\/h3\u003e\u003cp\u003eIt reads oxygen (O2), combustible gas (LEL), carbon monoxide (CO) and hydrogen sulfide (H2S) — the four confined-space hazards. It does not cover VOCs; for those, see PID options in the \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"Portable Gas Detectors\"\u003ePortable Gas Detectors\u003c\/a\u003e hub.\u003c\/p\u003e\n\u003ch3\u003eIs the TopTes Guard-101 a good first gas detector?\u003c\/h3\u003e\u003cp\u003eYes — it is the lowest-priced, most-reviewed unit in our range and covers the core four-gas set, which makes it a common first purchase for small crews.\u003c\/p\u003e\n\u003ch3\u003eHow long does the Guard-101 battery last?\u003c\/h3\u003e\u003cp\u003eUp to 14 hours per charge, enough for a typical work shift with margin for multiple entries.\u003c\/p\u003e\n\u003ch3\u003eIs the Guard-101 explosion-proof?\u003c\/h3\u003e\u003cp\u003eIt uses an explosion-proof design intended for use in flammable atmospheres. Confirm the rating against your site's area classification before use.\u003c\/p\u003e\n\u003ch3\u003eCan I use it for confined-space entry?\u003c\/h3\u003e\u003cp\u003eYes for monitoring the O2\/CO\/H2S\/LEL hazards. To sample a space before entry, use a pump model such as the \u003ca href=\"\/products\/forsensal-4-gas-detector-with-pump\" title=\"Forsensal pump detector\"\u003eForsensal pump detector\u003c\/a\u003e.\u003c\/p\u003e\n\u003ch3\u003eHow does the Guard-101 compare to the Guard-156?\u003c\/h3\u003e\u003cp\u003eBoth are LCD four-gas units; the \u003ca href=\"\/products\/toptes-guard-156-4-gas-monitor\" title=\"Guard-156\"\u003eGuard-156\u003c\/a\u003e adds a faster 0.5-second response, while the Guard-101 is the lower-cost, higher-review option.\u003c\/p\u003e\n\u003ch3\u003eDoes it have a pump?\u003c\/h3\u003e\u003cp\u003eNo — it is diffusion only. For remote sampling choose a pump-equipped monitor such as the \u003ca href=\"\/products\/forensics-detectors-4-gas-monitor-with-pump\" title=\"Forensics 4 Gas Monitor with Pump\"\u003eForensics 4 Gas Monitor with Pump\u003c\/a\u003e.\u003c\/p\u003e\n\u003ch3\u003eHow do I keep it accurate?\u003c\/h3\u003e\u003cp\u003eBump-test before each day of use with four-gas calibration gas and calibrate on the manufacturer's schedule or after a failed bump test.\u003c\/p\u003e\n\u003ch3\u003eWhat alarms does it have?\u003c\/h3\u003e\u003cp\u003eAudible, visual and vibration alarms activate when any monitored gas crosses its set point.\u003c\/p\u003e\n\u003ch3\u003eWhat does it not detect?\u003c\/h3\u003e\u003cp\u003eNo VOCs, CO2 or gas-specific toxics like ammonia or chlorine. For VOC work you need a PID — explore the \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"Portable Gas Detectors\"\u003ePortable Gas Detectors\u003c\/a\u003e hub.\u003c\/p\u003e\n\u003ch3\u003eIs it in stock?\u003c\/h3\u003e\u003cp\u003eUse the Amazon buy button for live availability and shipping timing through our fulfillment partner.\u003c\/p\u003e\n\u003ch3\u003eDoes it come with calibration gas?\u003c\/h3\u003e\u003cp\u003eCalibration gas is generally sold separately. Plan to add four-gas calibration gas and a regulator for bump testing and periodic calibration.\u003c\/p\u003e\n\n\u003cdiv style=\"background:#1a1a1a;border:1px solid #3a3a3a;border-radius:6px;padding:16px 18px;margin:22px 0;\"\u003e\n\u003cp style=\"margin:0 0 10px 0;color:#f5e6d3;\"\u003eReady to order the \u003cstrong\u003eTopTes Guard-101\u003c\/strong\u003e? Add it to your cart above, or check the current Amazon price below. Compare it against the rest of our \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"Portable Gas Detectors\"\u003ePortable Gas Detectors\u003c\/a\u003e lineup before you buy.\u003c\/p\u003e\n\u003cp style=\"display:flex;gap:10px;flex-wrap:wrap;align-items:center;margin:0;\"\u003e\u003ca href=\"https:\/\/www.amazon.com\/dp\/B0D7C8BJL1?tag=wcsafety04-20\" rel=\"sponsored nofollow noopener\" target=\"_blank\" style=\"display:inline-block;background:#FFD814;color:#0F1111;padding:13px 26px;text-decoration:none;font-weight:bold;border-radius:4px;border:1px solid #FCD200;\"\u003eCHECK PRICE ON AMAZON →\u003c\/a\u003e\u003cspan style=\"font-size:0.8em;color:#bdae9d;\"\u003eAs an Amazon Associate, WC Safety earns from qualifying purchases.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/div\u003e\n\n\u003cdiv style=\"background:#1a2733;border:1px dashed #4fc3f7;padding:16px 20px;margin:30px 0 18px 0;color:#cfd8dc;font-size:0.92em;\"\u003e\n  \u003cstrong style=\"color:#4fc3f7;\"\u003eWhy trust this TopTes page?\u003c\/strong\u003e WC Safety is an independent industrial safety-equipment retailer serving safety managers, procurement teams and field supervisors. The specifications on this page are taken from the manufacturer’s published listing for TopTes Guard-101 and framed against \u003ca href=\"https:\/\/www.osha.gov\/laws-regs\/regulations\/standardnumber\/1910\/1910.146\" rel=\"noopener\" target=\"_blank\" style=\"color:#4fc3f7;\"\u003eOSHA 29 CFR 1910.146\u003c\/a\u003e for confined-space atmospheric testing. Disclosed: WC Safety earns Amazon affiliate commissions on outbound clicks; that does not influence the specs shown or where this unit sits in our lineup.\n\u003c\/div\u003e\n\u003cdiv style=\"background:#1a2733;border-left:4px solid #4fc3f7;padding:18px 22px;margin:18px 0;color:#cfd8dc;font-size:0.92em;\"\u003e\n  \u003cstrong style=\"color:#4fc3f7;\"\u003eBy Steven Eaton, WC Safety Editorial\u003c\/strong\u003e — Industrial safety-equipment desk · specialization: portable atmospheric monitoring, confined-space gas detection and instrument selection.\u003cbr\u003e\n  \u003cstrong\u003eLast updated:\u003c\/strong\u003e \u003ctime datetime=\"2026-06-22\"\u003eJune 22, 2026\u003c\/time\u003e · \u003cstrong\u003eSources reviewed:\u003c\/strong\u003e manufacturer product listing \u0026amp; specifications, OSHA 29 CFR 1910.146, OSHA Annotated PEL tables, ACGIH Threshold Limit Values.\u003cbr\u003e\n  \u003cstrong\u003eEditorial standard:\u003c\/strong\u003e \u003cem\u003eZero sponsored listings. No manufacturer input. Specs verified against the manufacturer’s published data.\u003c\/em\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"background:#1a2733;border-left:4px solid #4fc3f7;padding:16px 20px;margin:18px 0;color:#cfd8dc;font-size:0.92em;\"\u003e\n  \u003cstrong style=\"color:#4fc3f7;\"\u003eHow this page is maintained.\u003c\/strong\u003e Specifications and pricing are reviewed against the manufacturer’s current listing and re-checked whenever the lineup changes. Gas-detection guidance follows \u003ca href=\"https:\/\/www.osha.gov\/laws-regs\/regulations\/standardnumber\/1910\/1910.146\" rel=\"noopener\" target=\"_blank\" style=\"color:#4fc3f7;\"\u003eOSHA 1910.146\u003c\/a\u003e (permit-required confined spaces) and \u003ca href=\"https:\/\/www.osha.gov\/annotated-pels\" rel=\"noopener\" target=\"_blank\" style=\"color:#4fc3f7;\"\u003eOSHA Permissible Exposure Limits\u003c\/a\u003e, cross-referenced with ACGIH TLVs.\n\u003c\/div\u003e\n\u003cdiv style=\"background:#2a2520;border-left:4px solid #ff9800;padding:16px 20px;margin:18px 0;color:#f5e6d3;font-size:0.92em;\"\u003e\n  \u003cstrong style=\"color:#ffb74d;\"\u003eDisclosure.\u003c\/strong\u003e WC Safety participates in the Amazon Associates Program and earns commissions on qualifying purchases through outbound links on this page (tag wcsafety04-20). We are not sponsored by any instrument manufacturer. This page is buyer guidance, not medical, legal or regulatory advice — confirm gas-detection requirements for your site against the applicable OSHA standard and, for commercial monitoring programs, a Certified Industrial Hygienist (CIH).\n\u003c\/div\u003e\n\n\u003cscript type=\"application\/ld+json\"\u003e\n{\"@context\": \"https:\/\/schema.org\", \"@graph\": [{\"@type\": \"Product\", \"@id\": \"https:\/\/wcsafety.com\/products\/toptes-guard-101-4-gas-detector#product\", \"name\": \"TopTes Guard-101 4 Gas Detector (O2, CO, H2S, LEL, 14h Battery)\", \"description\": \"TopTes Guard-101 4 gas detector — O2, CO, H2S \u0026 LEL with triple alarm, 14-hour battery and explosion-proof design. Best-value monitor at WC Safety.\", \"sku\": \"B0D7C8BJL1\", \"mpn\": \"Guard-101\", \"image\": [\"https:\/\/wcsafety.com\/cdn\/shop\/products\/toptes-guard-101-4-gas-detector.jpg\"], \"brand\": {\"@type\": \"Brand\", \"name\": \"TopTes\"}, \"category\": \"Portable Gas Detector\", \"isPartOf\": {\"@type\": \"CollectionPage\", \"@id\": \"https:\/\/wcsafety.com\/collections\/portable-gas-detectors#collection\", \"name\": \"Portable Gas Detectors\", \"url\": \"https:\/\/wcsafety.com\/collections\/portable-gas-detectors\"}, \"isRelatedTo\": [{\"@type\": \"Product\", \"name\": \"Forensics Detectors 4 Gas Meter for Confined Space\", \"url\": \"https:\/\/wcsafety.com\/products\/forensics-detectors-4-gas-meter-confined-space\"}, {\"@type\": \"Product\", \"name\": \"Forensics Detectors 4 Gas Monitor (USB Rechargeable)\", \"url\": \"https:\/\/wcsafety.com\/products\/forensics-detectors-4-gas-monitor-usb-rechargeable\"}, {\"@type\": \"Product\", \"name\": \"TopTes Guard-863Pro 4 Gas Monitor\", \"url\": \"https:\/\/wcsafety.com\/products\/toptes-guard-863pro-4-gas-monitor\"}, {\"@type\": \"Product\", \"name\": \"TopTes Guard-156 4 Gas Monitor\", \"url\": \"https:\/\/wcsafety.com\/products\/toptes-guard-156-4-gas-monitor\"}, {\"@type\": \"Product\", \"name\": \"Forensics Detectors 4 Gas Monitor with Pump\", \"url\": \"https:\/\/wcsafety.com\/products\/forensics-detectors-4-gas-monitor-with-pump\"}, {\"@type\": \"Product\", \"name\": \"Forsensal 4 Gas Detector with Pump\", \"url\": \"https:\/\/wcsafety.com\/products\/forsensal-4-gas-detector-with-pump\"}], \"offers\": {\"@type\": \"Offer\", \"url\": \"https:\/\/wcsafety.com\/products\/toptes-guard-101-4-gas-detector\", \"priceCurrency\": \"USD\", \"price\": \"106.24\", \"availability\": \"https:\/\/schema.org\/InStock\", \"seller\": {\"@type\": \"Organization\", \"name\": \"WC Safety\"}}}, {\"@type\": \"BreadcrumbList\", \"@id\": \"https:\/\/wcsafety.com\/products\/toptes-guard-101-4-gas-detector#breadcrumb\", \"itemListElement\": [{\"@type\": \"ListItem\", \"position\": 1, \"name\": \"Home\", \"item\": \"https:\/\/wcsafety.com\/\"}, {\"@type\": \"ListItem\", \"position\": 2, \"name\": \"Gas Detectors\", \"item\": \"https:\/\/wcsafety.com\/collections\/gas-detectors\"}, {\"@type\": \"ListItem\", \"position\": 3, \"name\": \"Portable Gas Detectors\", \"item\": \"https:\/\/wcsafety.com\/collections\/portable-gas-detectors\"}, {\"@type\": \"ListItem\", \"position\": 4, \"name\": \"TopTes Guard-101 4 Gas Detector (O2, CO, H2S, LEL, 14h Battery)\"}]}, {\"@type\": \"FAQPage\", \"mainEntity\": [{\"@type\": \"Question\", \"name\": \"What gases does the TopTes Guard-101 detect?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"It reads oxygen (O2), combustible gas (LEL), carbon monoxide (CO) and hydrogen sulfide (H2S) — the four confined-space hazards. It does not cover VOCs; for those, see PID options in the Portable Gas Detectors hub.\"}}, {\"@type\": \"Question\", \"name\": \"Is the TopTes Guard-101 a good first gas detector?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Yes — it is the lowest-priced, most-reviewed unit in our range and covers the core four-gas set, which makes it a common first purchase for small crews.\"}}, {\"@type\": \"Question\", \"name\": \"How long does the Guard-101 battery last?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Up to 14 hours per charge, enough for a typical work shift with margin for multiple entries.\"}}, {\"@type\": \"Question\", \"name\": \"Is the Guard-101 explosion-proof?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"It uses an explosion-proof design intended for use in flammable atmospheres. Confirm the rating against your site's area classification before use.\"}}, {\"@type\": \"Question\", \"name\": \"Can I use it for confined-space entry?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Yes for monitoring the O2\/CO\/H2S\/LEL hazards. To sample a space before entry, use a pump model such as the Forsensal pump detector.\"}}, {\"@type\": \"Question\", \"name\": \"How does the Guard-101 compare to the Guard-156?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Both are LCD four-gas units; the Guard-156 adds a faster 0.5-second response, while the Guard-101 is the lower-cost, higher-review option.\"}}, {\"@type\": \"Question\", \"name\": \"Does it have a pump?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"No — it is diffusion only. For remote sampling choose a pump-equipped monitor such as the Forensics 4 Gas Monitor with Pump.\"}}, {\"@type\": \"Question\", \"name\": \"How do I keep it accurate?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Bump-test before each day of use with four-gas calibration gas and calibrate on the manufacturer's schedule or after a failed bump test.\"}}, {\"@type\": \"Question\", \"name\": \"What alarms does it have?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Audible, visual and vibration alarms activate when any monitored gas crosses its set point.\"}}, {\"@type\": \"Question\", \"name\": \"What does it not detect?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"No VOCs, CO2 or gas-specific toxics like ammonia or chlorine. For VOC work you need a PID — explore the Portable Gas Detectors hub.\"}}, {\"@type\": \"Question\", \"name\": \"Is it in stock?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Use the Amazon buy button for live availability and shipping timing through our fulfillment partner.\"}}, {\"@type\": \"Question\", \"name\": \"Does it come with calibration gas?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Calibration gas is generally sold separately. Plan to add four-gas calibration gas and a regulator for bump testing and periodic calibration.\"}}]}, {\"@type\": \"Organization\", \"@id\": \"https:\/\/wcsafety.com\/#org\", \"name\": \"WC Safety\", \"url\": \"https:\/\/wcsafety.com\", \"logo\": \"https:\/\/wcsafety.com\/cdn\/shop\/files\/logo.png\"}, {\"@type\": \"Person\", \"@id\": \"https:\/\/wcsafety.com\/#editor\", \"name\": \"Steven Eaton\", \"jobTitle\": \"Editorial Lead\", \"worksFor\": {\"@id\": \"https:\/\/wcsafety.com\/#org\"}, \"knowsAbout\": [\"industrial gas detection\", \"confined-space atmospheric monitoring\", \"personal protective equipment\"]}, {\"@type\": \"Brand\", \"name\": \"TopTes\"}]}\n\u003c\/script\u003e","brand":"TopTes","offers":[{"title":"Default Title","offer_id":44266357227608,"sku":"B0D7C8BJL1","price":106.24,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0594\/1900\/0920\/files\/71uT1adVhsL._AC_SL1500.jpg?v=1782119877"},{"product_id":"toptes-guard-156-4-gas-monitor","title":"TopTes Guard-156 4 Gas Monitor (O2, CO, H2S, LEL, 0.5s Response)","description":"\u003c!-- PRODUCT B0DHK54PKM | tag portable-gas-detector | TODO: add matching Product Review + best-of guide links when those silo layers exist --\u003e\n\n\u003cdiv style=\"background:#1a1a1a;border-left:4px solid #ff9800;padding:14px 18px;margin:0 0 18px 0;color:#f5e6d3;font-size:0.95em;\"\u003e\n\u003cstrong style=\"color:#ffb74d;\"\u003eEditor’s note:\u003c\/strong\u003e the TopTes Guard-156 is one of the portable instruments we curate in our \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"Portable Gas Detectors\"\u003ePortable Gas Detectors\u003c\/a\u003e buyer’s hub. Compare it head-to-head with the \u003ca href=\"\/products\/forensics-detectors-4-gas-meter-confined-space\" title=\"Forensics Detectors 4 Gas Meter\"\u003eForensics Detectors 4 Gas Meter\u003c\/a\u003e below before you order.\u003c\/div\u003e\n\n\u003ch2 id=\"top\"\u003eTopTes Guard-156 4 Gas Monitor — Fast-Response O2, CO, H2S \u0026amp; LEL\u003c\/h2\u003e\n\n\u003cp\u003eThe \u003cstrong\u003eTopTes Guard-156\u003c\/strong\u003e adds a fast 0.5-second sensor response to the TopTes four-gas line — a \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"portable gas detector\"\u003eportable gas detector\u003c\/a\u003e reading oxygen (O2), combustible gas (LEL), carbon monoxide (CO) and hydrogen sulfide (H2S) in a dust-proof, explosion-proof body, priced between the entry Guard-101 and the flagship Guard-863Pro.\u003c\/p\u003e\n\n\u003cp style=\"font-size:0.9em;color:#bdae9d;margin:10px 0 18px 0;\"\u003eJump to: \u003ca href=\"#features\" style=\"color:#ffb74d;\"\u003eFeatures\u003c\/a\u003e · \u003ca href=\"#specs\" style=\"color:#ffb74d;\"\u003eSpecs\u003c\/a\u003e · \u003ca href=\"#compatibility\" style=\"color:#ffb74d;\"\u003eWhat it detects\u003c\/a\u003e · \u003ca href=\"#comparison\" style=\"color:#ffb74d;\"\u003eComparison\u003c\/a\u003e · \u003ca href=\"#faq\" style=\"color:#ffb74d;\"\u003eFAQ\u003c\/a\u003e\u003c\/p\u003e\n\n\u003cp\u003eThe TopTes Guard-156 is a rechargeable four-gas monitor (O2, CO, H2S, LEL) with a 0.5-second response time, triple alarms and a dust-proof, explosion-proof design.\u003c\/p\u003e\n\n\u003ch3 id=\"features\"\u003eKey features\u003c\/h3\u003e\n\n\u003cul\u003e\n\u003cli\u003eReads oxygen (O2), combustible gas (LEL), carbon monoxide (CO) and hydrogen sulfide (H2S) with a fast 0.5-second sensor response\u003c\/li\u003e\n\u003cli\u003eTriple alarm modes — visual, vibration and sound\u003c\/li\u003e\n\u003cli\u003eDust-proof and explosion-proof design for harsh sites\u003c\/li\u003e\n\u003cli\u003eBacklit LCD for clear readings in low light\u003c\/li\u003e\n\u003cli\u003eMid-priced step up from the entry Guard-101\u003c\/li\u003e\n\u003cli\u003eRechargeable battery sized for full-shift use\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cdiv style=\"display:flex;gap:14px;flex-wrap:wrap;margin:18px 0;\"\u003e\n\u003cdiv style=\"flex:1;min-width:240px;background:#1b3a2a;border:1px solid #4caf50;border-radius:6px;padding:14px 18px;\"\u003e\n\u003cstrong style=\"color:#81c784;\"\u003ePros\u003c\/strong\u003e\u003cul style=\"margin:8px 0 0 0;\"\u003e\n\u003cli\u003eFast 0.5-second response\u003c\/li\u003e\n\u003cli\u003eDust-proof and explosion-proof build\u003c\/li\u003e\n\u003cli\u003eTriple alarm modes\u003c\/li\u003e\n\u003cli\u003eMid-range price\u003c\/li\u003e\n\u003cli\u003eSolid review base (160+)\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"flex:1;min-width:240px;background:#3a1e1e;border:1px solid #ef5350;border-radius:6px;padding:14px 18px;\"\u003e\n\u003cstrong style=\"color:#e57373;\"\u003eCons\u003c\/strong\u003e\u003cul style=\"margin:8px 0 0 0;\"\u003e\n\u003cli\u003eDiffusion only — no pump\u003c\/li\u003e\n\u003cli\u003eMonochrome LCD, no USB data export\u003c\/li\u003e\n\u003cli\u003eValue brand, not a managed fleet platform\u003c\/li\u003e\n\u003cli\u003eSensors need periodic replacement\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\n\u003ch3 id=\"specs\"\u003eSpecifications\u003c\/h3\u003e\n\n\u003cdiv style=\"overflow-x:auto;\"\u003e\u003ctable style=\"width:100%;border-collapse:collapse;background:#1a1a1a;margin:14px 0;\"\u003e\n\u003cthead\u003e\u003ctr style=\"background:#2a2a2a;\"\u003e\n\u003cth style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;text-align:left;\"\u003eSpecification\u003c\/th\u003e\n\u003cth style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;text-align:left;\"\u003eDetail\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eGases detected\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eO2, CO, H2S, LEL combustibles\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eResponse time\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003e0.5 seconds\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eDisplay\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eBacklit LCD\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eAlarms\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eAudible, visual \u0026amp; vibration (triple mode)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eBuild\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eDust-proof \u0026amp; explosion-proof\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003ePower\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eRechargeable battery\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eWeight\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003e~0.6 kg\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eColor\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eOrange\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003c\/div\u003e\n\n\u003ch3\u003eWhere the TopTes Guard-156 fits\u003c\/h3\u003e\n\n\u003cul\u003e\n\u003cli\u003eConfined-space and pre-entry checks\u003c\/li\u003e\n\u003cli\u003eFast-changing atmospheres needing quick response\u003c\/li\u003e\n\u003cli\u003eDusty industrial and construction sites\u003c\/li\u003e\n\u003cli\u003eSewer and utility work\u003c\/li\u003e\n\u003cli\u003eFacilities monitoring rounds\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2 id=\"compatibility\"\u003eWhat the TopTes Guard-156 detects (and what it doesn’t)\u003c\/h2\u003e\n\n\u003cp\u003eThe Guard-156 detects oxygen (O2), combustible gas (LEL), carbon monoxide (CO) and hydrogen sulfide (H2S) only — no VOCs, CO2 or single toxics like chlorine or ammonia. It is a diffusion instrument, so for remote sampling before entry choose a pump unit such as the \u003ca href=\"\/products\/forensics-detectors-4-gas-monitor-with-pump\" title=\"Forensics Detectors 4 Gas Monitor with Pump\"\u003eForensics Detectors 4 Gas Monitor with Pump\u003c\/a\u003e. Bump-test with four-gas calibration gas before use. The \u003ca href=\"\/products\/toptes-guard-101-4-gas-detector\" title=\"Guard-101\"\u003eGuard-101\u003c\/a\u003e is the lower-cost sibling; the \u003ca href=\"\/products\/toptes-guard-863pro-4-gas-monitor\" title=\"Guard-863Pro\"\u003eGuard-863Pro\u003c\/a\u003e adds color screen and USB export. Pair with a clip from \u003ca href=\"\/collections\/personal-gas-detectors\" title=\"Personal \u0026amp; Wearable Gas Detectors\"\u003ePersonal \u0026amp; Wearable Gas Detectors\u003c\/a\u003e for single-worker wear.\u003c\/p\u003e\n\n\u003cp\u003eCross-shopping? This unit sits in our \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"Portable Gas Detectors\"\u003ePortable Gas Detectors\u003c\/a\u003e hub alongside the \u003ca href=\"\/products\/forensics-detectors-4-gas-meter-confined-space\" title=\"Forensics Detectors 4 Gas Meter\"\u003eForensics Detectors 4 Gas Meter\u003c\/a\u003e, \u003ca href=\"\/products\/forensics-detectors-4-gas-monitor-usb-rechargeable\" title=\"Forensics Detectors USB 4 Gas Monitor\"\u003eForensics Detectors USB 4 Gas Monitor\u003c\/a\u003e, \u003ca href=\"\/products\/toptes-guard-863pro-4-gas-monitor\" title=\"TopTes Guard-863Pro\"\u003eTopTes Guard-863Pro\u003c\/a\u003e, \u003ca href=\"\/products\/toptes-guard-101-4-gas-detector\" title=\"TopTes Guard-101\"\u003eTopTes Guard-101\u003c\/a\u003e. If one worker needs all-shift wear instead of a carried meter, see \u003ca href=\"\/collections\/personal-gas-detectors\" title=\"Personal \u0026amp; Wearable Gas Detectors\"\u003ePersonal \u0026amp; Wearable Gas Detectors\u003c\/a\u003e; for a fixed install or a job-site perimeter, see \u003ca href=\"\/collections\/fixed-gas-detection-systems\" title=\"Fixed Gas Detection Systems\"\u003eFixed Gas Detection Systems\u003c\/a\u003e and \u003ca href=\"\/collections\/area-gas-monitors\" title=\"Area \u0026amp; Transportable Gas Monitors\"\u003eArea \u0026amp; Transportable Gas Monitors\u003c\/a\u003e.\u003c\/p\u003e\n\n\u003ch2 id=\"comparison\"\u003eTopTes 4-gas family compared\u003c\/h2\u003e\n\n\u003cdiv style=\"overflow-x:auto;\"\u003e\u003ctable style=\"width:100%;border-collapse:collapse;background:#1a1a1a;margin:14px 0;\"\u003e\n\u003ccaption style=\"color:#bdae9d;font-size:0.85em;text-align:left;padding:4px 0;\"\u003eTopTes portable 4-gas family (O2, CO, H2S, LEL)\u003c\/caption\u003e\n\u003cthead\u003e\u003ctr style=\"background:#2a2a2a;\"\u003e\n\u003cth style=\"color:#ffb74d;padding:9px;border:1px solid #3a3a3a;text-align:left;\"\u003eModel\u003c\/th\u003e\n\u003cth style=\"color:#ffb74d;padding:9px;border:1px solid #3a3a3a;text-align:left;\"\u003eDisplay\u003c\/th\u003e\n\u003cth style=\"color:#ffb74d;padding:9px;border:1px solid #3a3a3a;text-align:left;\"\u003eBattery\u003c\/th\u003e\n\u003cth style=\"color:#ffb74d;padding:9px;border:1px solid #3a3a3a;text-align:left;\"\u003eNotable\u003c\/th\u003e\n\u003cth style=\"color:#ffb74d;padding:9px;border:1px solid #3a3a3a;text-align:left;\"\u003eStreet price\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e\u003ca href=\"\/products\/toptes-guard-101-4-gas-detector\" title=\"Guard-101\"\u003eGuard-101\u003c\/a\u003e\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eLCD\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e14 h\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eBest value\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e~$106\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e\u003ca href=\"\/products\/toptes-guard-156-4-gas-monitor\" title=\"Guard-156\"\u003eGuard-156\u003c\/a\u003e\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eLCD\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eLong-life\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e0.5 s response\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e~$127\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#2a2520;\"\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e\u003cstrong\u003e\u003ca href=\"\/products\/toptes-guard-863pro-4-gas-monitor\" title=\"Guard-863Pro\"\u003eGuard-863Pro\u003c\/a\u003e\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eTFT color\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e18 h\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e5-yr O2 sensor, USB data export\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e~$170\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003c\/div\u003e\n\n\u003cul\u003e\n\u003cli\u003eChoose the \u003cstrong\u003eGuard-156\u003c\/strong\u003e for fast 0.5-second response in a rugged dust\/explosion-proof body.\u003c\/li\u003e\n\u003cli\u003ePick the \u003ca href=\"\/products\/toptes-guard-101-4-gas-detector\" title=\"Guard-101\"\u003eGuard-101\u003c\/a\u003e to spend less on a simpler LCD unit.\u003c\/li\u003e\n\u003cli\u003ePick the \u003ca href=\"\/products\/toptes-guard-863pro-4-gas-monitor\" title=\"Guard-863Pro\"\u003eGuard-863Pro\u003c\/a\u003e for a color screen, USB export and 5-year O2 sensor.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2 id=\"faq\"\u003eFrequently asked questions\u003c\/h2\u003e\n\n\u003ch3\u003eWhat gases does the TopTes Guard-156 detect?\u003c\/h3\u003e\u003cp\u003eIt reads oxygen (O2), combustible gas (LEL), carbon monoxide (CO) and hydrogen sulfide (H2S). For VOC detection you need a separate PID; browse the \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"Portable Gas Detectors\"\u003ePortable Gas Detectors\u003c\/a\u003e hub.\u003c\/p\u003e\n\u003ch3\u003eWhat is the Guard-156 response time?\u003c\/h3\u003e\u003cp\u003eIts sensors respond in about 0.5 seconds, which helps in fast-changing atmospheres where you need an immediate reading.\u003c\/p\u003e\n\u003ch3\u003eIs the Guard-156 explosion-proof?\u003c\/h3\u003e\u003cp\u003eYes — it uses a dust-proof and explosion-proof design for harsh and flammable environments. Confirm the rating against your area classification.\u003c\/p\u003e\n\u003ch3\u003eHow does the Guard-156 compare to the Guard-101?\u003c\/h3\u003e\u003cp\u003eThe Guard-156 adds faster 0.5-second response and a dust\/explosion-proof build over the \u003ca href=\"\/products\/toptes-guard-101-4-gas-detector\" title=\"Guard-101\"\u003eGuard-101\u003c\/a\u003e, at a moderately higher price.\u003c\/p\u003e\n\u003ch3\u003eCan I use it for confined-space entry?\u003c\/h3\u003e\u003cp\u003eYes for monitoring O2\/CO\/H2S\/LEL. For sampling a sealed space before entry, use a \u003ca href=\"\/products\/forensics-detectors-4-gas-monitor-with-pump\" title=\"pump-equipped monitor\"\u003epump-equipped monitor\u003c\/a\u003e.\u003c\/p\u003e\n\u003ch3\u003eDoes it export data?\u003c\/h3\u003e\u003cp\u003eNo — it does not have USB data export. If you need exportable logs, choose the \u003ca href=\"\/products\/toptes-guard-863pro-4-gas-monitor\" title=\"Guard-863Pro\"\u003eGuard-863Pro\u003c\/a\u003e.\u003c\/p\u003e\n\u003ch3\u003eHow long does the battery last?\u003c\/h3\u003e\u003cp\u003eIts rechargeable battery is sized for a full work shift; recharge between shifts so it is ready for the next entry.\u003c\/p\u003e\n\u003ch3\u003eHow do I keep it accurate?\u003c\/h3\u003e\u003cp\u003eBump-test before each use with four-gas calibration gas and calibrate on the manufacturer's schedule or after any failed bump test.\u003c\/p\u003e\n\u003ch3\u003eWhat alarms does it have?\u003c\/h3\u003e\u003cp\u003eTriple alarms — visual, vibration and sound — trigger when a monitored gas exceeds its threshold.\u003c\/p\u003e\n\u003ch3\u003eWhat does it not detect?\u003c\/h3\u003e\u003cp\u003eNo VOCs, CO2 or gas-specific toxics. For VOC monitoring use a PID; see the \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"Portable Gas Detectors\"\u003ePortable Gas Detectors\u003c\/a\u003e hub for instrument types.\u003c\/p\u003e\n\u003ch3\u003eIs it in stock and how does it ship?\u003c\/h3\u003e\u003cp\u003eUse the Amazon buy button for current availability and delivery timing through our fulfillment partner.\u003c\/p\u003e\n\u003ch3\u003eIs the Guard-156 industrial grade?\u003c\/h3\u003e\u003cp\u003eIt is a capable value-tier monitor for crews and facilities. Large fleet programs with docking automation usually specify Industrial Scientific or BW Honeywell.\u003c\/p\u003e\n\n\u003cdiv style=\"background:#1a1a1a;border:1px solid #3a3a3a;border-radius:6px;padding:16px 18px;margin:22px 0;\"\u003e\n\u003cp style=\"margin:0 0 10px 0;color:#f5e6d3;\"\u003eReady to order the \u003cstrong\u003eTopTes Guard-156\u003c\/strong\u003e? Add it to your cart above, or check the current Amazon price below. Compare it against the rest of our \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"Portable Gas Detectors\"\u003ePortable Gas Detectors\u003c\/a\u003e lineup before you buy.\u003c\/p\u003e\n\u003cp style=\"display:flex;gap:10px;flex-wrap:wrap;align-items:center;margin:0;\"\u003e\u003ca href=\"https:\/\/www.amazon.com\/dp\/B0DHK54PKM?tag=wcsafety04-20\" rel=\"sponsored nofollow noopener\" target=\"_blank\" style=\"display:inline-block;background:#FFD814;color:#0F1111;padding:13px 26px;text-decoration:none;font-weight:bold;border-radius:4px;border:1px solid #FCD200;\"\u003eCHECK PRICE ON AMAZON →\u003c\/a\u003e\u003cspan style=\"font-size:0.8em;color:#bdae9d;\"\u003eAs an Amazon Associate, WC Safety earns from qualifying purchases.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/div\u003e\n\n\u003cdiv style=\"background:#1a2733;border:1px dashed #4fc3f7;padding:16px 20px;margin:30px 0 18px 0;color:#cfd8dc;font-size:0.92em;\"\u003e\n  \u003cstrong style=\"color:#4fc3f7;\"\u003eWhy trust this TopTes page?\u003c\/strong\u003e WC Safety is an independent industrial safety-equipment retailer serving safety managers, procurement teams and field supervisors. The specifications on this page are taken from the manufacturer’s published listing for TopTes Guard-156 and framed against \u003ca href=\"https:\/\/www.osha.gov\/laws-regs\/regulations\/standardnumber\/1910\/1910.146\" rel=\"noopener\" target=\"_blank\" style=\"color:#4fc3f7;\"\u003eOSHA 29 CFR 1910.146\u003c\/a\u003e for confined-space atmospheric testing. Disclosed: WC Safety earns Amazon affiliate commissions on outbound clicks; that does not influence the specs shown or where this unit sits in our lineup.\n\u003c\/div\u003e\n\u003cdiv style=\"background:#1a2733;border-left:4px solid #4fc3f7;padding:18px 22px;margin:18px 0;color:#cfd8dc;font-size:0.92em;\"\u003e\n  \u003cstrong style=\"color:#4fc3f7;\"\u003eBy Steven Eaton, WC Safety Editorial\u003c\/strong\u003e — Industrial safety-equipment desk · specialization: portable atmospheric monitoring, confined-space gas detection and instrument selection.\u003cbr\u003e\n  \u003cstrong\u003eLast updated:\u003c\/strong\u003e \u003ctime datetime=\"2026-06-22\"\u003eJune 22, 2026\u003c\/time\u003e · \u003cstrong\u003eSources reviewed:\u003c\/strong\u003e manufacturer product listing \u0026amp; specifications, OSHA 29 CFR 1910.146, OSHA Annotated PEL tables, ACGIH Threshold Limit Values.\u003cbr\u003e\n  \u003cstrong\u003eEditorial standard:\u003c\/strong\u003e \u003cem\u003eZero sponsored listings. No manufacturer input. Specs verified against the manufacturer’s published data.\u003c\/em\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"background:#1a2733;border-left:4px solid #4fc3f7;padding:16px 20px;margin:18px 0;color:#cfd8dc;font-size:0.92em;\"\u003e\n  \u003cstrong style=\"color:#4fc3f7;\"\u003eHow this page is maintained.\u003c\/strong\u003e Specifications and pricing are reviewed against the manufacturer’s current listing and re-checked whenever the lineup changes. Gas-detection guidance follows \u003ca href=\"https:\/\/www.osha.gov\/laws-regs\/regulations\/standardnumber\/1910\/1910.146\" rel=\"noopener\" target=\"_blank\" style=\"color:#4fc3f7;\"\u003eOSHA 1910.146\u003c\/a\u003e (permit-required confined spaces) and \u003ca href=\"https:\/\/www.osha.gov\/annotated-pels\" rel=\"noopener\" target=\"_blank\" style=\"color:#4fc3f7;\"\u003eOSHA Permissible Exposure Limits\u003c\/a\u003e, cross-referenced with ACGIH TLVs.\n\u003c\/div\u003e\n\u003cdiv style=\"background:#2a2520;border-left:4px solid #ff9800;padding:16px 20px;margin:18px 0;color:#f5e6d3;font-size:0.92em;\"\u003e\n  \u003cstrong style=\"color:#ffb74d;\"\u003eDisclosure.\u003c\/strong\u003e WC Safety participates in the Amazon Associates Program and earns commissions on qualifying purchases through outbound links on this page (tag wcsafety04-20). We are not sponsored by any instrument manufacturer. This page is buyer guidance, not medical, legal or regulatory advice — confirm gas-detection requirements for your site against the applicable OSHA standard and, for commercial monitoring programs, a Certified Industrial Hygienist (CIH).\n\u003c\/div\u003e\n\n\u003cscript type=\"application\/ld+json\"\u003e\n{\"@context\": \"https:\/\/schema.org\", \"@graph\": [{\"@type\": \"Product\", \"@id\": \"https:\/\/wcsafety.com\/products\/toptes-guard-156-4-gas-monitor#product\", \"name\": \"TopTes Guard-156 4 Gas Monitor (O2, CO, H2S, LEL, 0.5s Response)\", \"description\": \"TopTes Guard-156 4 gas monitor — O2, CO, H2S \u0026 LEL with 0.5s fast response, triple alarm and dust\/explosion-proof design. Order at WC Safety.\", \"sku\": \"B0DHK54PKM\", \"mpn\": \"Guard-156\", \"image\": [\"https:\/\/wcsafety.com\/cdn\/shop\/products\/toptes-guard-156-4-gas-monitor.jpg\"], \"brand\": {\"@type\": \"Brand\", \"name\": \"TopTes\"}, \"category\": \"Portable Gas Detector\", \"isPartOf\": {\"@type\": \"CollectionPage\", \"@id\": \"https:\/\/wcsafety.com\/collections\/portable-gas-detectors#collection\", \"name\": \"Portable Gas Detectors\", \"url\": \"https:\/\/wcsafety.com\/collections\/portable-gas-detectors\"}, \"isRelatedTo\": [{\"@type\": \"Product\", \"name\": \"Forensics Detectors 4 Gas Meter for Confined Space\", \"url\": \"https:\/\/wcsafety.com\/products\/forensics-detectors-4-gas-meter-confined-space\"}, {\"@type\": \"Product\", \"name\": \"Forensics Detectors 4 Gas Monitor (USB Rechargeable)\", \"url\": \"https:\/\/wcsafety.com\/products\/forensics-detectors-4-gas-monitor-usb-rechargeable\"}, {\"@type\": \"Product\", \"name\": \"TopTes Guard-863Pro 4 Gas Monitor\", \"url\": \"https:\/\/wcsafety.com\/products\/toptes-guard-863pro-4-gas-monitor\"}, {\"@type\": \"Product\", \"name\": \"TopTes Guard-101 4 Gas Detector\", \"url\": \"https:\/\/wcsafety.com\/products\/toptes-guard-101-4-gas-detector\"}, {\"@type\": \"Product\", \"name\": \"Forensics Detectors 4 Gas Monitor with Pump\", \"url\": \"https:\/\/wcsafety.com\/products\/forensics-detectors-4-gas-monitor-with-pump\"}, {\"@type\": \"Product\", \"name\": \"Forsensal 4 Gas Detector with Pump\", \"url\": \"https:\/\/wcsafety.com\/products\/forsensal-4-gas-detector-with-pump\"}], \"offers\": {\"@type\": \"Offer\", \"url\": \"https:\/\/wcsafety.com\/products\/toptes-guard-156-4-gas-monitor\", \"priceCurrency\": \"USD\", \"price\": \"127.49\", \"availability\": \"https:\/\/schema.org\/InStock\", \"seller\": {\"@type\": \"Organization\", \"name\": \"WC Safety\"}}}, {\"@type\": \"BreadcrumbList\", \"@id\": \"https:\/\/wcsafety.com\/products\/toptes-guard-156-4-gas-monitor#breadcrumb\", \"itemListElement\": [{\"@type\": \"ListItem\", \"position\": 1, \"name\": \"Home\", \"item\": \"https:\/\/wcsafety.com\/\"}, {\"@type\": \"ListItem\", \"position\": 2, \"name\": \"Gas Detectors\", \"item\": \"https:\/\/wcsafety.com\/collections\/gas-detectors\"}, {\"@type\": \"ListItem\", \"position\": 3, \"name\": \"Portable Gas Detectors\", \"item\": \"https:\/\/wcsafety.com\/collections\/portable-gas-detectors\"}, {\"@type\": \"ListItem\", \"position\": 4, \"name\": \"TopTes Guard-156 4 Gas Monitor (O2, CO, H2S, LEL, 0.5s Response)\"}]}, {\"@type\": \"FAQPage\", \"mainEntity\": [{\"@type\": \"Question\", \"name\": \"What gases does the TopTes Guard-156 detect?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"It reads oxygen (O2), combustible gas (LEL), carbon monoxide (CO) and hydrogen sulfide (H2S). For VOC detection you need a separate PID; browse the Portable Gas Detectors hub.\"}}, {\"@type\": \"Question\", \"name\": \"What is the Guard-156 response time?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Its sensors respond in about 0.5 seconds, which helps in fast-changing atmospheres where you need an immediate reading.\"}}, {\"@type\": \"Question\", \"name\": \"Is the Guard-156 explosion-proof?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Yes — it uses a dust-proof and explosion-proof design for harsh and flammable environments. Confirm the rating against your area classification.\"}}, {\"@type\": \"Question\", \"name\": \"How does the Guard-156 compare to the Guard-101?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"The Guard-156 adds faster 0.5-second response and a dust\/explosion-proof build over the Guard-101, at a moderately higher price.\"}}, {\"@type\": \"Question\", \"name\": \"Can I use it for confined-space entry?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Yes for monitoring O2\/CO\/H2S\/LEL. For sampling a sealed space before entry, use a pump-equipped monitor.\"}}, {\"@type\": \"Question\", \"name\": \"Does it export data?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"No — it does not have USB data export. If you need exportable logs, choose the Guard-863Pro.\"}}, {\"@type\": \"Question\", \"name\": \"How long does the battery last?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Its rechargeable battery is sized for a full work shift; recharge between shifts so it is ready for the next entry.\"}}, {\"@type\": \"Question\", \"name\": \"How do I keep it accurate?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Bump-test before each use with four-gas calibration gas and calibrate on the manufacturer's schedule or after any failed bump test.\"}}, {\"@type\": \"Question\", \"name\": \"What alarms does it have?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Triple alarms — visual, vibration and sound — trigger when a monitored gas exceeds its threshold.\"}}, {\"@type\": \"Question\", \"name\": \"What does it not detect?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"No VOCs, CO2 or gas-specific toxics. For VOC monitoring use a PID; see the Portable Gas Detectors hub for instrument types.\"}}, {\"@type\": \"Question\", \"name\": \"Is it in stock and how does it ship?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Use the Amazon buy button for current availability and delivery timing through our fulfillment partner.\"}}, {\"@type\": \"Question\", \"name\": \"Is the Guard-156 industrial grade?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"It is a capable value-tier monitor for crews and facilities. Large fleet programs with docking automation usually specify Industrial Scientific or BW Honeywell.\"}}]}, {\"@type\": \"Organization\", \"@id\": \"https:\/\/wcsafety.com\/#org\", \"name\": \"WC Safety\", \"url\": \"https:\/\/wcsafety.com\", \"logo\": \"https:\/\/wcsafety.com\/cdn\/shop\/files\/logo.png\"}, {\"@type\": \"Person\", \"@id\": \"https:\/\/wcsafety.com\/#editor\", \"name\": \"Steven Eaton\", \"jobTitle\": \"Editorial Lead\", \"worksFor\": {\"@id\": \"https:\/\/wcsafety.com\/#org\"}, \"knowsAbout\": [\"industrial gas detection\", \"confined-space atmospheric monitoring\", \"personal protective equipment\"]}, {\"@type\": \"Brand\", \"name\": \"TopTes\"}]}\n\u003c\/script\u003e","brand":"TopTes","offers":[{"title":"Default Title","offer_id":44266357358680,"sku":"B0DHK54PKM","price":127.49,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0594\/1900\/0920\/files\/61oVO4WJLfL._AC_SL1500.jpg?v=1782119881"},{"product_id":"forensics-detectors-4-gas-monitor-with-pump","title":"Forensics Detectors 4 Gas Monitor with Pump (NIST, Confined-Space Probe)","description":"\u003c!-- PRODUCT B07J1TTDY3 | tag portable-gas-detector | TODO: add matching Product Review + best-of guide links when those silo layers exist --\u003e\n\n\u003cdiv style=\"background:#1a1a1a;border-left:4px solid #ff9800;padding:14px 18px;margin:0 0 18px 0;color:#f5e6d3;font-size:0.95em;\"\u003e\n\u003cstrong style=\"color:#ffb74d;\"\u003eEditor’s note:\u003c\/strong\u003e the Forensics Detectors 4 gas monitor with pump is one of the portable instruments we curate in our \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"Portable Gas Detectors\"\u003ePortable Gas Detectors\u003c\/a\u003e buyer’s hub. Compare it head-to-head with the \u003ca href=\"\/products\/forensics-detectors-4-gas-meter-confined-space\" title=\"Forensics Detectors 4 Gas Meter\"\u003eForensics Detectors 4 Gas Meter\u003c\/a\u003e below before you order.\u003c\/div\u003e\n\n\u003ch2 id=\"top\"\u003eForensics Detectors 4 Gas Monitor with Pump — Pre-Entry Sample-Draw\u003c\/h2\u003e\n\n\u003cp\u003eThe \u003cstrong\u003eForensics Detectors 4 gas monitor with pump\u003c\/strong\u003e is the pre-entry tool of the family — a \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"portable gas detector\"\u003eportable gas detector\u003c\/a\u003e with a motorized pump and probe that draws a sample from a sealed space so you can test oxygen (O2), combustible gas (LEL), carbon monoxide (CO) and hydrogen sulfide (H2S) before anyone goes in. It ships NIST-calibrated.\u003c\/p\u003e\n\n\u003cp style=\"font-size:0.9em;color:#bdae9d;margin:10px 0 18px 0;\"\u003eJump to: \u003ca href=\"#features\" style=\"color:#ffb74d;\"\u003eFeatures\u003c\/a\u003e · \u003ca href=\"#specs\" style=\"color:#ffb74d;\"\u003eSpecs\u003c\/a\u003e · \u003ca href=\"#compatibility\" style=\"color:#ffb74d;\"\u003eWhat it detects\u003c\/a\u003e · \u003ca href=\"#comparison\" style=\"color:#ffb74d;\"\u003eComparison\u003c\/a\u003e · \u003ca href=\"#faq\" style=\"color:#ffb74d;\"\u003eFAQ\u003c\/a\u003e\u003c\/p\u003e\n\n\u003cp\u003eThe Forensics Detectors 4 Gas Monitor with Pump is a NIST-calibrated, electrochemical four-gas instrument (O2, CO, H2S, LEL) with a motorized sample-draw pump and probe for confined-space pre-entry testing.\u003c\/p\u003e\n\n\u003ch3 id=\"features\"\u003eKey features\u003c\/h3\u003e\n\n\u003cul\u003e\n\u003cli\u003eBuilt-in motorized pump and probe to draw a remote sample before anyone enters a space\u003c\/li\u003e\n\u003cli\u003eMonitors oxygen (O2), combustible gas (LEL), carbon monoxide (CO) and hydrogen sulfide (H2S) — the confined-space hazard set — with a NIST certificate\u003c\/li\u003e\n\u003cli\u003eTests the bottom of a tank, vault or manhole from the surface\u003c\/li\u003e\n\u003cli\u003eAudible, vibration and visual alarms with adjustable set points\u003c\/li\u003e\n\u003cli\u003eUSB-rechargeable for shift-long readiness\u003c\/li\u003e\n\u003cli\u003eThe pre-entry tool in the Forensics four-gas family\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cdiv style=\"display:flex;gap:14px;flex-wrap:wrap;margin:18px 0;\"\u003e\n\u003cdiv style=\"flex:1;min-width:240px;background:#1b3a2a;border:1px solid #4caf50;border-radius:6px;padding:14px 18px;\"\u003e\n\u003cstrong style=\"color:#81c784;\"\u003ePros\u003c\/strong\u003e\u003cul style=\"margin:8px 0 0 0;\"\u003e\n\u003cli\u003eMotorized pump for remote pre-entry sampling\u003c\/li\u003e\n\u003cli\u003eNIST calibration certificate included\u003c\/li\u003e\n\u003cli\u003eTests sealed spaces before entry\u003c\/li\u003e\n\u003cli\u003eTriple alarm modes\u003c\/li\u003e\n\u003cli\u003eUSB-rechargeable\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"flex:1;min-width:240px;background:#3a1e1e;border:1px solid #ef5350;border-radius:6px;padding:14px 18px;\"\u003e\n\u003cstrong style=\"color:#e57373;\"\u003eCons\u003c\/strong\u003e\u003cul style=\"margin:8px 0 0 0;\"\u003e\n\u003cli\u003eHighest price in the Forensics family\u003c\/li\u003e\n\u003cli\u003ePump and probe add bulk and weight\u003c\/li\u003e\n\u003cli\u003eElectrochemical sensors need periodic replacement\u003c\/li\u003e\n\u003cli\u003ePump and probe need cleaning\/maintenance\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\n\u003ch3 id=\"specs\"\u003eSpecifications\u003c\/h3\u003e\n\n\u003cdiv style=\"overflow-x:auto;\"\u003e\u003ctable style=\"width:100%;border-collapse:collapse;background:#1a1a1a;margin:14px 0;\"\u003e\n\u003cthead\u003e\u003ctr style=\"background:#2a2a2a;\"\u003e\n\u003cth style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;text-align:left;\"\u003eSpecification\u003c\/th\u003e\n\u003cth style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;text-align:left;\"\u003eDetail\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eGases detected\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eO2, CO, H2S, LEL combustibles\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eSampling\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eMotorized pump + probe (sample-draw)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eSensor type\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eElectrochemical\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eAlarms\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eAudible, vibration \u0026amp; visual\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eCalibration\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eZero \u0026amp; span; NIST certificate included\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003ePower\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eUSB-rechargeable battery\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eDimensions\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003e1.18\" x 2.56\" x 8.86\"\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eColor\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eBlack \/ yellow\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003c\/div\u003e\n\n\u003ch3\u003eWhere the Forensics Detectors 4 Gas Monitor with Pump fits\u003c\/h3\u003e\n\n\u003cul\u003e\n\u003cli\u003eConfined-space pre-entry sampling\u003c\/li\u003e\n\u003cli\u003eTank, vessel and vault testing from the surface\u003c\/li\u003e\n\u003cli\u003eSewer and manhole pre-entry checks\u003c\/li\u003e\n\u003cli\u003eEmergency-response atmosphere assessment\u003c\/li\u003e\n\u003cli\u003ePermit-entry programs requiring remote sampling\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2 id=\"compatibility\"\u003eWhat the Forensics Detectors 4 Gas Monitor with Pump detects (and what it doesn’t)\u003c\/h2\u003e\n\n\u003cp\u003eIt measures oxygen (O2), combustible gas (LEL), carbon monoxide (CO) and hydrogen sulfide (H2S) and uses a motorized pump with a probe to sample remotely — its key advantage over diffusion meters like the \u003ca href=\"\/products\/forensics-detectors-4-gas-meter-confined-space\" title=\"Forensics 4 Gas Meter\"\u003eForensics 4 Gas Meter\u003c\/a\u003e. It does not detect VOCs, CO2 or single toxics such as chlorine; those need a PID or dedicated sensor. Keep the pump and probe clean, bump-test with four-gas calibration gas, and calibrate on schedule. For all-shift wear after entry is cleared, add a clip from \u003ca href=\"\/collections\/personal-gas-detectors\" title=\"Personal \u0026amp; Wearable Gas Detectors\"\u003ePersonal \u0026amp; Wearable Gas Detectors\u003c\/a\u003e; for ongoing area coverage during the job, see \u003ca href=\"\/collections\/area-gas-monitors\" title=\"Area \u0026amp; Transportable Gas Monitors\"\u003eArea \u0026amp; Transportable Gas Monitors\u003c\/a\u003e.\u003c\/p\u003e\n\n\u003cp\u003eCross-shopping? This unit sits in our \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"Portable Gas Detectors\"\u003ePortable Gas Detectors\u003c\/a\u003e hub alongside the \u003ca href=\"\/products\/forensics-detectors-4-gas-meter-confined-space\" title=\"Forensics Detectors 4 Gas Meter\"\u003eForensics Detectors 4 Gas Meter\u003c\/a\u003e, \u003ca href=\"\/products\/forensics-detectors-4-gas-monitor-usb-rechargeable\" title=\"Forensics Detectors USB 4 Gas Monitor\"\u003eForensics Detectors USB 4 Gas Monitor\u003c\/a\u003e, \u003ca href=\"\/products\/toptes-guard-863pro-4-gas-monitor\" title=\"TopTes Guard-863Pro\"\u003eTopTes Guard-863Pro\u003c\/a\u003e, \u003ca href=\"\/products\/toptes-guard-101-4-gas-detector\" title=\"TopTes Guard-101\"\u003eTopTes Guard-101\u003c\/a\u003e. If one worker needs all-shift wear instead of a carried meter, see \u003ca href=\"\/collections\/personal-gas-detectors\" title=\"Personal \u0026amp; Wearable Gas Detectors\"\u003ePersonal \u0026amp; Wearable Gas Detectors\u003c\/a\u003e; for a fixed install or a job-site perimeter, see \u003ca href=\"\/collections\/fixed-gas-detection-systems\" title=\"Fixed Gas Detection Systems\"\u003eFixed Gas Detection Systems\u003c\/a\u003e and \u003ca href=\"\/collections\/area-gas-monitors\" title=\"Area \u0026amp; Transportable Gas Monitors\"\u003eArea \u0026amp; Transportable Gas Monitors\u003c\/a\u003e.\u003c\/p\u003e\n\n\u003ch2 id=\"comparison\"\u003eForensics Detectors 4-gas family compared\u003c\/h2\u003e\n\n\u003cdiv style=\"overflow-x:auto;\"\u003e\u003ctable style=\"width:100%;border-collapse:collapse;background:#1a1a1a;margin:14px 0;\"\u003e\n\u003ccaption style=\"color:#bdae9d;font-size:0.85em;text-align:left;padding:4px 0;\"\u003eForensics Detectors portable 4-gas family (O2, CO, H2S, LEL)\u003c\/caption\u003e\n\u003cthead\u003e\u003ctr style=\"background:#2a2a2a;\"\u003e\n\u003cth style=\"color:#ffb74d;padding:9px;border:1px solid #3a3a3a;text-align:left;\"\u003eModel\u003c\/th\u003e\n\u003cth style=\"color:#ffb74d;padding:9px;border:1px solid #3a3a3a;text-align:left;\"\u003eSampling\u003c\/th\u003e\n\u003cth style=\"color:#ffb74d;padding:9px;border:1px solid #3a3a3a;text-align:left;\"\u003eNIST cert\u003c\/th\u003e\n\u003cth style=\"color:#ffb74d;padding:9px;border:1px solid #3a3a3a;text-align:left;\"\u003eRecharge\u003c\/th\u003e\n\u003cth style=\"color:#ffb74d;padding:9px;border:1px solid #3a3a3a;text-align:left;\"\u003eStreet price\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e\u003ca href=\"\/products\/forensics-detectors-4-gas-meter-confined-space\" title=\"4 Gas Meter (Confined Space)\"\u003e4 Gas Meter (Confined Space)\u003c\/a\u003e\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eDiffusion\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eYes\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eBattery\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e~$199\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e\u003ca href=\"\/products\/forensics-detectors-4-gas-monitor-usb-rechargeable\" title=\"4 Gas Monitor (USB)\"\u003e4 Gas Monitor (USB)\u003c\/a\u003e\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eDiffusion\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eYes\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eUSB rechargeable\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e~$225\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#2a2520;\"\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e\u003cstrong\u003e\u003ca href=\"\/products\/forensics-detectors-4-gas-monitor-with-pump\" title=\"4 Gas Monitor + Pump\"\u003e4 Gas Monitor + Pump\u003c\/a\u003e\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eMotorized pump + probe\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eYes\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eUSB rechargeable\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e~$299\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003c\/div\u003e\n\n\u003cul\u003e\n\u003cli\u003eChoose this \u003cstrong\u003e4 Gas Monitor with Pump\u003c\/strong\u003e when you must sample a space before entry.\u003c\/li\u003e\n\u003cli\u003ePick the \u003ca href=\"\/products\/forensics-detectors-4-gas-monitor-usb-rechargeable\" title=\"USB 4 Gas Monitor\"\u003eUSB 4 Gas Monitor\u003c\/a\u003e for ongoing monitoring without remote sampling.\u003c\/li\u003e\n\u003cli\u003ePick the \u003ca href=\"\/products\/forensics-detectors-4-gas-meter-confined-space\" title=\"4 Gas Meter\"\u003e4 Gas Meter\u003c\/a\u003e for the lightest, lowest-cost diffusion option.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2 id=\"faq\"\u003eFrequently asked questions\u003c\/h2\u003e\n\n\u003ch3\u003eWhy choose a 4 gas monitor with a pump?\u003c\/h3\u003e\u003cp\u003eA pump lets you draw a sample from a sealed or remote space — the bottom of a tank, vault or manhole — so you can test the atmosphere before anyone enters. Diffusion meters can only read the air around them.\u003c\/p\u003e\n\u003ch3\u003eWhat gases does it detect?\u003c\/h3\u003e\u003cp\u003eIt reads oxygen (O2), combustible gas (LEL), carbon monoxide (CO) and hydrogen sulfide (H2S) with a NIST certificate. For VOCs you need a separate PID; see the \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"Portable Gas Detectors\"\u003ePortable Gas Detectors\u003c\/a\u003e hub.\u003c\/p\u003e\n\u003ch3\u003eIs the pump monitor NIST calibrated?\u003c\/h3\u003e\u003cp\u003eYes — it ships with a USA NIST calibration certificate. Bump-test before each use and calibrate on the manufacturer's schedule.\u003c\/p\u003e\n\u003ch3\u003eHow long is the probe and how do I use it?\u003c\/h3\u003e\u003cp\u003eThe unit includes a probe you lower into the space; the motorized pump draws the sample up to the sensors. Follow the manufacturer's pre-entry testing sequence: oxygen first, then combustibles, then toxics.\u003c\/p\u003e\n\u003ch3\u003eHow does it compare to the diffusion Forensics meters?\u003c\/h3\u003e\u003cp\u003eIt adds a motorized pump and probe over the \u003ca href=\"\/products\/forensics-detectors-4-gas-meter-confined-space\" title=\"4 Gas Meter\"\u003e4 Gas Meter\u003c\/a\u003e and \u003ca href=\"\/products\/forensics-detectors-4-gas-monitor-usb-rechargeable\" title=\"USB 4 Gas Monitor\"\u003eUSB 4 Gas Monitor\u003c\/a\u003e, at a higher price — choose it specifically when remote sampling is required.\u003c\/p\u003e\n\u003ch3\u003eIs it good for permit-required confined spaces?\u003c\/h3\u003e\u003cp\u003eYes — remote sampling before entry is exactly what permit-entry programs need, and its O2\/CO\/H2S\/LEL set matches OSHA 1910.146 hazards.\u003c\/p\u003e\n\u003ch3\u003eHow is it powered?\u003c\/h3\u003e\u003cp\u003eIt uses a USB-rechargeable battery sized for shift-long use, including pump operation during sampling.\u003c\/p\u003e\n\u003ch3\u003eDoes the pump need maintenance?\u003c\/h3\u003e\u003cp\u003eYes — keep the pump and probe clean and clear of moisture and debris, and check pump flow per the manufacturer's instructions so samples draw correctly.\u003c\/p\u003e\n\u003ch3\u003eWhat alarms does it have?\u003c\/h3\u003e\u003cp\u003eAudible, vibration and visual alarms with adjustable set points trigger when a gas exceeds its threshold.\u003c\/p\u003e\n\u003ch3\u003eWhat does it not detect?\u003c\/h3\u003e\u003cp\u003eNo VOCs, CO2 or specific toxics like ammonia or chlorine. For VOC work, a PID is required — explore the \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"Portable Gas Detectors\"\u003ePortable Gas Detectors\u003c\/a\u003e hub.\u003c\/p\u003e\n\u003ch3\u003eIs it in stock?\u003c\/h3\u003e\u003cp\u003eUse the Amazon buy button for live availability and delivery timing through our fulfillment partner.\u003c\/p\u003e\n\u003ch3\u003eDo I still need a personal monitor with this?\u003c\/h3\u003e\u003cp\u003eOften yes — the pump unit handles pre-entry and shared testing, while each worker can wear a clip from \u003ca href=\"\/collections\/personal-gas-detectors\" title=\"Personal \u0026amp; Wearable Gas Detectors\"\u003ePersonal \u0026amp; Wearable Gas Detectors\u003c\/a\u003e for personal exposure once inside.\u003c\/p\u003e\n\n\u003cdiv style=\"background:#1a1a1a;border:1px solid #3a3a3a;border-radius:6px;padding:16px 18px;margin:22px 0;\"\u003e\n\u003cp style=\"margin:0 0 10px 0;color:#f5e6d3;\"\u003eReady to order the \u003cstrong\u003eForensics Detectors 4 gas monitor with pump\u003c\/strong\u003e? Add it to your cart above, or check the current Amazon price below. Compare it against the rest of our \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"Portable Gas Detectors\"\u003ePortable Gas Detectors\u003c\/a\u003e lineup before you buy.\u003c\/p\u003e\n\u003cp style=\"display:flex;gap:10px;flex-wrap:wrap;align-items:center;margin:0;\"\u003e\u003ca href=\"https:\/\/www.amazon.com\/dp\/B07J1TTDY3?tag=wcsafety04-20\" rel=\"sponsored nofollow noopener\" target=\"_blank\" style=\"display:inline-block;background:#FFD814;color:#0F1111;padding:13px 26px;text-decoration:none;font-weight:bold;border-radius:4px;border:1px solid #FCD200;\"\u003eCHECK PRICE ON AMAZON →\u003c\/a\u003e\u003cspan style=\"font-size:0.8em;color:#bdae9d;\"\u003eAs an Amazon Associate, WC Safety earns from qualifying purchases.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/div\u003e\n\n\u003cdiv style=\"background:#1a2733;border:1px dashed #4fc3f7;padding:16px 20px;margin:30px 0 18px 0;color:#cfd8dc;font-size:0.92em;\"\u003e\n  \u003cstrong style=\"color:#4fc3f7;\"\u003eWhy trust this Forensics Detectors page?\u003c\/strong\u003e WC Safety is an independent industrial safety-equipment retailer serving safety managers, procurement teams and field supervisors. The specifications on this page are taken from the manufacturer’s published listing for Forensics Detectors 4 Gas Monitor with Pump and framed against \u003ca href=\"https:\/\/www.osha.gov\/laws-regs\/regulations\/standardnumber\/1910\/1910.146\" rel=\"noopener\" target=\"_blank\" style=\"color:#4fc3f7;\"\u003eOSHA 29 CFR 1910.146\u003c\/a\u003e for confined-space atmospheric testing. Disclosed: WC Safety earns Amazon affiliate commissions on outbound clicks; that does not influence the specs shown or where this unit sits in our lineup.\n\u003c\/div\u003e\n\u003cdiv style=\"background:#1a2733;border-left:4px solid #4fc3f7;padding:18px 22px;margin:18px 0;color:#cfd8dc;font-size:0.92em;\"\u003e\n  \u003cstrong style=\"color:#4fc3f7;\"\u003eBy Steven Eaton, WC Safety Editorial\u003c\/strong\u003e — Industrial safety-equipment desk · specialization: portable atmospheric monitoring, confined-space gas detection and instrument selection.\u003cbr\u003e\n  \u003cstrong\u003eLast updated:\u003c\/strong\u003e \u003ctime datetime=\"2026-06-22\"\u003eJune 22, 2026\u003c\/time\u003e · \u003cstrong\u003eSources reviewed:\u003c\/strong\u003e manufacturer product listing \u0026amp; specifications, OSHA 29 CFR 1910.146, OSHA Annotated PEL tables, ACGIH Threshold Limit Values.\u003cbr\u003e\n  \u003cstrong\u003eEditorial standard:\u003c\/strong\u003e \u003cem\u003eZero sponsored listings. No manufacturer input. Specs verified against the manufacturer’s published data.\u003c\/em\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"background:#1a2733;border-left:4px solid #4fc3f7;padding:16px 20px;margin:18px 0;color:#cfd8dc;font-size:0.92em;\"\u003e\n  \u003cstrong style=\"color:#4fc3f7;\"\u003eHow this page is maintained.\u003c\/strong\u003e Specifications and pricing are reviewed against the manufacturer’s current listing and re-checked whenever the lineup changes. Gas-detection guidance follows \u003ca href=\"https:\/\/www.osha.gov\/laws-regs\/regulations\/standardnumber\/1910\/1910.146\" rel=\"noopener\" target=\"_blank\" style=\"color:#4fc3f7;\"\u003eOSHA 1910.146\u003c\/a\u003e (permit-required confined spaces) and \u003ca href=\"https:\/\/www.osha.gov\/annotated-pels\" rel=\"noopener\" target=\"_blank\" style=\"color:#4fc3f7;\"\u003eOSHA Permissible Exposure Limits\u003c\/a\u003e, cross-referenced with ACGIH TLVs.\n\u003c\/div\u003e\n\u003cdiv style=\"background:#2a2520;border-left:4px solid #ff9800;padding:16px 20px;margin:18px 0;color:#f5e6d3;font-size:0.92em;\"\u003e\n  \u003cstrong style=\"color:#ffb74d;\"\u003eDisclosure.\u003c\/strong\u003e WC Safety participates in the Amazon Associates Program and earns commissions on qualifying purchases through outbound links on this page (tag wcsafety04-20). We are not sponsored by any instrument manufacturer. This page is buyer guidance, not medical, legal or regulatory advice — confirm gas-detection requirements for your site against the applicable OSHA standard and, for commercial monitoring programs, a Certified Industrial Hygienist (CIH).\n\u003c\/div\u003e\n\n\u003cscript type=\"application\/ld+json\"\u003e\n{\"@context\": \"https:\/\/schema.org\", \"@graph\": [{\"@type\": \"Product\", \"@id\": \"https:\/\/wcsafety.com\/products\/forensics-detectors-4-gas-monitor-with-pump#product\", \"name\": \"Forensics Detectors 4 Gas Monitor with Pump (NIST, Confined-Space Probe)\", \"description\": \"Forensics Detectors 4 gas monitor with pump — motorized sample-draw and probe for confined-space pre-entry testing. NIST-calibrated O2, CO, H2S \u0026 LEL.\", \"sku\": \"B07J1TTDY3\", \"mpn\": \"FD-90A-P\", \"image\": [\"https:\/\/wcsafety.com\/cdn\/shop\/products\/forensics-detectors-4-gas-monitor-with-pump.jpg\"], \"brand\": {\"@type\": \"Brand\", \"name\": \"Forensics Detectors\"}, \"category\": \"Portable Gas Detector\", \"isPartOf\": {\"@type\": \"CollectionPage\", \"@id\": \"https:\/\/wcsafety.com\/collections\/portable-gas-detectors#collection\", \"name\": \"Portable Gas Detectors\", \"url\": \"https:\/\/wcsafety.com\/collections\/portable-gas-detectors\"}, \"isRelatedTo\": [{\"@type\": \"Product\", \"name\": \"Forensics Detectors 4 Gas Meter for Confined Space\", \"url\": \"https:\/\/wcsafety.com\/products\/forensics-detectors-4-gas-meter-confined-space\"}, {\"@type\": \"Product\", \"name\": \"Forensics Detectors 4 Gas Monitor (USB Rechargeable)\", \"url\": \"https:\/\/wcsafety.com\/products\/forensics-detectors-4-gas-monitor-usb-rechargeable\"}, {\"@type\": \"Product\", \"name\": \"TopTes Guard-863Pro 4 Gas Monitor\", \"url\": \"https:\/\/wcsafety.com\/products\/toptes-guard-863pro-4-gas-monitor\"}, {\"@type\": \"Product\", \"name\": \"TopTes Guard-101 4 Gas Detector\", \"url\": \"https:\/\/wcsafety.com\/products\/toptes-guard-101-4-gas-detector\"}, {\"@type\": \"Product\", \"name\": \"TopTes Guard-156 4 Gas Monitor\", \"url\": \"https:\/\/wcsafety.com\/products\/toptes-guard-156-4-gas-monitor\"}, {\"@type\": \"Product\", \"name\": \"Forsensal 4 Gas Detector with Pump\", \"url\": \"https:\/\/wcsafety.com\/products\/forsensal-4-gas-detector-with-pump\"}], \"offers\": {\"@type\": \"Offer\", \"url\": \"https:\/\/wcsafety.com\/products\/forensics-detectors-4-gas-monitor-with-pump\", \"priceCurrency\": \"USD\", \"price\": \"299.45\", \"availability\": \"https:\/\/schema.org\/InStock\", \"seller\": {\"@type\": \"Organization\", \"name\": \"WC Safety\"}}}, {\"@type\": \"BreadcrumbList\", \"@id\": \"https:\/\/wcsafety.com\/products\/forensics-detectors-4-gas-monitor-with-pump#breadcrumb\", \"itemListElement\": [{\"@type\": \"ListItem\", \"position\": 1, \"name\": \"Home\", \"item\": \"https:\/\/wcsafety.com\/\"}, {\"@type\": \"ListItem\", \"position\": 2, \"name\": \"Gas Detectors\", \"item\": \"https:\/\/wcsafety.com\/collections\/gas-detectors\"}, {\"@type\": \"ListItem\", \"position\": 3, \"name\": \"Portable Gas Detectors\", \"item\": \"https:\/\/wcsafety.com\/collections\/portable-gas-detectors\"}, {\"@type\": \"ListItem\", \"position\": 4, \"name\": \"Forensics Detectors 4 Gas Monitor with Pump (NIST, Confined-Space Probe)\"}]}, {\"@type\": \"FAQPage\", \"mainEntity\": [{\"@type\": \"Question\", \"name\": \"Why choose a 4 gas monitor with a pump?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"A pump lets you draw a sample from a sealed or remote space — the bottom of a tank, vault or manhole — so you can test the atmosphere before anyone enters. Diffusion meters can only read the air around them.\"}}, {\"@type\": \"Question\", \"name\": \"What gases does it detect?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"It reads oxygen (O2), combustible gas (LEL), carbon monoxide (CO) and hydrogen sulfide (H2S) with a NIST certificate. For VOCs you need a separate PID; see the Portable Gas Detectors hub.\"}}, {\"@type\": \"Question\", \"name\": \"Is the pump monitor NIST calibrated?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Yes — it ships with a USA NIST calibration certificate. Bump-test before each use and calibrate on the manufacturer's schedule.\"}}, {\"@type\": \"Question\", \"name\": \"How long is the probe and how do I use it?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"The unit includes a probe you lower into the space; the motorized pump draws the sample up to the sensors. Follow the manufacturer's pre-entry testing sequence: oxygen first, then combustibles, then toxics.\"}}, {\"@type\": \"Question\", \"name\": \"How does it compare to the diffusion Forensics meters?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"It adds a motorized pump and probe over the 4 Gas Meter and USB 4 Gas Monitor, at a higher price — choose it specifically when remote sampling is required.\"}}, {\"@type\": \"Question\", \"name\": \"Is it good for permit-required confined spaces?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Yes — remote sampling before entry is exactly what permit-entry programs need, and its O2\/CO\/H2S\/LEL set matches OSHA 1910.146 hazards.\"}}, {\"@type\": \"Question\", \"name\": \"How is it powered?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"It uses a USB-rechargeable battery sized for shift-long use, including pump operation during sampling.\"}}, {\"@type\": \"Question\", \"name\": \"Does the pump need maintenance?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Yes — keep the pump and probe clean and clear of moisture and debris, and check pump flow per the manufacturer's instructions so samples draw correctly.\"}}, {\"@type\": \"Question\", \"name\": \"What alarms does it have?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Audible, vibration and visual alarms with adjustable set points trigger when a gas exceeds its threshold.\"}}, {\"@type\": \"Question\", \"name\": \"What does it not detect?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"No VOCs, CO2 or specific toxics like ammonia or chlorine. For VOC work, a PID is required — explore the Portable Gas Detectors hub.\"}}, {\"@type\": \"Question\", \"name\": \"Is it in stock?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Use the Amazon buy button for live availability and delivery timing through our fulfillment partner.\"}}, {\"@type\": \"Question\", \"name\": \"Do I still need a personal monitor with this?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Often yes — the pump unit handles pre-entry and shared testing, while each worker can wear a clip from Personal \u0026 Wearable Gas Detectors for personal exposure once inside.\"}}]}, {\"@type\": \"Organization\", \"@id\": \"https:\/\/wcsafety.com\/#org\", \"name\": \"WC Safety\", \"url\": \"https:\/\/wcsafety.com\", \"logo\": \"https:\/\/wcsafety.com\/cdn\/shop\/files\/logo.png\"}, {\"@type\": \"Person\", \"@id\": \"https:\/\/wcsafety.com\/#editor\", \"name\": \"Steven Eaton\", \"jobTitle\": \"Editorial Lead\", \"worksFor\": {\"@id\": \"https:\/\/wcsafety.com\/#org\"}, \"knowsAbout\": [\"industrial gas detection\", \"confined-space atmospheric monitoring\", \"personal protective equipment\"]}, {\"@type\": \"Brand\", \"name\": \"Forensics Detectors\"}]}\n\u003c\/script\u003e","brand":"Forensics Detectors","offers":[{"title":"Default Title","offer_id":44266357653592,"sku":"B07J1TTDY3","price":299.45,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0594\/1900\/0920\/files\/71c7U6vwjgL._AC_SL1500.jpg?v=1782119884"},{"product_id":"forsensal-4-gas-detector-with-pump","title":"Forsensal 4 Gas Detector with Pump (CO, EX\/LEL, O2, H2S, Calibration Kit)","description":"\u003c!-- PRODUCT B0D72WZYSX | tag portable-gas-detector | TODO: add matching Product Review + best-of guide links when those silo layers exist --\u003e\n\n\u003cdiv style=\"background:#1a1a1a;border-left:4px solid #ff9800;padding:14px 18px;margin:0 0 18px 0;color:#f5e6d3;font-size:0.95em;\"\u003e\n\u003cstrong style=\"color:#ffb74d;\"\u003eEditor’s note:\u003c\/strong\u003e the Forsensal 4 gas detector with pump is one of the portable instruments we curate in our \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"Portable Gas Detectors\"\u003ePortable Gas Detectors\u003c\/a\u003e buyer’s hub. Compare it head-to-head with the \u003ca href=\"\/products\/forensics-detectors-4-gas-meter-confined-space\" title=\"Forensics Detectors 4 Gas Meter\"\u003eForensics Detectors 4 Gas Meter\u003c\/a\u003e below before you order.\u003c\/div\u003e\n\n\u003ch2 id=\"top\"\u003eForsensal 4 Gas Detector with Pump — Sample-Draw CO, EX, O2 \u0026amp; H2S\u003c\/h2\u003e\n\n\u003cp\u003eThe \u003cstrong\u003eForsensal 4 gas detector with pump\u003c\/strong\u003e brings sample-draw testing to a budget price — a \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"portable gas detector\"\u003eportable gas detector\u003c\/a\u003e that pumps a remote sample of oxygen (O2), combustible gas (LEL), carbon monoxide (CO) and hydrogen sulfide (H2S) and ships with a calibration kit and a 3000mAh battery, aimed at crews who need a pump without the premium-instrument cost.\u003c\/p\u003e\n\n\u003cp style=\"font-size:0.9em;color:#bdae9d;margin:10px 0 18px 0;\"\u003eJump to: \u003ca href=\"#features\" style=\"color:#ffb74d;\"\u003eFeatures\u003c\/a\u003e · \u003ca href=\"#specs\" style=\"color:#ffb74d;\"\u003eSpecs\u003c\/a\u003e · \u003ca href=\"#compatibility\" style=\"color:#ffb74d;\"\u003eWhat it detects\u003c\/a\u003e · \u003ca href=\"#comparison\" style=\"color:#ffb74d;\"\u003eComparison\u003c\/a\u003e · \u003ca href=\"#faq\" style=\"color:#ffb74d;\"\u003eFAQ\u003c\/a\u003e\u003c\/p\u003e\n\n\u003cp\u003eThe Forsensal 4 Gas Detector with Pump is a rechargeable electrochemical four-gas instrument (CO, EX\/LEL, O2, H2S) with a built-in sample-draw pump and an included calibration kit, built for confined-space pre-entry testing.\u003c\/p\u003e\n\n\u003ch3 id=\"features\"\u003eKey features\u003c\/h3\u003e\n\n\u003cul\u003e\n\u003cli\u003eBuilt-in pump for sample-draw testing of sewers, tanks and confined spaces\u003c\/li\u003e\n\u003cli\u003eReads oxygen (O2), combustible gas (LEL), carbon monoxide (CO) and hydrogen sulfide (H2S) — written CO, EX, O2 and H2S on the unit\u003c\/li\u003e\n\u003cli\u003eLarge 3000mAh rechargeable battery for extended runtime\u003c\/li\u003e\n\u003cli\u003eIncludes a calibration kit so you can verify accuracy out of the box\u003c\/li\u003e\n\u003cli\u003eAudible, visual and vibration alarms\u003c\/li\u003e\n\u003cli\u003eLCD display with belt clip for portable use\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cdiv style=\"display:flex;gap:14px;flex-wrap:wrap;margin:18px 0;\"\u003e\n\u003cdiv style=\"flex:1;min-width:240px;background:#1b3a2a;border:1px solid #4caf50;border-radius:6px;padding:14px 18px;\"\u003e\n\u003cstrong style=\"color:#81c784;\"\u003ePros\u003c\/strong\u003e\u003cul style=\"margin:8px 0 0 0;\"\u003e\n\u003cli\u003ePump-equipped at a low price point\u003c\/li\u003e\n\u003cli\u003eCalibration kit included\u003c\/li\u003e\n\u003cli\u003eLarge 3000mAh battery\u003c\/li\u003e\n\u003cli\u003eTriple alarm modes\u003c\/li\u003e\n\u003cli\u003eBelt-clip portability\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"flex:1;min-width:240px;background:#3a1e1e;border:1px solid #ef5350;border-radius:6px;padding:14px 18px;\"\u003e\n\u003cstrong style=\"color:#e57373;\"\u003eCons\u003c\/strong\u003e\u003cul style=\"margin:8px 0 0 0;\"\u003e\n\u003cli\u003eValue brand with a smaller track record\u003c\/li\u003e\n\u003cli\u003ePump and probe need cleaning\/maintenance\u003c\/li\u003e\n\u003cli\u003eElectrochemical sensors need periodic replacement\u003c\/li\u003e\n\u003cli\u003eNo NIST certificate as standard\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\n\u003ch3 id=\"specs\"\u003eSpecifications\u003c\/h3\u003e\n\n\u003cdiv style=\"overflow-x:auto;\"\u003e\u003ctable style=\"width:100%;border-collapse:collapse;background:#1a1a1a;margin:14px 0;\"\u003e\n\u003cthead\u003e\u003ctr style=\"background:#2a2a2a;\"\u003e\n\u003cth style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;text-align:left;\"\u003eSpecification\u003c\/th\u003e\n\u003cth style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;text-align:left;\"\u003eDetail\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eGases detected\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eCO, EX (LEL), O2, H2S\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eSampling\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eBuilt-in pump (sample-draw)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eSensor type\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eElectrochemical\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eBattery\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003e3000 mAh rechargeable\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eIncluded\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eCalibration kit\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eAlarms\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eAudible, visual \u0026amp; vibration\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eDisplay\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eLCD with clip\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eWeight\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003e11.2 oz\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003c\/div\u003e\n\n\u003ch3\u003eWhere the Forsensal 4 Gas Detector with Pump fits\u003c\/h3\u003e\n\n\u003cul\u003e\n\u003cli\u003eSewer and drain gas sampling\u003c\/li\u003e\n\u003cli\u003eConfined-space pre-entry testing on a budget\u003c\/li\u003e\n\u003cli\u003eTank and vault checks\u003c\/li\u003e\n\u003cli\u003eMaintenance and utility work\u003c\/li\u003e\n\u003cli\u003eBackup pump unit for a tool crib\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2 id=\"compatibility\"\u003eWhat the Forsensal 4 Gas Detector with Pump detects (and what it doesn’t)\u003c\/h2\u003e\n\n\u003cp\u003eIt detects oxygen (O2), combustible gas (LEL), carbon monoxide (CO) and hydrogen sulfide (H2S) and uses a built-in pump to draw remote samples — handy for sewers, drains and tanks. It does not read VOCs, CO2 or single toxics like chlorine or ammonia; those need a PID or dedicated sensor. The included calibration kit lets you verify accuracy; still bump-test before use. For a NIST-certified pump alternative, compare the \u003ca href=\"\/products\/forensics-detectors-4-gas-monitor-with-pump\" title=\"Forensics Detectors 4 Gas Monitor with Pump\"\u003eForensics Detectors 4 Gas Monitor with Pump\u003c\/a\u003e. For single-worker wear, add a clip from \u003ca href=\"\/collections\/personal-gas-detectors\" title=\"Personal \u0026amp; Wearable Gas Detectors\"\u003ePersonal \u0026amp; Wearable Gas Detectors\u003c\/a\u003e.\u003c\/p\u003e\n\n\u003cp\u003eCross-shopping? This unit sits in our \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"Portable Gas Detectors\"\u003ePortable Gas Detectors\u003c\/a\u003e hub alongside the \u003ca href=\"\/products\/forensics-detectors-4-gas-meter-confined-space\" title=\"Forensics Detectors 4 Gas Meter\"\u003eForensics Detectors 4 Gas Meter\u003c\/a\u003e, \u003ca href=\"\/products\/forensics-detectors-4-gas-monitor-usb-rechargeable\" title=\"Forensics Detectors USB 4 Gas Monitor\"\u003eForensics Detectors USB 4 Gas Monitor\u003c\/a\u003e, \u003ca href=\"\/products\/toptes-guard-863pro-4-gas-monitor\" title=\"TopTes Guard-863Pro\"\u003eTopTes Guard-863Pro\u003c\/a\u003e, \u003ca href=\"\/products\/toptes-guard-101-4-gas-detector\" title=\"TopTes Guard-101\"\u003eTopTes Guard-101\u003c\/a\u003e. If one worker needs all-shift wear instead of a carried meter, see \u003ca href=\"\/collections\/personal-gas-detectors\" title=\"Personal \u0026amp; Wearable Gas Detectors\"\u003ePersonal \u0026amp; Wearable Gas Detectors\u003c\/a\u003e; for a fixed install or a job-site perimeter, see \u003ca href=\"\/collections\/fixed-gas-detection-systems\" title=\"Fixed Gas Detection Systems\"\u003eFixed Gas Detection Systems\u003c\/a\u003e and \u003ca href=\"\/collections\/area-gas-monitors\" title=\"Area \u0026amp; Transportable Gas Monitors\"\u003eArea \u0026amp; Transportable Gas Monitors\u003c\/a\u003e.\u003c\/p\u003e\n\n\u003ch2 id=\"comparison\"\u003eHow the Forsensal pump detector compares\u003c\/h2\u003e\n\n\u003cdiv style=\"overflow-x:auto;\"\u003e\u003ctable style=\"width:100%;border-collapse:collapse;background:#1a1a1a;margin:14px 0;\"\u003e\n\u003ccaption style=\"color:#bdae9d;font-size:0.85em;text-align:left;padding:4px 0;\"\u003ePortable pump (sample-draw) options we stock\u003c\/caption\u003e\n\u003cthead\u003e\u003ctr style=\"background:#2a2a2a;\"\u003e\n\u003cth style=\"color:#ffb74d;padding:9px;border:1px solid #3a3a3a;text-align:left;\"\u003eModel\u003c\/th\u003e\n\u003cth style=\"color:#ffb74d;padding:9px;border:1px solid #3a3a3a;text-align:left;\"\u003eSampling\u003c\/th\u003e\n\u003cth style=\"color:#ffb74d;padding:9px;border:1px solid #3a3a3a;text-align:left;\"\u003eExtras\u003c\/th\u003e\n\u003cth style=\"color:#ffb74d;padding:9px;border:1px solid #3a3a3a;text-align:left;\"\u003eStreet price\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr style=\"background:#2a2520;\"\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e\u003cstrong\u003e\u003ca href=\"\/products\/forsensal-4-gas-detector-with-pump\" title=\"Forsensal 4 Gas + Pump\"\u003eForsensal 4 Gas + Pump\u003c\/a\u003e\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eBuilt-in pump\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eCalibration kit, 3000mAh\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e~$140\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e\u003ca href=\"\/products\/forensics-detectors-4-gas-monitor-with-pump\" title=\"Forensics 4 Gas + Pump\"\u003eForensics 4 Gas + Pump\u003c\/a\u003e\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eMotorized pump + probe\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eNIST certificate, USB\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e~$299\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003c\/div\u003e\n\n\u003cul\u003e\n\u003cli\u003eChoose the \u003cstrong\u003eForsensal 4 Gas + Pump\u003c\/strong\u003e for the lowest-cost way to get sample-draw plus an included calibration kit.\u003c\/li\u003e\n\u003cli\u003eStep up to the \u003ca href=\"\/products\/forensics-detectors-4-gas-monitor-with-pump\" title=\"Forensics Detectors 4 Gas Monitor with Pump\"\u003eForensics Detectors 4 Gas Monitor with Pump\u003c\/a\u003e if you need a NIST certificate and probe for formal permit programs.\u003c\/li\u003e\n\u003cli\u003eIf you do not need a pump at all, the diffusion \u003ca href=\"\/products\/toptes-guard-101-4-gas-detector\" title=\"TopTes Guard-101\"\u003eTopTes Guard-101\u003c\/a\u003e costs less.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2 id=\"faq\"\u003eFrequently asked questions\u003c\/h2\u003e\n\n\u003ch3\u003eWhat gases does the Forsensal 4 gas detector with pump detect?\u003c\/h3\u003e\u003cp\u003eIt reads oxygen (O2), combustible gas (LEL), carbon monoxide (CO) and hydrogen sulfide (H2S) (labelled CO, EX, O2 and H2S on the unit). For VOCs you need a separate PID; see the \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"Portable Gas Detectors\"\u003ePortable Gas Detectors\u003c\/a\u003e hub.\u003c\/p\u003e\n\u003ch3\u003eDoes the Forsensal come with a calibration kit?\u003c\/h3\u003e\u003cp\u003eYes — it includes a calibration kit so you can verify accuracy out of the box. You should still bump-test before each use with four-gas calibration gas.\u003c\/p\u003e\n\u003ch3\u003eWhat is the pump for?\u003c\/h3\u003e\u003cp\u003eThe built-in pump draws a remote sample so you can test a sewer, drain, tank or confined space before anyone enters, rather than relying on diffusion of the air around the unit.\u003c\/p\u003e\n\u003ch3\u003eHow big is the battery?\u003c\/h3\u003e\u003cp\u003eIt uses a 3000mAh rechargeable battery for extended runtime across long shifts and pump operation.\u003c\/p\u003e\n\u003ch3\u003eHow does it compare to the Forensics pump monitor?\u003c\/h3\u003e\u003cp\u003eThe Forsensal is lower cost and includes a calibration kit; the \u003ca href=\"\/products\/forensics-detectors-4-gas-monitor-with-pump\" title=\"Forensics 4 Gas Monitor with Pump\"\u003eForensics 4 Gas Monitor with Pump\u003c\/a\u003e adds a NIST certificate and probe, which formal permit programs often require.\u003c\/p\u003e\n\u003ch3\u003eCan I use it for confined-space entry?\u003c\/h3\u003e\u003cp\u003eYes — its sample-draw pump and O2\/CO\/H2S\/LEL set suit pre-entry testing. Follow the standard sequence: oxygen first, then combustibles, then toxics.\u003c\/p\u003e\n\u003ch3\u003eIs it NIST calibrated?\u003c\/h3\u003e\u003cp\u003eIt includes a calibration kit but is not sold with a NIST certificate as standard. If you need documented NIST calibration, choose the \u003ca href=\"\/products\/forensics-detectors-4-gas-monitor-with-pump\" title=\"Forensics pump monitor\"\u003eForensics pump monitor\u003c\/a\u003e.\u003c\/p\u003e\n\u003ch3\u003eDoes the pump need maintenance?\u003c\/h3\u003e\u003cp\u003eYes — keep the pump path and probe clean and free of moisture and debris so samples draw correctly, and check flow per the instructions.\u003c\/p\u003e\n\u003ch3\u003eWhat alarms does it have?\u003c\/h3\u003e\u003cp\u003eAudible, visual and vibration alarms trigger when any monitored gas exceeds its set point.\u003c\/p\u003e\n\u003ch3\u003eWhat does it not detect?\u003c\/h3\u003e\u003cp\u003eNo VOCs, CO2 or gas-specific toxics like ammonia or chlorine. For VOC work, use a PID — see the \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"Portable Gas Detectors\"\u003ePortable Gas Detectors\u003c\/a\u003e hub.\u003c\/p\u003e\n\u003ch3\u003eIs it in stock and how does it ship?\u003c\/h3\u003e\u003cp\u003eUse the Amazon buy button for live availability and delivery timing through our fulfillment partner.\u003c\/p\u003e\n\u003ch3\u003eDo I still need a personal monitor?\u003c\/h3\u003e\u003cp\u003eFor per-worker exposure, yes — pair it with a wearable clip from \u003ca href=\"\/collections\/personal-gas-detectors\" title=\"Personal \u0026amp; Wearable Gas Detectors\"\u003ePersonal \u0026amp; Wearable Gas Detectors\u003c\/a\u003e; the pump unit handles pre-entry and shared testing.\u003c\/p\u003e\n\n\u003cdiv style=\"background:#1a1a1a;border:1px solid #3a3a3a;border-radius:6px;padding:16px 18px;margin:22px 0;\"\u003e\n\u003cp style=\"margin:0 0 10px 0;color:#f5e6d3;\"\u003eReady to order the \u003cstrong\u003eForsensal 4 gas detector with pump\u003c\/strong\u003e? Add it to your cart above, or check the current Amazon price below. Compare it against the rest of our \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"Portable Gas Detectors\"\u003ePortable Gas Detectors\u003c\/a\u003e lineup before you buy.\u003c\/p\u003e\n\u003cp style=\"display:flex;gap:10px;flex-wrap:wrap;align-items:center;margin:0;\"\u003e\u003ca href=\"https:\/\/www.amazon.com\/dp\/B0D72WZYSX?tag=wcsafety04-20\" rel=\"sponsored nofollow noopener\" target=\"_blank\" style=\"display:inline-block;background:#FFD814;color:#0F1111;padding:13px 26px;text-decoration:none;font-weight:bold;border-radius:4px;border:1px solid #FCD200;\"\u003eCHECK PRICE ON AMAZON →\u003c\/a\u003e\u003cspan style=\"font-size:0.8em;color:#bdae9d;\"\u003eAs an Amazon Associate, WC Safety earns from qualifying purchases.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/div\u003e\n\n\u003cdiv style=\"background:#1a2733;border:1px dashed #4fc3f7;padding:16px 20px;margin:30px 0 18px 0;color:#cfd8dc;font-size:0.92em;\"\u003e\n  \u003cstrong style=\"color:#4fc3f7;\"\u003eWhy trust this Forsensal page?\u003c\/strong\u003e WC Safety is an independent industrial safety-equipment retailer serving safety managers, procurement teams and field supervisors. The specifications on this page are taken from the manufacturer’s published listing for Forsensal 4 Gas Detector with Pump and framed against \u003ca href=\"https:\/\/www.osha.gov\/laws-regs\/regulations\/standardnumber\/1910\/1910.146\" rel=\"noopener\" target=\"_blank\" style=\"color:#4fc3f7;\"\u003eOSHA 29 CFR 1910.146\u003c\/a\u003e for confined-space atmospheric testing. Disclosed: WC Safety earns Amazon affiliate commissions on outbound clicks; that does not influence the specs shown or where this unit sits in our lineup.\n\u003c\/div\u003e\n\u003cdiv style=\"background:#1a2733;border-left:4px solid #4fc3f7;padding:18px 22px;margin:18px 0;color:#cfd8dc;font-size:0.92em;\"\u003e\n  \u003cstrong style=\"color:#4fc3f7;\"\u003eBy Steven Eaton, WC Safety Editorial\u003c\/strong\u003e — Industrial safety-equipment desk · specialization: portable atmospheric monitoring, confined-space gas detection and instrument selection.\u003cbr\u003e\n  \u003cstrong\u003eLast updated:\u003c\/strong\u003e \u003ctime datetime=\"2026-06-22\"\u003eJune 22, 2026\u003c\/time\u003e · \u003cstrong\u003eSources reviewed:\u003c\/strong\u003e manufacturer product listing \u0026amp; specifications, OSHA 29 CFR 1910.146, OSHA Annotated PEL tables, ACGIH Threshold Limit Values.\u003cbr\u003e\n  \u003cstrong\u003eEditorial standard:\u003c\/strong\u003e \u003cem\u003eZero sponsored listings. No manufacturer input. Specs verified against the manufacturer’s published data.\u003c\/em\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"background:#1a2733;border-left:4px solid #4fc3f7;padding:16px 20px;margin:18px 0;color:#cfd8dc;font-size:0.92em;\"\u003e\n  \u003cstrong style=\"color:#4fc3f7;\"\u003eHow this page is maintained.\u003c\/strong\u003e Specifications and pricing are reviewed against the manufacturer’s current listing and re-checked whenever the lineup changes. Gas-detection guidance follows \u003ca href=\"https:\/\/www.osha.gov\/laws-regs\/regulations\/standardnumber\/1910\/1910.146\" rel=\"noopener\" target=\"_blank\" style=\"color:#4fc3f7;\"\u003eOSHA 1910.146\u003c\/a\u003e (permit-required confined spaces) and \u003ca href=\"https:\/\/www.osha.gov\/annotated-pels\" rel=\"noopener\" target=\"_blank\" style=\"color:#4fc3f7;\"\u003eOSHA Permissible Exposure Limits\u003c\/a\u003e, cross-referenced with ACGIH TLVs.\n\u003c\/div\u003e\n\u003cdiv style=\"background:#2a2520;border-left:4px solid #ff9800;padding:16px 20px;margin:18px 0;color:#f5e6d3;font-size:0.92em;\"\u003e\n  \u003cstrong style=\"color:#ffb74d;\"\u003eDisclosure.\u003c\/strong\u003e WC Safety participates in the Amazon Associates Program and earns commissions on qualifying purchases through outbound links on this page (tag wcsafety04-20). We are not sponsored by any instrument manufacturer. This page is buyer guidance, not medical, legal or regulatory advice — confirm gas-detection requirements for your site against the applicable OSHA standard and, for commercial monitoring programs, a Certified Industrial Hygienist (CIH).\n\u003c\/div\u003e\n\n\u003cscript type=\"application\/ld+json\"\u003e\n{\"@context\": \"https:\/\/schema.org\", \"@graph\": [{\"@type\": \"Product\", \"@id\": \"https:\/\/wcsafety.com\/products\/forsensal-4-gas-detector-with-pump#product\", \"name\": \"Forsensal 4 Gas Detector with Pump (CO, EX\/LEL, O2, H2S, Calibration Kit)\", \"description\": \"Forsensal 4 gas detector with pump — CO, EX\/LEL, O2 \u0026 H2S with sample-draw, 3000mAh battery and calibration kit. Confined-space monitor at WC Safety.\", \"sku\": \"B0D72WZYSX\", \"mpn\": \"Forsensal-4GP\", \"image\": [\"https:\/\/wcsafety.com\/cdn\/shop\/products\/forsensal-4-gas-detector-with-pump.jpg\"], \"brand\": {\"@type\": \"Brand\", \"name\": \"Forsensal\"}, \"category\": \"Portable Gas Detector\", \"isPartOf\": {\"@type\": \"CollectionPage\", \"@id\": \"https:\/\/wcsafety.com\/collections\/portable-gas-detectors#collection\", \"name\": \"Portable Gas Detectors\", \"url\": \"https:\/\/wcsafety.com\/collections\/portable-gas-detectors\"}, \"isRelatedTo\": [{\"@type\": \"Product\", \"name\": \"Forensics Detectors 4 Gas Meter for Confined Space\", \"url\": \"https:\/\/wcsafety.com\/products\/forensics-detectors-4-gas-meter-confined-space\"}, {\"@type\": \"Product\", \"name\": \"Forensics Detectors 4 Gas Monitor (USB Rechargeable)\", \"url\": \"https:\/\/wcsafety.com\/products\/forensics-detectors-4-gas-monitor-usb-rechargeable\"}, {\"@type\": \"Product\", \"name\": \"TopTes Guard-863Pro 4 Gas Monitor\", \"url\": \"https:\/\/wcsafety.com\/products\/toptes-guard-863pro-4-gas-monitor\"}, {\"@type\": \"Product\", \"name\": \"TopTes Guard-101 4 Gas Detector\", \"url\": \"https:\/\/wcsafety.com\/products\/toptes-guard-101-4-gas-detector\"}, {\"@type\": \"Product\", \"name\": \"TopTes Guard-156 4 Gas Monitor\", \"url\": \"https:\/\/wcsafety.com\/products\/toptes-guard-156-4-gas-monitor\"}, {\"@type\": \"Product\", \"name\": \"Forensics Detectors 4 Gas Monitor with Pump\", \"url\": \"https:\/\/wcsafety.com\/products\/forensics-detectors-4-gas-monitor-with-pump\"}], \"offers\": {\"@type\": \"Offer\", \"url\": \"https:\/\/wcsafety.com\/products\/forsensal-4-gas-detector-with-pump\", \"priceCurrency\": \"USD\", \"price\": \"139.99\", \"availability\": \"https:\/\/schema.org\/InStock\", \"seller\": {\"@type\": \"Organization\", \"name\": \"WC Safety\"}}}, {\"@type\": \"BreadcrumbList\", \"@id\": \"https:\/\/wcsafety.com\/products\/forsensal-4-gas-detector-with-pump#breadcrumb\", \"itemListElement\": [{\"@type\": \"ListItem\", \"position\": 1, \"name\": \"Home\", \"item\": \"https:\/\/wcsafety.com\/\"}, {\"@type\": \"ListItem\", \"position\": 2, \"name\": \"Gas Detectors\", \"item\": \"https:\/\/wcsafety.com\/collections\/gas-detectors\"}, {\"@type\": \"ListItem\", \"position\": 3, \"name\": \"Portable Gas Detectors\", \"item\": \"https:\/\/wcsafety.com\/collections\/portable-gas-detectors\"}, {\"@type\": \"ListItem\", \"position\": 4, \"name\": \"Forsensal 4 Gas Detector with Pump (CO, EX\/LEL, O2, H2S, Calibration Kit)\"}]}, {\"@type\": \"FAQPage\", \"mainEntity\": [{\"@type\": \"Question\", \"name\": \"What gases does the Forsensal 4 gas detector with pump detect?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"It reads oxygen (O2), combustible gas (LEL), carbon monoxide (CO) and hydrogen sulfide (H2S) (labelled CO, EX, O2 and H2S on the unit). For VOCs you need a separate PID; see the Portable Gas Detectors hub.\"}}, {\"@type\": \"Question\", \"name\": \"Does the Forsensal come with a calibration kit?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Yes — it includes a calibration kit so you can verify accuracy out of the box. You should still bump-test before each use with four-gas calibration gas.\"}}, {\"@type\": \"Question\", \"name\": \"What is the pump for?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"The built-in pump draws a remote sample so you can test a sewer, drain, tank or confined space before anyone enters, rather than relying on diffusion of the air around the unit.\"}}, {\"@type\": \"Question\", \"name\": \"How big is the battery?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"It uses a 3000mAh rechargeable battery for extended runtime across long shifts and pump operation.\"}}, {\"@type\": \"Question\", \"name\": \"How does it compare to the Forensics pump monitor?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"The Forsensal is lower cost and includes a calibration kit; the Forensics 4 Gas Monitor with Pump adds a NIST certificate and probe, which formal permit programs often require.\"}}, {\"@type\": \"Question\", \"name\": \"Can I use it for confined-space entry?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Yes — its sample-draw pump and O2\/CO\/H2S\/LEL set suit pre-entry testing. Follow the standard sequence: oxygen first, then combustibles, then toxics.\"}}, {\"@type\": \"Question\", \"name\": \"Is it NIST calibrated?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"It includes a calibration kit but is not sold with a NIST certificate as standard. If you need documented NIST calibration, choose the Forensics pump monitor.\"}}, {\"@type\": \"Question\", \"name\": \"Does the pump need maintenance?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Yes — keep the pump path and probe clean and free of moisture and debris so samples draw correctly, and check flow per the instructions.\"}}, {\"@type\": \"Question\", \"name\": \"What alarms does it have?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Audible, visual and vibration alarms trigger when any monitored gas exceeds its set point.\"}}, {\"@type\": \"Question\", \"name\": \"What does it not detect?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"No VOCs, CO2 or gas-specific toxics like ammonia or chlorine. For VOC work, use a PID — see the Portable Gas Detectors hub.\"}}, {\"@type\": \"Question\", \"name\": \"Is it in stock and how does it ship?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Use the Amazon buy button for live availability and delivery timing through our fulfillment partner.\"}}, {\"@type\": \"Question\", \"name\": \"Do I still need a personal monitor?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"For per-worker exposure, yes — pair it with a wearable clip from Personal \u0026 Wearable Gas Detectors; the pump unit handles pre-entry and shared testing.\"}}]}, {\"@type\": \"Organization\", \"@id\": \"https:\/\/wcsafety.com\/#org\", \"name\": \"WC Safety\", \"url\": \"https:\/\/wcsafety.com\", \"logo\": \"https:\/\/wcsafety.com\/cdn\/shop\/files\/logo.png\"}, {\"@type\": \"Person\", \"@id\": \"https:\/\/wcsafety.com\/#editor\", \"name\": \"Steven Eaton\", \"jobTitle\": \"Editorial Lead\", \"worksFor\": {\"@id\": \"https:\/\/wcsafety.com\/#org\"}, \"knowsAbout\": [\"industrial gas detection\", \"confined-space atmospheric monitoring\", \"personal protective equipment\"]}, {\"@type\": \"Brand\", \"name\": \"Forsensal\"}]}\n\u003c\/script\u003e","brand":"Forsensal","offers":[{"title":"Default Title","offer_id":44266357751896,"sku":"B0D72WZYSX","price":139.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0594\/1900\/0920\/files\/61TVosJNHXL._AC_SL1500.jpg?v=1782119887"},{"product_id":"honeywell-bw-clip-h2s-monitor-bwc2-h","title":"Honeywell BW Clip H2S Monitor — BWC2-H Single-Gas (2-Year Maintenance-Free)","description":"\u003c!-- PRODUCT B00UZ1WWUK | tag personal-gas-detector | TODO: add matching Product Review + best-of guide links when those silo layers exist --\u003e\n\n\u003cdiv style=\"background:#1a1a1a;border-left:4px solid #ff9800;padding:14px 18px;margin:0 0 18px 0;color:#f5e6d3;font-size:0.95em;\"\u003e\n\u003cstrong style=\"color:#ffb74d;\"\u003eEditor’s note:\u003c\/strong\u003e the Honeywell BW Clip H2S monitor is one of the instruments we curate in our \u003ca href=\"\/collections\/personal-gas-detectors\" title=\"Personal \u0026amp; Wearable Gas Detectors\"\u003ePersonal \u0026amp; Wearable Gas Detectors\u003c\/a\u003e buyer’s hub. Compare it with the \u003ca href=\"\/products\/honeywell-bw-clip-co-monitor-bwc2-m\" title=\"Honeywell BW Clip CO\"\u003eHoneywell BW Clip CO\u003c\/a\u003e below before you order.\u003c\/div\u003e\n\n\u003ch2 id=\"top\"\u003eHoneywell BW Clip H2S Monitor — Maintenance-Free Single-Gas Detector\u003c\/h2\u003e\n\n\u003cp\u003eThe \u003cstrong\u003eHoneywell BW Clip H2S monitor\u003c\/strong\u003e (BWC2-H) is a 2-year maintenance-free single-gas clip worn in the breathing zone — the industry-standard \u003ca href=\"\/collections\/personal-gas-detectors\" title=\"personal gas detector\"\u003epersonal gas detector\u003c\/a\u003e for hydrogen sulfide exposure. Turn it on once and it runs for two years with no sensor or battery service.\u003c\/p\u003e\n\n\u003cp style=\"font-size:0.9em;color:#bdae9d;margin:10px 0 18px 0;\"\u003eJump to: \u003ca href=\"#features\" style=\"color:#ffb74d;\"\u003eFeatures\u003c\/a\u003e · \u003ca href=\"#specs\" style=\"color:#ffb74d;\"\u003eSpecs\u003c\/a\u003e · \u003ca href=\"#compatibility\" style=\"color:#ffb74d;\"\u003eWhat it detects\u003c\/a\u003e · \u003ca href=\"#comparison\" style=\"color:#ffb74d;\"\u003eComparison\u003c\/a\u003e · \u003ca href=\"#faq\" style=\"color:#ffb74d;\"\u003eFAQ\u003c\/a\u003e\u003c\/p\u003e\n\n\u003cp\u003eThe Honeywell BW Clip BWC2-H is a 2-year maintenance-free, electrochemical single-gas personal monitor for hydrogen sulfide (H2S), with audible, visual and vibrating alarms at 10 and 15 ppm.\u003c\/p\u003e\n\n\u003ch3 id=\"features\"\u003eKey features\u003c\/h3\u003e\n\n\u003cul\u003e\n\u003cli\u003eWorn in the breathing zone to alarm on hydrogen sulfide (H2S) exposure\u003c\/li\u003e\n\u003cli\u003eRuns continuously for 2 years with no battery or sensor replacement — turn it on day one and use it\u003c\/li\u003e\n\u003cli\u003eAudible (~95 dB), visual red-LED and vibrating alarms at 10 ppm and 15 ppm\u003c\/li\u003e\n\u003cli\u003eHighest-reviewed personal monitor we stock (990+ ratings, 4.7 stars)\u003c\/li\u003e\n\u003cli\u003eConstant real-time H2S reading on the display\u003c\/li\u003e\n\u003cli\u003eCompatible with IntelliDoX and MicroDock docking for automated bump tests\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cdiv style=\"display:flex;gap:14px;flex-wrap:wrap;margin:18px 0;\"\u003e\n\u003cdiv style=\"flex:1;min-width:240px;background:#1b3a2a;border:1px solid #4caf50;border-radius:6px;padding:14px 18px;\"\u003e\n\u003cstrong style=\"color:#81c784;\"\u003ePros\u003c\/strong\u003e\u003cul style=\"margin:8px 0 0 0;\"\u003e\n\u003cli\u003e2-year maintenance-free — no sensor or battery swaps\u003c\/li\u003e\n\u003cli\u003eLowest cost per worker over its life\u003c\/li\u003e\n\u003cli\u003eTriple alarm (audible, visual, vibrating)\u003c\/li\u003e\n\u003cli\u003eOutstanding 4.7-star, 990+ review track record\u003c\/li\u003e\n\u003cli\u003eCompact, lightweight clip\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"flex:1;min-width:240px;background:#3a1e1e;border:1px solid #ef5350;border-radius:6px;padding:14px 18px;\"\u003e\n\u003cstrong style=\"color:#e57373;\"\u003eCons\u003c\/strong\u003e\u003cul style=\"margin:8px 0 0 0;\"\u003e\n\u003cli\u003eSingle gas only — H2S, nothing else\u003c\/li\u003e\n\u003cli\u003eNot rechargeable or serviceable; replace the unit at end of life\u003c\/li\u003e\n\u003cli\u003eNeeds bump testing like any monitor\u003c\/li\u003e\n\u003cli\u003eNo color display or data export\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\n\u003ch3 id=\"specs\"\u003eSpecifications\u003c\/h3\u003e\n\n\u003cdiv style=\"overflow-x:auto;\"\u003e\u003ctable style=\"width:100%;border-collapse:collapse;background:#1a1a1a;margin:14px 0;\"\u003e\n\u003cthead\u003e\u003ctr style=\"background:#2a2a2a;\"\u003e\n\u003cth style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;text-align:left;\"\u003eSpecification\u003c\/th\u003e\n\u003cth style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;text-align:left;\"\u003eDetail\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eGas detected\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eHydrogen sulfide (H2S)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eAlarm set points\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003e10 ppm low \/ 15 ppm high\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eSensor\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eElectrochemical\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eService life\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003e2 years continuous, maintenance-free\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eAlarms\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eAudible (~95 dB), visual (red LEDs) \u0026amp; vibrating\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eCalibration\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eFactory-calibrated; bump\/cal optional via IntelliDoX\/MicroDock\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eDatalogging\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eEvent logging\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eHousing\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eRugged, water- \u0026amp; dust-resistant; clip-on\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003c\/div\u003e\n\n\u003ch3\u003eWhere the Honeywell BW Clip BWC2-H fits\u003c\/h3\u003e\n\n\u003cul\u003e\n\u003cli\u003eOil-and-gas and wellsite work\u003c\/li\u003e\n\u003cli\u003eWastewater and sewer entry\u003c\/li\u003e\n\u003cli\u003ePulp, paper and refinery areas\u003c\/li\u003e\n\u003cli\u003eTank and vessel work with H2S risk\u003c\/li\u003e\n\u003cli\u003eIssuing one clip per worker across a crew\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2 id=\"compatibility\"\u003eWhat the Honeywell BW Clip BWC2-H detects (and what it doesn’t)\u003c\/h2\u003e\n\n\u003cp\u003eThis monitor detects \u003cstrong\u003ehydrogen sulfide (H2S) only\u003c\/strong\u003e — it does not read CO, O2, combustibles or any other gas. If a worker faces several hazards, choose a wearable 4-gas unit such as the \u003ca href=\"\/products\/bw-gasalertmicroclip-xl-4-gas-detector\" title=\"BW GasAlertMicroClip XL\"\u003eBW GasAlertMicroClip XL\u003c\/a\u003e or the sealed \u003ca href=\"\/products\/honeywell-bw-clip4-4-gas-detector\" title=\"BW Clip4\"\u003eBW Clip4\u003c\/a\u003e, or pre-test a space with a \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"Portable Gas Detectors\"\u003ePortable Gas Detectors\u003c\/a\u003e instrument. For carbon monoxide instead, see the \u003ca href=\"\/products\/honeywell-bw-clip-co-monitor-bwc2-m\" title=\"BW Clip CO\"\u003eBW Clip CO\u003c\/a\u003e; for oxygen, the \u003ca href=\"\/products\/honeywell-bw-clip-o2-monitor-bwc2-x\" title=\"BW Clip O2\"\u003eBW Clip O2\u003c\/a\u003e. Bump-test with H2S calibration gas; docking via IntelliDoX\/MicroDock automates it.\u003c\/p\u003e\n\n\u003cp\u003eCross-shopping? This unit sits in our \u003ca href=\"\/collections\/personal-gas-detectors\" title=\"Personal \u0026amp; Wearable Gas Detectors\"\u003ePersonal \u0026amp; Wearable Gas Detectors\u003c\/a\u003e hub alongside \u003ca href=\"\/products\/honeywell-bw-clip-co-monitor-bwc2-m\" title=\"Honeywell BW Clip CO\"\u003eHoneywell BW Clip CO\u003c\/a\u003e, \u003ca href=\"\/products\/honeywell-bw-clip-o2-monitor-bwc2-x\" title=\"Honeywell BW Clip O2\"\u003eHoneywell BW Clip O2\u003c\/a\u003e, \u003ca href=\"\/products\/toptes-ct-580-co-detector\" title=\"TopTes CT-580 CO\"\u003eTopTes CT-580 CO\u003c\/a\u003e, \u003ca href=\"\/products\/bw-gasalertmicroclip-xl-4-gas-detector\" title=\"BW GasAlertMicroClip XL\"\u003eBW GasAlertMicroClip XL\u003c\/a\u003e. For other gas-detection form factors see \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"Portable Gas Detectors\"\u003ePortable Gas Detectors\u003c\/a\u003e, \u003ca href=\"\/collections\/fixed-gas-detection-systems\" title=\"Fixed Gas Detection Systems\"\u003eFixed Gas Detection Systems\u003c\/a\u003e, \u003ca href=\"\/collections\/area-gas-monitors\" title=\"Area \u0026amp; Transportable Gas Monitors\"\u003eArea \u0026amp; Transportable Gas Monitors\u003c\/a\u003e, or browse the full \u003ca href=\"\/collections\/gas-detectors\" title=\"Gas Detectors\"\u003eGas Detectors\u003c\/a\u003e range.\u003c\/p\u003e\n\n\u003ch2 id=\"comparison\"\u003eHoneywell BW Clip single-gas family compared\u003c\/h2\u003e\n\n\u003cdiv style=\"overflow-x:auto;\"\u003e\u003ctable style=\"width:100%;border-collapse:collapse;background:#1a1a1a;margin:14px 0;\"\u003e\n\u003ccaption style=\"color:#bdae9d;font-size:0.85em;text-align:left;padding:4px 0;\"\u003eHoneywell BW Clip single-gas family (2-year maintenance-free)\u003c\/caption\u003e\n\u003cthead\u003e\u003ctr style=\"background:#2a2a2a;\"\u003e\n\u003cth style=\"color:#ffb74d;padding:9px;border:1px solid #3a3a3a;text-align:left;\"\u003eModel\u003c\/th\u003e\n\u003cth style=\"color:#ffb74d;padding:9px;border:1px solid #3a3a3a;text-align:left;\"\u003eGas\u003c\/th\u003e\n\u003cth style=\"color:#ffb74d;padding:9px;border:1px solid #3a3a3a;text-align:left;\"\u003eAlarm set points\u003c\/th\u003e\n\u003cth style=\"color:#ffb74d;padding:9px;border:1px solid #3a3a3a;text-align:left;\"\u003eService life\u003c\/th\u003e\n\u003cth style=\"color:#ffb74d;padding:9px;border:1px solid #3a3a3a;text-align:left;\"\u003eStreet price\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e\u003ca href=\"\/products\/honeywell-bw-clip-h2s-monitor-bwc2-h\" title=\"BW Clip H2S (BWC2-H)\"\u003eBW Clip H2S (BWC2-H)\u003c\/a\u003e\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eH2S\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e10 \/ 15 ppm\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e2 yr sealed\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e~$125\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e\u003ca href=\"\/products\/honeywell-bw-clip-co-monitor-bwc2-m\" title=\"BW Clip CO (BWC2-M)\"\u003eBW Clip CO (BWC2-M)\u003c\/a\u003e\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eCO\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e35 \/ 200 ppm\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e2 yr sealed\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e~$131\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e\u003ca href=\"\/products\/honeywell-bw-clip-o2-monitor-bwc2-x\" title=\"BW Clip O2 (BWC2-X)\"\u003eBW Clip O2 (BWC2-X)\u003c\/a\u003e\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eO2\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e19.5 \/ 23.5 %\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e2 yr sealed\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e~$120\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003c\/div\u003e\n\n\u003cul\u003e\n\u003cli\u003eChoose the \u003cstrong\u003eBW Clip H2S\u003c\/strong\u003e when hydrogen sulfide is the dominant hazard.\u003c\/li\u003e\n\u003cli\u003ePick the \u003ca href=\"\/products\/honeywell-bw-clip-co-monitor-bwc2-m\" title=\"BW Clip CO\"\u003eBW Clip CO\u003c\/a\u003e for carbon-monoxide exposure, or the \u003ca href=\"\/products\/honeywell-bw-clip-o2-monitor-bwc2-x\" title=\"BW Clip O2\"\u003eBW Clip O2\u003c\/a\u003e for oxygen.\u003c\/li\u003e\n\u003cli\u003eNeed several gases on one worker? Step up to the \u003ca href=\"\/products\/bw-gasalertmicroclip-xl-4-gas-detector\" title=\"GasAlertMicroClip XL\"\u003eGasAlertMicroClip XL\u003c\/a\u003e or \u003ca href=\"\/products\/honeywell-bw-clip4-4-gas-detector\" title=\"BW Clip4\"\u003eBW Clip4\u003c\/a\u003e.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2 id=\"faq\"\u003eFrequently asked questions\u003c\/h2\u003e\n\n\u003ch3\u003eWhat gas does the Honeywell BW Clip H2S monitor detect?\u003c\/h3\u003e\u003cp\u003eHydrogen sulfide (H2S) only, with alarms at 10 and 15 ppm. For multiple gases on one worker, use a wearable 4-gas unit like the \u003ca href=\"\/products\/bw-gasalertmicroclip-xl-4-gas-detector\" title=\"GasAlertMicroClip XL\"\u003eGasAlertMicroClip XL\u003c\/a\u003e.\u003c\/p\u003e\n\u003ch3\u003eHow long does the BW Clip H2S last?\u003c\/h3\u003e\u003cp\u003eIt runs continuously for two years with no battery or sensor replacement. At end of life you replace the whole unit — that is the maintenance-free design.\u003c\/p\u003e\n\u003ch3\u003eDo I still need to bump-test a maintenance-free monitor?\u003c\/h3\u003e\u003cp\u003eYes — bump-test to confirm the sensor and alarms respond. The unit needs no sensor or battery service, but bump testing verifies it is working; IntelliDoX\/MicroDock docks automate it.\u003c\/p\u003e\n\u003ch3\u003eWhere should I wear the BW Clip?\u003c\/h3\u003e\u003cp\u003eIn the breathing zone — clipped to the collar or upper chest within about 12 inches of the nose and mouth — so it reads the air the worker actually breathes.\u003c\/p\u003e\n\u003ch3\u003eIs the BW Clip H2S rechargeable?\u003c\/h3\u003e\u003cp\u003eNo — it is a sealed 2-year unit, not rechargeable or serviceable. The trade-off is zero maintenance and the lowest cost per worker over its life.\u003c\/p\u003e\n\u003ch3\u003eWhat alarms does it have?\u003c\/h3\u003e\u003cp\u003eAudible (~95 dB), visual red-LED and vibrating alarms trigger at the 10 ppm and 15 ppm set points, so alerts register in loud or low-visibility work.\u003c\/p\u003e\n\u003ch3\u003eCan one BW Clip cover a whole crew?\u003c\/h3\u003e\u003cp\u003eNo — each worker needs their own clip for personal exposure. For area or pre-entry coverage use a \u003ca href=\"\/collections\/area-gas-monitors\" title=\"Area \u0026amp; Transportable Gas Monitors\"\u003eArea \u0026amp; Transportable Gas Monitors\u003c\/a\u003e monitor or a \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"Portable Gas Detectors\"\u003ePortable Gas Detectors\u003c\/a\u003e instrument.\u003c\/p\u003e\n\u003ch3\u003eWhat is the difference between the BW Clip and the BW Clip4?\u003c\/h3\u003e\u003cp\u003eThe BW Clip is single-gas (H2S here); the \u003ca href=\"\/products\/honeywell-bw-clip4-4-gas-detector\" title=\"BW Clip4\"\u003eBW Clip4\u003c\/a\u003e reads four gases (O2, LEL, CO, H2S) in the same 2-year maintenance-free format.\u003c\/p\u003e\n\u003ch3\u003eDoes it log data?\u003c\/h3\u003e\u003cp\u003eYes — it logs alarm events, which can be downloaded via the docking system for compliance records.\u003c\/p\u003e\n\u003ch3\u003eIs it in stock and how does it ship?\u003c\/h3\u003e\u003cp\u003eUse the Amazon buy button for current availability and delivery timing through our fulfillment partner.\u003c\/p\u003e\n\u003ch3\u003eDoes it come with calibration gas?\u003c\/h3\u003e\u003cp\u003eCalibration gas and docking are sold separately. Plan to add H2S calibration gas (and a dock if you want automated bump tests) for your program.\u003c\/p\u003e\n\u003ch3\u003eIs the BW Clip suitable for confined-space entry?\u003c\/h3\u003e\u003cp\u003eIt provides personal H2S coverage during work, but confined-space entry also requires pre-entry atmospheric testing — use a \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"Portable Gas Detectors\"\u003ePortable Gas Detectors\u003c\/a\u003e 4-gas instrument for that.\u003c\/p\u003e\n\n\u003cdiv style=\"background:#1a1a1a;border:1px solid #3a3a3a;border-radius:6px;padding:16px 18px;margin:22px 0;\"\u003e\n\u003cp style=\"margin:0 0 10px 0;color:#f5e6d3;\"\u003eReady to order the \u003cstrong\u003eHoneywell BW Clip H2S monitor\u003c\/strong\u003e? Add it to your cart above, or check the current Amazon price below. Compare it against the rest of our \u003ca href=\"\/collections\/personal-gas-detectors\" title=\"Personal \u0026amp; Wearable Gas Detectors\"\u003ePersonal \u0026amp; Wearable Gas Detectors\u003c\/a\u003e lineup before you buy.\u003c\/p\u003e\n\u003cp style=\"display:flex;gap:10px;flex-wrap:wrap;align-items:center;margin:0;\"\u003e\u003ca href=\"https:\/\/www.amazon.com\/dp\/B00UZ1WWUK?tag=wcsafety04-20\" rel=\"sponsored nofollow noopener\" target=\"_blank\" style=\"display:inline-block;background:#FFD814;color:#0F1111;padding:13px 26px;text-decoration:none;font-weight:bold;border-radius:4px;border:1px solid #FCD200;\"\u003eCHECK PRICE ON AMAZON →\u003c\/a\u003e\u003cspan style=\"font-size:0.8em;color:#bdae9d;\"\u003eAs an Amazon Associate, WC Safety earns from qualifying purchases.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/div\u003e\n\n\u003cdiv style=\"background:#1a2733;border:1px dashed #4fc3f7;padding:16px 20px;margin:30px 0 18px 0;color:#cfd8dc;font-size:0.92em;\"\u003e\n  \u003cstrong style=\"color:#4fc3f7;\"\u003eWhy trust this Honeywell BW page?\u003c\/strong\u003e WC Safety is an independent industrial safety-equipment retailer serving safety managers, procurement teams and field supervisors. The specifications here are taken from the manufacturer’s published listing for Honeywell BW Clip BWC2-H and framed against \u003ca href=\"https:\/\/www.osha.gov\/laws-regs\/regulations\/standardnumber\/1910\/1910.146\" rel=\"noopener\" target=\"_blank\" style=\"color:#4fc3f7;\"\u003eOSHA 29 CFR 1910.146\u003c\/a\u003e and \u003ca href=\"https:\/\/www.osha.gov\/annotated-pels\" rel=\"noopener\" target=\"_blank\" style=\"color:#4fc3f7;\"\u003eOSHA Permissible Exposure Limits\u003c\/a\u003e. Disclosed: WC Safety earns Amazon affiliate commissions on outbound clicks; that does not influence the specs shown or our lineup.\n\u003c\/div\u003e\n\u003cdiv style=\"background:#1a2733;border-left:4px solid #4fc3f7;padding:18px 22px;margin:18px 0;color:#cfd8dc;font-size:0.92em;\"\u003e\n  \u003cstrong style=\"color:#4fc3f7;\"\u003eBy Steven Eaton, WC Safety Editorial\u003c\/strong\u003e — Industrial safety-equipment desk · specialization: atmospheric monitoring, gas detection and instrument selection.\u003cbr\u003e\n  \u003cstrong\u003eLast updated:\u003c\/strong\u003e \u003ctime datetime=\"2026-06-22\"\u003eJune 22, 2026\u003c\/time\u003e · \u003cstrong\u003eSources reviewed:\u003c\/strong\u003e manufacturer product listing \u0026amp; specifications, OSHA 29 CFR 1910.146, OSHA Annotated PEL tables, ACGIH Threshold Limit Values.\u003cbr\u003e\n  \u003cstrong\u003eEditorial standard:\u003c\/strong\u003e \u003cem\u003eZero sponsored listings. No manufacturer input. Specs verified against the manufacturer’s published data.\u003c\/em\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"background:#1a2733;border-left:4px solid #4fc3f7;padding:16px 20px;margin:18px 0;color:#cfd8dc;font-size:0.92em;\"\u003e\n  \u003cstrong style=\"color:#4fc3f7;\"\u003eHow this page is maintained.\u003c\/strong\u003e Specifications and pricing are reviewed against the manufacturer’s current listing and re-checked whenever the lineup changes. Gas-detection guidance follows \u003ca href=\"https:\/\/www.osha.gov\/laws-regs\/regulations\/standardnumber\/1910\/1910.146\" rel=\"noopener\" target=\"_blank\" style=\"color:#4fc3f7;\"\u003eOSHA 1910.146\u003c\/a\u003e and \u003ca href=\"https:\/\/www.osha.gov\/annotated-pels\" rel=\"noopener\" target=\"_blank\" style=\"color:#4fc3f7;\"\u003eOSHA PELs\u003c\/a\u003e, cross-referenced with ACGIH TLVs.\n\u003c\/div\u003e\n\u003cdiv style=\"background:#2a2520;border-left:4px solid #ff9800;padding:16px 20px;margin:18px 0;color:#f5e6d3;font-size:0.92em;\"\u003e\n  \u003cstrong style=\"color:#ffb74d;\"\u003eDisclosure.\u003c\/strong\u003e WC Safety participates in the Amazon Associates Program and earns commissions on qualifying purchases through outbound links on this page (tag wcsafety04-20). We are not sponsored by any instrument manufacturer. This page is buyer guidance, not medical, legal or regulatory advice — confirm gas-detection requirements for your site against the applicable OSHA standard and, for commercial monitoring programs, a Certified Industrial Hygienist (CIH).\n\u003c\/div\u003e\n\n\u003cscript type=\"application\/ld+json\"\u003e\n{\"@context\": \"https:\/\/schema.org\", \"@graph\": [{\"@type\": \"Product\", \"@id\": \"https:\/\/wcsafety.com\/products\/honeywell-bw-clip-h2s-monitor-bwc2-h#product\", \"name\": \"Honeywell BW Clip H2S Monitor — BWC2-H Single-Gas (2-Year Maintenance-Free)\", \"description\": \"Honeywell BW Clip H2S monitor — 2-year maintenance-free single-gas detector with audible, visual \u0026 vibrating alarms. Order the BWC2-H at WC Safety.\", \"sku\": \"B00UZ1WWUK\", \"mpn\": \"BWC2-H\", \"image\": [\"https:\/\/wcsafety.com\/cdn\/shop\/products\/honeywell-bw-clip-h2s-monitor-bwc2-h.jpg\"], \"brand\": {\"@type\": \"Brand\", \"name\": \"Honeywell BW\"}, \"category\": \"Personal Gas Detector\", \"isPartOf\": {\"@type\": \"CollectionPage\", \"@id\": \"https:\/\/wcsafety.com\/collections\/personal-gas-detectors#collection\", \"name\": \"Personal \u0026 Wearable Gas Detectors\", \"url\": \"https:\/\/wcsafety.com\/collections\/personal-gas-detectors\"}, \"isRelatedTo\": [{\"@type\": \"Product\", \"name\": \"Honeywell BW Clip CO Monitor (BWC2-M)\", \"url\": \"https:\/\/wcsafety.com\/products\/honeywell-bw-clip-co-monitor-bwc2-m\"}, {\"@type\": \"Product\", \"name\": \"Honeywell BW Clip O2 Monitor (BWC2-X)\", \"url\": \"https:\/\/wcsafety.com\/products\/honeywell-bw-clip-o2-monitor-bwc2-x\"}, {\"@type\": \"Product\", \"name\": \"TopTes CT-580 CO Detector\", \"url\": \"https:\/\/wcsafety.com\/products\/toptes-ct-580-co-detector\"}, {\"@type\": \"Product\", \"name\": \"BW GasAlertMicroClip XL 4 Gas Detector\", \"url\": \"https:\/\/wcsafety.com\/products\/bw-gasalertmicroclip-xl-4-gas-detector\"}, {\"@type\": \"Product\", \"name\": \"Honeywell BW Clip4 4 Gas Detector\", \"url\": \"https:\/\/wcsafety.com\/products\/honeywell-bw-clip4-4-gas-detector\"}, {\"@type\": \"Product\", \"name\": \"RKI GX3R 4 Gas Monitor\", \"url\": \"https:\/\/wcsafety.com\/products\/rki-gx3r-4-gas-monitor\"}], \"offers\": {\"@type\": \"Offer\", \"url\": \"https:\/\/wcsafety.com\/products\/honeywell-bw-clip-h2s-monitor-bwc2-h\", \"priceCurrency\": \"USD\", \"price\": \"124.90\", \"availability\": \"https:\/\/schema.org\/InStock\", \"seller\": {\"@type\": \"Organization\", \"name\": \"WC Safety\"}}}, {\"@type\": \"BreadcrumbList\", \"@id\": \"https:\/\/wcsafety.com\/products\/honeywell-bw-clip-h2s-monitor-bwc2-h#breadcrumb\", \"itemListElement\": [{\"@type\": \"ListItem\", \"position\": 1, \"name\": \"Home\", \"item\": \"https:\/\/wcsafety.com\/\"}, {\"@type\": \"ListItem\", \"position\": 2, \"name\": \"Gas Detectors\", \"item\": \"https:\/\/wcsafety.com\/collections\/gas-detectors\"}, {\"@type\": \"ListItem\", \"position\": 3, \"name\": \"Personal \u0026 Wearable Gas Detectors\", \"item\": \"https:\/\/wcsafety.com\/collections\/personal-gas-detectors\"}, {\"@type\": \"ListItem\", \"position\": 4, \"name\": \"Honeywell BW Clip H2S Monitor — BWC2-H Single-Gas (2-Year Maintenance-Free)\"}]}, {\"@type\": \"FAQPage\", \"mainEntity\": [{\"@type\": \"Question\", \"name\": \"What gas does the Honeywell BW Clip H2S monitor detect?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Hydrogen sulfide (H2S) only, with alarms at 10 and 15 ppm. For multiple gases on one worker, use a wearable 4-gas unit like the GasAlertMicroClip XL.\"}}, {\"@type\": \"Question\", \"name\": \"How long does the BW Clip H2S last?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"It runs continuously for two years with no battery or sensor replacement. At end of life you replace the whole unit — that is the maintenance-free design.\"}}, {\"@type\": \"Question\", \"name\": \"Do I still need to bump-test a maintenance-free monitor?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Yes — bump-test to confirm the sensor and alarms respond. The unit needs no sensor or battery service, but bump testing verifies it is working; IntelliDoX\/MicroDock docks automate it.\"}}, {\"@type\": \"Question\", \"name\": \"Where should I wear the BW Clip?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"In the breathing zone — clipped to the collar or upper chest within about 12 inches of the nose and mouth — so it reads the air the worker actually breathes.\"}}, {\"@type\": \"Question\", \"name\": \"Is the BW Clip H2S rechargeable?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"No — it is a sealed 2-year unit, not rechargeable or serviceable. The trade-off is zero maintenance and the lowest cost per worker over its life.\"}}, {\"@type\": \"Question\", \"name\": \"What alarms does it have?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Audible (~95 dB), visual red-LED and vibrating alarms trigger at the 10 ppm and 15 ppm set points, so alerts register in loud or low-visibility work.\"}}, {\"@type\": \"Question\", \"name\": \"Can one BW Clip cover a whole crew?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"No — each worker needs their own clip for personal exposure. For area or pre-entry coverage use a Area \u0026 Transportable Gas Monitors monitor or a Portable Gas Detectors instrument.\"}}, {\"@type\": \"Question\", \"name\": \"What is the difference between the BW Clip and the BW Clip4?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"The BW Clip is single-gas (H2S here); the BW Clip4 reads four gases (O2, LEL, CO, H2S) in the same 2-year maintenance-free format.\"}}, {\"@type\": \"Question\", \"name\": \"Does it log data?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Yes — it logs alarm events, which can be downloaded via the docking system for compliance records.\"}}, {\"@type\": \"Question\", \"name\": \"Is it in stock and how does it ship?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Use the Amazon buy button for current availability and delivery timing through our fulfillment partner.\"}}, {\"@type\": \"Question\", \"name\": \"Does it come with calibration gas?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Calibration gas and docking are sold separately. Plan to add H2S calibration gas (and a dock if you want automated bump tests) for your program.\"}}, {\"@type\": \"Question\", \"name\": \"Is the BW Clip suitable for confined-space entry?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"It provides personal H2S coverage during work, but confined-space entry also requires pre-entry atmospheric testing — use a Portable Gas Detectors 4-gas instrument for that.\"}}]}, {\"@type\": \"Organization\", \"@id\": \"https:\/\/wcsafety.com\/#org\", \"name\": \"WC Safety\", \"url\": \"https:\/\/wcsafety.com\", \"logo\": \"https:\/\/wcsafety.com\/cdn\/shop\/files\/logo.png\"}, {\"@type\": \"Person\", \"@id\": \"https:\/\/wcsafety.com\/#editor\", \"name\": \"Steven Eaton\", \"jobTitle\": \"Editorial Lead\", \"worksFor\": {\"@id\": \"https:\/\/wcsafety.com\/#org\"}, \"knowsAbout\": [\"industrial gas detection\", \"atmospheric monitoring\", \"personal protective equipment\"]}, {\"@type\": \"Brand\", \"name\": \"Honeywell BW\"}]}\n\u003c\/script\u003e","brand":"Honeywell BW","offers":[{"title":"Default Title","offer_id":44266436362328,"sku":"B00UZ1WWUK","price":124.9,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0594\/1900\/0920\/files\/617-vDgCsIL._SL1362.jpg?v=1782121772"},{"product_id":"bw-gasalertmicroclip-xl-4-gas-detector","title":"BW GasAlertMicroClip XL 4 Gas Detector (O2, LEL, CO, H2S)","description":"\u003c!-- PRODUCT B00N9SXUH0 | tag personal-gas-detector | TODO: add matching Product Review + best-of guide links when those silo layers exist --\u003e\n\n\u003cdiv style=\"background:#1a1a1a;border-left:4px solid #ff9800;padding:14px 18px;margin:0 0 18px 0;color:#f5e6d3;font-size:0.95em;\"\u003e\n\u003cstrong style=\"color:#ffb74d;\"\u003eEditor’s note:\u003c\/strong\u003e the BW GasAlertMicroClip XL is one of the instruments we curate in our \u003ca href=\"\/collections\/personal-gas-detectors\" title=\"Personal \u0026amp; Wearable Gas Detectors\"\u003ePersonal \u0026amp; Wearable Gas Detectors\u003c\/a\u003e buyer’s hub. Compare it with the \u003ca href=\"\/products\/honeywell-bw-clip-h2s-monitor-bwc2-h\" title=\"Honeywell BW Clip H2S\"\u003eHoneywell BW Clip H2S\u003c\/a\u003e below before you order.\u003c\/div\u003e\n\n\u003ch2 id=\"top\"\u003eBW GasAlertMicroClip XL 4 Gas Detector — Wearable O2, LEL, CO \u0026amp; H2S\u003c\/h2\u003e\n\n\u003cp\u003eThe \u003cstrong\u003eBW GasAlertMicroClip XL\u003c\/strong\u003e is the wearable 4-gas workhorse — a \u003ca href=\"\/collections\/personal-gas-detectors\" title=\"personal gas detector\"\u003epersonal gas detector\u003c\/a\u003e that puts O2, LEL combustibles, CO and H2S on one worker with datalogging and automated docking. It is the industrial standard when one person needs full four-gas coverage all shift.\u003c\/p\u003e\n\n\u003cp style=\"font-size:0.9em;color:#bdae9d;margin:10px 0 18px 0;\"\u003eJump to: \u003ca href=\"#features\" style=\"color:#ffb74d;\"\u003eFeatures\u003c\/a\u003e · \u003ca href=\"#specs\" style=\"color:#ffb74d;\"\u003eSpecs\u003c\/a\u003e · \u003ca href=\"#compatibility\" style=\"color:#ffb74d;\"\u003eWhat it detects\u003c\/a\u003e · \u003ca href=\"#comparison\" style=\"color:#ffb74d;\"\u003eComparison\u003c\/a\u003e · \u003ca href=\"#faq\" style=\"color:#ffb74d;\"\u003eFAQ\u003c\/a\u003e\u003c\/p\u003e\n\n\u003cp\u003eThe BW GasAlertMicroClip XL is a compact, wearable four-gas monitor (O2, LEL, CO, H2S) with datalogging, triple alarms and automated docking via IntelliDoX or MicroDock II.\u003c\/p\u003e\n\n\u003ch3 id=\"features\"\u003eKey features\u003c\/h3\u003e\n\n\u003cul\u003e\n\u003cli\u003eWearable 4-gas monitor reading O2, LEL combustibles, CO and H2S on one worker\u003c\/li\u003e\n\u003cli\u003eExtended run time and compact body for all-shift wear\u003c\/li\u003e\n\u003cli\u003eAudible, visual and vibrating alarms for high-noise environments\u003c\/li\u003e\n\u003cli\u003eFull datalogging for compliance records\u003c\/li\u003e\n\u003cli\u003eAutomated bump testing and calibration via IntelliDoX or MicroDock II\u003c\/li\u003e\n\u003cli\u003eA long-standing industrial standard for personal confined-space monitoring\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cdiv style=\"display:flex;gap:14px;flex-wrap:wrap;margin:18px 0;\"\u003e\n\u003cdiv style=\"flex:1;min-width:240px;background:#1b3a2a;border:1px solid #4caf50;border-radius:6px;padding:14px 18px;\"\u003e\n\u003cstrong style=\"color:#81c784;\"\u003ePros\u003c\/strong\u003e\u003cul style=\"margin:8px 0 0 0;\"\u003e\n\u003cli\u003eFull 4-gas coverage on one worker\u003c\/li\u003e\n\u003cli\u003eProven industrial-standard platform\u003c\/li\u003e\n\u003cli\u003eDatalogging for compliance\u003c\/li\u003e\n\u003cli\u003eAutomated docking bump\/cal\u003c\/li\u003e\n\u003cli\u003eRugged, reliable build\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"flex:1;min-width:240px;background:#3a1e1e;border:1px solid #ef5350;border-radius:6px;padding:14px 18px;\"\u003e\n\u003cstrong style=\"color:#e57373;\"\u003eCons\u003c\/strong\u003e\u003cul style=\"margin:8px 0 0 0;\"\u003e\n\u003cli\u003eFar higher cost than single-gas clips\u003c\/li\u003e\n\u003cli\u003eRechargeable\/serviceable — needs charging and sensor upkeep\u003c\/li\u003e\n\u003cli\u003eDiffusion only (pump versions are separate models)\u003c\/li\u003e\n\u003cli\u003eNo VOC\/PID coverage\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\n\u003ch3 id=\"specs\"\u003eSpecifications\u003c\/h3\u003e\n\n\u003cdiv style=\"overflow-x:auto;\"\u003e\u003ctable style=\"width:100%;border-collapse:collapse;background:#1a1a1a;margin:14px 0;\"\u003e\n\u003cthead\u003e\u003ctr style=\"background:#2a2a2a;\"\u003e\n\u003cth style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;text-align:left;\"\u003eSpecification\u003c\/th\u003e\n\u003cth style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;text-align:left;\"\u003eDetail\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eGases detected\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eO2, LEL combustibles, CO, H2S\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eForm factor\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eCompact wearable, clip-on\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003ePower\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eRechargeable battery, extended run time\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eAlarms\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eAudible, visual \u0026amp; vibrating\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eSensors\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eElectrochemical (O2\/CO\/H2S) + catalytic bead (LEL)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eDatalogging\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eYes\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eDocking\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eIntelliDoX \/ MicroDock II for automated bump\/cal\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eHousing\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eRugged, water- \u0026amp; dust-resistant\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003c\/div\u003e\n\n\u003ch3\u003eWhere the BW GasAlertMicroClip XL fits\u003c\/h3\u003e\n\n\u003cul\u003e\n\u003cli\u003eConfined-space entry teams\u003c\/li\u003e\n\u003cli\u003eUtilities and municipal crews\u003c\/li\u003e\n\u003cli\u003eOil, gas and refinery work\u003c\/li\u003e\n\u003cli\u003eIndustrial maintenance\u003c\/li\u003e\n\u003cli\u003ePrograms needing datalogging and docking\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2 id=\"compatibility\"\u003eWhat the BW GasAlertMicroClip XL detects (and what it doesn’t)\u003c\/h2\u003e\n\n\u003cp\u003eIt monitors \u003cstrong\u003eO2, LEL combustibles, CO and H2S\u003c\/strong\u003e — the confined-space four-gas set. It does not read VOCs, CO2 or specific toxics like chlorine; those need a PID or dedicated sensor. It is a diffusion instrument, so for remote pre-entry sampling use a \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"Portable Gas Detectors\"\u003ePortable Gas Detectors\u003c\/a\u003e pump monitor. For the lowest-maintenance wearable 4-gas, compare the sealed \u003ca href=\"\/products\/honeywell-bw-clip4-4-gas-detector\" title=\"BW Clip4\"\u003eBW Clip4\u003c\/a\u003e; for single-hazard wear, the \u003ca href=\"\/products\/honeywell-bw-clip-h2s-monitor-bwc2-h\" title=\"BW Clip H2S\"\u003eBW Clip H2S\u003c\/a\u003e family. Automate bump\/cal with IntelliDoX or MicroDock.\u003c\/p\u003e\n\n\u003cp\u003eCross-shopping? This unit sits in our \u003ca href=\"\/collections\/personal-gas-detectors\" title=\"Personal \u0026amp; Wearable Gas Detectors\"\u003ePersonal \u0026amp; Wearable Gas Detectors\u003c\/a\u003e hub alongside \u003ca href=\"\/products\/honeywell-bw-clip-h2s-monitor-bwc2-h\" title=\"Honeywell BW Clip H2S\"\u003eHoneywell BW Clip H2S\u003c\/a\u003e, \u003ca href=\"\/products\/honeywell-bw-clip-co-monitor-bwc2-m\" title=\"Honeywell BW Clip CO\"\u003eHoneywell BW Clip CO\u003c\/a\u003e, \u003ca href=\"\/products\/honeywell-bw-clip-o2-monitor-bwc2-x\" title=\"Honeywell BW Clip O2\"\u003eHoneywell BW Clip O2\u003c\/a\u003e, \u003ca href=\"\/products\/toptes-ct-580-co-detector\" title=\"TopTes CT-580 CO\"\u003eTopTes CT-580 CO\u003c\/a\u003e. For other gas-detection form factors see \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"Portable Gas Detectors\"\u003ePortable Gas Detectors\u003c\/a\u003e, \u003ca href=\"\/collections\/fixed-gas-detection-systems\" title=\"Fixed Gas Detection Systems\"\u003eFixed Gas Detection Systems\u003c\/a\u003e, \u003ca href=\"\/collections\/area-gas-monitors\" title=\"Area \u0026amp; Transportable Gas Monitors\"\u003eArea \u0026amp; Transportable Gas Monitors\u003c\/a\u003e, or browse the full \u003ca href=\"\/collections\/gas-detectors\" title=\"Gas Detectors\"\u003eGas Detectors\u003c\/a\u003e range.\u003c\/p\u003e\n\n\u003ch2 id=\"comparison\"\u003eHoneywell BW wearable 4-gas family compared\u003c\/h2\u003e\n\n\u003cdiv style=\"overflow-x:auto;\"\u003e\u003ctable style=\"width:100%;border-collapse:collapse;background:#1a1a1a;margin:14px 0;\"\u003e\n\u003ccaption style=\"color:#bdae9d;font-size:0.85em;text-align:left;padding:4px 0;\"\u003eHoneywell BW wearable 4-gas family (O2, LEL, CO, H2S)\u003c\/caption\u003e\n\u003cthead\u003e\u003ctr style=\"background:#2a2a2a;\"\u003e\n\u003cth style=\"color:#ffb74d;padding:9px;border:1px solid #3a3a3a;text-align:left;\"\u003eModel\u003c\/th\u003e\n\u003cth style=\"color:#ffb74d;padding:9px;border:1px solid #3a3a3a;text-align:left;\"\u003eService model\u003c\/th\u003e\n\u003cth style=\"color:#ffb74d;padding:9px;border:1px solid #3a3a3a;text-align:left;\"\u003eBump\/cal docking\u003c\/th\u003e\n\u003cth style=\"color:#ffb74d;padding:9px;border:1px solid #3a3a3a;text-align:left;\"\u003eNotable\u003c\/th\u003e\n\u003cth style=\"color:#ffb74d;padding:9px;border:1px solid #3a3a3a;text-align:left;\"\u003eStreet price\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e\u003ca href=\"\/products\/bw-gasalertmicroclip-xl-4-gas-detector\" title=\"GasAlertMicroClip XL\"\u003eGasAlertMicroClip XL\u003c\/a\u003e\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eRechargeable, serviceable\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eIntelliDoX \/ MicroDock\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eDatalogging, motion alert\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e~$539\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#2a2520;\"\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e\u003cstrong\u003e\u003ca href=\"\/products\/honeywell-bw-clip4-4-gas-detector\" title=\"BW Clip4\"\u003eBW Clip4\u003c\/a\u003e\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e2-yr maintenance-free\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eOptional\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eSealed, hibernate mode\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e~$820\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003c\/div\u003e\n\n\u003cul\u003e\n\u003cli\u003eChoose the \u003cstrong\u003eGasAlertMicroClip XL\u003c\/strong\u003e for a serviceable, datalogging 4-gas wearable with docking automation.\u003c\/li\u003e\n\u003cli\u003ePick the \u003ca href=\"\/products\/honeywell-bw-clip4-4-gas-detector\" title=\"BW Clip4\"\u003eBW Clip4\u003c\/a\u003e for a sealed 2-year maintenance-free 4-gas with no charging.\u003c\/li\u003e\n\u003cli\u003eOnly one hazard? A single-gas \u003ca href=\"\/products\/honeywell-bw-clip-h2s-monitor-bwc2-h\" title=\"BW Clip\"\u003eBW Clip\u003c\/a\u003e costs far less per worker.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2 id=\"faq\"\u003eFrequently asked questions\u003c\/h2\u003e\n\n\u003ch3\u003eWhat gases does the GasAlertMicroClip XL detect?\u003c\/h3\u003e\u003cp\u003eO2, LEL combustibles, CO and H2S — the standard confined-space set. For VOCs you need a PID; see the \u003ca href=\"\/collections\/gas-detectors\" title=\"Gas Detectors\"\u003eGas Detectors\u003c\/a\u003e range.\u003c\/p\u003e\n\u003ch3\u003eHow is the MicroClip XL different from the BW Clip4?\u003c\/h3\u003e\u003cp\u003eThe MicroClip XL is rechargeable and serviceable with datalogging and docking; the \u003ca href=\"\/products\/honeywell-bw-clip4-4-gas-detector\" title=\"BW Clip4\"\u003eBW Clip4\u003c\/a\u003e is sealed and 2-year maintenance-free with no charging.\u003c\/p\u003e\n\u003ch3\u003eDoes it log data?\u003c\/h3\u003e\u003cp\u003eYes — it provides full datalogging that downloads through IntelliDoX or MicroDock II for compliance records.\u003c\/p\u003e\n\u003ch3\u003eHow do I bump-test and calibrate it?\u003c\/h3\u003e\u003cp\u003eUse four-gas calibration gas; the IntelliDoX or MicroDock II docking stations automate bump testing and calibration and record the results.\u003c\/p\u003e\n\u003ch3\u003eIs it good for confined-space entry?\u003c\/h3\u003e\u003cp\u003eYes for personal monitoring during entry. Pre-entry sampling of a sealed space still needs a \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"Portable Gas Detectors\"\u003ePortable Gas Detectors\u003c\/a\u003e pump instrument.\u003c\/p\u003e\n\u003ch3\u003eIs the MicroClip XL rechargeable?\u003c\/h3\u003e\u003cp\u003eYes — it uses a rechargeable battery with extended run time for full-shift wear; recharge between shifts.\u003c\/p\u003e\n\u003ch3\u003eWhat alarms does it have?\u003c\/h3\u003e\u003cp\u003eAudible, visual and vibrating alarms trigger when any of the four gases exceeds its set point.\u003c\/p\u003e\n\u003ch3\u003eDoes it have a pump?\u003c\/h3\u003e\u003cp\u003eThis model is diffusion. For remote sample-draw before entry, use a pump-equipped \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"Portable Gas Detectors\"\u003ePortable Gas Detectors\u003c\/a\u003e monitor.\u003c\/p\u003e\n\u003ch3\u003eWhat does it not detect?\u003c\/h3\u003e\u003cp\u003eNo VOCs, CO2 or gas-specific toxics like chlorine or ammonia. For VOC work use a PID; browse the \u003ca href=\"\/collections\/gas-detectors\" title=\"Gas Detectors\"\u003eGas Detectors\u003c\/a\u003e hub.\u003c\/p\u003e\n\u003ch3\u003eWho is the MicroClip XL for?\u003c\/h3\u003e\u003cp\u003eCrews that need full four-gas coverage per worker with datalogging and docking — utilities, oil and gas, and confined-space teams. For one hazard, a \u003ca href=\"\/products\/honeywell-bw-clip-h2s-monitor-bwc2-h\" title=\"single-gas BW Clip\"\u003esingle-gas BW Clip\u003c\/a\u003e is cheaper.\u003c\/p\u003e\n\u003ch3\u003eIs it in stock and how does it ship?\u003c\/h3\u003e\u003cp\u003eUse the Amazon buy button for live availability and delivery timing through our fulfillment partner.\u003c\/p\u003e\n\u003ch3\u003eDoes it come with docking or calibration gas?\u003c\/h3\u003e\u003cp\u003eDocking stations and calibration gas are sold separately. Budget for IntelliDoX\/MicroDock and four-gas calibration gas for an automated program.\u003c\/p\u003e\n\n\u003cdiv style=\"background:#1a1a1a;border:1px solid #3a3a3a;border-radius:6px;padding:16px 18px;margin:22px 0;\"\u003e\n\u003cp style=\"margin:0 0 10px 0;color:#f5e6d3;\"\u003eReady to order the \u003cstrong\u003eBW GasAlertMicroClip XL\u003c\/strong\u003e? Add it to your cart above, or check the current Amazon price below. Compare it against the rest of our \u003ca href=\"\/collections\/personal-gas-detectors\" title=\"Personal \u0026amp; Wearable Gas Detectors\"\u003ePersonal \u0026amp; Wearable Gas Detectors\u003c\/a\u003e lineup before you buy.\u003c\/p\u003e\n\u003cp style=\"display:flex;gap:10px;flex-wrap:wrap;align-items:center;margin:0;\"\u003e\u003ca href=\"https:\/\/www.amazon.com\/dp\/B00N9SXUH0?tag=wcsafety04-20\" rel=\"sponsored nofollow noopener\" target=\"_blank\" style=\"display:inline-block;background:#FFD814;color:#0F1111;padding:13px 26px;text-decoration:none;font-weight:bold;border-radius:4px;border:1px solid #FCD200;\"\u003eCHECK PRICE ON AMAZON →\u003c\/a\u003e\u003cspan style=\"font-size:0.8em;color:#bdae9d;\"\u003eAs an Amazon Associate, WC Safety earns from qualifying purchases.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/div\u003e\n\n\u003cdiv style=\"background:#1a2733;border:1px dashed #4fc3f7;padding:16px 20px;margin:30px 0 18px 0;color:#cfd8dc;font-size:0.92em;\"\u003e\n  \u003cstrong style=\"color:#4fc3f7;\"\u003eWhy trust this Honeywell BW page?\u003c\/strong\u003e WC Safety is an independent industrial safety-equipment retailer serving safety managers, procurement teams and field supervisors. The specifications here are taken from the manufacturer’s published listing for BW GasAlertMicroClip XL and framed against \u003ca href=\"https:\/\/www.osha.gov\/laws-regs\/regulations\/standardnumber\/1910\/1910.146\" rel=\"noopener\" target=\"_blank\" style=\"color:#4fc3f7;\"\u003eOSHA 29 CFR 1910.146\u003c\/a\u003e and \u003ca href=\"https:\/\/www.osha.gov\/annotated-pels\" rel=\"noopener\" target=\"_blank\" style=\"color:#4fc3f7;\"\u003eOSHA Permissible Exposure Limits\u003c\/a\u003e. Disclosed: WC Safety earns Amazon affiliate commissions on outbound clicks; that does not influence the specs shown or our lineup.\n\u003c\/div\u003e\n\u003cdiv style=\"background:#1a2733;border-left:4px solid #4fc3f7;padding:18px 22px;margin:18px 0;color:#cfd8dc;font-size:0.92em;\"\u003e\n  \u003cstrong style=\"color:#4fc3f7;\"\u003eBy Steven Eaton, WC Safety Editorial\u003c\/strong\u003e — Industrial safety-equipment desk · specialization: atmospheric monitoring, gas detection and instrument selection.\u003cbr\u003e\n  \u003cstrong\u003eLast updated:\u003c\/strong\u003e \u003ctime datetime=\"2026-06-22\"\u003eJune 22, 2026\u003c\/time\u003e · \u003cstrong\u003eSources reviewed:\u003c\/strong\u003e manufacturer product listing \u0026amp; specifications, OSHA 29 CFR 1910.146, OSHA Annotated PEL tables, ACGIH Threshold Limit Values.\u003cbr\u003e\n  \u003cstrong\u003eEditorial standard:\u003c\/strong\u003e \u003cem\u003eZero sponsored listings. No manufacturer input. Specs verified against the manufacturer’s published data.\u003c\/em\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"background:#1a2733;border-left:4px solid #4fc3f7;padding:16px 20px;margin:18px 0;color:#cfd8dc;font-size:0.92em;\"\u003e\n  \u003cstrong style=\"color:#4fc3f7;\"\u003eHow this page is maintained.\u003c\/strong\u003e Specifications and pricing are reviewed against the manufacturer’s current listing and re-checked whenever the lineup changes. Gas-detection guidance follows \u003ca href=\"https:\/\/www.osha.gov\/laws-regs\/regulations\/standardnumber\/1910\/1910.146\" rel=\"noopener\" target=\"_blank\" style=\"color:#4fc3f7;\"\u003eOSHA 1910.146\u003c\/a\u003e and \u003ca href=\"https:\/\/www.osha.gov\/annotated-pels\" rel=\"noopener\" target=\"_blank\" style=\"color:#4fc3f7;\"\u003eOSHA PELs\u003c\/a\u003e, cross-referenced with ACGIH TLVs.\n\u003c\/div\u003e\n\u003cdiv style=\"background:#2a2520;border-left:4px solid #ff9800;padding:16px 20px;margin:18px 0;color:#f5e6d3;font-size:0.92em;\"\u003e\n  \u003cstrong style=\"color:#ffb74d;\"\u003eDisclosure.\u003c\/strong\u003e WC Safety participates in the Amazon Associates Program and earns commissions on qualifying purchases through outbound links on this page (tag wcsafety04-20). We are not sponsored by any instrument manufacturer. This page is buyer guidance, not medical, legal or regulatory advice — confirm gas-detection requirements for your site against the applicable OSHA standard and, for commercial monitoring programs, a Certified Industrial Hygienist (CIH).\n\u003c\/div\u003e\n\n\u003cscript type=\"application\/ld+json\"\u003e\n{\"@context\": \"https:\/\/schema.org\", \"@graph\": [{\"@type\": \"Product\", \"@id\": \"https:\/\/wcsafety.com\/products\/bw-gasalertmicroclip-xl-4-gas-detector#product\", \"name\": \"BW GasAlertMicroClip XL 4 Gas Detector (O2, LEL, CO, H2S)\", \"description\": \"BW GasAlertMicroClip XL 4 gas detector — wearable O2, LEL, CO \u0026 H2S monitor with datalogging and triple alarm. Order this Honeywell BW unit at WC Safety.\", \"sku\": \"B00N9SXUH0\", \"mpn\": \"MCXL-XWHM-Y-NA\", \"image\": [\"https:\/\/wcsafety.com\/cdn\/shop\/products\/bw-gasalertmicroclip-xl-4-gas-detector.jpg\"], \"brand\": {\"@type\": \"Brand\", \"name\": \"Honeywell BW\"}, \"category\": \"Personal Gas Detector\", \"isPartOf\": {\"@type\": \"CollectionPage\", \"@id\": \"https:\/\/wcsafety.com\/collections\/personal-gas-detectors#collection\", \"name\": \"Personal \u0026 Wearable Gas Detectors\", \"url\": \"https:\/\/wcsafety.com\/collections\/personal-gas-detectors\"}, \"isRelatedTo\": [{\"@type\": \"Product\", \"name\": \"Honeywell BW Clip H2S Monitor (BWC2-H)\", \"url\": \"https:\/\/wcsafety.com\/products\/honeywell-bw-clip-h2s-monitor-bwc2-h\"}, {\"@type\": \"Product\", \"name\": \"Honeywell BW Clip CO Monitor (BWC2-M)\", \"url\": \"https:\/\/wcsafety.com\/products\/honeywell-bw-clip-co-monitor-bwc2-m\"}, {\"@type\": \"Product\", \"name\": \"Honeywell BW Clip O2 Monitor (BWC2-X)\", \"url\": \"https:\/\/wcsafety.com\/products\/honeywell-bw-clip-o2-monitor-bwc2-x\"}, {\"@type\": \"Product\", \"name\": \"TopTes CT-580 CO Detector\", \"url\": \"https:\/\/wcsafety.com\/products\/toptes-ct-580-co-detector\"}, {\"@type\": \"Product\", \"name\": \"Honeywell BW Clip4 4 Gas Detector\", \"url\": \"https:\/\/wcsafety.com\/products\/honeywell-bw-clip4-4-gas-detector\"}, {\"@type\": \"Product\", \"name\": \"RKI GX3R 4 Gas Monitor\", \"url\": \"https:\/\/wcsafety.com\/products\/rki-gx3r-4-gas-monitor\"}], \"offers\": {\"@type\": \"Offer\", \"url\": \"https:\/\/wcsafety.com\/products\/bw-gasalertmicroclip-xl-4-gas-detector\", \"priceCurrency\": \"USD\", \"price\": \"538.89\", \"availability\": \"https:\/\/schema.org\/InStock\", \"seller\": {\"@type\": \"Organization\", \"name\": \"WC Safety\"}}}, {\"@type\": \"BreadcrumbList\", \"@id\": \"https:\/\/wcsafety.com\/products\/bw-gasalertmicroclip-xl-4-gas-detector#breadcrumb\", \"itemListElement\": [{\"@type\": \"ListItem\", \"position\": 1, \"name\": \"Home\", \"item\": \"https:\/\/wcsafety.com\/\"}, {\"@type\": \"ListItem\", \"position\": 2, \"name\": \"Gas Detectors\", \"item\": \"https:\/\/wcsafety.com\/collections\/gas-detectors\"}, {\"@type\": \"ListItem\", \"position\": 3, \"name\": \"Personal \u0026 Wearable Gas Detectors\", \"item\": \"https:\/\/wcsafety.com\/collections\/personal-gas-detectors\"}, {\"@type\": \"ListItem\", \"position\": 4, \"name\": \"BW GasAlertMicroClip XL 4 Gas Detector (O2, LEL, CO, H2S)\"}]}, {\"@type\": \"FAQPage\", \"mainEntity\": [{\"@type\": \"Question\", \"name\": \"What gases does the GasAlertMicroClip XL detect?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"O2, LEL combustibles, CO and H2S — the standard confined-space set. For VOCs you need a PID; see the Gas Detectors range.\"}}, {\"@type\": \"Question\", \"name\": \"How is the MicroClip XL different from the BW Clip4?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"The MicroClip XL is rechargeable and serviceable with datalogging and docking; the BW Clip4 is sealed and 2-year maintenance-free with no charging.\"}}, {\"@type\": \"Question\", \"name\": \"Does it log data?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Yes — it provides full datalogging that downloads through IntelliDoX or MicroDock II for compliance records.\"}}, {\"@type\": \"Question\", \"name\": \"How do I bump-test and calibrate it?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Use four-gas calibration gas; the IntelliDoX or MicroDock II docking stations automate bump testing and calibration and record the results.\"}}, {\"@type\": \"Question\", \"name\": \"Is it good for confined-space entry?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Yes for personal monitoring during entry. Pre-entry sampling of a sealed space still needs a Portable Gas Detectors pump instrument.\"}}, {\"@type\": \"Question\", \"name\": \"Is the MicroClip XL rechargeable?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Yes — it uses a rechargeable battery with extended run time for full-shift wear; recharge between shifts.\"}}, {\"@type\": \"Question\", \"name\": \"What alarms does it have?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Audible, visual and vibrating alarms trigger when any of the four gases exceeds its set point.\"}}, {\"@type\": \"Question\", \"name\": \"Does it have a pump?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"This model is diffusion. For remote sample-draw before entry, use a pump-equipped Portable Gas Detectors monitor.\"}}, {\"@type\": \"Question\", \"name\": \"What does it not detect?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"No VOCs, CO2 or gas-specific toxics like chlorine or ammonia. For VOC work use a PID; browse the Gas Detectors hub.\"}}, {\"@type\": \"Question\", \"name\": \"Who is the MicroClip XL for?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Crews that need full four-gas coverage per worker with datalogging and docking — utilities, oil and gas, and confined-space teams. For one hazard, a single-gas BW Clip is cheaper.\"}}, {\"@type\": \"Question\", \"name\": \"Is it in stock and how does it ship?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Use the Amazon buy button for live availability and delivery timing through our fulfillment partner.\"}}, {\"@type\": \"Question\", \"name\": \"Does it come with docking or calibration gas?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Docking stations and calibration gas are sold separately. Budget for IntelliDoX\/MicroDock and four-gas calibration gas for an automated program.\"}}]}, {\"@type\": \"Organization\", \"@id\": \"https:\/\/wcsafety.com\/#org\", \"name\": \"WC Safety\", \"url\": \"https:\/\/wcsafety.com\", \"logo\": \"https:\/\/wcsafety.com\/cdn\/shop\/files\/logo.png\"}, {\"@type\": \"Person\", \"@id\": \"https:\/\/wcsafety.com\/#editor\", \"name\": \"Steven Eaton\", \"jobTitle\": \"Editorial Lead\", \"worksFor\": {\"@id\": \"https:\/\/wcsafety.com\/#org\"}, \"knowsAbout\": [\"industrial gas detection\", \"atmospheric monitoring\", \"personal protective equipment\"]}, {\"@type\": \"Brand\", \"name\": \"Honeywell BW\"}]}\n\u003c\/script\u003e","brand":"Honeywell BW","offers":[{"title":"Default Title","offer_id":44266437279832,"sku":"B00N9SXUH0","price":538.89,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0594\/1900\/0920\/files\/61IxGevGldL._SL1091.jpg?v=1782121787"},{"product_id":"honeywell-bw-clip4-4-gas-detector","title":"Honeywell BW Clip4 4 Gas Detector — 2-Year Maintenance-Free (O2, LEL, CO, H2S)","description":"\u003c!-- PRODUCT B072MKBNL1 | tag personal-gas-detector | TODO: add matching Product Review + best-of guide links when those silo layers exist --\u003e\n\n\u003cdiv style=\"background:#1a1a1a;border-left:4px solid #ff9800;padding:14px 18px;margin:0 0 18px 0;color:#f5e6d3;font-size:0.95em;\"\u003e\n\u003cstrong style=\"color:#ffb74d;\"\u003eEditor’s note:\u003c\/strong\u003e the BW Clip4 4 gas detector is one of the instruments we curate in our \u003ca href=\"\/collections\/personal-gas-detectors\" title=\"Personal \u0026amp; Wearable Gas Detectors\"\u003ePersonal \u0026amp; Wearable Gas Detectors\u003c\/a\u003e buyer’s hub. Compare it with the \u003ca href=\"\/products\/honeywell-bw-clip-h2s-monitor-bwc2-h\" title=\"Honeywell BW Clip H2S\"\u003eHoneywell BW Clip H2S\u003c\/a\u003e below before you order.\u003c\/div\u003e\n\n\u003ch2 id=\"top\"\u003eHoneywell BW Clip4 4 Gas Detector — 2-Year Maintenance-Free Wearable\u003c\/h2\u003e\n\n\u003cp\u003eThe \u003cstrong\u003eBW Clip4 4 gas detector\u003c\/strong\u003e brings the BW Clip’s zero-maintenance philosophy to all four confined-space gases — a \u003ca href=\"\/collections\/personal-gas-detectors\" title=\"personal gas detector\"\u003epersonal gas detector\u003c\/a\u003e that runs two years with no charging, sensor swaps or docking. Issue it, use it, replace it at end of life.\u003c\/p\u003e\n\n\u003cp style=\"font-size:0.9em;color:#bdae9d;margin:10px 0 18px 0;\"\u003eJump to: \u003ca href=\"#features\" style=\"color:#ffb74d;\"\u003eFeatures\u003c\/a\u003e · \u003ca href=\"#specs\" style=\"color:#ffb74d;\"\u003eSpecs\u003c\/a\u003e · \u003ca href=\"#compatibility\" style=\"color:#ffb74d;\"\u003eWhat it detects\u003c\/a\u003e · \u003ca href=\"#comparison\" style=\"color:#ffb74d;\"\u003eComparison\u003c\/a\u003e · \u003ca href=\"#faq\" style=\"color:#ffb74d;\"\u003eFAQ\u003c\/a\u003e\u003c\/p\u003e\n\n\u003cp\u003eThe Honeywell BW Clip4 is a 2-year maintenance-free wearable four-gas detector (O2, LEL, CO, H2S) with hibernate mode and no charging, sensor replacement or docking required.\u003c\/p\u003e\n\n\u003ch3 id=\"features\"\u003eKey features\u003c\/h3\u003e\n\n\u003cul\u003e\n\u003cli\u003eReads all four confined-space gases — O2, LEL, CO and H2S — with zero maintenance\u003c\/li\u003e\n\u003cli\u003eRuns 2 years with no charging, no battery swaps and no sensor replacement\u003c\/li\u003e\n\u003cli\u003eHibernate mode pauses the clock between deployments to stretch the 2-year life\u003c\/li\u003e\n\u003cli\u003eAudible, visual and vibrating alarms\u003c\/li\u003e\n\u003cli\u003eCompact, rugged Lexan\/TPE wearable body\u003c\/li\u003e\n\u003cli\u003eThe simplest 4-gas program — issue it, use it, replace at end of life\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cdiv style=\"display:flex;gap:14px;flex-wrap:wrap;margin:18px 0;\"\u003e\n\u003cdiv style=\"flex:1;min-width:240px;background:#1b3a2a;border:1px solid #4caf50;border-radius:6px;padding:14px 18px;\"\u003e\n\u003cstrong style=\"color:#81c784;\"\u003ePros\u003c\/strong\u003e\u003cul style=\"margin:8px 0 0 0;\"\u003e\n\u003cli\u003e4-gas coverage with zero maintenance\u003c\/li\u003e\n\u003cli\u003eNo charging, sensor swaps or docking required\u003c\/li\u003e\n\u003cli\u003eHibernate mode extends usable life\u003c\/li\u003e\n\u003cli\u003eTriple alarm modes\u003c\/li\u003e\n\u003cli\u003eLowest lifetime admin of any 4-gas\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"flex:1;min-width:240px;background:#3a1e1e;border:1px solid #ef5350;border-radius:6px;padding:14px 18px;\"\u003e\n\u003cstrong style=\"color:#e57373;\"\u003eCons\u003c\/strong\u003e\u003cul style=\"margin:8px 0 0 0;\"\u003e\n\u003cli\u003eHighest upfront price of the wearables\u003c\/li\u003e\n\u003cli\u003eNot serviceable — replace at end of life\u003c\/li\u003e\n\u003cli\u003eDiffusion only (no pump)\u003c\/li\u003e\n\u003cli\u003eNo VOC\/PID coverage; limited datalogging vs MicroClip XL\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\n\u003ch3 id=\"specs\"\u003eSpecifications\u003c\/h3\u003e\n\n\u003cdiv style=\"overflow-x:auto;\"\u003e\u003ctable style=\"width:100%;border-collapse:collapse;background:#1a1a1a;margin:14px 0;\"\u003e\n\u003cthead\u003e\u003ctr style=\"background:#2a2a2a;\"\u003e\n\u003cth style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;text-align:left;\"\u003eSpecification\u003c\/th\u003e\n\u003cth style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;text-align:left;\"\u003eDetail\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eGases detected\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eO2, LEL combustibles, CO, H2S\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eService life\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003e2 years continuous, maintenance-free\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eForm factor\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eCompact wearable, clip-on (4.7\" x 2.7\" x 1.3\")\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003ePower\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eSealed — no charging\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eAlarms\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eAudible, visual \u0026amp; vibrating\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eSpecial feature\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eHibernate mode to extend deployment\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eSensors\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eElectrochemical (O2\/CO\/H2S) + catalytic bead (LEL)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eHousing\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eLexan\/TPE, rugged\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003c\/div\u003e\n\n\u003ch3\u003eWhere the Honeywell BW Clip4 fits\u003c\/h3\u003e\n\n\u003cul\u003e\n\u003cli\u003eIntermittent confined-space entry\u003c\/li\u003e\n\u003cli\u003eContractors who want zero upkeep\u003c\/li\u003e\n\u003cli\u003eFleet programs avoiding charging logistics\u003c\/li\u003e\n\u003cli\u003eRemote sites without docking infrastructure\u003c\/li\u003e\n\u003cli\u003eBackup 4-gas units kept ready in hibernate\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2 id=\"compatibility\"\u003eWhat the Honeywell BW Clip4 detects (and what it doesn’t)\u003c\/h2\u003e\n\n\u003cp\u003eIt monitors \u003cstrong\u003eO2, LEL combustibles, CO and H2S\u003c\/strong\u003e — not VOCs, CO2 or specific toxics. It is diffusion, so pre-entry sampling needs a \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"Portable Gas Detectors\"\u003ePortable Gas Detectors\u003c\/a\u003e pump instrument. Compared with the serviceable \u003ca href=\"\/products\/bw-gasalertmicroclip-xl-4-gas-detector\" title=\"GasAlertMicroClip XL\"\u003eGasAlertMicroClip XL\u003c\/a\u003e, the Clip4 trades datalogging depth and rechargeability for zero maintenance. For single-hazard wear, the \u003ca href=\"\/products\/honeywell-bw-clip-h2s-monitor-bwc2-h\" title=\"BW Clip\"\u003eBW Clip\u003c\/a\u003e single-gas family costs far less. Bump-test before use; hibernate it between jobs to preserve the 2-year clock.\u003c\/p\u003e\n\n\u003cp\u003eCross-shopping? This unit sits in our \u003ca href=\"\/collections\/personal-gas-detectors\" title=\"Personal \u0026amp; Wearable Gas Detectors\"\u003ePersonal \u0026amp; Wearable Gas Detectors\u003c\/a\u003e hub alongside \u003ca href=\"\/products\/honeywell-bw-clip-h2s-monitor-bwc2-h\" title=\"Honeywell BW Clip H2S\"\u003eHoneywell BW Clip H2S\u003c\/a\u003e, \u003ca href=\"\/products\/honeywell-bw-clip-co-monitor-bwc2-m\" title=\"Honeywell BW Clip CO\"\u003eHoneywell BW Clip CO\u003c\/a\u003e, \u003ca href=\"\/products\/honeywell-bw-clip-o2-monitor-bwc2-x\" title=\"Honeywell BW Clip O2\"\u003eHoneywell BW Clip O2\u003c\/a\u003e, \u003ca href=\"\/products\/toptes-ct-580-co-detector\" title=\"TopTes CT-580 CO\"\u003eTopTes CT-580 CO\u003c\/a\u003e. For other gas-detection form factors see \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"Portable Gas Detectors\"\u003ePortable Gas Detectors\u003c\/a\u003e, \u003ca href=\"\/collections\/fixed-gas-detection-systems\" title=\"Fixed Gas Detection Systems\"\u003eFixed Gas Detection Systems\u003c\/a\u003e, \u003ca href=\"\/collections\/area-gas-monitors\" title=\"Area \u0026amp; Transportable Gas Monitors\"\u003eArea \u0026amp; Transportable Gas Monitors\u003c\/a\u003e, or browse the full \u003ca href=\"\/collections\/gas-detectors\" title=\"Gas Detectors\"\u003eGas Detectors\u003c\/a\u003e range.\u003c\/p\u003e\n\n\u003ch2 id=\"comparison\"\u003eHoneywell BW wearable 4-gas family compared\u003c\/h2\u003e\n\n\u003cdiv style=\"overflow-x:auto;\"\u003e\u003ctable style=\"width:100%;border-collapse:collapse;background:#1a1a1a;margin:14px 0;\"\u003e\n\u003ccaption style=\"color:#bdae9d;font-size:0.85em;text-align:left;padding:4px 0;\"\u003eHoneywell BW wearable 4-gas family (O2, LEL, CO, H2S)\u003c\/caption\u003e\n\u003cthead\u003e\u003ctr style=\"background:#2a2a2a;\"\u003e\n\u003cth style=\"color:#ffb74d;padding:9px;border:1px solid #3a3a3a;text-align:left;\"\u003eModel\u003c\/th\u003e\n\u003cth style=\"color:#ffb74d;padding:9px;border:1px solid #3a3a3a;text-align:left;\"\u003eService model\u003c\/th\u003e\n\u003cth style=\"color:#ffb74d;padding:9px;border:1px solid #3a3a3a;text-align:left;\"\u003eBump\/cal docking\u003c\/th\u003e\n\u003cth style=\"color:#ffb74d;padding:9px;border:1px solid #3a3a3a;text-align:left;\"\u003eNotable\u003c\/th\u003e\n\u003cth style=\"color:#ffb74d;padding:9px;border:1px solid #3a3a3a;text-align:left;\"\u003eStreet price\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e\u003ca href=\"\/products\/bw-gasalertmicroclip-xl-4-gas-detector\" title=\"GasAlertMicroClip XL\"\u003eGasAlertMicroClip XL\u003c\/a\u003e\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eRechargeable, serviceable\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eIntelliDoX \/ MicroDock\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eDatalogging, motion alert\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e~$539\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#2a2520;\"\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e\u003cstrong\u003e\u003ca href=\"\/products\/honeywell-bw-clip4-4-gas-detector\" title=\"BW Clip4\"\u003eBW Clip4\u003c\/a\u003e\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e2-yr maintenance-free\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eOptional\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eSealed, hibernate mode\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e~$820\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003c\/div\u003e\n\n\u003cul\u003e\n\u003cli\u003eChoose the \u003cstrong\u003eBW Clip4\u003c\/strong\u003e for the lowest-upkeep 4-gas wearable — no charging, no sensor swaps for 2 years.\u003c\/li\u003e\n\u003cli\u003ePick the \u003ca href=\"\/products\/bw-gasalertmicroclip-xl-4-gas-detector\" title=\"GasAlertMicroClip XL\"\u003eGasAlertMicroClip XL\u003c\/a\u003e if you need datalogging, rechargeability and docking automation.\u003c\/li\u003e\n\u003cli\u003eOnly one hazard? A single-gas \u003ca href=\"\/products\/honeywell-bw-clip-co-monitor-bwc2-m\" title=\"BW Clip\"\u003eBW Clip\u003c\/a\u003e is far cheaper per worker.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2 id=\"faq\"\u003eFrequently asked questions\u003c\/h2\u003e\n\n\u003ch3\u003eWhat gases does the BW Clip4 detect?\u003c\/h3\u003e\u003cp\u003eO2, LEL combustibles, CO and H2S — the confined-space four-gas set, with no VOC or CO2 coverage (use a PID for those; see the \u003ca href=\"\/collections\/gas-detectors\" title=\"Gas Detectors\"\u003eGas Detectors\u003c\/a\u003e hub).\u003c\/p\u003e\n\u003ch3\u003eHow long does the BW Clip4 last?\u003c\/h3\u003e\u003cp\u003eTwo years of continuous use with no charging, no battery swaps and no sensor replacement. Hibernate mode pauses the clock between deployments to extend usable life.\u003c\/p\u003e\n\u003ch3\u003eHow is the Clip4 different from the GasAlertMicroClip XL?\u003c\/h3\u003e\u003cp\u003eThe Clip4 is sealed and 2-year maintenance-free; the \u003ca href=\"\/products\/bw-gasalertmicroclip-xl-4-gas-detector\" title=\"MicroClip XL\"\u003eMicroClip XL\u003c\/a\u003e is rechargeable and serviceable with deeper datalogging and docking automation.\u003c\/p\u003e\n\u003ch3\u003eDo I need to charge the BW Clip4?\u003c\/h3\u003e\u003cp\u003eNo — it is sealed with no charging required for its full 2-year life, which removes charging logistics from your program.\u003c\/p\u003e\n\u003ch3\u003eWhat is hibernate mode?\u003c\/h3\u003e\u003cp\u003eHibernate pauses the 2-year service clock when the unit is not in use, so intermittent users get more usable life from the sealed battery.\u003c\/p\u003e\n\u003ch3\u003eDo I still bump-test the Clip4?\u003c\/h3\u003e\u003cp\u003eYes — bump-test before use to confirm sensors and alarms respond, even though no sensor or battery service is needed.\u003c\/p\u003e\n\u003ch3\u003eIs it good for confined-space entry?\u003c\/h3\u003e\u003cp\u003eYes for personal monitoring. Pre-entry sampling of a sealed space still needs a \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"Portable Gas Detectors\"\u003ePortable Gas Detectors\u003c\/a\u003e pump instrument.\u003c\/p\u003e\n\u003ch3\u003eDoes it have a pump?\u003c\/h3\u003e\u003cp\u003eNo — it is diffusion. For remote sample-draw, use a pump-equipped \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"Portable Gas Detectors\"\u003ePortable Gas Detectors\u003c\/a\u003e monitor.\u003c\/p\u003e\n\u003ch3\u003eWhat alarms does it have?\u003c\/h3\u003e\u003cp\u003eAudible, visual and vibrating alarms trigger when any of the four gases exceeds its set point.\u003c\/p\u003e\n\u003ch3\u003eWhat does it not detect?\u003c\/h3\u003e\u003cp\u003eVOCs, CO2 and specific toxics like chlorine or ammonia are outside its range; use a PID or dedicated sensor for those.\u003c\/p\u003e\n\u003ch3\u003eIs it in stock and how does it ship?\u003c\/h3\u003e\u003cp\u003eUse the Amazon buy button for live availability and delivery timing through our fulfillment partner.\u003c\/p\u003e\n\u003ch3\u003eWho should buy the BW Clip4 over a single-gas clip?\u003c\/h3\u003e\u003cp\u003eWorkers facing several gases who want zero upkeep. If only one hazard applies, a single-gas \u003ca href=\"\/products\/honeywell-bw-clip-h2s-monitor-bwc2-h\" title=\"BW Clip\"\u003eBW Clip\u003c\/a\u003e is more economical per worker.\u003c\/p\u003e\n\n\u003cdiv style=\"background:#1a1a1a;border:1px solid #3a3a3a;border-radius:6px;padding:16px 18px;margin:22px 0;\"\u003e\n\u003cp style=\"margin:0 0 10px 0;color:#f5e6d3;\"\u003eReady to order the \u003cstrong\u003eBW Clip4 4 gas detector\u003c\/strong\u003e? Add it to your cart above, or check the current Amazon price below. Compare it against the rest of our \u003ca href=\"\/collections\/personal-gas-detectors\" title=\"Personal \u0026amp; Wearable Gas Detectors\"\u003ePersonal \u0026amp; Wearable Gas Detectors\u003c\/a\u003e lineup before you buy.\u003c\/p\u003e\n\u003cp style=\"display:flex;gap:10px;flex-wrap:wrap;align-items:center;margin:0;\"\u003e\u003ca href=\"https:\/\/www.amazon.com\/dp\/B072MKBNL1?tag=wcsafety04-20\" rel=\"sponsored nofollow noopener\" target=\"_blank\" style=\"display:inline-block;background:#FFD814;color:#0F1111;padding:13px 26px;text-decoration:none;font-weight:bold;border-radius:4px;border:1px solid #FCD200;\"\u003eCHECK PRICE ON AMAZON →\u003c\/a\u003e\u003cspan style=\"font-size:0.8em;color:#bdae9d;\"\u003eAs an Amazon Associate, WC Safety earns from qualifying purchases.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/div\u003e\n\n\u003cdiv style=\"background:#1a2733;border:1px dashed #4fc3f7;padding:16px 20px;margin:30px 0 18px 0;color:#cfd8dc;font-size:0.92em;\"\u003e\n  \u003cstrong style=\"color:#4fc3f7;\"\u003eWhy trust this Honeywell BW page?\u003c\/strong\u003e WC Safety is an independent industrial safety-equipment retailer serving safety managers, procurement teams and field supervisors. The specifications here are taken from the manufacturer’s published listing for Honeywell BW Clip4 and framed against \u003ca href=\"https:\/\/www.osha.gov\/laws-regs\/regulations\/standardnumber\/1910\/1910.146\" rel=\"noopener\" target=\"_blank\" style=\"color:#4fc3f7;\"\u003eOSHA 29 CFR 1910.146\u003c\/a\u003e and \u003ca href=\"https:\/\/www.osha.gov\/annotated-pels\" rel=\"noopener\" target=\"_blank\" style=\"color:#4fc3f7;\"\u003eOSHA Permissible Exposure Limits\u003c\/a\u003e. Disclosed: WC Safety earns Amazon affiliate commissions on outbound clicks; that does not influence the specs shown or our lineup.\n\u003c\/div\u003e\n\u003cdiv style=\"background:#1a2733;border-left:4px solid #4fc3f7;padding:18px 22px;margin:18px 0;color:#cfd8dc;font-size:0.92em;\"\u003e\n  \u003cstrong style=\"color:#4fc3f7;\"\u003eBy Steven Eaton, WC Safety Editorial\u003c\/strong\u003e — Industrial safety-equipment desk · specialization: atmospheric monitoring, gas detection and instrument selection.\u003cbr\u003e\n  \u003cstrong\u003eLast updated:\u003c\/strong\u003e \u003ctime datetime=\"2026-06-22\"\u003eJune 22, 2026\u003c\/time\u003e · \u003cstrong\u003eSources reviewed:\u003c\/strong\u003e manufacturer product listing \u0026amp; specifications, OSHA 29 CFR 1910.146, OSHA Annotated PEL tables, ACGIH Threshold Limit Values.\u003cbr\u003e\n  \u003cstrong\u003eEditorial standard:\u003c\/strong\u003e \u003cem\u003eZero sponsored listings. No manufacturer input. Specs verified against the manufacturer’s published data.\u003c\/em\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"background:#1a2733;border-left:4px solid #4fc3f7;padding:16px 20px;margin:18px 0;color:#cfd8dc;font-size:0.92em;\"\u003e\n  \u003cstrong style=\"color:#4fc3f7;\"\u003eHow this page is maintained.\u003c\/strong\u003e Specifications and pricing are reviewed against the manufacturer’s current listing and re-checked whenever the lineup changes. Gas-detection guidance follows \u003ca href=\"https:\/\/www.osha.gov\/laws-regs\/regulations\/standardnumber\/1910\/1910.146\" rel=\"noopener\" target=\"_blank\" style=\"color:#4fc3f7;\"\u003eOSHA 1910.146\u003c\/a\u003e and \u003ca href=\"https:\/\/www.osha.gov\/annotated-pels\" rel=\"noopener\" target=\"_blank\" style=\"color:#4fc3f7;\"\u003eOSHA PELs\u003c\/a\u003e, cross-referenced with ACGIH TLVs.\n\u003c\/div\u003e\n\u003cdiv style=\"background:#2a2520;border-left:4px solid #ff9800;padding:16px 20px;margin:18px 0;color:#f5e6d3;font-size:0.92em;\"\u003e\n  \u003cstrong style=\"color:#ffb74d;\"\u003eDisclosure.\u003c\/strong\u003e WC Safety participates in the Amazon Associates Program and earns commissions on qualifying purchases through outbound links on this page (tag wcsafety04-20). We are not sponsored by any instrument manufacturer. This page is buyer guidance, not medical, legal or regulatory advice — confirm gas-detection requirements for your site against the applicable OSHA standard and, for commercial monitoring programs, a Certified Industrial Hygienist (CIH).\n\u003c\/div\u003e\n\n\u003cscript type=\"application\/ld+json\"\u003e\n{\"@context\": \"https:\/\/schema.org\", \"@graph\": [{\"@type\": \"Product\", \"@id\": \"https:\/\/wcsafety.com\/products\/honeywell-bw-clip4-4-gas-detector#product\", \"name\": \"Honeywell BW Clip4 4 Gas Detector — 2-Year Maintenance-Free (O2, LEL, CO, H2S)\", \"description\": \"BW Clip4 4 gas detector — 2-year maintenance-free wearable O2, LEL, CO \u0026 H2S monitor, no charging or sensor swaps. Order this Honeywell BW unit at WC Safety.\", \"sku\": \"B072MKBNL1\", \"mpn\": \"BWC4-Y-N\", \"image\": [\"https:\/\/wcsafety.com\/cdn\/shop\/products\/honeywell-bw-clip4-4-gas-detector.jpg\"], \"brand\": {\"@type\": \"Brand\", \"name\": \"Honeywell BW\"}, \"category\": \"Personal Gas Detector\", \"isPartOf\": {\"@type\": \"CollectionPage\", \"@id\": \"https:\/\/wcsafety.com\/collections\/personal-gas-detectors#collection\", \"name\": \"Personal \u0026 Wearable Gas Detectors\", \"url\": \"https:\/\/wcsafety.com\/collections\/personal-gas-detectors\"}, \"isRelatedTo\": [{\"@type\": \"Product\", \"name\": \"Honeywell BW Clip H2S Monitor (BWC2-H)\", \"url\": \"https:\/\/wcsafety.com\/products\/honeywell-bw-clip-h2s-monitor-bwc2-h\"}, {\"@type\": \"Product\", \"name\": \"Honeywell BW Clip CO Monitor (BWC2-M)\", \"url\": \"https:\/\/wcsafety.com\/products\/honeywell-bw-clip-co-monitor-bwc2-m\"}, {\"@type\": \"Product\", \"name\": \"Honeywell BW Clip O2 Monitor (BWC2-X)\", \"url\": \"https:\/\/wcsafety.com\/products\/honeywell-bw-clip-o2-monitor-bwc2-x\"}, {\"@type\": \"Product\", \"name\": \"TopTes CT-580 CO Detector\", \"url\": \"https:\/\/wcsafety.com\/products\/toptes-ct-580-co-detector\"}, {\"@type\": \"Product\", \"name\": \"BW GasAlertMicroClip XL 4 Gas Detector\", \"url\": \"https:\/\/wcsafety.com\/products\/bw-gasalertmicroclip-xl-4-gas-detector\"}, {\"@type\": \"Product\", \"name\": \"RKI GX3R 4 Gas Monitor\", \"url\": \"https:\/\/wcsafety.com\/products\/rki-gx3r-4-gas-monitor\"}], \"offers\": {\"@type\": \"Offer\", \"url\": \"https:\/\/wcsafety.com\/products\/honeywell-bw-clip4-4-gas-detector\", \"priceCurrency\": \"USD\", \"price\": \"819.88\", \"availability\": \"https:\/\/schema.org\/InStock\", \"seller\": {\"@type\": \"Organization\", \"name\": \"WC Safety\"}}}, {\"@type\": \"BreadcrumbList\", \"@id\": \"https:\/\/wcsafety.com\/products\/honeywell-bw-clip4-4-gas-detector#breadcrumb\", \"itemListElement\": [{\"@type\": \"ListItem\", \"position\": 1, \"name\": \"Home\", \"item\": \"https:\/\/wcsafety.com\/\"}, {\"@type\": \"ListItem\", \"position\": 2, \"name\": \"Gas Detectors\", \"item\": \"https:\/\/wcsafety.com\/collections\/gas-detectors\"}, {\"@type\": \"ListItem\", \"position\": 3, \"name\": \"Personal \u0026 Wearable Gas Detectors\", \"item\": \"https:\/\/wcsafety.com\/collections\/personal-gas-detectors\"}, {\"@type\": \"ListItem\", \"position\": 4, \"name\": \"Honeywell BW Clip4 4 Gas Detector — 2-Year Maintenance-Free (O2, LEL, CO, H2S)\"}]}, {\"@type\": \"FAQPage\", \"mainEntity\": [{\"@type\": \"Question\", \"name\": \"What gases does the BW Clip4 detect?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"O2, LEL combustibles, CO and H2S — the confined-space four-gas set, with no VOC or CO2 coverage (use a PID for those; see the Gas Detectors hub).\"}}, {\"@type\": \"Question\", \"name\": \"How long does the BW Clip4 last?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Two years of continuous use with no charging, no battery swaps and no sensor replacement. Hibernate mode pauses the clock between deployments to extend usable life.\"}}, {\"@type\": \"Question\", \"name\": \"How is the Clip4 different from the GasAlertMicroClip XL?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"The Clip4 is sealed and 2-year maintenance-free; the MicroClip XL is rechargeable and serviceable with deeper datalogging and docking automation.\"}}, {\"@type\": \"Question\", \"name\": \"Do I need to charge the BW Clip4?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"No — it is sealed with no charging required for its full 2-year life, which removes charging logistics from your program.\"}}, {\"@type\": \"Question\", \"name\": \"What is hibernate mode?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Hibernate pauses the 2-year service clock when the unit is not in use, so intermittent users get more usable life from the sealed battery.\"}}, {\"@type\": \"Question\", \"name\": \"Do I still bump-test the Clip4?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Yes — bump-test before use to confirm sensors and alarms respond, even though no sensor or battery service is needed.\"}}, {\"@type\": \"Question\", \"name\": \"Is it good for confined-space entry?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Yes for personal monitoring. Pre-entry sampling of a sealed space still needs a Portable Gas Detectors pump instrument.\"}}, {\"@type\": \"Question\", \"name\": \"Does it have a pump?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"No — it is diffusion. For remote sample-draw, use a pump-equipped Portable Gas Detectors monitor.\"}}, {\"@type\": \"Question\", \"name\": \"What alarms does it have?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Audible, visual and vibrating alarms trigger when any of the four gases exceeds its set point.\"}}, {\"@type\": \"Question\", \"name\": \"What does it not detect?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"VOCs, CO2 and specific toxics like chlorine or ammonia are outside its range; use a PID or dedicated sensor for those.\"}}, {\"@type\": \"Question\", \"name\": \"Is it in stock and how does it ship?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Use the Amazon buy button for live availability and delivery timing through our fulfillment partner.\"}}, {\"@type\": \"Question\", \"name\": \"Who should buy the BW Clip4 over a single-gas clip?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Workers facing several gases who want zero upkeep. If only one hazard applies, a single-gas BW Clip is more economical per worker.\"}}]}, {\"@type\": \"Organization\", \"@id\": \"https:\/\/wcsafety.com\/#org\", \"name\": \"WC Safety\", \"url\": \"https:\/\/wcsafety.com\", \"logo\": \"https:\/\/wcsafety.com\/cdn\/shop\/files\/logo.png\"}, {\"@type\": \"Person\", \"@id\": \"https:\/\/wcsafety.com\/#editor\", \"name\": \"Steven Eaton\", \"jobTitle\": \"Editorial Lead\", \"worksFor\": {\"@id\": \"https:\/\/wcsafety.com\/#org\"}, \"knowsAbout\": [\"industrial gas detection\", \"atmospheric monitoring\", \"personal protective equipment\"]}, {\"@type\": \"Brand\", \"name\": \"Honeywell BW\"}]}\n\u003c\/script\u003e","brand":"Honeywell BW","offers":[{"title":"Default Title","offer_id":44266437509208,"sku":"B072MKBNL1","price":819.88,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0594\/1900\/0920\/files\/612pPffRltL._SL1200.jpg?v=1782121790"},{"product_id":"rki-gx3r-4-gas-monitor","title":"RKI GX3R 4 Gas Monitor — LEL, O2, H2S, CO (Factory Calibrated)","description":"\u003c!-- PRODUCT B0FP5TCPHS | tag personal-gas-detector | TODO: add matching Product Review + best-of guide links when those silo layers exist --\u003e\n\n\u003cdiv style=\"background:#1a1a1a;border-left:4px solid #ff9800;padding:14px 18px;margin:0 0 18px 0;color:#f5e6d3;font-size:0.95em;\"\u003e\n\u003cstrong style=\"color:#ffb74d;\"\u003eEditor’s note:\u003c\/strong\u003e the RKI GX3R 4 gas monitor is one of the instruments we curate in our \u003ca href=\"\/collections\/personal-gas-detectors\" title=\"Personal \u0026amp; Wearable Gas Detectors\"\u003ePersonal \u0026amp; Wearable Gas Detectors\u003c\/a\u003e buyer’s hub. Compare it with the \u003ca href=\"\/products\/honeywell-bw-clip-h2s-monitor-bwc2-h\" title=\"Honeywell BW Clip H2S\"\u003eHoneywell BW Clip H2S\u003c\/a\u003e below before you order.\u003c\/div\u003e\n\n\u003ch2 id=\"top\"\u003eRKI GX3R 4 Gas Monitor — Compact Wearable LEL, O2, H2S \u0026amp; CO\u003c\/h2\u003e\n\n\u003cp\u003eThe \u003cstrong\u003eRKI GX3R 4 gas monitor\u003c\/strong\u003e is one of the smallest wearable four-gas instruments available — a \u003ca href=\"\/collections\/personal-gas-detectors\" title=\"personal gas detector\"\u003epersonal gas detector\u003c\/a\u003e reading LEL, O2, H2S and CO that ships factory-calibrated with a certificate, for workers who want full coverage in the lightest possible body.\u003c\/p\u003e\n\n\u003cp style=\"font-size:0.9em;color:#bdae9d;margin:10px 0 18px 0;\"\u003eJump to: \u003ca href=\"#features\" style=\"color:#ffb74d;\"\u003eFeatures\u003c\/a\u003e · \u003ca href=\"#specs\" style=\"color:#ffb74d;\"\u003eSpecs\u003c\/a\u003e · \u003ca href=\"#compatibility\" style=\"color:#ffb74d;\"\u003eWhat it detects\u003c\/a\u003e · \u003ca href=\"#comparison\" style=\"color:#ffb74d;\"\u003eComparison\u003c\/a\u003e · \u003ca href=\"#faq\" style=\"color:#ffb74d;\"\u003eFAQ\u003c\/a\u003e\u003c\/p\u003e\n\n\u003cp\u003eThe RKI GX3R is a compact, rechargeable wearable four-gas monitor (LEL, O2, H2S, CO) that ships factory-calibrated with a calibration certificate and includes datalogging.\u003c\/p\u003e\n\n\u003ch3 id=\"features\"\u003eKey features\u003c\/h3\u003e\n\n\u003cul\u003e\n\u003cli\u003eCompact, lightweight wearable reading LEL, O2, H2S and CO — one of the smallest 4-gas monitors\u003c\/li\u003e\n\u003cli\u003eShips factory-calibrated with a calibration certificate\u003c\/li\u003e\n\u003cli\u003eRechargeable Li-ion battery for full-shift use\u003c\/li\u003e\n\u003cli\u003eVisual, audible and vibration alarms\u003c\/li\u003e\n\u003cli\u003eIncludes a carry bag and certificate out of the box\u003c\/li\u003e\n\u003cli\u003eRKI Instruments build with warranty support\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cdiv style=\"display:flex;gap:14px;flex-wrap:wrap;margin:18px 0;\"\u003e\n\u003cdiv style=\"flex:1;min-width:240px;background:#1b3a2a;border:1px solid #4caf50;border-radius:6px;padding:14px 18px;\"\u003e\n\u003cstrong style=\"color:#81c784;\"\u003ePros\u003c\/strong\u003e\u003cul style=\"margin:8px 0 0 0;\"\u003e\n\u003cli\u003eVery compact and light for all-day wear\u003c\/li\u003e\n\u003cli\u003eFactory-calibrated with certificate included\u003c\/li\u003e\n\u003cli\u003eRechargeable Li-ion\u003c\/li\u003e\n\u003cli\u003eTriple alarm modes\u003c\/li\u003e\n\u003cli\u003eDatalogging for records\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"flex:1;min-width:240px;background:#3a1e1e;border:1px solid #ef5350;border-radius:6px;padding:14px 18px;\"\u003e\n\u003cstrong style=\"color:#e57373;\"\u003eCons\u003c\/strong\u003e\u003cul style=\"margin:8px 0 0 0;\"\u003e\n\u003cli\u003ePremium price\u003c\/li\u003e\n\u003cli\u003eNewer listing with limited public review history\u003c\/li\u003e\n\u003cli\u003eDiffusion only (no pump)\u003c\/li\u003e\n\u003cli\u003eNo VOC\/PID coverage\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\n\u003ch3 id=\"specs\"\u003eSpecifications\u003c\/h3\u003e\n\n\u003cdiv style=\"overflow-x:auto;\"\u003e\u003ctable style=\"width:100%;border-collapse:collapse;background:#1a1a1a;margin:14px 0;\"\u003e\n\u003cthead\u003e\u003ctr style=\"background:#2a2a2a;\"\u003e\n\u003cth style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;text-align:left;\"\u003eSpecification\u003c\/th\u003e\n\u003cth style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;text-align:left;\"\u003eDetail\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eGases detected\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eLEL combustibles, O2, H2S, CO\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eForm factor\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eCompact wearable (one of the smallest 4-gas)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003ePower\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eRechargeable Li-ion\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eAlarms\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eVisual, audible \u0026amp; vibration\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eCalibration\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eFactory-calibrated; calibration certificate included\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eIncluded\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eCarry bag \u0026amp; certificate\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eSensors\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eCatalytic LEL + electrochemical O2\/H2S\/CO\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eDatalogging\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eYes\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003c\/div\u003e\n\n\u003ch3\u003eWhere the RKI GX3R fits\u003c\/h3\u003e\n\n\u003cul\u003e\n\u003cli\u003eConfined-space entry\u003c\/li\u003e\n\u003cli\u003eUtilities and field service\u003c\/li\u003e\n\u003cli\u003eOil-and-gas spot monitoring\u003c\/li\u003e\n\u003cli\u003eIndustrial maintenance\u003c\/li\u003e\n\u003cli\u003eCrews wanting the smallest wearable 4-gas\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2 id=\"compatibility\"\u003eWhat the RKI GX3R detects (and what it doesn’t)\u003c\/h2\u003e\n\n\u003cp\u003eIt detects \u003cstrong\u003eLEL combustibles, O2, H2S and CO\u003c\/strong\u003e — the confined-space set. It does not read VOCs, CO2 or specific toxics; those need a PID or dedicated sensor. It is diffusion, so pre-entry sampling needs a \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"Portable Gas Detectors\"\u003ePortable Gas Detectors\u003c\/a\u003e pump instrument. Among wearables, compare it with the serviceable \u003ca href=\"\/products\/bw-gasalertmicroclip-xl-4-gas-detector\" title=\"BW GasAlertMicroClip XL\"\u003eBW GasAlertMicroClip XL\u003c\/a\u003e and the sealed \u003ca href=\"\/products\/honeywell-bw-clip4-4-gas-detector\" title=\"BW Clip4\"\u003eBW Clip4\u003c\/a\u003e. It ships factory-calibrated; bump-test before use and recalibrate on schedule.\u003c\/p\u003e\n\n\u003cp\u003eCross-shopping? This unit sits in our \u003ca href=\"\/collections\/personal-gas-detectors\" title=\"Personal \u0026amp; Wearable Gas Detectors\"\u003ePersonal \u0026amp; Wearable Gas Detectors\u003c\/a\u003e hub alongside \u003ca href=\"\/products\/honeywell-bw-clip-h2s-monitor-bwc2-h\" title=\"Honeywell BW Clip H2S\"\u003eHoneywell BW Clip H2S\u003c\/a\u003e, \u003ca href=\"\/products\/honeywell-bw-clip-co-monitor-bwc2-m\" title=\"Honeywell BW Clip CO\"\u003eHoneywell BW Clip CO\u003c\/a\u003e, \u003ca href=\"\/products\/honeywell-bw-clip-o2-monitor-bwc2-x\" title=\"Honeywell BW Clip O2\"\u003eHoneywell BW Clip O2\u003c\/a\u003e, \u003ca href=\"\/products\/toptes-ct-580-co-detector\" title=\"TopTes CT-580 CO\"\u003eTopTes CT-580 CO\u003c\/a\u003e. For other gas-detection form factors see \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"Portable Gas Detectors\"\u003ePortable Gas Detectors\u003c\/a\u003e, \u003ca href=\"\/collections\/fixed-gas-detection-systems\" title=\"Fixed Gas Detection Systems\"\u003eFixed Gas Detection Systems\u003c\/a\u003e, \u003ca href=\"\/collections\/area-gas-monitors\" title=\"Area \u0026amp; Transportable Gas Monitors\"\u003eArea \u0026amp; Transportable Gas Monitors\u003c\/a\u003e, or browse the full \u003ca href=\"\/collections\/gas-detectors\" title=\"Gas Detectors\"\u003eGas Detectors\u003c\/a\u003e range.\u003c\/p\u003e\n\n\u003ch2 id=\"comparison\"\u003eWhere the RKI GX3R fits among wearable 4-gas monitors\u003c\/h2\u003e\n\n\u003cp\u003eThe GX3R is RKI’s ultra-compact wearable four-gas, shipped factory-calibrated with a certificate. Against the Honeywell BW wearables, it emphasises small size; the \u003ca href=\"\/products\/bw-gasalertmicroclip-xl-4-gas-detector\" title=\"GasAlertMicroClip XL\"\u003eGasAlertMicroClip XL\u003c\/a\u003e emphasises datalogging and docking automation, while the \u003ca href=\"\/products\/honeywell-bw-clip4-4-gas-detector\" title=\"BW Clip4\"\u003eBW Clip4\u003c\/a\u003e is sealed and 2-year maintenance-free.\u003c\/p\u003e\n\n\u003cul\u003e\n\u003cli\u003eChoose the \u003cstrong\u003eRKI GX3R\u003c\/strong\u003e for the smallest, lightest wearable 4-gas with a calibration certificate in the box.\u003c\/li\u003e\n\u003cli\u003ePick the \u003ca href=\"\/products\/bw-gasalertmicroclip-xl-4-gas-detector\" title=\"GasAlertMicroClip XL\"\u003eGasAlertMicroClip XL\u003c\/a\u003e for datalogging and docking automation.\u003c\/li\u003e\n\u003cli\u003ePick the \u003ca href=\"\/products\/honeywell-bw-clip4-4-gas-detector\" title=\"BW Clip4\"\u003eBW Clip4\u003c\/a\u003e for sealed 2-year zero-maintenance operation.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2 id=\"faq\"\u003eFrequently asked questions\u003c\/h2\u003e\n\n\u003ch3\u003eWhat gases does the RKI GX3R detect?\u003c\/h3\u003e\u003cp\u003eLEL combustibles, O2, H2S and CO — the confined-space four-gas set. For VOCs you need a PID; see the \u003ca href=\"\/collections\/gas-detectors\" title=\"Gas Detectors\"\u003eGas Detectors\u003c\/a\u003e range.\u003c\/p\u003e\n\u003ch3\u003eDoes the GX3R come calibrated?\u003c\/h3\u003e\u003cp\u003eYes — it ships factory-calibrated with a calibration certificate, plus a carry bag. Bump-test before use and recalibrate on schedule.\u003c\/p\u003e\n\u003ch3\u003eWhy choose the GX3R over other wearables?\u003c\/h3\u003e\u003cp\u003eSize — it is one of the smallest and lightest four-gas monitors, which makes all-day wear more comfortable while still covering all four gases.\u003c\/p\u003e\n\u003ch3\u003eIs the RKI GX3R rechargeable?\u003c\/h3\u003e\u003cp\u003eYes — it uses a rechargeable Li-ion battery sized for full-shift use; recharge between shifts.\u003c\/p\u003e\n\u003ch3\u003eHow does it compare to the BW GasAlertMicroClip XL?\u003c\/h3\u003e\u003cp\u003eBoth are serviceable rechargeable 4-gas wearables; the GX3R is smaller, while the \u003ca href=\"\/products\/bw-gasalertmicroclip-xl-4-gas-detector\" title=\"MicroClip XL\"\u003eMicroClip XL\u003c\/a\u003e is a longer-established platform with broad docking support.\u003c\/p\u003e\n\u003ch3\u003eIs it good for confined-space entry?\u003c\/h3\u003e\u003cp\u003eYes for personal monitoring. Pre-entry sampling of a sealed space still requires a \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"Portable Gas Detectors\"\u003ePortable Gas Detectors\u003c\/a\u003e pump instrument.\u003c\/p\u003e\n\u003ch3\u003eDoes it log data?\u003c\/h3\u003e\u003cp\u003eYes — it includes datalogging for compliance records, downloadable per RKI's software\/dock.\u003c\/p\u003e\n\u003ch3\u003eDoes it have a pump?\u003c\/h3\u003e\u003cp\u003eThis is the diffusion model. For remote sample-draw before entry, use a pump-equipped \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"Portable Gas Detectors\"\u003ePortable Gas Detectors\u003c\/a\u003e monitor.\u003c\/p\u003e\n\u003ch3\u003eWhat alarms does it have?\u003c\/h3\u003e\u003cp\u003eVisual, audible and vibration alarms trigger when any of the four gases exceeds its set point.\u003c\/p\u003e\n\u003ch3\u003eWhat does it not detect?\u003c\/h3\u003e\u003cp\u003eVOCs, CO2 and specific toxics like chlorine or ammonia are outside its range; use a PID or dedicated sensor for those.\u003c\/p\u003e\n\u003ch3\u003eIs it in stock and how does it ship?\u003c\/h3\u003e\u003cp\u003eUse the Amazon buy button for live availability and delivery timing through our fulfillment partner.\u003c\/p\u003e\n\u003ch3\u003eDoes it include a warranty?\u003c\/h3\u003e\u003cp\u003eThe listing notes factory calibration and warranty support from RKI; confirm current warranty terms with the manufacturer for your purchase.\u003c\/p\u003e\n\n\u003cdiv style=\"background:#1a1a1a;border:1px solid #3a3a3a;border-radius:6px;padding:16px 18px;margin:22px 0;\"\u003e\n\u003cp style=\"margin:0 0 10px 0;color:#f5e6d3;\"\u003eReady to order the \u003cstrong\u003eRKI GX3R 4 gas monitor\u003c\/strong\u003e? Add it to your cart above, or check the current Amazon price below. Compare it against the rest of our \u003ca href=\"\/collections\/personal-gas-detectors\" title=\"Personal \u0026amp; Wearable Gas Detectors\"\u003ePersonal \u0026amp; Wearable Gas Detectors\u003c\/a\u003e lineup before you buy.\u003c\/p\u003e\n\u003cp style=\"display:flex;gap:10px;flex-wrap:wrap;align-items:center;margin:0;\"\u003e\u003ca href=\"https:\/\/www.amazon.com\/dp\/B0FP5TCPHS?tag=wcsafety04-20\" rel=\"sponsored nofollow noopener\" target=\"_blank\" style=\"display:inline-block;background:#FFD814;color:#0F1111;padding:13px 26px;text-decoration:none;font-weight:bold;border-radius:4px;border:1px solid #FCD200;\"\u003eCHECK PRICE ON AMAZON →\u003c\/a\u003e\u003cspan style=\"font-size:0.8em;color:#bdae9d;\"\u003eAs an Amazon Associate, WC Safety earns from qualifying purchases.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/div\u003e\n\n\u003cdiv style=\"background:#1a2733;border:1px dashed #4fc3f7;padding:16px 20px;margin:30px 0 18px 0;color:#cfd8dc;font-size:0.92em;\"\u003e\n  \u003cstrong style=\"color:#4fc3f7;\"\u003eWhy trust this RKI Instruments page?\u003c\/strong\u003e WC Safety is an independent industrial safety-equipment retailer serving safety managers, procurement teams and field supervisors. The specifications here are taken from the manufacturer’s published listing for RKI GX3R and framed against \u003ca href=\"https:\/\/www.osha.gov\/laws-regs\/regulations\/standardnumber\/1910\/1910.146\" rel=\"noopener\" target=\"_blank\" style=\"color:#4fc3f7;\"\u003eOSHA 29 CFR 1910.146\u003c\/a\u003e and \u003ca href=\"https:\/\/www.osha.gov\/annotated-pels\" rel=\"noopener\" target=\"_blank\" style=\"color:#4fc3f7;\"\u003eOSHA Permissible Exposure Limits\u003c\/a\u003e. Disclosed: WC Safety earns Amazon affiliate commissions on outbound clicks; that does not influence the specs shown or our lineup.\n\u003c\/div\u003e\n\u003cdiv style=\"background:#1a2733;border-left:4px solid #4fc3f7;padding:18px 22px;margin:18px 0;color:#cfd8dc;font-size:0.92em;\"\u003e\n  \u003cstrong style=\"color:#4fc3f7;\"\u003eBy Steven Eaton, WC Safety Editorial\u003c\/strong\u003e — Industrial safety-equipment desk · specialization: atmospheric monitoring, gas detection and instrument selection.\u003cbr\u003e\n  \u003cstrong\u003eLast updated:\u003c\/strong\u003e \u003ctime datetime=\"2026-06-22\"\u003eJune 22, 2026\u003c\/time\u003e · \u003cstrong\u003eSources reviewed:\u003c\/strong\u003e manufacturer product listing \u0026amp; specifications, OSHA 29 CFR 1910.146, OSHA Annotated PEL tables, ACGIH Threshold Limit Values.\u003cbr\u003e\n  \u003cstrong\u003eEditorial standard:\u003c\/strong\u003e \u003cem\u003eZero sponsored listings. No manufacturer input. Specs verified against the manufacturer’s published data.\u003c\/em\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"background:#1a2733;border-left:4px solid #4fc3f7;padding:16px 20px;margin:18px 0;color:#cfd8dc;font-size:0.92em;\"\u003e\n  \u003cstrong style=\"color:#4fc3f7;\"\u003eHow this page is maintained.\u003c\/strong\u003e Specifications and pricing are reviewed against the manufacturer’s current listing and re-checked whenever the lineup changes. Gas-detection guidance follows \u003ca href=\"https:\/\/www.osha.gov\/laws-regs\/regulations\/standardnumber\/1910\/1910.146\" rel=\"noopener\" target=\"_blank\" style=\"color:#4fc3f7;\"\u003eOSHA 1910.146\u003c\/a\u003e and \u003ca href=\"https:\/\/www.osha.gov\/annotated-pels\" rel=\"noopener\" target=\"_blank\" style=\"color:#4fc3f7;\"\u003eOSHA PELs\u003c\/a\u003e, cross-referenced with ACGIH TLVs.\n\u003c\/div\u003e\n\u003cdiv style=\"background:#2a2520;border-left:4px solid #ff9800;padding:16px 20px;margin:18px 0;color:#f5e6d3;font-size:0.92em;\"\u003e\n  \u003cstrong style=\"color:#ffb74d;\"\u003eDisclosure.\u003c\/strong\u003e WC Safety participates in the Amazon Associates Program and earns commissions on qualifying purchases through outbound links on this page (tag wcsafety04-20). We are not sponsored by any instrument manufacturer. This page is buyer guidance, not medical, legal or regulatory advice — confirm gas-detection requirements for your site against the applicable OSHA standard and, for commercial monitoring programs, a Certified Industrial Hygienist (CIH).\n\u003c\/div\u003e\n\n\u003cscript type=\"application\/ld+json\"\u003e\n{\"@context\": \"https:\/\/schema.org\", \"@graph\": [{\"@type\": \"Product\", \"@id\": \"https:\/\/wcsafety.com\/products\/rki-gx3r-4-gas-monitor#product\", \"name\": \"RKI GX3R 4 Gas Monitor — LEL, O2, H2S, CO (Factory Calibrated)\", \"description\": \"RKI GX3R 4 gas monitor — compact wearable LEL, O2, H2S \u0026 CO detector, factory-calibrated with certificate, rechargeable. Order at WC Safety.\", \"sku\": \"B0FP5TCPHS\", \"mpn\": \"GX3R\", \"image\": [\"https:\/\/wcsafety.com\/cdn\/shop\/products\/rki-gx3r-4-gas-monitor.jpg\"], \"brand\": {\"@type\": \"Brand\", \"name\": \"RKI Instruments\"}, \"category\": \"Personal Gas Detector\", \"isPartOf\": {\"@type\": \"CollectionPage\", \"@id\": \"https:\/\/wcsafety.com\/collections\/personal-gas-detectors#collection\", \"name\": \"Personal \u0026 Wearable Gas Detectors\", \"url\": \"https:\/\/wcsafety.com\/collections\/personal-gas-detectors\"}, \"isRelatedTo\": [{\"@type\": \"Product\", \"name\": \"Honeywell BW Clip H2S Monitor (BWC2-H)\", \"url\": \"https:\/\/wcsafety.com\/products\/honeywell-bw-clip-h2s-monitor-bwc2-h\"}, {\"@type\": \"Product\", \"name\": \"Honeywell BW Clip CO Monitor (BWC2-M)\", \"url\": \"https:\/\/wcsafety.com\/products\/honeywell-bw-clip-co-monitor-bwc2-m\"}, {\"@type\": \"Product\", \"name\": \"Honeywell BW Clip O2 Monitor (BWC2-X)\", \"url\": \"https:\/\/wcsafety.com\/products\/honeywell-bw-clip-o2-monitor-bwc2-x\"}, {\"@type\": \"Product\", \"name\": \"TopTes CT-580 CO Detector\", \"url\": \"https:\/\/wcsafety.com\/products\/toptes-ct-580-co-detector\"}, {\"@type\": \"Product\", \"name\": \"BW GasAlertMicroClip XL 4 Gas Detector\", \"url\": \"https:\/\/wcsafety.com\/products\/bw-gasalertmicroclip-xl-4-gas-detector\"}, {\"@type\": \"Product\", \"name\": \"Honeywell BW Clip4 4 Gas Detector\", \"url\": \"https:\/\/wcsafety.com\/products\/honeywell-bw-clip4-4-gas-detector\"}], \"offers\": {\"@type\": \"Offer\", \"url\": \"https:\/\/wcsafety.com\/products\/rki-gx3r-4-gas-monitor\", \"priceCurrency\": \"USD\", \"price\": \"640.00\", \"availability\": \"https:\/\/schema.org\/InStock\", \"seller\": {\"@type\": \"Organization\", \"name\": \"WC Safety\"}}}, {\"@type\": \"BreadcrumbList\", \"@id\": \"https:\/\/wcsafety.com\/products\/rki-gx3r-4-gas-monitor#breadcrumb\", \"itemListElement\": [{\"@type\": \"ListItem\", \"position\": 1, \"name\": \"Home\", \"item\": \"https:\/\/wcsafety.com\/\"}, {\"@type\": \"ListItem\", \"position\": 2, \"name\": \"Gas Detectors\", \"item\": \"https:\/\/wcsafety.com\/collections\/gas-detectors\"}, {\"@type\": \"ListItem\", \"position\": 3, \"name\": \"Personal \u0026 Wearable Gas Detectors\", \"item\": \"https:\/\/wcsafety.com\/collections\/personal-gas-detectors\"}, {\"@type\": \"ListItem\", \"position\": 4, \"name\": \"RKI GX3R 4 Gas Monitor — LEL, O2, H2S, CO (Factory Calibrated)\"}]}, {\"@type\": \"FAQPage\", \"mainEntity\": [{\"@type\": \"Question\", \"name\": \"What gases does the RKI GX3R detect?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"LEL combustibles, O2, H2S and CO — the confined-space four-gas set. For VOCs you need a PID; see the Gas Detectors range.\"}}, {\"@type\": \"Question\", \"name\": \"Does the GX3R come calibrated?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Yes — it ships factory-calibrated with a calibration certificate, plus a carry bag. Bump-test before use and recalibrate on schedule.\"}}, {\"@type\": \"Question\", \"name\": \"Why choose the GX3R over other wearables?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Size — it is one of the smallest and lightest four-gas monitors, which makes all-day wear more comfortable while still covering all four gases.\"}}, {\"@type\": \"Question\", \"name\": \"Is the RKI GX3R rechargeable?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Yes — it uses a rechargeable Li-ion battery sized for full-shift use; recharge between shifts.\"}}, {\"@type\": \"Question\", \"name\": \"How does it compare to the BW GasAlertMicroClip XL?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Both are serviceable rechargeable 4-gas wearables; the GX3R is smaller, while the MicroClip XL is a longer-established platform with broad docking support.\"}}, {\"@type\": \"Question\", \"name\": \"Is it good for confined-space entry?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Yes for personal monitoring. Pre-entry sampling of a sealed space still requires a Portable Gas Detectors pump instrument.\"}}, {\"@type\": \"Question\", \"name\": \"Does it log data?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Yes — it includes datalogging for compliance records, downloadable per RKI's software\/dock.\"}}, {\"@type\": \"Question\", \"name\": \"Does it have a pump?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"This is the diffusion model. For remote sample-draw before entry, use a pump-equipped Portable Gas Detectors monitor.\"}}, {\"@type\": \"Question\", \"name\": \"What alarms does it have?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Visual, audible and vibration alarms trigger when any of the four gases exceeds its set point.\"}}, {\"@type\": \"Question\", \"name\": \"What does it not detect?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"VOCs, CO2 and specific toxics like chlorine or ammonia are outside its range; use a PID or dedicated sensor for those.\"}}, {\"@type\": \"Question\", \"name\": \"Is it in stock and how does it ship?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Use the Amazon buy button for live availability and delivery timing through our fulfillment partner.\"}}, {\"@type\": \"Question\", \"name\": \"Does it include a warranty?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"The listing notes factory calibration and warranty support from RKI; confirm current warranty terms with the manufacturer for your purchase.\"}}]}, {\"@type\": \"Organization\", \"@id\": \"https:\/\/wcsafety.com\/#org\", \"name\": \"WC Safety\", \"url\": \"https:\/\/wcsafety.com\", \"logo\": \"https:\/\/wcsafety.com\/cdn\/shop\/files\/logo.png\"}, {\"@type\": \"Person\", \"@id\": \"https:\/\/wcsafety.com\/#editor\", \"name\": \"Steven Eaton\", \"jobTitle\": \"Editorial Lead\", \"worksFor\": {\"@id\": \"https:\/\/wcsafety.com\/#org\"}, \"knowsAbout\": [\"industrial gas detection\", \"atmospheric monitoring\", \"personal protective equipment\"]}, {\"@type\": \"Brand\", \"name\": \"RKI Instruments\"}]}\n\u003c\/script\u003e","brand":"RKI Instruments","offers":[{"title":"Default Title","offer_id":44266437705816,"sku":"B0FP5TCPHS","price":640.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0594\/1900\/0920\/files\/41QvxKVjLKL._AC.jpg?v=1782121794"},{"product_id":"forensics-4-gas-wall-mount-monitor","title":"Forensics 4 Gas Wall-Mount Monitor — CO, H2S, O2 \u0026 LEL (Relay Output)","description":"\u003c!-- PRODUCT B0C19GM4XC | tag fixed-gas-detector | TODO: add matching Product Review + best-of guide links when those silo layers exist --\u003e\n\n\u003cdiv style=\"background:#1a1a1a;border-left:4px solid #ff9800;padding:14px 18px;margin:0 0 18px 0;color:#f5e6d3;font-size:0.95em;\"\u003e\n\u003cstrong style=\"color:#ffb74d;\"\u003eEditor’s note:\u003c\/strong\u003e the Forensics 4 gas wall-mount monitor is one of the instruments we curate in our \u003ca href=\"\/collections\/fixed-gas-detection-systems\" title=\"Fixed Gas Detection Systems\"\u003eFixed Gas Detection Systems\u003c\/a\u003e buyer’s hub. Compare it with the \u003ca href=\"\/products\/forensics-ex-lel-gas-detector-wall-mount\" title=\"Forensics EX\/LEL Wall-Mount\"\u003eForensics EX\/LEL Wall-Mount\u003c\/a\u003e below before you order.\u003c\/div\u003e\n\n\u003ch2 id=\"top\"\u003eForensics 4 Gas Wall-Mount Monitor — Fixed CO, H2S, O2 \u0026amp; LEL\u003c\/h2\u003e\n\n\u003cp\u003eThe \u003cstrong\u003eForensics 4 gas wall-mount monitor\u003c\/strong\u003e reads CO, H2S, O2 and combustible LEL from a single fixed head — a \u003ca href=\"\/collections\/fixed-gas-detection-systems\" title=\"fixed gas detection system\"\u003efixed gas detection system\u003c\/a\u003e that covers all four atmospheric hazards continuously and drives ventilation or shutdown through its relay output.\u003c\/p\u003e\n\n\u003cp style=\"font-size:0.9em;color:#bdae9d;margin:10px 0 18px 0;\"\u003eJump to: \u003ca href=\"#features\" style=\"color:#ffb74d;\"\u003eFeatures\u003c\/a\u003e · \u003ca href=\"#specs\" style=\"color:#ffb74d;\"\u003eSpecs\u003c\/a\u003e · \u003ca href=\"#compatibility\" style=\"color:#ffb74d;\"\u003eWhat it detects\u003c\/a\u003e · \u003ca href=\"#comparison\" style=\"color:#ffb74d;\"\u003eComparison\u003c\/a\u003e · \u003ca href=\"#faq\" style=\"color:#ffb74d;\"\u003eFAQ\u003c\/a\u003e\u003c\/p\u003e\n\n\u003cp\u003eThe Forensics 4 Gas Wall-Mount Monitor is a fixed, continuously-monitoring detector for CO, H2S, O2 and combustible LEL, with relay output and NIST-traceable calibration.\u003c\/p\u003e\n\n\u003ch3 id=\"features\"\u003eKey features\u003c\/h3\u003e\n\n\u003cul\u003e\n\u003cli\u003eMonitors all four atmospheric hazards — CO, H2S, O2 and combustible LEL — from one fixed head\u003c\/li\u003e\n\u003cli\u003eContinuous wall-mounted coverage of an unattended space\u003c\/li\u003e\n\u003cli\u003eRelay output drives ventilation, alarms or shutdown\u003c\/li\u003e\n\u003cli\u003eAdjustable audible and visual alarms per gas\u003c\/li\u003e\n\u003cli\u003eUSA NIST-traceable calibration\u003c\/li\u003e\n\u003cli\u003eThe all-in-one fixed solution where several gases are a risk\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cdiv style=\"display:flex;gap:14px;flex-wrap:wrap;margin:18px 0;\"\u003e\n\u003cdiv style=\"flex:1;min-width:240px;background:#1b3a2a;border:1px solid #4caf50;border-radius:6px;padding:14px 18px;\"\u003e\n\u003cstrong style=\"color:#81c784;\"\u003ePros\u003c\/strong\u003e\u003cul style=\"margin:8px 0 0 0;\"\u003e\n\u003cli\u003eFour gases from one fixed head\u003c\/li\u003e\n\u003cli\u003eContinuous unattended monitoring\u003c\/li\u003e\n\u003cli\u003eRelay output for ventilation\/shutdown\u003c\/li\u003e\n\u003cli\u003eNIST-traceable calibration\u003c\/li\u003e\n\u003cli\u003eSimplifies multi-gas install\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"flex:1;min-width:240px;background:#3a1e1e;border:1px solid #ef5350;border-radius:6px;padding:14px 18px;\"\u003e\n\u003cstrong style=\"color:#e57373;\"\u003eCons\u003c\/strong\u003e\u003cul style=\"margin:8px 0 0 0;\"\u003e\n\u003cli\u003eHighest cost in the Forensics fixed family\u003c\/li\u003e\n\u003cli\u003eSingle point coverage\u003c\/li\u003e\n\u003cli\u003eHard-wired install required\u003c\/li\u003e\n\u003cli\u003eNot portable\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\n\u003ch3 id=\"specs\"\u003eSpecifications\u003c\/h3\u003e\n\n\u003cdiv style=\"overflow-x:auto;\"\u003e\u003ctable style=\"width:100%;border-collapse:collapse;background:#1a1a1a;margin:14px 0;\"\u003e\n\u003cthead\u003e\u003ctr style=\"background:#2a2a2a;\"\u003e\n\u003cth style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;text-align:left;\"\u003eSpecification\u003c\/th\u003e\n\u003cth style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;text-align:left;\"\u003eDetail\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eGases detected\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eCO, H2S, O2, EX (LEL) combustibles\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eMounting\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eWall-mount, fixed\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eMonitoring\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eContinuous (always on)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eOutput\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eRelay output + adjustable sound \u0026amp; light alarms\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eCalibration\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eUSA NIST-traceable\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eEnclosure\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eIndustrial\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eWeight\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003e3 lb\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003c\/div\u003e\n\n\u003ch3\u003eWhere the Forensics 4 Gas Wall-Mount Monitor fits\u003c\/h3\u003e\n\n\u003cul\u003e\n\u003cli\u003eWastewater and pump stations\u003c\/li\u003e\n\u003cli\u003eConfined or below-grade plant rooms\u003c\/li\u003e\n\u003cli\u003eParking and loading areas (CO)\u003c\/li\u003e\n\u003cli\u003eDigesters and tanks (H2S, O2)\u003c\/li\u003e\n\u003cli\u003eAny space with multiple gas hazards\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2 id=\"compatibility\"\u003eWhat the Forensics 4 Gas Wall-Mount Monitor detects (and what it doesn’t)\u003c\/h2\u003e\n\n\u003cp\u003eThis monitor covers \u003cstrong\u003eCO, H2S, O2 and combustible LEL\u003c\/strong\u003e — the four atmospheric hazards — but not VOCs, CO2 or specific toxics like chlorine. For a single combustible point use the \u003ca href=\"\/products\/forensics-ex-lel-gas-detector-wall-mount\" title=\"Forensics EX LEL Detector\"\u003eForensics EX LEL Detector\u003c\/a\u003e; for hydrogen the \u003ca href=\"\/products\/forensics-hydrogen-gas-detector-wall-mount\" title=\"Hydrogen Detector\"\u003eHydrogen Detector\u003c\/a\u003e. Mount it considering each gas’s density and the room layout, and tie the relay into ventilation or shutdown. It protects the installed space; entrants still need a \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"Portable Gas Detectors\"\u003ePortable Gas Detectors\u003c\/a\u003e instrument for pre-entry testing and a \u003ca href=\"\/collections\/personal-gas-detectors\" title=\"Personal \u0026amp; Wearable Gas Detectors\"\u003ePersonal \u0026amp; Wearable Gas Detectors\u003c\/a\u003e clip during work.\u003c\/p\u003e\n\n\u003cp\u003eCross-shopping? This unit sits in our \u003ca href=\"\/collections\/fixed-gas-detection-systems\" title=\"Fixed Gas Detection Systems\"\u003eFixed Gas Detection Systems\u003c\/a\u003e hub alongside \u003ca href=\"\/products\/forensics-ex-lel-gas-detector-wall-mount\" title=\"Forensics EX\/LEL Wall-Mount\"\u003eForensics EX\/LEL Wall-Mount\u003c\/a\u003e, \u003ca href=\"\/products\/forensics-hydrogen-gas-detector-wall-mount\" title=\"Forensics Hydrogen Wall-Mount\"\u003eForensics Hydrogen Wall-Mount\u003c\/a\u003e, \u003ca href=\"\/products\/macurco-pm100-co-fixed-carbon-monoxide-monitor\" title=\"Macurco PM100-CO\"\u003eMacurco PM100-CO\u003c\/a\u003e, \u003ca href=\"\/products\/macurco-gbc-24-2-gas-detection-controller\" title=\"Macurco GBC-24-2\"\u003eMacurco GBC-24-2\u003c\/a\u003e. For other gas-detection form factors see \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"Portable Gas Detectors\"\u003ePortable Gas Detectors\u003c\/a\u003e, \u003ca href=\"\/collections\/personal-gas-detectors\" title=\"Personal \u0026amp; Wearable Gas Detectors\"\u003ePersonal \u0026amp; Wearable Gas Detectors\u003c\/a\u003e, \u003ca href=\"\/collections\/area-gas-monitors\" title=\"Area \u0026amp; Transportable Gas Monitors\"\u003eArea \u0026amp; Transportable Gas Monitors\u003c\/a\u003e, or browse the full \u003ca href=\"\/collections\/gas-detectors\" title=\"Gas Detectors\"\u003eGas Detectors\u003c\/a\u003e range.\u003c\/p\u003e\n\n\u003ch2 id=\"comparison\"\u003eForensics fixed wall-mount family compared\u003c\/h2\u003e\n\n\u003cdiv style=\"overflow-x:auto;\"\u003e\u003ctable style=\"width:100%;border-collapse:collapse;background:#1a1a1a;margin:14px 0;\"\u003e\n\u003ccaption style=\"color:#bdae9d;font-size:0.85em;text-align:left;padding:4px 0;\"\u003eForensics Detectors fixed wall-mount family (continuous monitoring, relay output, NIST-traceable)\u003c\/caption\u003e\n\u003cthead\u003e\u003ctr style=\"background:#2a2a2a;\"\u003e\n\u003cth style=\"color:#ffb74d;padding:9px;border:1px solid #3a3a3a;text-align:left;\"\u003eModel\u003c\/th\u003e\n\u003cth style=\"color:#ffb74d;padding:9px;border:1px solid #3a3a3a;text-align:left;\"\u003eGas(es)\u003c\/th\u003e\n\u003cth style=\"color:#ffb74d;padding:9px;border:1px solid #3a3a3a;text-align:left;\"\u003eRange\u003c\/th\u003e\n\u003cth style=\"color:#ffb74d;padding:9px;border:1px solid #3a3a3a;text-align:left;\"\u003eOutput\u003c\/th\u003e\n\u003cth style=\"color:#ffb74d;padding:9px;border:1px solid #3a3a3a;text-align:left;\"\u003eStreet price\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e\u003ca href=\"\/products\/forensics-ex-lel-gas-detector-wall-mount\" title=\"EX LEL Detector\"\u003eEX LEL Detector\u003c\/a\u003e\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eCombustibles (EX)\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e0-100% LEL\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eRelay + alarms\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e~$599\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e\u003ca href=\"\/products\/forensics-hydrogen-gas-detector-wall-mount\" title=\"Hydrogen Detector\"\u003eHydrogen Detector\u003c\/a\u003e\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eHydrogen (H2)\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e0-1000 ppm\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eRelay + alarms\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e~$799\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#2a2520;\"\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e\u003cstrong\u003e\u003ca href=\"\/products\/forensics-4-gas-wall-mount-monitor\" title=\"4 Gas Monitor\"\u003e4 Gas Monitor\u003c\/a\u003e\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eCO, H2S, O2, EX LEL\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eMulti-gas\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eRelay + alarms\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e~$1,395\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003c\/div\u003e\n\n\u003cul\u003e\n\u003cli\u003eChoose the \u003cstrong\u003e4 Gas Wall-Mount Monitor\u003c\/strong\u003e when a space has several gas hazards and you want one fixed head.\u003c\/li\u003e\n\u003cli\u003eFor combustibles only, the \u003ca href=\"\/products\/forensics-ex-lel-gas-detector-wall-mount\" title=\"EX LEL Detector\"\u003eEX LEL Detector\u003c\/a\u003e costs less.\u003c\/li\u003e\n\u003cli\u003eFor battery-room hydrogen, use the \u003ca href=\"\/products\/forensics-hydrogen-gas-detector-wall-mount\" title=\"Hydrogen Detector\"\u003eHydrogen Detector\u003c\/a\u003e.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2 id=\"faq\"\u003eFrequently asked questions\u003c\/h2\u003e\n\n\u003ch3\u003eWhat gases does the Forensics 4 gas wall-mount monitor detect?\u003c\/h3\u003e\u003cp\u003eCO, H2S, O2 and combustible LEL — the four atmospheric hazards — continuously, from one fixed head. It does not detect VOCs or specific toxics like chlorine.\u003c\/p\u003e\n\u003ch3\u003eWhy choose a fixed 4-gas monitor over single-gas heads?\u003c\/h3\u003e\u003cp\u003eOne unit covers all four hazards, simplifying installation and wiring where several gases are a risk. For a single hazard, a dedicated head like the \u003ca href=\"\/products\/forensics-ex-lel-gas-detector-wall-mount\" title=\"EX LEL Detector\"\u003eEX LEL Detector\u003c\/a\u003e costs less.\u003c\/p\u003e\n\u003ch3\u003eWhat is the relay output used for?\u003c\/h3\u003e\u003cp\u003eIt triggers external action — ventilation, remote alarms or equipment shutdown — when any monitored gas reaches its set point.\u003c\/p\u003e\n\u003ch3\u003eWhere should it be mounted?\u003c\/h3\u003e\u003cp\u003ePosition it considering each gas's density and the room's release points and occupied zones; below-grade and enclosed plant rooms are common applications.\u003c\/p\u003e\n\u003ch3\u003eIs it NIST calibrated?\u003c\/h3\u003e\u003cp\u003eYes — USA NIST-traceable calibration; plan periodic recalibration of each sensor with the appropriate calibration gas.\u003c\/p\u003e\n\u003ch3\u003eCan it replace portable detectors for entry?\u003c\/h3\u003e\u003cp\u003eNo — pre-entry testing still needs a \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"Portable Gas Detectors\"\u003ePortable Gas Detectors\u003c\/a\u003e instrument. The fixed monitor provides continuous coverage of the installed space.\u003c\/p\u003e\n\u003ch3\u003eDoes it monitor oxygen deficiency?\u003c\/h3\u003e\u003cp\u003eYes — oxygen is one of its four channels, alarming on deficiency (and typically enrichment) alongside CO, H2S and combustibles.\u003c\/p\u003e\n\u003ch3\u003eHow is it powered and installed?\u003c\/h3\u003e\u003cp\u003eIt is a hard-wired fixed monitor; installation and relay wiring should follow local electrical code and any area-classification requirements.\u003c\/p\u003e\n\u003ch3\u003eWhat does it not detect?\u003c\/h3\u003e\u003cp\u003eVOCs, CO2 and specific toxics such as chlorine or ammonia. For a single combustible point use the \u003ca href=\"\/products\/forensics-ex-lel-gas-detector-wall-mount\" title=\"EX LEL Detector\"\u003eEX LEL Detector\u003c\/a\u003e; for hydrogen the \u003ca href=\"\/products\/forensics-hydrogen-gas-detector-wall-mount\" title=\"Hydrogen Detector\"\u003eHydrogen Detector\u003c\/a\u003e.\u003c\/p\u003e\n\u003ch3\u003eIs it in stock and how does it ship?\u003c\/h3\u003e\u003cp\u003eUse the Amazon buy button for current availability and delivery timing through our fulfillment partner.\u003c\/p\u003e\n\u003ch3\u003eCan it drive building ventilation automatically?\u003c\/h3\u003e\u003cp\u003eYes — that is a core use of the relay output: energise exhaust or a shutdown circuit when gas reaches the alarm level.\u003c\/p\u003e\n\u003ch3\u003eHow many heads does a facility need?\u003c\/h3\u003e\u003cp\u003eOne per area near its release points; larger or multi-room facilities add heads positioned by airflow and gas density, often wired to a central controller.\u003c\/p\u003e\n\n\u003cdiv style=\"background:#1a1a1a;border:1px solid #3a3a3a;border-radius:6px;padding:16px 18px;margin:22px 0;\"\u003e\n\u003cp style=\"margin:0 0 10px 0;color:#f5e6d3;\"\u003eReady to order the \u003cstrong\u003eForensics 4 gas wall-mount monitor\u003c\/strong\u003e? Add it to your cart above, or check the current Amazon price below. Compare it against the rest of our \u003ca href=\"\/collections\/fixed-gas-detection-systems\" title=\"Fixed Gas Detection Systems\"\u003eFixed Gas Detection Systems\u003c\/a\u003e lineup before you buy.\u003c\/p\u003e\n\u003cp style=\"display:flex;gap:10px;flex-wrap:wrap;align-items:center;margin:0;\"\u003e\u003ca href=\"https:\/\/www.amazon.com\/dp\/B0C19GM4XC?tag=wcsafety04-20\" rel=\"sponsored nofollow noopener\" target=\"_blank\" style=\"display:inline-block;background:#FFD814;color:#0F1111;padding:13px 26px;text-decoration:none;font-weight:bold;border-radius:4px;border:1px solid #FCD200;\"\u003eCHECK PRICE ON AMAZON →\u003c\/a\u003e\u003cspan style=\"font-size:0.8em;color:#bdae9d;\"\u003eAs an Amazon Associate, WC Safety earns from qualifying purchases.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/div\u003e\n\n\u003cdiv style=\"background:#1a2733;border:1px dashed #4fc3f7;padding:16px 20px;margin:30px 0 18px 0;color:#cfd8dc;font-size:0.92em;\"\u003e\n  \u003cstrong style=\"color:#4fc3f7;\"\u003eWhy trust this Forensics Detectors page?\u003c\/strong\u003e WC Safety is an independent industrial safety-equipment retailer serving safety managers, procurement teams and field supervisors. The specifications here are taken from the manufacturer’s published listing for Forensics 4 Gas Wall-Mount Monitor and framed against \u003ca href=\"https:\/\/www.osha.gov\/laws-regs\/regulations\/standardnumber\/1910\/1910.146\" rel=\"noopener\" target=\"_blank\" style=\"color:#4fc3f7;\"\u003eOSHA 29 CFR 1910.146\u003c\/a\u003e and \u003ca href=\"https:\/\/www.osha.gov\/annotated-pels\" rel=\"noopener\" target=\"_blank\" style=\"color:#4fc3f7;\"\u003eOSHA Permissible Exposure Limits\u003c\/a\u003e. Disclosed: WC Safety earns Amazon affiliate commissions on outbound clicks; that does not influence the specs shown or our lineup.\n\u003c\/div\u003e\n\u003cdiv style=\"background:#1a2733;border-left:4px solid #4fc3f7;padding:18px 22px;margin:18px 0;color:#cfd8dc;font-size:0.92em;\"\u003e\n  \u003cstrong style=\"color:#4fc3f7;\"\u003eBy Steven Eaton, WC Safety Editorial\u003c\/strong\u003e — Industrial safety-equipment desk · specialization: atmospheric monitoring, gas detection and instrument selection.\u003cbr\u003e\n  \u003cstrong\u003eLast updated:\u003c\/strong\u003e \u003ctime datetime=\"2026-06-22\"\u003eJune 22, 2026\u003c\/time\u003e · \u003cstrong\u003eSources reviewed:\u003c\/strong\u003e manufacturer product listing \u0026amp; specifications, OSHA 29 CFR 1910.146, OSHA Annotated PEL tables, ACGIH Threshold Limit Values.\u003cbr\u003e\n  \u003cstrong\u003eEditorial standard:\u003c\/strong\u003e \u003cem\u003eZero sponsored listings. No manufacturer input. Specs verified against the manufacturer’s published data.\u003c\/em\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"background:#1a2733;border-left:4px solid #4fc3f7;padding:16px 20px;margin:18px 0;color:#cfd8dc;font-size:0.92em;\"\u003e\n  \u003cstrong style=\"color:#4fc3f7;\"\u003eHow this page is maintained.\u003c\/strong\u003e Specifications and pricing are reviewed against the manufacturer’s current listing and re-checked whenever the lineup changes. Gas-detection guidance follows \u003ca href=\"https:\/\/www.osha.gov\/laws-regs\/regulations\/standardnumber\/1910\/1910.146\" rel=\"noopener\" target=\"_blank\" style=\"color:#4fc3f7;\"\u003eOSHA 1910.146\u003c\/a\u003e and \u003ca href=\"https:\/\/www.osha.gov\/annotated-pels\" rel=\"noopener\" target=\"_blank\" style=\"color:#4fc3f7;\"\u003eOSHA PELs\u003c\/a\u003e, cross-referenced with ACGIH TLVs.\n\u003c\/div\u003e\n\u003cdiv style=\"background:#2a2520;border-left:4px solid #ff9800;padding:16px 20px;margin:18px 0;color:#f5e6d3;font-size:0.92em;\"\u003e\n  \u003cstrong style=\"color:#ffb74d;\"\u003eDisclosure.\u003c\/strong\u003e WC Safety participates in the Amazon Associates Program and earns commissions on qualifying purchases through outbound links on this page (tag wcsafety04-20). We are not sponsored by any instrument manufacturer. This page is buyer guidance, not medical, legal or regulatory advice — confirm gas-detection requirements for your site against the applicable OSHA standard and, for commercial monitoring programs, a Certified Industrial Hygienist (CIH).\n\u003c\/div\u003e\n\n\u003cscript type=\"application\/ld+json\"\u003e\n{\"@context\": \"https:\/\/schema.org\", \"@graph\": [{\"@type\": \"Product\", \"@id\": \"https:\/\/wcsafety.com\/products\/forensics-4-gas-wall-mount-monitor#product\", \"name\": \"Forensics 4 Gas Wall-Mount Monitor — CO, H2S, O2 \u0026 LEL (Relay Output)\", \"description\": \"Forensics 4 gas wall-mount monitor — fixed CO, H2S, O2 \u0026 LEL detector, continuous monitoring with relay output and NIST-traceable calibration.\", \"sku\": \"B0C19GM4XC\", \"mpn\": \"FD-4GWM\", \"image\": [\"https:\/\/wcsafety.com\/cdn\/shop\/products\/forensics-4-gas-wall-mount-monitor.jpg\"], \"brand\": {\"@type\": \"Brand\", \"name\": \"Forensics Detectors\"}, \"category\": \"Fixed Gas Detector\", \"isPartOf\": {\"@type\": \"CollectionPage\", \"@id\": \"https:\/\/wcsafety.com\/collections\/fixed-gas-detection-systems#collection\", \"name\": \"Fixed Gas Detection Systems\", \"url\": \"https:\/\/wcsafety.com\/collections\/fixed-gas-detection-systems\"}, \"isRelatedTo\": [{\"@type\": \"Product\", \"name\": \"Forensics EX LEL Gas Detector (Wall-Mount)\", \"url\": \"https:\/\/wcsafety.com\/products\/forensics-ex-lel-gas-detector-wall-mount\"}, {\"@type\": \"Product\", \"name\": \"Forensics Hydrogen Gas Detector (Wall-Mount)\", \"url\": \"https:\/\/wcsafety.com\/products\/forensics-hydrogen-gas-detector-wall-mount\"}, {\"@type\": \"Product\", \"name\": \"Macurco PM100-CO Fixed CO Monitor\", \"url\": \"https:\/\/wcsafety.com\/products\/macurco-pm100-co-fixed-carbon-monoxide-monitor\"}, {\"@type\": \"Product\", \"name\": \"Macurco GBC-24-2 Gas Detection Controller\", \"url\": \"https:\/\/wcsafety.com\/products\/macurco-gbc-24-2-gas-detection-controller\"}], \"offers\": {\"@type\": \"Offer\", \"url\": \"https:\/\/wcsafety.com\/products\/forensics-4-gas-wall-mount-monitor\", \"priceCurrency\": \"USD\", \"price\": \"1395.00\", \"availability\": \"https:\/\/schema.org\/InStock\", \"seller\": {\"@type\": \"Organization\", \"name\": \"WC Safety\"}}}, {\"@type\": \"BreadcrumbList\", \"@id\": \"https:\/\/wcsafety.com\/products\/forensics-4-gas-wall-mount-monitor#breadcrumb\", \"itemListElement\": [{\"@type\": \"ListItem\", \"position\": 1, \"name\": \"Home\", \"item\": \"https:\/\/wcsafety.com\/\"}, {\"@type\": \"ListItem\", \"position\": 2, \"name\": \"Gas Detectors\", \"item\": \"https:\/\/wcsafety.com\/collections\/gas-detectors\"}, {\"@type\": \"ListItem\", \"position\": 3, \"name\": \"Fixed Gas Detection Systems\", \"item\": \"https:\/\/wcsafety.com\/collections\/fixed-gas-detection-systems\"}, {\"@type\": \"ListItem\", \"position\": 4, \"name\": \"Forensics 4 Gas Wall-Mount Monitor — CO, H2S, O2 \u0026 LEL (Relay Output)\"}]}, {\"@type\": \"FAQPage\", \"mainEntity\": [{\"@type\": \"Question\", \"name\": \"What gases does the Forensics 4 gas wall-mount monitor detect?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"CO, H2S, O2 and combustible LEL — the four atmospheric hazards — continuously, from one fixed head. It does not detect VOCs or specific toxics like chlorine.\"}}, {\"@type\": \"Question\", \"name\": \"Why choose a fixed 4-gas monitor over single-gas heads?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"One unit covers all four hazards, simplifying installation and wiring where several gases are a risk. For a single hazard, a dedicated head like the EX LEL Detector costs less.\"}}, {\"@type\": \"Question\", \"name\": \"What is the relay output used for?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"It triggers external action — ventilation, remote alarms or equipment shutdown — when any monitored gas reaches its set point.\"}}, {\"@type\": \"Question\", \"name\": \"Where should it be mounted?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Position it considering each gas's density and the room's release points and occupied zones; below-grade and enclosed plant rooms are common applications.\"}}, {\"@type\": \"Question\", \"name\": \"Is it NIST calibrated?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Yes — USA NIST-traceable calibration; plan periodic recalibration of each sensor with the appropriate calibration gas.\"}}, {\"@type\": \"Question\", \"name\": \"Can it replace portable detectors for entry?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"No — pre-entry testing still needs a Portable Gas Detectors instrument. The fixed monitor provides continuous coverage of the installed space.\"}}, {\"@type\": \"Question\", \"name\": \"Does it monitor oxygen deficiency?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Yes — oxygen is one of its four channels, alarming on deficiency (and typically enrichment) alongside CO, H2S and combustibles.\"}}, {\"@type\": \"Question\", \"name\": \"How is it powered and installed?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"It is a hard-wired fixed monitor; installation and relay wiring should follow local electrical code and any area-classification requirements.\"}}, {\"@type\": \"Question\", \"name\": \"What does it not detect?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"VOCs, CO2 and specific toxics such as chlorine or ammonia. For a single combustible point use the EX LEL Detector; for hydrogen the Hydrogen Detector.\"}}, {\"@type\": \"Question\", \"name\": \"Is it in stock and how does it ship?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Use the Amazon buy button for current availability and delivery timing through our fulfillment partner.\"}}, {\"@type\": \"Question\", \"name\": \"Can it drive building ventilation automatically?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Yes — that is a core use of the relay output: energise exhaust or a shutdown circuit when gas reaches the alarm level.\"}}, {\"@type\": \"Question\", \"name\": \"How many heads does a facility need?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"One per area near its release points; larger or multi-room facilities add heads positioned by airflow and gas density, often wired to a central controller.\"}}]}, {\"@type\": \"Organization\", \"@id\": \"https:\/\/wcsafety.com\/#org\", \"name\": \"WC Safety\", \"url\": \"https:\/\/wcsafety.com\", \"logo\": \"https:\/\/wcsafety.com\/cdn\/shop\/files\/logo.png\"}, {\"@type\": \"Person\", \"@id\": \"https:\/\/wcsafety.com\/#editor\", \"name\": \"Steven Eaton\", \"jobTitle\": \"Editorial Lead\", \"worksFor\": {\"@id\": \"https:\/\/wcsafety.com\/#org\"}, \"knowsAbout\": [\"industrial gas detection\", \"atmospheric monitoring\", \"personal protective equipment\"]}, {\"@type\": \"Brand\", \"name\": \"Forensics Detectors\"}]}\n\u003c\/script\u003e","brand":"Forensics Detectors","offers":[{"title":"Default Title","offer_id":44266497146968,"sku":"B0C19GM4XC","price":1395.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0594\/1900\/0920\/files\/71YQjzkBeeL._AC_SL1500.jpg?v=1782122849"},{"product_id":"forensics-4-gas-pump-monitor-datalogging","title":"Forensics 4 Gas Pump Monitor — Datalogging, Color Display (O2, CO, H2S, LEL)","description":"\u003c!-- PRODUCT B07WKC4FTV | tag area-gas-monitor | TODO: add matching Product Review + best-of guide links when those silo layers exist --\u003e\n\n\u003cdiv style=\"background:#1a1a1a;border-left:4px solid #ff9800;padding:14px 18px;margin:0 0 18px 0;color:#f5e6d3;font-size:0.95em;\"\u003e\n\u003cstrong style=\"color:#ffb74d;\"\u003eEditor’s note:\u003c\/strong\u003e the Forensics 4 gas pump monitor is one of the instruments we curate in our \u003ca href=\"\/collections\/area-gas-monitors\" title=\"Area \u0026amp; Transportable Gas Monitors\"\u003eArea \u0026amp; Transportable Gas Monitors\u003c\/a\u003e buyer’s hub. Compare it with the \u003ca href=\"\/products\/forensics-4-gas-data-logger-monitor\" title=\"Forensics 4 Gas Data Logger\"\u003eForensics 4 Gas Data Logger\u003c\/a\u003e below before you order.\u003c\/div\u003e\n\n\u003ch2 id=\"top\"\u003eForensics 4 Gas Pump Monitor — Transportable Continuous Monitoring\u003c\/h2\u003e\n\n\u003cp\u003eThe \u003cstrong\u003eForensics 4 gas pump monitor\u003c\/strong\u003e is a transportable continuous monitor with a built-in pump, color graphing and datalogging — an \u003ca href=\"\/collections\/area-gas-monitors\" title=\"area and transportable gas monitor\"\u003earea and transportable gas monitor\u003c\/a\u003e you set down at the hazard to watch oxygen (O2), combustible gas (LEL), carbon monoxide (CO) and hydrogen sulfide (H2S) for the length of a job, or carry for pre-entry checks.\u003c\/p\u003e\n\n\u003cp style=\"font-size:0.9em;color:#bdae9d;margin:10px 0 18px 0;\"\u003eJump to: \u003ca href=\"#features\" style=\"color:#ffb74d;\"\u003eFeatures\u003c\/a\u003e · \u003ca href=\"#specs\" style=\"color:#ffb74d;\"\u003eSpecs\u003c\/a\u003e · \u003ca href=\"#compatibility\" style=\"color:#ffb74d;\"\u003eWhat it detects\u003c\/a\u003e · \u003ca href=\"#comparison\" style=\"color:#ffb74d;\"\u003eComparison\u003c\/a\u003e · \u003ca href=\"#faq\" style=\"color:#ffb74d;\"\u003eFAQ\u003c\/a\u003e\u003c\/p\u003e\n\n\u003cp\u003eThe Forensics 4 Gas Pump Monitor is a transportable, NIST-calibrated continuous monitor for O2, CO, H2S and LEL with a built-in sample-draw pump, color graphing display and computer datalogging.\u003c\/p\u003e\n\n\u003ch3 id=\"features\"\u003eKey features\u003c\/h3\u003e\n\n\u003cul\u003e\n\u003cli\u003eMonitors oxygen (O2), combustible gas (LEL), carbon monoxide (CO) and hydrogen sulfide (H2S) continuously with a built-in sample-draw pump\u003c\/li\u003e\n\u003cli\u003eColor display with live graphing to watch trends as you monitor a zone\u003c\/li\u003e\n\u003cli\u003eOn-board datalogging with computer download for records\u003c\/li\u003e\n\u003cli\u003eUSA NIST-traceable calibration\u003c\/li\u003e\n\u003cli\u003eSet it down at the hazard for continuous job-site monitoring, or carry it for pre-entry checks\u003c\/li\u003e\n\u003cli\u003eAudible, visual and vibration alarms\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cdiv style=\"display:flex;gap:14px;flex-wrap:wrap;margin:18px 0;\"\u003e\n\u003cdiv style=\"flex:1;min-width:240px;background:#1b3a2a;border:1px solid #4caf50;border-radius:6px;padding:14px 18px;\"\u003e\n\u003cstrong style=\"color:#81c784;\"\u003ePros\u003c\/strong\u003e\u003cul style=\"margin:8px 0 0 0;\"\u003e\n\u003cli\u003eBuilt-in pump + datalogging\u003c\/li\u003e\n\u003cli\u003eColor live-graphing display\u003c\/li\u003e\n\u003cli\u003eNIST-traceable calibration\u003c\/li\u003e\n\u003cli\u003eDoubles as placed continuous monitor and portable\u003c\/li\u003e\n\u003cli\u003eComputer data download for records\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"flex:1;min-width:240px;background:#3a1e1e;border:1px solid #ef5350;border-radius:6px;padding:14px 18px;\"\u003e\n\u003cstrong style=\"color:#e57373;\"\u003eCons\u003c\/strong\u003e\u003cul style=\"margin:8px 0 0 0;\"\u003e\n\u003cli\u003eNot a wireless-mesh area monitor (single unit)\u003c\/li\u003e\n\u003cli\u003eNo networked multi-zone base station\u003c\/li\u003e\n\u003cli\u003eElectrochemical sensors need periodic replacement\u003c\/li\u003e\n\u003cli\u003ePump and probe need maintenance\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\n\u003ch3 id=\"specs\"\u003eSpecifications\u003c\/h3\u003e\n\n\u003cdiv style=\"overflow-x:auto;\"\u003e\u003ctable style=\"width:100%;border-collapse:collapse;background:#1a1a1a;margin:14px 0;\"\u003e\n\u003cthead\u003e\u003ctr style=\"background:#2a2a2a;\"\u003e\n\u003cth style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;text-align:left;\"\u003eSpecification\u003c\/th\u003e\n\u003cth style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;text-align:left;\"\u003eDetail\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eGases detected\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eO2, CO, H2S, LEL combustibles\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eSampling\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eBuilt-in pump (sample-draw)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eDisplay\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eColor with live graphing\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eDatalogging\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eYes — computer download\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eSensor\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eElectrochemical\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eCalibration\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eUSA NIST-traceable\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eWeight\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003e14.4 oz\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eAlarms\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eAudible, visual \u0026amp; vibration\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003c\/div\u003e\n\n\u003ch3\u003eWhere the Forensics 4 Gas Pump Monitor fits\u003c\/h3\u003e\n\n\u003cul\u003e\n\u003cli\u003ePlaced continuous monitoring during a job\u003c\/li\u003e\n\u003cli\u003eConfined-space hole watch at the entry\u003c\/li\u003e\n\u003cli\u003eHot-work and turnaround monitoring\u003c\/li\u003e\n\u003cli\u003ePre-entry sampling (pump)\u003c\/li\u003e\n\u003cli\u003eDatalogged exposure records for a task\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2 id=\"compatibility\"\u003eWhat the Forensics 4 Gas Pump Monitor detects (and what it doesn’t)\u003c\/h2\u003e\n\n\u003cp\u003eIt monitors oxygen (O2), combustible gas (LEL), carbon monoxide (CO) and hydrogen sulfide (H2S) with a built-in pump and logs the data — ideal for placing at a worksite for continuous coverage during a job, or carrying for pre-entry sampling. It is a single unit, \u003cstrong\u003enot\u003c\/strong\u003e a wireless-mesh area monitor: for a networked multi-zone perimeter (AreaRAE\/Radius class), distributor sourcing is required. It does not read VOCs or specific toxics. For permanent unattended coverage use a \u003ca href=\"\/collections\/fixed-gas-detection-systems\" title=\"Fixed Gas Detection Systems\"\u003eFixed Gas Detection Systems\u003c\/a\u003e system; for per-worker wear a \u003ca href=\"\/collections\/personal-gas-detectors\" title=\"Personal \u0026amp; Wearable Gas Detectors\"\u003ePersonal \u0026amp; Wearable Gas Detectors\u003c\/a\u003e clip; for a carried handheld see \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"Portable Gas Detectors\"\u003ePortable Gas Detectors\u003c\/a\u003e.\u003c\/p\u003e\u003cp style=\"background:#1a2733;border-left:4px solid #4fc3f7;padding:12px 16px;color:#cfd8dc;font-size:0.92em;\"\u003e\u003cstrong style=\"color:#4fc3f7;\"\u003eNote on wireless area monitors:\u003c\/strong\u003e true wireless-mesh area monitors (the AreaRAE, Industrial Scientific Radius and RAE MeshGuard class) are sold through industrial distributors, not retail. The instruments here are transportable continuous monitors you place at the hazard for the length of a job — for a networked multi-zone perimeter, contact us about distributor-sourced wireless area monitors.\u003c\/p\u003e\n\n\u003cp\u003eCross-shopping? This unit sits in our \u003ca href=\"\/collections\/area-gas-monitors\" title=\"Area \u0026amp; Transportable Gas Monitors\"\u003eArea \u0026amp; Transportable Gas Monitors\u003c\/a\u003e hub alongside \u003ca href=\"\/products\/forensics-4-gas-data-logger-monitor\" title=\"Forensics 4 Gas Data Logger\"\u003eForensics 4 Gas Data Logger\u003c\/a\u003e, \u003ca href=\"\/products\/forensics-detectors-4-gas-monitor-with-pump\" title=\"Forensics 4 Gas Monitor + Pump\"\u003eForensics 4 Gas Monitor + Pump\u003c\/a\u003e. For other gas-detection form factors see \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"Portable Gas Detectors\"\u003ePortable Gas Detectors\u003c\/a\u003e, \u003ca href=\"\/collections\/personal-gas-detectors\" title=\"Personal \u0026amp; Wearable Gas Detectors\"\u003ePersonal \u0026amp; Wearable Gas Detectors\u003c\/a\u003e, \u003ca href=\"\/collections\/fixed-gas-detection-systems\" title=\"Fixed Gas Detection Systems\"\u003eFixed Gas Detection Systems\u003c\/a\u003e, or browse the full \u003ca href=\"\/collections\/gas-detectors\" title=\"Gas Detectors\"\u003eGas Detectors\u003c\/a\u003e range.\u003c\/p\u003e\n\n\u003ch2 id=\"comparison\"\u003eForensics transportable continuous-monitoring family compared\u003c\/h2\u003e\n\n\u003cdiv style=\"overflow-x:auto;\"\u003e\u003ctable style=\"width:100%;border-collapse:collapse;background:#1a1a1a;margin:14px 0;\"\u003e\n\u003ccaption style=\"color:#bdae9d;font-size:0.85em;text-align:left;padding:4px 0;\"\u003eForensics transportable continuous-monitoring family (O2, CO, H2S, LEL, NIST-calibrated)\u003c\/caption\u003e\n\u003cthead\u003e\u003ctr style=\"background:#2a2a2a;\"\u003e\n\u003cth style=\"color:#ffb74d;padding:9px;border:1px solid #3a3a3a;text-align:left;\"\u003eModel\u003c\/th\u003e\n\u003cth style=\"color:#ffb74d;padding:9px;border:1px solid #3a3a3a;text-align:left;\"\u003eForm\u003c\/th\u003e\n\u003cth style=\"color:#ffb74d;padding:9px;border:1px solid #3a3a3a;text-align:left;\"\u003eDatalogging\u003c\/th\u003e\n\u003cth style=\"color:#ffb74d;padding:9px;border:1px solid #3a3a3a;text-align:left;\"\u003eBest for\u003c\/th\u003e\n\u003cth style=\"color:#ffb74d;padding:9px;border:1px solid #3a3a3a;text-align:left;\"\u003eStreet price\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e\u003ca href=\"\/products\/forensics-detectors-4-gas-monitor-with-pump\" title=\"4 Gas + Pump\"\u003e4 Gas + Pump\u003c\/a\u003e\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eHandheld pump\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eEvent log\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003ePre-entry + spot continuous\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e~$299\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e\u003ca href=\"\/products\/forensics-4-gas-pump-monitor-datalogging\" title=\"4 Gas Pump + Datalogging\"\u003e4 Gas Pump + Datalogging\u003c\/a\u003e\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eHandheld pump\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eColor graphing log\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003ePlaced continuous monitoring\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e~$595\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#2a2520;\"\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e\u003cstrong\u003e\u003ca href=\"\/products\/forensics-4-gas-data-logger-monitor\" title=\"4 Gas Data Logger\"\u003e4 Gas Data Logger\u003c\/a\u003e\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eLarger transportable\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eComputer datalogging\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eExtended job-site monitoring\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e~$1,399\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003c\/div\u003e\n\n\u003cul\u003e\n\u003cli\u003eChoose this \u003cstrong\u003e4 Gas Pump Monitor\u003c\/strong\u003e for placed continuous monitoring with color graphing and datalogging at a mid price.\u003c\/li\u003e\n\u003cli\u003eStep up to the \u003ca href=\"\/products\/forensics-4-gas-data-logger-monitor\" title=\"4 Gas Data Logger\"\u003e4 Gas Data Logger\u003c\/a\u003e for a larger transportable unit with extended computer datalogging.\u003c\/li\u003e\n\u003cli\u003eFor a lighter pre-entry-focused pump unit, the \u003ca href=\"\/products\/forensics-detectors-4-gas-monitor-with-pump\" title=\"4 Gas Monitor + Pump\"\u003e4 Gas Monitor + Pump\u003c\/a\u003e costs less.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2 id=\"faq\"\u003eFrequently asked questions\u003c\/h2\u003e\n\n\u003ch3\u003eIs the Forensics 4 gas pump monitor an area monitor?\u003c\/h3\u003e\u003cp\u003eIt is a transportable continuous monitor you place at a hazard for a job — an area-monitoring use. It is not a wireless-mesh networked area monitor; for that class, distributor-sourced units like AreaRAE are needed. See the \u003ca href=\"\/collections\/area-gas-monitors\" title=\"Area \u0026amp; Transportable Gas Monitors\"\u003eArea \u0026amp; Transportable Gas Monitors\u003c\/a\u003e hub note.\u003c\/p\u003e\n\u003ch3\u003eWhat gases does it monitor?\u003c\/h3\u003e\u003cp\u003eIt monitors oxygen (O2), combustible gas (LEL), carbon monoxide (CO) and hydrogen sulfide (H2S) with a built-in pump. It does not read VOCs, CO2 or specific toxics like chlorine.\u003c\/p\u003e\n\u003ch3\u003eDoes it log data?\u003c\/h3\u003e\u003cp\u003eYes — it has on-board datalogging with computer download and a color display with live graphing, so you can record and review a job's exposure trend.\u003c\/p\u003e\n\u003ch3\u003eCan I use it for confined-space hole watch?\u003c\/h3\u003e\u003cp\u003eYes — placed at the entry it provides continuous monitoring during entry, alongside the entrant's \u003ca href=\"\/collections\/personal-gas-detectors\" title=\"Personal \u0026amp; Wearable Gas Detectors\"\u003ePersonal \u0026amp; Wearable Gas Detectors\u003c\/a\u003e clip and pre-entry testing with a \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"Portable Gas Detectors\"\u003ePortable Gas Detectors\u003c\/a\u003e instrument.\u003c\/p\u003e\n\u003ch3\u003eDoes it have a pump for pre-entry sampling?\u003c\/h3\u003e\u003cp\u003eYes — the built-in sample-draw pump lets you test a space before entry as well as monitor continuously during the job.\u003c\/p\u003e\n\u003ch3\u003eHow is it different from the larger Data Logger model?\u003c\/h3\u003e\u003cp\u003eThe \u003ca href=\"\/products\/forensics-4-gas-data-logger-monitor\" title=\"4 Gas Data Logger\"\u003e4 Gas Data Logger\u003c\/a\u003e is a larger, higher-tier transportable unit with extended computer datalogging; this model is the lighter, lower-cost continuous monitor.\u003c\/p\u003e\n\u003ch3\u003eIs it NIST calibrated?\u003c\/h3\u003e\u003cp\u003eYes — it ships with USA NIST-traceable calibration; bump-test before use and recalibrate on schedule.\u003c\/p\u003e\n\u003ch3\u003eCan it cover a whole perimeter?\u003c\/h3\u003e\u003cp\u003eOne unit covers the zone where it sits. For a multi-zone perimeter you place several monitors or use a distributor-sourced wireless-mesh system; for permanent coverage use a \u003ca href=\"\/collections\/fixed-gas-detection-systems\" title=\"Fixed Gas Detection Systems\"\u003eFixed Gas Detection Systems\u003c\/a\u003e system.\u003c\/p\u003e\n\u003ch3\u003eWhat alarms does it have?\u003c\/h3\u003e\u003cp\u003eAudible, visual and vibration alarms trigger when any of the four gases exceeds its set point.\u003c\/p\u003e\n\u003ch3\u003eWhat does it not detect?\u003c\/h3\u003e\u003cp\u003eVOCs, CO2 and specific toxics. For VOC monitoring a PID is required; see the \u003ca href=\"\/collections\/gas-detectors\" title=\"Gas Detectors\"\u003eGas Detectors\u003c\/a\u003e hub for instrument types.\u003c\/p\u003e\n\u003ch3\u003eIs it in stock and how does it ship?\u003c\/h3\u003e\u003cp\u003eUse the Amazon buy button for current availability and delivery timing through our fulfillment partner.\u003c\/p\u003e\n\u003ch3\u003eDoes the pump need maintenance?\u003c\/h3\u003e\u003cp\u003eYes — keep the pump path and probe clean and check flow per the instructions so samples draw correctly during continuous monitoring.\u003c\/p\u003e\n\n\u003cdiv style=\"background:#1a1a1a;border:1px solid #3a3a3a;border-radius:6px;padding:16px 18px;margin:22px 0;\"\u003e\n\u003cp style=\"margin:0 0 10px 0;color:#f5e6d3;\"\u003eReady to order the \u003cstrong\u003eForensics 4 gas pump monitor\u003c\/strong\u003e? Add it to your cart above, or check the current Amazon price below. Compare it against the rest of our \u003ca href=\"\/collections\/area-gas-monitors\" title=\"Area \u0026amp; Transportable Gas Monitors\"\u003eArea \u0026amp; Transportable Gas Monitors\u003c\/a\u003e lineup before you buy.\u003c\/p\u003e\n\u003cp style=\"display:flex;gap:10px;flex-wrap:wrap;align-items:center;margin:0;\"\u003e\u003ca href=\"https:\/\/www.amazon.com\/dp\/B07WKC4FTV?tag=wcsafety04-20\" rel=\"sponsored nofollow noopener\" target=\"_blank\" style=\"display:inline-block;background:#FFD814;color:#0F1111;padding:13px 26px;text-decoration:none;font-weight:bold;border-radius:4px;border:1px solid #FCD200;\"\u003eCHECK PRICE ON AMAZON →\u003c\/a\u003e\u003cspan style=\"font-size:0.8em;color:#bdae9d;\"\u003eAs an Amazon Associate, WC Safety earns from qualifying purchases.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/div\u003e\n\n\u003cdiv style=\"background:#1a2733;border:1px dashed #4fc3f7;padding:16px 20px;margin:30px 0 18px 0;color:#cfd8dc;font-size:0.92em;\"\u003e\n  \u003cstrong style=\"color:#4fc3f7;\"\u003eWhy trust this Forensics Detectors page?\u003c\/strong\u003e WC Safety is an independent industrial safety-equipment retailer serving safety managers, procurement teams and field supervisors. The specifications here are taken from the manufacturer’s published listing for Forensics 4 Gas Pump Monitor and framed against \u003ca href=\"https:\/\/www.osha.gov\/laws-regs\/regulations\/standardnumber\/1910\/1910.146\" rel=\"noopener\" target=\"_blank\" style=\"color:#4fc3f7;\"\u003eOSHA 29 CFR 1910.146\u003c\/a\u003e and \u003ca href=\"https:\/\/www.osha.gov\/annotated-pels\" rel=\"noopener\" target=\"_blank\" style=\"color:#4fc3f7;\"\u003eOSHA Permissible Exposure Limits\u003c\/a\u003e. Disclosed: WC Safety earns Amazon affiliate commissions on outbound clicks; that does not influence the specs shown or our lineup.\n\u003c\/div\u003e\n\u003cdiv style=\"background:#1a2733;border-left:4px solid #4fc3f7;padding:18px 22px;margin:18px 0;color:#cfd8dc;font-size:0.92em;\"\u003e\n  \u003cstrong style=\"color:#4fc3f7;\"\u003eBy Steven Eaton, WC Safety Editorial\u003c\/strong\u003e — Industrial safety-equipment desk · specialization: atmospheric monitoring, gas detection and instrument selection.\u003cbr\u003e\n  \u003cstrong\u003eLast updated:\u003c\/strong\u003e \u003ctime datetime=\"2026-06-22\"\u003eJune 22, 2026\u003c\/time\u003e · \u003cstrong\u003eSources reviewed:\u003c\/strong\u003e manufacturer product listing \u0026amp; specifications, OSHA 29 CFR 1910.146, OSHA Annotated PEL tables, ACGIH Threshold Limit Values.\u003cbr\u003e\n  \u003cstrong\u003eEditorial standard:\u003c\/strong\u003e \u003cem\u003eZero sponsored listings. No manufacturer input. Specs verified against the manufacturer’s published data.\u003c\/em\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"background:#1a2733;border-left:4px solid #4fc3f7;padding:16px 20px;margin:18px 0;color:#cfd8dc;font-size:0.92em;\"\u003e\n  \u003cstrong style=\"color:#4fc3f7;\"\u003eHow this page is maintained.\u003c\/strong\u003e Specifications and pricing are reviewed against the manufacturer’s current listing and re-checked whenever the lineup changes. Gas-detection guidance follows \u003ca href=\"https:\/\/www.osha.gov\/laws-regs\/regulations\/standardnumber\/1910\/1910.146\" rel=\"noopener\" target=\"_blank\" style=\"color:#4fc3f7;\"\u003eOSHA 1910.146\u003c\/a\u003e and \u003ca href=\"https:\/\/www.osha.gov\/annotated-pels\" rel=\"noopener\" target=\"_blank\" style=\"color:#4fc3f7;\"\u003eOSHA PELs\u003c\/a\u003e, cross-referenced with ACGIH TLVs.\n\u003c\/div\u003e\n\u003cdiv style=\"background:#2a2520;border-left:4px solid #ff9800;padding:16px 20px;margin:18px 0;color:#f5e6d3;font-size:0.92em;\"\u003e\n  \u003cstrong style=\"color:#ffb74d;\"\u003eDisclosure.\u003c\/strong\u003e WC Safety participates in the Amazon Associates Program and earns commissions on qualifying purchases through outbound links on this page (tag wcsafety04-20). We are not sponsored by any instrument manufacturer. This page is buyer guidance, not medical, legal or regulatory advice — confirm gas-detection requirements for your site against the applicable OSHA standard and, for commercial monitoring programs, a Certified Industrial Hygienist (CIH).\n\u003c\/div\u003e\n\n\u003cscript type=\"application\/ld+json\"\u003e\n{\"@context\": \"https:\/\/schema.org\", \"@graph\": [{\"@type\": \"Product\", \"@id\": \"https:\/\/wcsafety.com\/products\/forensics-4-gas-pump-monitor-datalogging#product\", \"name\": \"Forensics 4 Gas Pump Monitor — Datalogging, Color Display (O2, CO, H2S, LEL)\", \"description\": \"Forensics 4 gas pump monitor — transportable continuous O2, CO, H2S \u0026 LEL monitor with built-in pump, color graphing and datalogging. NIST-calibrated.\", \"sku\": \"B07WKC4FTV\", \"mpn\": \"FD-4GP-DL\", \"image\": [\"https:\/\/wcsafety.com\/cdn\/shop\/products\/forensics-4-gas-pump-monitor-datalogging.jpg\"], \"brand\": {\"@type\": \"Brand\", \"name\": \"Forensics Detectors\"}, \"category\": \"Area Gas Monitor\", \"isPartOf\": {\"@type\": \"CollectionPage\", \"@id\": \"https:\/\/wcsafety.com\/collections\/area-gas-monitors#collection\", \"name\": \"Area \u0026 Transportable Gas Monitors\", \"url\": \"https:\/\/wcsafety.com\/collections\/area-gas-monitors\"}, \"isRelatedTo\": [{\"@type\": \"Product\", \"name\": \"Forensics 4 Gas Data Logger Monitor\", \"url\": \"https:\/\/wcsafety.com\/products\/forensics-4-gas-data-logger-monitor\"}, {\"@type\": \"Product\", \"name\": \"Forensics Detectors 4 Gas Monitor with Pump\", \"url\": \"https:\/\/wcsafety.com\/products\/forensics-detectors-4-gas-monitor-with-pump\"}], \"offers\": {\"@type\": \"Offer\", \"url\": \"https:\/\/wcsafety.com\/products\/forensics-4-gas-pump-monitor-datalogging\", \"priceCurrency\": \"USD\", \"price\": \"595.45\", \"availability\": \"https:\/\/schema.org\/InStock\", \"seller\": {\"@type\": \"Organization\", \"name\": \"WC Safety\"}}}, {\"@type\": \"BreadcrumbList\", \"@id\": \"https:\/\/wcsafety.com\/products\/forensics-4-gas-pump-monitor-datalogging#breadcrumb\", \"itemListElement\": [{\"@type\": \"ListItem\", \"position\": 1, \"name\": \"Home\", \"item\": \"https:\/\/wcsafety.com\/\"}, {\"@type\": \"ListItem\", \"position\": 2, \"name\": \"Gas Detectors\", \"item\": \"https:\/\/wcsafety.com\/collections\/gas-detectors\"}, {\"@type\": \"ListItem\", \"position\": 3, \"name\": \"Area \u0026 Transportable Gas Monitors\", \"item\": \"https:\/\/wcsafety.com\/collections\/area-gas-monitors\"}, {\"@type\": \"ListItem\", \"position\": 4, \"name\": \"Forensics 4 Gas Pump Monitor — Datalogging, Color Display (O2, CO, H2S, LEL)\"}]}, {\"@type\": \"FAQPage\", \"mainEntity\": [{\"@type\": \"Question\", \"name\": \"Is the Forensics 4 gas pump monitor an area monitor?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"It is a transportable continuous monitor you place at a hazard for a job — an area-monitoring use. It is not a wireless-mesh networked area monitor; for that class, distributor-sourced units like AreaRAE are needed. See the Area \u0026 Transportable Gas Monitors hub note.\"}}, {\"@type\": \"Question\", \"name\": \"What gases does it monitor?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"It monitors oxygen (O2), combustible gas (LEL), carbon monoxide (CO) and hydrogen sulfide (H2S) with a built-in pump. It does not read VOCs, CO2 or specific toxics like chlorine.\"}}, {\"@type\": \"Question\", \"name\": \"Does it log data?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Yes — it has on-board datalogging with computer download and a color display with live graphing, so you can record and review a job's exposure trend.\"}}, {\"@type\": \"Question\", \"name\": \"Can I use it for confined-space hole watch?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Yes — placed at the entry it provides continuous monitoring during entry, alongside the entrant's Personal \u0026 Wearable Gas Detectors clip and pre-entry testing with a Portable Gas Detectors instrument.\"}}, {\"@type\": \"Question\", \"name\": \"Does it have a pump for pre-entry sampling?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Yes — the built-in sample-draw pump lets you test a space before entry as well as monitor continuously during the job.\"}}, {\"@type\": \"Question\", \"name\": \"How is it different from the larger Data Logger model?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"The 4 Gas Data Logger is a larger, higher-tier transportable unit with extended computer datalogging; this model is the lighter, lower-cost continuous monitor.\"}}, {\"@type\": \"Question\", \"name\": \"Is it NIST calibrated?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Yes — it ships with USA NIST-traceable calibration; bump-test before use and recalibrate on schedule.\"}}, {\"@type\": \"Question\", \"name\": \"Can it cover a whole perimeter?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"One unit covers the zone where it sits. For a multi-zone perimeter you place several monitors or use a distributor-sourced wireless-mesh system; for permanent coverage use a Fixed Gas Detection Systems system.\"}}, {\"@type\": \"Question\", \"name\": \"What alarms does it have?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Audible, visual and vibration alarms trigger when any of the four gases exceeds its set point.\"}}, {\"@type\": \"Question\", \"name\": \"What does it not detect?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"VOCs, CO2 and specific toxics. For VOC monitoring a PID is required; see the Gas Detectors hub for instrument types.\"}}, {\"@type\": \"Question\", \"name\": \"Is it in stock and how does it ship?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Use the Amazon buy button for current availability and delivery timing through our fulfillment partner.\"}}, {\"@type\": \"Question\", \"name\": \"Does the pump need maintenance?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Yes — keep the pump path and probe clean and check flow per the instructions so samples draw correctly during continuous monitoring.\"}}]}, {\"@type\": \"Organization\", \"@id\": \"https:\/\/wcsafety.com\/#org\", \"name\": \"WC Safety\", \"url\": \"https:\/\/wcsafety.com\", \"logo\": \"https:\/\/wcsafety.com\/cdn\/shop\/files\/logo.png\"}, {\"@type\": \"Person\", \"@id\": \"https:\/\/wcsafety.com\/#editor\", \"name\": \"Steven Eaton\", \"jobTitle\": \"Editorial Lead\", \"worksFor\": {\"@id\": \"https:\/\/wcsafety.com\/#org\"}, \"knowsAbout\": [\"industrial gas detection\", \"atmospheric monitoring\", \"personal protective equipment\"]}, {\"@type\": \"Brand\", \"name\": \"Forensics Detectors\"}]}\n\u003c\/script\u003e","brand":"Forensics Detectors","offers":[{"title":"Default Title","offer_id":44266505633880,"sku":"B07WKC4FTV","price":595.45,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0594\/1900\/0920\/files\/71rtlJMgoPL._AC_SL1500.jpg?v=1782123129"},{"product_id":"forensics-4-gas-data-logger-monitor","title":"Forensics 4 Gas Data Logger Monitor — Built-in Pump, Graphing (O2, CO, H2S, LEL)","description":"\u003c!-- PRODUCT B0DM712D9P | tag area-gas-monitor | TODO: add matching Product Review + best-of guide links when those silo layers exist --\u003e\n\n\u003cdiv style=\"background:#1a1a1a;border-left:4px solid #ff9800;padding:14px 18px;margin:0 0 18px 0;color:#f5e6d3;font-size:0.95em;\"\u003e\n\u003cstrong style=\"color:#ffb74d;\"\u003eEditor’s note:\u003c\/strong\u003e the Forensics 4 gas data logger monitor is one of the instruments we curate in our \u003ca href=\"\/collections\/area-gas-monitors\" title=\"Area \u0026amp; Transportable Gas Monitors\"\u003eArea \u0026amp; Transportable Gas Monitors\u003c\/a\u003e buyer’s hub. Compare it with the \u003ca href=\"\/products\/forensics-4-gas-pump-monitor-datalogging\" title=\"Forensics 4 Gas Pump Monitor\"\u003eForensics 4 Gas Pump Monitor\u003c\/a\u003e below before you order.\u003c\/div\u003e\n\n\u003ch2 id=\"top\"\u003eForensics 4 Gas Data Logger Monitor — Transportable Job-Site Monitoring\u003c\/h2\u003e\n\n\u003cp\u003eThe \u003cstrong\u003eForensics 4 gas data logger monitor\u003c\/strong\u003e is the larger, datalogging-focused transportable in the family — an \u003ca href=\"\/collections\/area-gas-monitors\" title=\"area and transportable gas monitor\"\u003earea and transportable gas monitor\u003c\/a\u003e you place at a worksite to monitor oxygen (O2), combustible gas (LEL), carbon monoxide (CO) and hydrogen sulfide (H2S) continuously with full computer datalogging for the record.\u003c\/p\u003e\n\n\u003cp style=\"font-size:0.9em;color:#bdae9d;margin:10px 0 18px 0;\"\u003eJump to: \u003ca href=\"#features\" style=\"color:#ffb74d;\"\u003eFeatures\u003c\/a\u003e · \u003ca href=\"#specs\" style=\"color:#ffb74d;\"\u003eSpecs\u003c\/a\u003e · \u003ca href=\"#compatibility\" style=\"color:#ffb74d;\"\u003eWhat it detects\u003c\/a\u003e · \u003ca href=\"#comparison\" style=\"color:#ffb74d;\"\u003eComparison\u003c\/a\u003e · \u003ca href=\"#faq\" style=\"color:#ffb74d;\"\u003eFAQ\u003c\/a\u003e\u003c\/p\u003e\n\n\u003cp\u003eThe Forensics 4 Gas Data Logger Monitor is a larger transportable, NIST-calibrated continuous monitor for O2, CO, H2S and LEL with a built-in pump, color graphing display and full computer datalogging.\u003c\/p\u003e\n\n\u003ch3 id=\"features\"\u003eKey features\u003c\/h3\u003e\n\n\u003cul\u003e\n\u003cli\u003eLarger transportable unit monitoring oxygen (O2), combustible gas (LEL), carbon monoxide (CO) and hydrogen sulfide (H2S) continuously with a built-in pump\u003c\/li\u003e\n\u003cli\u003eColor display with live graphing for trend visibility during a job\u003c\/li\u003e\n\u003cli\u003eFull computer datalogging for detailed exposure records\u003c\/li\u003e\n\u003cli\u003eUSA NIST-traceable calibration\u003c\/li\u003e\n\u003cli\u003eBuilt for extended placed monitoring of a worksite zone\u003c\/li\u003e\n\u003cli\u003eAudible and visual alarms\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cdiv style=\"display:flex;gap:14px;flex-wrap:wrap;margin:18px 0;\"\u003e\n\u003cdiv style=\"flex:1;min-width:240px;background:#1b3a2a;border:1px solid #4caf50;border-radius:6px;padding:14px 18px;\"\u003e\n\u003cstrong style=\"color:#81c784;\"\u003ePros\u003c\/strong\u003e\u003cul style=\"margin:8px 0 0 0;\"\u003e\n\u003cli\u003eExtended computer datalogging\u003c\/li\u003e\n\u003cli\u003eLarger transportable form for job-site placement\u003c\/li\u003e\n\u003cli\u003eBuilt-in pump + color graphing\u003c\/li\u003e\n\u003cli\u003eNIST-traceable calibration\u003c\/li\u003e\n\u003cli\u003eDetailed records for compliance\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"flex:1;min-width:240px;background:#3a1e1e;border:1px solid #ef5350;border-radius:6px;padding:14px 18px;\"\u003e\n\u003cstrong style=\"color:#e57373;\"\u003eCons\u003c\/strong\u003e\u003cul style=\"margin:8px 0 0 0;\"\u003e\n\u003cli\u003eHighest price in the transportable family\u003c\/li\u003e\n\u003cli\u003eNot a wireless-mesh networked area monitor\u003c\/li\u003e\n\u003cli\u003eHeavier (3.1 lb)\u003c\/li\u003e\n\u003cli\u003eElectrochemical sensors and pump need upkeep\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\n\u003ch3 id=\"specs\"\u003eSpecifications\u003c\/h3\u003e\n\n\u003cdiv style=\"overflow-x:auto;\"\u003e\u003ctable style=\"width:100%;border-collapse:collapse;background:#1a1a1a;margin:14px 0;\"\u003e\n\u003cthead\u003e\u003ctr style=\"background:#2a2a2a;\"\u003e\n\u003cth style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;text-align:left;\"\u003eSpecification\u003c\/th\u003e\n\u003cth style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;text-align:left;\"\u003eDetail\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eGases detected\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eO2, CO, H2S, LEL combustibles\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eSampling\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eBuilt-in pump (sample-draw)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eDisplay\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eColor with live graphing\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eDatalogging\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eComputer datalogging\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eCalibration\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eUSA NIST-traceable\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eForm\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eLarger transportable unit\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eWeight\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003e3.1 lb\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003c\/div\u003e\n\n\u003ch3\u003eWhere the Forensics 4 Gas Data Logger fits\u003c\/h3\u003e\n\n\u003cul\u003e\n\u003cli\u003eExtended turnaround and shutdown monitoring\u003c\/li\u003e\n\u003cli\u003ePlaced continuous job-site coverage\u003c\/li\u003e\n\u003cli\u003eDatalogged compliance records for a task\u003c\/li\u003e\n\u003cli\u003eConfined-space attendant monitoring\u003c\/li\u003e\n\u003cli\u003eEnvironmental\/spill response logging\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2 id=\"compatibility\"\u003eWhat the Forensics 4 Gas Data Logger detects (and what it doesn’t)\u003c\/h2\u003e\n\n\u003cp\u003eIt monitors oxygen (O2), combustible gas (LEL), carbon monoxide (CO) and hydrogen sulfide (H2S) with a built-in pump and full computer datalogging — built for extended placed monitoring of a zone with detailed records. Like the rest of the family it is a single transportable unit, \u003cstrong\u003enot\u003c\/strong\u003e a wireless-mesh networked area monitor; for a multi-zone perimeter (AreaRAE\/Radius class) distributor sourcing is required. It does not read VOCs or specific toxics. For permanent coverage use a \u003ca href=\"\/collections\/fixed-gas-detection-systems\" title=\"Fixed Gas Detection Systems\"\u003eFixed Gas Detection Systems\u003c\/a\u003e system; for per-worker wear a \u003ca href=\"\/collections\/personal-gas-detectors\" title=\"Personal \u0026amp; Wearable Gas Detectors\"\u003ePersonal \u0026amp; Wearable Gas Detectors\u003c\/a\u003e clip; for a lighter carried unit see \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"Portable Gas Detectors\"\u003ePortable Gas Detectors\u003c\/a\u003e.\u003c\/p\u003e\u003cp style=\"background:#1a2733;border-left:4px solid #4fc3f7;padding:12px 16px;color:#cfd8dc;font-size:0.92em;\"\u003e\u003cstrong style=\"color:#4fc3f7;\"\u003eNote on wireless area monitors:\u003c\/strong\u003e true wireless-mesh area monitors (the AreaRAE, Industrial Scientific Radius and RAE MeshGuard class) are sold through industrial distributors, not retail. The instruments here are transportable continuous monitors you place at the hazard for the length of a job — for a networked multi-zone perimeter, contact us about distributor-sourced wireless area monitors.\u003c\/p\u003e\n\n\u003cp\u003eCross-shopping? This unit sits in our \u003ca href=\"\/collections\/area-gas-monitors\" title=\"Area \u0026amp; Transportable Gas Monitors\"\u003eArea \u0026amp; Transportable Gas Monitors\u003c\/a\u003e hub alongside \u003ca href=\"\/products\/forensics-4-gas-pump-monitor-datalogging\" title=\"Forensics 4 Gas Pump Monitor\"\u003eForensics 4 Gas Pump Monitor\u003c\/a\u003e, \u003ca href=\"\/products\/forensics-detectors-4-gas-monitor-with-pump\" title=\"Forensics 4 Gas Monitor + Pump\"\u003eForensics 4 Gas Monitor + Pump\u003c\/a\u003e. For other gas-detection form factors see \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"Portable Gas Detectors\"\u003ePortable Gas Detectors\u003c\/a\u003e, \u003ca href=\"\/collections\/personal-gas-detectors\" title=\"Personal \u0026amp; Wearable Gas Detectors\"\u003ePersonal \u0026amp; Wearable Gas Detectors\u003c\/a\u003e, \u003ca href=\"\/collections\/fixed-gas-detection-systems\" title=\"Fixed Gas Detection Systems\"\u003eFixed Gas Detection Systems\u003c\/a\u003e, or browse the full \u003ca href=\"\/collections\/gas-detectors\" title=\"Gas Detectors\"\u003eGas Detectors\u003c\/a\u003e range.\u003c\/p\u003e\n\n\u003ch2 id=\"comparison\"\u003eForensics transportable continuous-monitoring family compared\u003c\/h2\u003e\n\n\u003cdiv style=\"overflow-x:auto;\"\u003e\u003ctable style=\"width:100%;border-collapse:collapse;background:#1a1a1a;margin:14px 0;\"\u003e\n\u003ccaption style=\"color:#bdae9d;font-size:0.85em;text-align:left;padding:4px 0;\"\u003eForensics transportable continuous-monitoring family (O2, CO, H2S, LEL, NIST-calibrated)\u003c\/caption\u003e\n\u003cthead\u003e\u003ctr style=\"background:#2a2a2a;\"\u003e\n\u003cth style=\"color:#ffb74d;padding:9px;border:1px solid #3a3a3a;text-align:left;\"\u003eModel\u003c\/th\u003e\n\u003cth style=\"color:#ffb74d;padding:9px;border:1px solid #3a3a3a;text-align:left;\"\u003eForm\u003c\/th\u003e\n\u003cth style=\"color:#ffb74d;padding:9px;border:1px solid #3a3a3a;text-align:left;\"\u003eDatalogging\u003c\/th\u003e\n\u003cth style=\"color:#ffb74d;padding:9px;border:1px solid #3a3a3a;text-align:left;\"\u003eBest for\u003c\/th\u003e\n\u003cth style=\"color:#ffb74d;padding:9px;border:1px solid #3a3a3a;text-align:left;\"\u003eStreet price\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e\u003ca href=\"\/products\/forensics-detectors-4-gas-monitor-with-pump\" title=\"4 Gas + Pump\"\u003e4 Gas + Pump\u003c\/a\u003e\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eHandheld pump\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eEvent log\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003ePre-entry + spot continuous\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e~$299\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e\u003ca href=\"\/products\/forensics-4-gas-pump-monitor-datalogging\" title=\"4 Gas Pump + Datalogging\"\u003e4 Gas Pump + Datalogging\u003c\/a\u003e\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eHandheld pump\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eColor graphing log\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003ePlaced continuous monitoring\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e~$595\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#2a2520;\"\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e\u003cstrong\u003e\u003ca href=\"\/products\/forensics-4-gas-data-logger-monitor\" title=\"4 Gas Data Logger\"\u003e4 Gas Data Logger\u003c\/a\u003e\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eLarger transportable\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eComputer datalogging\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eExtended job-site monitoring\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e~$1,399\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003c\/div\u003e\n\n\u003cul\u003e\n\u003cli\u003eChoose the \u003cstrong\u003e4 Gas Data Logger\u003c\/strong\u003e for extended placed monitoring with full computer datalogging and a larger transportable body.\u003c\/li\u003e\n\u003cli\u003eFor a lighter, lower-cost continuous monitor, the \u003ca href=\"\/products\/forensics-4-gas-pump-monitor-datalogging\" title=\"4 Gas Pump Monitor\"\u003e4 Gas Pump Monitor\u003c\/a\u003e covers most jobs.\u003c\/li\u003e\n\u003cli\u003eFor pre-entry-focused use, the \u003ca href=\"\/products\/forensics-detectors-4-gas-monitor-with-pump\" title=\"4 Gas Monitor + Pump\"\u003e4 Gas Monitor + Pump\u003c\/a\u003e is the value pump option.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2 id=\"faq\"\u003eFrequently asked questions\u003c\/h2\u003e\n\n\u003ch3\u003eIs the Forensics 4 gas data logger an area monitor?\u003c\/h3\u003e\u003cp\u003eIt is a larger transportable continuous monitor for placed job-site monitoring — an area-monitoring use. It is not a wireless-mesh networked monitor; for that class see the distributor note in the \u003ca href=\"\/collections\/area-gas-monitors\" title=\"Area \u0026amp; Transportable Gas Monitors\"\u003eArea \u0026amp; Transportable Gas Monitors\u003c\/a\u003e hub.\u003c\/p\u003e\n\u003ch3\u003eWhat gases does it monitor?\u003c\/h3\u003e\u003cp\u003eIt monitors oxygen (O2), combustible gas (LEL), carbon monoxide (CO) and hydrogen sulfide (H2S) with a built-in pump. It does not read VOCs, CO2 or specific toxics.\u003c\/p\u003e\n\u003ch3\u003eWhat datalogging does it offer?\u003c\/h3\u003e\u003cp\u003eFull computer datalogging plus a color display with live graphing, giving you detailed records of a job's exposure over time for compliance.\u003c\/p\u003e\n\u003ch3\u003eHow is it different from the standard pump monitor?\u003c\/h3\u003e\u003cp\u003eIt is a larger, higher-tier transportable unit focused on extended datalogging; the \u003ca href=\"\/products\/forensics-4-gas-pump-monitor-datalogging\" title=\"4 Gas Pump Monitor\"\u003e4 Gas Pump Monitor\u003c\/a\u003e is lighter and lower cost for most jobs.\u003c\/p\u003e\n\u003ch3\u003eCan it do pre-entry sampling?\u003c\/h3\u003e\u003cp\u003eYes — the built-in sample-draw pump lets you test a space before entry as well as monitor continuously during the work.\u003c\/p\u003e\n\u003ch3\u003eIs it good for turnarounds and shutdowns?\u003c\/h3\u003e\u003cp\u003eYes — its extended datalogging and transportable form suit long placed-monitoring tasks like turnarounds, with a record of the whole job.\u003c\/p\u003e\n\u003ch3\u003eIs it NIST calibrated?\u003c\/h3\u003e\u003cp\u003eYes — USA NIST-traceable calibration; bump-test before use and recalibrate on schedule.\u003c\/p\u003e\n\u003ch3\u003eCan it monitor a whole perimeter alone?\u003c\/h3\u003e\u003cp\u003eOne unit covers its zone. For a networked multi-zone perimeter use several units or a distributor-sourced wireless-mesh system; for permanent coverage a \u003ca href=\"\/collections\/fixed-gas-detection-systems\" title=\"Fixed Gas Detection Systems\"\u003eFixed Gas Detection Systems\u003c\/a\u003e system.\u003c\/p\u003e\n\u003ch3\u003eWhat alarms does it have?\u003c\/h3\u003e\u003cp\u003eAudible and visual alarms trigger when any of the four gases exceeds its set point.\u003c\/p\u003e\n\u003ch3\u003eWhat does it not detect?\u003c\/h3\u003e\u003cp\u003eVOCs, CO2 and specific toxics like chlorine or ammonia. For VOC monitoring use a PID; see the \u003ca href=\"\/collections\/gas-detectors\" title=\"Gas Detectors\"\u003eGas Detectors\u003c\/a\u003e hub.\u003c\/p\u003e\n\u003ch3\u003eIs it in stock and how does it ship?\u003c\/h3\u003e\u003cp\u003eUse the Amazon buy button for current availability and delivery timing through our fulfillment partner.\u003c\/p\u003e\n\u003ch3\u003eDoes it require maintenance?\u003c\/h3\u003e\u003cp\u003eYes — keep the pump and probe clean, replace electrochemical sensors periodically, and recalibrate on schedule to keep readings and logs accurate.\u003c\/p\u003e\n\n\u003cdiv style=\"background:#1a1a1a;border:1px solid #3a3a3a;border-radius:6px;padding:16px 18px;margin:22px 0;\"\u003e\n\u003cp style=\"margin:0 0 10px 0;color:#f5e6d3;\"\u003eReady to order the \u003cstrong\u003eForensics 4 gas data logger monitor\u003c\/strong\u003e? Add it to your cart above, or check the current Amazon price below. Compare it against the rest of our \u003ca href=\"\/collections\/area-gas-monitors\" title=\"Area \u0026amp; Transportable Gas Monitors\"\u003eArea \u0026amp; Transportable Gas Monitors\u003c\/a\u003e lineup before you buy.\u003c\/p\u003e\n\u003cp style=\"display:flex;gap:10px;flex-wrap:wrap;align-items:center;margin:0;\"\u003e\u003ca href=\"https:\/\/www.amazon.com\/dp\/B0DM712D9P?tag=wcsafety04-20\" rel=\"sponsored nofollow noopener\" target=\"_blank\" style=\"display:inline-block;background:#FFD814;color:#0F1111;padding:13px 26px;text-decoration:none;font-weight:bold;border-radius:4px;border:1px solid #FCD200;\"\u003eCHECK PRICE ON AMAZON →\u003c\/a\u003e\u003cspan style=\"font-size:0.8em;color:#bdae9d;\"\u003eAs an Amazon Associate, WC Safety earns from qualifying purchases.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/div\u003e\n\n\u003cdiv style=\"background:#1a2733;border:1px dashed #4fc3f7;padding:16px 20px;margin:30px 0 18px 0;color:#cfd8dc;font-size:0.92em;\"\u003e\n  \u003cstrong style=\"color:#4fc3f7;\"\u003eWhy trust this Forensics Detectors page?\u003c\/strong\u003e WC Safety is an independent industrial safety-equipment retailer serving safety managers, procurement teams and field supervisors. The specifications here are taken from the manufacturer’s published listing for Forensics 4 Gas Data Logger and framed against \u003ca href=\"https:\/\/www.osha.gov\/laws-regs\/regulations\/standardnumber\/1910\/1910.146\" rel=\"noopener\" target=\"_blank\" style=\"color:#4fc3f7;\"\u003eOSHA 29 CFR 1910.146\u003c\/a\u003e and \u003ca href=\"https:\/\/www.osha.gov\/annotated-pels\" rel=\"noopener\" target=\"_blank\" style=\"color:#4fc3f7;\"\u003eOSHA Permissible Exposure Limits\u003c\/a\u003e. Disclosed: WC Safety earns Amazon affiliate commissions on outbound clicks; that does not influence the specs shown or our lineup.\n\u003c\/div\u003e\n\u003cdiv style=\"background:#1a2733;border-left:4px solid #4fc3f7;padding:18px 22px;margin:18px 0;color:#cfd8dc;font-size:0.92em;\"\u003e\n  \u003cstrong style=\"color:#4fc3f7;\"\u003eBy Steven Eaton, WC Safety Editorial\u003c\/strong\u003e — Industrial safety-equipment desk · specialization: atmospheric monitoring, gas detection and instrument selection.\u003cbr\u003e\n  \u003cstrong\u003eLast updated:\u003c\/strong\u003e \u003ctime datetime=\"2026-06-22\"\u003eJune 22, 2026\u003c\/time\u003e · \u003cstrong\u003eSources reviewed:\u003c\/strong\u003e manufacturer product listing \u0026amp; specifications, OSHA 29 CFR 1910.146, OSHA Annotated PEL tables, ACGIH Threshold Limit Values.\u003cbr\u003e\n  \u003cstrong\u003eEditorial standard:\u003c\/strong\u003e \u003cem\u003eZero sponsored listings. No manufacturer input. Specs verified against the manufacturer’s published data.\u003c\/em\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"background:#1a2733;border-left:4px solid #4fc3f7;padding:16px 20px;margin:18px 0;color:#cfd8dc;font-size:0.92em;\"\u003e\n  \u003cstrong style=\"color:#4fc3f7;\"\u003eHow this page is maintained.\u003c\/strong\u003e Specifications and pricing are reviewed against the manufacturer’s current listing and re-checked whenever the lineup changes. Gas-detection guidance follows \u003ca href=\"https:\/\/www.osha.gov\/laws-regs\/regulations\/standardnumber\/1910\/1910.146\" rel=\"noopener\" target=\"_blank\" style=\"color:#4fc3f7;\"\u003eOSHA 1910.146\u003c\/a\u003e and \u003ca href=\"https:\/\/www.osha.gov\/annotated-pels\" rel=\"noopener\" target=\"_blank\" style=\"color:#4fc3f7;\"\u003eOSHA PELs\u003c\/a\u003e, cross-referenced with ACGIH TLVs.\n\u003c\/div\u003e\n\u003cdiv style=\"background:#2a2520;border-left:4px solid #ff9800;padding:16px 20px;margin:18px 0;color:#f5e6d3;font-size:0.92em;\"\u003e\n  \u003cstrong style=\"color:#ffb74d;\"\u003eDisclosure.\u003c\/strong\u003e WC Safety participates in the Amazon Associates Program and earns commissions on qualifying purchases through outbound links on this page (tag wcsafety04-20). We are not sponsored by any instrument manufacturer. This page is buyer guidance, not medical, legal or regulatory advice — confirm gas-detection requirements for your site against the applicable OSHA standard and, for commercial monitoring programs, a Certified Industrial Hygienist (CIH).\n\u003c\/div\u003e\n\n\u003cscript type=\"application\/ld+json\"\u003e\n{\"@context\": \"https:\/\/schema.org\", \"@graph\": [{\"@type\": \"Product\", \"@id\": \"https:\/\/wcsafety.com\/products\/forensics-4-gas-data-logger-monitor#product\", \"name\": \"Forensics 4 Gas Data Logger Monitor — Built-in Pump, Graphing (O2, CO, H2S, LEL)\", \"description\": \"Forensics 4 gas data logger monitor — larger transportable O2, CO, H2S \u0026 LEL monitor with built-in pump, color graphing and datalogging. NIST-calibrated.\", \"sku\": \"B0DM712D9P\", \"mpn\": \"FD-4GDL\", \"image\": [\"https:\/\/wcsafety.com\/cdn\/shop\/products\/forensics-4-gas-data-logger-monitor.jpg\"], \"brand\": {\"@type\": \"Brand\", \"name\": \"Forensics Detectors\"}, \"category\": \"Area Gas Monitor\", \"isPartOf\": {\"@type\": \"CollectionPage\", \"@id\": \"https:\/\/wcsafety.com\/collections\/area-gas-monitors#collection\", \"name\": \"Area \u0026 Transportable Gas Monitors\", \"url\": \"https:\/\/wcsafety.com\/collections\/area-gas-monitors\"}, \"isRelatedTo\": [{\"@type\": \"Product\", \"name\": \"Forensics 4 Gas Monitor with Pump \u0026 Datalogging\", \"url\": \"https:\/\/wcsafety.com\/products\/forensics-4-gas-pump-monitor-datalogging\"}, {\"@type\": \"Product\", \"name\": \"Forensics Detectors 4 Gas Monitor with Pump\", \"url\": \"https:\/\/wcsafety.com\/products\/forensics-detectors-4-gas-monitor-with-pump\"}], \"offers\": {\"@type\": \"Offer\", \"url\": \"https:\/\/wcsafety.com\/products\/forensics-4-gas-data-logger-monitor\", \"priceCurrency\": \"USD\", \"price\": \"1399.00\", \"availability\": \"https:\/\/schema.org\/InStock\", \"seller\": {\"@type\": \"Organization\", \"name\": \"WC Safety\"}}}, {\"@type\": \"BreadcrumbList\", \"@id\": \"https:\/\/wcsafety.com\/products\/forensics-4-gas-data-logger-monitor#breadcrumb\", \"itemListElement\": [{\"@type\": \"ListItem\", \"position\": 1, \"name\": \"Home\", \"item\": \"https:\/\/wcsafety.com\/\"}, {\"@type\": \"ListItem\", \"position\": 2, \"name\": \"Gas Detectors\", \"item\": \"https:\/\/wcsafety.com\/collections\/gas-detectors\"}, {\"@type\": \"ListItem\", \"position\": 3, \"name\": \"Area \u0026 Transportable Gas Monitors\", \"item\": \"https:\/\/wcsafety.com\/collections\/area-gas-monitors\"}, {\"@type\": \"ListItem\", \"position\": 4, \"name\": \"Forensics 4 Gas Data Logger Monitor — Built-in Pump, Graphing (O2, CO, H2S, LEL)\"}]}, {\"@type\": \"FAQPage\", \"mainEntity\": [{\"@type\": \"Question\", \"name\": \"Is the Forensics 4 gas data logger an area monitor?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"It is a larger transportable continuous monitor for placed job-site monitoring — an area-monitoring use. It is not a wireless-mesh networked monitor; for that class see the distributor note in the Area \u0026 Transportable Gas Monitors hub.\"}}, {\"@type\": \"Question\", \"name\": \"What gases does it monitor?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"It monitors oxygen (O2), combustible gas (LEL), carbon monoxide (CO) and hydrogen sulfide (H2S) with a built-in pump. It does not read VOCs, CO2 or specific toxics.\"}}, {\"@type\": \"Question\", \"name\": \"What datalogging does it offer?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Full computer datalogging plus a color display with live graphing, giving you detailed records of a job's exposure over time for compliance.\"}}, {\"@type\": \"Question\", \"name\": \"How is it different from the standard pump monitor?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"It is a larger, higher-tier transportable unit focused on extended datalogging; the 4 Gas Pump Monitor is lighter and lower cost for most jobs.\"}}, {\"@type\": \"Question\", \"name\": \"Can it do pre-entry sampling?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Yes — the built-in sample-draw pump lets you test a space before entry as well as monitor continuously during the work.\"}}, {\"@type\": \"Question\", \"name\": \"Is it good for turnarounds and shutdowns?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Yes — its extended datalogging and transportable form suit long placed-monitoring tasks like turnarounds, with a record of the whole job.\"}}, {\"@type\": \"Question\", \"name\": \"Is it NIST calibrated?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Yes — USA NIST-traceable calibration; bump-test before use and recalibrate on schedule.\"}}, {\"@type\": \"Question\", \"name\": \"Can it monitor a whole perimeter alone?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"One unit covers its zone. For a networked multi-zone perimeter use several units or a distributor-sourced wireless-mesh system; for permanent coverage a Fixed Gas Detection Systems system.\"}}, {\"@type\": \"Question\", \"name\": \"What alarms does it have?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Audible and visual alarms trigger when any of the four gases exceeds its set point.\"}}, {\"@type\": \"Question\", \"name\": \"What does it not detect?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"VOCs, CO2 and specific toxics like chlorine or ammonia. For VOC monitoring use a PID; see the Gas Detectors hub.\"}}, {\"@type\": \"Question\", \"name\": \"Is it in stock and how does it ship?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Use the Amazon buy button for current availability and delivery timing through our fulfillment partner.\"}}, {\"@type\": \"Question\", \"name\": \"Does it require maintenance?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Yes — keep the pump and probe clean, replace electrochemical sensors periodically, and recalibrate on schedule to keep readings and logs accurate.\"}}]}, {\"@type\": \"Organization\", \"@id\": \"https:\/\/wcsafety.com\/#org\", \"name\": \"WC Safety\", \"url\": \"https:\/\/wcsafety.com\", \"logo\": \"https:\/\/wcsafety.com\/cdn\/shop\/files\/logo.png\"}, {\"@type\": \"Person\", \"@id\": \"https:\/\/wcsafety.com\/#editor\", \"name\": \"Steven Eaton\", \"jobTitle\": \"Editorial Lead\", \"worksFor\": {\"@id\": \"https:\/\/wcsafety.com\/#org\"}, \"knowsAbout\": [\"industrial gas detection\", \"atmospheric monitoring\", \"personal protective equipment\"]}, {\"@type\": \"Brand\", \"name\": \"Forensics Detectors\"}]}\n\u003c\/script\u003e","brand":"Forensics Detectors","offers":[{"title":"Default Title","offer_id":44266505764952,"sku":"B0DM712D9P","price":1399.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0594\/1900\/0920\/files\/81GpANeoJfL._AC_SL1500.jpg?v=1782123133"},{"product_id":"ato-handheld-4-gas-detector","title":"ATO Handheld 4 Gas Detector — CO, H2S, O2 \u0026 LEL","description":"\u003c!-- PRODUCT B09WVMPGDZ | tag portable-gas-detector | TODO: add matching Product Review + best-of guide links when those silo layers exist --\u003e\n\n\u003cdiv style=\"background:#1a1a1a;border-left:4px solid #ff9800;padding:14px 18px;margin:0 0 18px 0;color:#f5e6d3;font-size:0.95em;\"\u003e\n\u003cstrong style=\"color:#ffb74d;\"\u003eEditor’s note:\u003c\/strong\u003e the ATO handheld 4 gas detector is one of the instruments we curate in our \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"Portable Gas Detectors\"\u003ePortable Gas Detectors\u003c\/a\u003e buyer’s hub. Compare it with the \u003ca href=\"\/products\/forensics-voc-detector\" title=\"Forensics VOC Detector\"\u003eForensics VOC Detector\u003c\/a\u003e below before you order.\u003c\/div\u003e\n\n\u003ch2 id=\"top\"\u003eATO Handheld 4 Gas Detector — CO, H2S, O2 \u0026amp; LEL\u003c\/h2\u003e\n\n\u003cp\u003eThe \u003cstrong\u003eATO handheld 4 gas detector\u003c\/strong\u003e reads CO, H2S, O2 and combustible LEL with sound, light and vibration alarms — a mid-tier industrial-brand \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"portable gas detector\"\u003eportable gas detector\u003c\/a\u003e sitting between the value 4-gas units and the premium fleet instruments.\u003c\/p\u003e\n\n\u003cp style=\"font-size:0.9em;color:#bdae9d;margin:10px 0 18px 0;\"\u003eJump to: \u003ca href=\"#features\" style=\"color:#ffb74d;\"\u003eFeatures\u003c\/a\u003e · \u003ca href=\"#specs\" style=\"color:#ffb74d;\"\u003eSpecs\u003c\/a\u003e · \u003ca href=\"#compatibility\" style=\"color:#ffb74d;\"\u003eWhat it detects\u003c\/a\u003e · \u003ca href=\"#comparison\" style=\"color:#ffb74d;\"\u003eComparison\u003c\/a\u003e · \u003ca href=\"#faq\" style=\"color:#ffb74d;\"\u003eFAQ\u003c\/a\u003e\u003c\/p\u003e\n\n\u003cp\u003eThe ATO Handheld 4 Gas Detector is a rechargeable confined-space monitor for CO, H2S, O2 and combustible LEL with sound, light and vibration alarms (no datalogging on this model).\u003c\/p\u003e\n\n\u003ch3 id=\"features\"\u003eKey features\u003c\/h3\u003e\n\n\u003cul\u003e\n\u003cli\u003eReads the four confined-space gases — CO, H2S, O2 and combustible LEL\u003c\/li\u003e\n\u003cli\u003eSound, light and vibration alarms for multi-environment alerting\u003c\/li\u003e\n\u003cli\u003eRechargeable for full-shift use\u003c\/li\u003e\n\u003cli\u003eFrom ATO, an industrial instrument brand priced between value and premium\u003c\/li\u003e\n\u003cli\u003eA mid-tier alternative to value 4-gas monitors\u003c\/li\u003e\n\u003cli\u003eStraightforward operation for crews\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cdiv style=\"display:flex;gap:14px;flex-wrap:wrap;margin:18px 0;\"\u003e\n\u003cdiv style=\"flex:1;min-width:240px;background:#1b3a2a;border:1px solid #4caf50;border-radius:6px;padding:14px 18px;\"\u003e\n\u003cstrong style=\"color:#81c784;\"\u003ePros\u003c\/strong\u003e\u003cul style=\"margin:8px 0 0 0;\"\u003e\n\u003cli\u003eFour-gas coverage from an industrial brand\u003c\/li\u003e\n\u003cli\u003eTriple alarm modes\u003c\/li\u003e\n\u003cli\u003eRechargeable\u003c\/li\u003e\n\u003cli\u003eMid-tier positioning\u003c\/li\u003e\n\u003cli\u003eSimple operation\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"flex:1;min-width:240px;background:#3a1e1e;border:1px solid #ef5350;border-radius:6px;padding:14px 18px;\"\u003e\n\u003cstrong style=\"color:#e57373;\"\u003eCons\u003c\/strong\u003e\u003cul style=\"margin:8px 0 0 0;\"\u003e\n\u003cli\u003eNo datalogging on this model\u003c\/li\u003e\n\u003cli\u003eDiffusion only (no pump)\u003c\/li\u003e\n\u003cli\u003eNo VOC\/PID coverage\u003c\/li\u003e\n\u003cli\u003eNewer listing, limited reviews\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\n\u003ch3 id=\"specs\"\u003eSpecifications\u003c\/h3\u003e\n\n\u003cdiv style=\"overflow-x:auto;\"\u003e\u003ctable style=\"width:100%;border-collapse:collapse;background:#1a1a1a;margin:14px 0;\"\u003e\n\u003cthead\u003e\u003ctr style=\"background:#2a2a2a;\"\u003e\n\u003cth style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;text-align:left;\"\u003eSpecification\u003c\/th\u003e\n\u003cth style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;text-align:left;\"\u003eDetail\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eGases detected\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eCO, H2S, O2, LEL combustibles\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eAlarms\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eSound, light \u0026amp; vibration\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eDatalogging\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eNo\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eSensor\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eElectrochemical + catalytic\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003ePower\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eRechargeable battery\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eUse\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eConfined space, industrial\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003c\/div\u003e\n\n\u003ch3\u003eWhere the ATO 4 Gas Detector fits\u003c\/h3\u003e\n\n\u003cul\u003e\n\u003cli\u003eConfined-space entry monitoring\u003c\/li\u003e\n\u003cli\u003eUtility and municipal work\u003c\/li\u003e\n\u003cli\u003eIndustrial maintenance rounds\u003c\/li\u003e\n\u003cli\u003eSewer and water-treatment work\u003c\/li\u003e\n\u003cli\u003eGeneral multi-gas spot checks\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2 id=\"compatibility\"\u003eWhat the ATO 4 Gas Detector detects (and what it doesn’t)\u003c\/h2\u003e\n\n\u003cp\u003eIt monitors \u003cstrong\u003eCO, H2S, O2 and combustible LEL\u003c\/strong\u003e — not VOCs, CO2 or specific toxics. For VOCs use the \u003ca href=\"\/products\/forensics-voc-detector\" title=\"Forensics VOC Detector\"\u003eForensics VOC Detector\u003c\/a\u003e; for single toxics the \u003ca href=\"\/products\/forensics-chlorine-analyzer-cl2\" title=\"Chlorine\"\u003eChlorine\u003c\/a\u003e or \u003ca href=\"\/products\/forensics-ammonia-detector-nh3\" title=\"Ammonia\"\u003eAmmonia\u003c\/a\u003e analyzers. It is diffusion, so for remote pre-entry sampling use a \u003ca href=\"\/products\/forensics-detectors-4-gas-monitor-with-pump\" title=\"pump monitor\"\u003epump monitor\u003c\/a\u003e. Compare it with the value \u003ca href=\"\/products\/forensics-detectors-4-gas-meter-confined-space\" title=\"Forensics 4 Gas Meter\"\u003eForensics 4 Gas Meter\u003c\/a\u003e and \u003ca href=\"\/products\/forensics-mini-4-gas-monitor\" title=\"Forensics Mini 4 Gas\"\u003eForensics Mini 4 Gas\u003c\/a\u003e. Bump-test before use.\u003c\/p\u003e\n\n\u003cp\u003eCross-shopping? This unit sits in our \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"Portable Gas Detectors\"\u003ePortable Gas Detectors\u003c\/a\u003e hub alongside \u003ca href=\"\/products\/forensics-voc-detector\" title=\"Forensics VOC Detector\"\u003eForensics VOC Detector\u003c\/a\u003e, \u003ca href=\"\/products\/amprobe-co2-100-carbon-dioxide-meter\" title=\"Amprobe CO2-100\"\u003eAmprobe CO2-100\u003c\/a\u003e, \u003ca href=\"\/products\/forensics-ammonia-detector-nh3\" title=\"Forensics Ammonia Detector\"\u003eForensics Ammonia Detector\u003c\/a\u003e, \u003ca href=\"\/products\/forensics-chlorine-analyzer-cl2\" title=\"Forensics Chlorine Analyzer\"\u003eForensics Chlorine Analyzer\u003c\/a\u003e. For other gas-detection form factors see \u003ca href=\"\/collections\/personal-gas-detectors\" title=\"Personal \u0026amp; Wearable Gas Detectors\"\u003ePersonal \u0026amp; Wearable Gas Detectors\u003c\/a\u003e, \u003ca href=\"\/collections\/fixed-gas-detection-systems\" title=\"Fixed Gas Detection Systems\"\u003eFixed Gas Detection Systems\u003c\/a\u003e, \u003ca href=\"\/collections\/area-gas-monitors\" title=\"Area \u0026amp; Transportable Gas Monitors\"\u003eArea \u0026amp; Transportable Gas Monitors\u003c\/a\u003e, or browse the full \u003ca href=\"\/collections\/gas-detectors\" title=\"Gas Detectors\"\u003eGas Detectors\u003c\/a\u003e range.\u003c\/p\u003e\n\n\u003ch2 id=\"comparison\"\u003ePortable 4-gas options compared\u003c\/h2\u003e\n\n\u003cdiv style=\"overflow-x:auto;\"\u003e\u003ctable style=\"width:100%;border-collapse:collapse;background:#1a1a1a;margin:14px 0;\"\u003e\n\u003ccaption style=\"color:#bdae9d;font-size:0.85em;text-align:left;padding:4px 0;\"\u003ePortable 4-gas options (O2, CO, H2S, LEL)\u003c\/caption\u003e\n\u003cthead\u003e\u003ctr style=\"background:#2a2a2a;\"\u003e\n\u003cth style=\"color:#ffb74d;padding:9px;border:1px solid #3a3a3a;text-align:left;\"\u003eModel\u003c\/th\u003e\n\u003cth style=\"color:#ffb74d;padding:9px;border:1px solid #3a3a3a;text-align:left;\"\u003eBrand\u003c\/th\u003e\n\u003cth style=\"color:#ffb74d;padding:9px;border:1px solid #3a3a3a;text-align:left;\"\u003eNotable\u003c\/th\u003e\n\u003cth style=\"color:#ffb74d;padding:9px;border:1px solid #3a3a3a;text-align:left;\"\u003eStreet price\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e\u003ca href=\"\/products\/forensics-mini-4-gas-monitor\" title=\"Forensics Mini 4 Gas\"\u003eForensics Mini 4 Gas\u003c\/a\u003e\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eForensics\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eCompact, NIST, USB\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e~$295\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e\u003ca href=\"\/products\/forensics-detectors-4-gas-meter-confined-space\" title=\"Forensics 4 Gas Meter\"\u003eForensics 4 Gas Meter\u003c\/a\u003e\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eForensics\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eLightest, NIST\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e~$199\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#2a2520;\"\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e\u003cstrong\u003e\u003ca href=\"\/products\/ato-handheld-4-gas-detector\" title=\"ATO 4 Gas Detector\"\u003eATO 4 Gas Detector\u003c\/a\u003e\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eATO\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eSound\/light\/vibration\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e~$449\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003c\/div\u003e\n\n\u003cul\u003e\n\u003cli\u003eChoose the \u003cstrong\u003eATO 4 Gas Detector\u003c\/strong\u003e for a mid-tier industrial-brand 4-gas with triple alarms.\u003c\/li\u003e\n\u003cli\u003eSpend less with the \u003ca href=\"\/products\/forensics-detectors-4-gas-meter-confined-space\" title=\"Forensics 4 Gas Meter\"\u003eForensics 4 Gas Meter\u003c\/a\u003e or \u003ca href=\"\/products\/forensics-mini-4-gas-monitor\" title=\"Mini 4 Gas\"\u003eMini 4 Gas\u003c\/a\u003e.\u003c\/li\u003e\n\u003cli\u003eNeed a pump for pre-entry sampling? Use the \u003ca href=\"\/products\/forensics-detectors-4-gas-monitor-with-pump\" title=\"Forensics 4 Gas + Pump\"\u003eForensics 4 Gas + Pump\u003c\/a\u003e.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2 id=\"faq\"\u003eFrequently asked questions\u003c\/h2\u003e\n\n\u003ch3\u003eWhat gases does the ATO 4 gas detector measure?\u003c\/h3\u003e\u003cp\u003eCO, H2S, O2 and combustible LEL — the confined-space set. For VOCs use the \u003ca href=\"\/products\/forensics-voc-detector\" title=\"Forensics VOC Detector\"\u003eForensics VOC Detector\u003c\/a\u003e.\u003c\/p\u003e\n\u003ch3\u003eDoes the ATO 4 gas detector log data?\u003c\/h3\u003e\u003cp\u003eNo — this model does not have datalogging. If you need exposure records, choose a datalogging unit such as the \u003ca href=\"\/products\/forensics-detectors-4-gas-monitor-with-pump\" title=\"Forensics 4 Gas + Pump\"\u003eForensics 4 Gas + Pump\u003c\/a\u003e family.\u003c\/p\u003e\n\u003ch3\u003eIs it rechargeable?\u003c\/h3\u003e\u003cp\u003eYes — it uses a rechargeable battery sized for full-shift use.\u003c\/p\u003e\n\u003ch3\u003eHow does it compare to the value Forensics 4-gas units?\u003c\/h3\u003e\u003cp\u003eThe ATO is a mid-tier industrial-brand option; the \u003ca href=\"\/products\/forensics-detectors-4-gas-meter-confined-space\" title=\"Forensics 4 Gas Meter\"\u003eForensics 4 Gas Meter\u003c\/a\u003e and \u003ca href=\"\/products\/forensics-mini-4-gas-monitor\" title=\"Mini 4 Gas\"\u003eMini 4 Gas\u003c\/a\u003e are lower-cost NIST-calibrated alternatives.\u003c\/p\u003e\n\u003ch3\u003eCan I use it for confined-space entry?\u003c\/h3\u003e\u003cp\u003eYes for monitoring the four hazards. For pre-entry sampling of a sealed space, use a \u003ca href=\"\/products\/forensics-detectors-4-gas-monitor-with-pump\" title=\"pump-equipped monitor\"\u003epump-equipped monitor\u003c\/a\u003e.\u003c\/p\u003e\n\u003ch3\u003eDoes it have a pump?\u003c\/h3\u003e\u003cp\u003eNo — it is diffusion. For remote sampling choose a \u003ca href=\"\/products\/forensics-detectors-4-gas-monitor-with-pump\" title=\"pump monitor\"\u003epump monitor\u003c\/a\u003e.\u003c\/p\u003e\n\u003ch3\u003eWhat alarms does it have?\u003c\/h3\u003e\u003cp\u003eSound, light and vibration alarms trigger when any of the four gases exceeds its set point.\u003c\/p\u003e\n\u003ch3\u003eWhat does it not detect?\u003c\/h3\u003e\u003cp\u003eVOCs, CO2 and specific toxics. For VOCs use the \u003ca href=\"\/products\/forensics-voc-detector\" title=\"VOC Detector\"\u003eVOC Detector\u003c\/a\u003e; for chlorine the \u003ca href=\"\/products\/forensics-chlorine-analyzer-cl2\" title=\"Chlorine Analyzer\"\u003eChlorine Analyzer\u003c\/a\u003e.\u003c\/p\u003e\n\u003ch3\u003eHow do I keep it accurate?\u003c\/h3\u003e\u003cp\u003eBump-test before each day of use with four-gas calibration gas and calibrate on the manufacturer's schedule.\u003c\/p\u003e\n\u003ch3\u003eIs it in stock and how does it ship?\u003c\/h3\u003e\u003cp\u003eUse the Amazon buy button for current availability and delivery timing through our fulfillment partner.\u003c\/p\u003e\n\u003ch3\u003eIs ATO industrial grade?\u003c\/h3\u003e\u003cp\u003eATO is an industrial instrument supplier; this is a mid-tier 4-gas option. For managed-fleet docking automation, premium platforms still lead.\u003c\/p\u003e\n\u003ch3\u003eHow long do the sensors last?\u003c\/h3\u003e\u003cp\u003eElectrochemical and catalytic sensors typically last two to three years; budget for replacement sensors and calibration gas.\u003c\/p\u003e\n\n\u003cdiv style=\"background:#1a1a1a;border:1px solid #3a3a3a;border-radius:6px;padding:16px 18px;margin:22px 0;\"\u003e\n\u003cp style=\"margin:0 0 10px 0;color:#f5e6d3;\"\u003eReady to order the \u003cstrong\u003eATO handheld 4 gas detector\u003c\/strong\u003e? Add it to your cart above, or check the current Amazon price below. Compare it against the rest of our \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"Portable Gas Detectors\"\u003ePortable Gas Detectors\u003c\/a\u003e lineup before you buy.\u003c\/p\u003e\n\u003cp style=\"display:flex;gap:10px;flex-wrap:wrap;align-items:center;margin:0;\"\u003e\u003ca href=\"https:\/\/www.amazon.com\/dp\/B09WVMPGDZ?tag=wcsafety04-20\" rel=\"sponsored nofollow noopener\" target=\"_blank\" style=\"display:inline-block;background:#FFD814;color:#0F1111;padding:13px 26px;text-decoration:none;font-weight:bold;border-radius:4px;border:1px solid #FCD200;\"\u003eCHECK PRICE ON AMAZON →\u003c\/a\u003e\u003cspan style=\"font-size:0.8em;color:#bdae9d;\"\u003eAs an Amazon Associate, WC Safety earns from qualifying purchases.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/div\u003e\n\n\u003cdiv style=\"background:#1a2733;border:1px dashed #4fc3f7;padding:16px 20px;margin:30px 0 18px 0;color:#cfd8dc;font-size:0.92em;\"\u003e\n  \u003cstrong style=\"color:#4fc3f7;\"\u003eWhy trust this ATO page?\u003c\/strong\u003e WC Safety is an independent industrial safety-equipment retailer serving safety managers, procurement teams and field supervisors. The specifications here are taken from the manufacturer’s published listing for ATO 4 Gas Detector and framed against \u003ca href=\"https:\/\/www.osha.gov\/laws-regs\/regulations\/standardnumber\/1910\/1910.146\" rel=\"noopener\" target=\"_blank\" style=\"color:#4fc3f7;\"\u003eOSHA 29 CFR 1910.146\u003c\/a\u003e and \u003ca href=\"https:\/\/www.osha.gov\/annotated-pels\" rel=\"noopener\" target=\"_blank\" style=\"color:#4fc3f7;\"\u003eOSHA Permissible Exposure Limits\u003c\/a\u003e. Disclosed: WC Safety earns Amazon affiliate commissions on outbound clicks; that does not influence the specs shown or our lineup.\n\u003c\/div\u003e\n\u003cdiv style=\"background:#1a2733;border-left:4px solid #4fc3f7;padding:18px 22px;margin:18px 0;color:#cfd8dc;font-size:0.92em;\"\u003e\n  \u003cstrong style=\"color:#4fc3f7;\"\u003eBy Steven Eaton, WC Safety Editorial\u003c\/strong\u003e — Industrial safety-equipment desk · specialization: atmospheric monitoring, gas detection and instrument selection.\u003cbr\u003e\n  \u003cstrong\u003eLast updated:\u003c\/strong\u003e \u003ctime datetime=\"2026-06-22\"\u003eJune 22, 2026\u003c\/time\u003e · \u003cstrong\u003eSources reviewed:\u003c\/strong\u003e manufacturer product listing \u0026amp; specifications, OSHA 29 CFR 1910.146, OSHA Annotated PEL tables, ACGIH Threshold Limit Values.\u003cbr\u003e\n  \u003cstrong\u003eEditorial standard:\u003c\/strong\u003e \u003cem\u003eZero sponsored listings. No manufacturer input. Specs verified against the manufacturer’s published data.\u003c\/em\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"background:#1a2733;border-left:4px solid #4fc3f7;padding:16px 20px;margin:18px 0;color:#cfd8dc;font-size:0.92em;\"\u003e\n  \u003cstrong style=\"color:#4fc3f7;\"\u003eHow this page is maintained.\u003c\/strong\u003e Specifications and pricing are reviewed against the manufacturer’s current listing and re-checked whenever the lineup changes. Gas-detection guidance follows \u003ca href=\"https:\/\/www.osha.gov\/laws-regs\/regulations\/standardnumber\/1910\/1910.146\" rel=\"noopener\" target=\"_blank\" style=\"color:#4fc3f7;\"\u003eOSHA 1910.146\u003c\/a\u003e and \u003ca href=\"https:\/\/www.osha.gov\/annotated-pels\" rel=\"noopener\" target=\"_blank\" style=\"color:#4fc3f7;\"\u003eOSHA PELs\u003c\/a\u003e, cross-referenced with ACGIH TLVs.\n\u003c\/div\u003e\n\u003cdiv style=\"background:#2a2520;border-left:4px solid #ff9800;padding:16px 20px;margin:18px 0;color:#f5e6d3;font-size:0.92em;\"\u003e\n  \u003cstrong style=\"color:#ffb74d;\"\u003eDisclosure.\u003c\/strong\u003e WC Safety participates in the Amazon Associates Program and earns commissions on qualifying purchases through outbound links on this page (tag wcsafety04-20). We are not sponsored by any instrument manufacturer. This page is buyer guidance, not medical, legal or regulatory advice — confirm gas-detection requirements for your site against the applicable OSHA standard and, for commercial monitoring programs, a Certified Industrial Hygienist (CIH).\n\u003c\/div\u003e\n\n\u003cscript type=\"application\/ld+json\"\u003e\n{\"@context\": \"https:\/\/schema.org\", \"@graph\": [{\"@type\": \"Product\", \"@id\": \"https:\/\/wcsafety.com\/products\/ato-handheld-4-gas-detector#product\", \"name\": \"ATO Handheld 4 Gas Detector — CO, H2S, O2 \u0026 LEL\", \"description\": \"ATO handheld 4 gas detector — CO, H2S, O2 \u0026 LEL monitor with sound, light and vibration alarms for confined-space and industrial use. Order at WC Safety.\", \"sku\": \"B09WVMPGDZ\", \"mpn\": \"ATO-4GAS\", \"image\": [\"https:\/\/wcsafety.com\/cdn\/shop\/products\/ato-handheld-4-gas-detector.jpg\"], \"brand\": {\"@type\": \"Brand\", \"name\": \"ATO\"}, \"category\": \"Portable Gas Detector\", \"isPartOf\": {\"@type\": \"CollectionPage\", \"@id\": \"https:\/\/wcsafety.com\/collections\/portable-gas-detectors#collection\", \"name\": \"Portable Gas Detectors\", \"url\": \"https:\/\/wcsafety.com\/collections\/portable-gas-detectors\"}, \"isRelatedTo\": [{\"@type\": \"Product\", \"name\": \"Forensics VOC Detector\", \"url\": \"https:\/\/wcsafety.com\/products\/forensics-voc-detector\"}, {\"@type\": \"Product\", \"name\": \"Amprobe CO2-100 Carbon Dioxide Meter\", \"url\": \"https:\/\/wcsafety.com\/products\/amprobe-co2-100-carbon-dioxide-meter\"}, {\"@type\": \"Product\", \"name\": \"Forensics Ammonia (NH3) Detector\", \"url\": \"https:\/\/wcsafety.com\/products\/forensics-ammonia-detector-nh3\"}, {\"@type\": \"Product\", \"name\": \"Forensics Chlorine (Cl2) Analyzer\", \"url\": \"https:\/\/wcsafety.com\/products\/forensics-chlorine-analyzer-cl2\"}, {\"@type\": \"Product\", \"name\": \"Forensics Sulfur Dioxide (SO2) Analyzer\", \"url\": \"https:\/\/wcsafety.com\/products\/forensics-sulfur-dioxide-analyzer-so2\"}, {\"@type\": \"Product\", \"name\": \"ATO Ozone (O3) Gas Detector\", \"url\": \"https:\/\/wcsafety.com\/products\/ato-ozone-gas-detector-o3\"}, {\"@type\": \"Product\", \"name\": \"Forensics Mini 4 Gas Monitor\", \"url\": \"https:\/\/wcsafety.com\/products\/forensics-mini-4-gas-monitor\"}, {\"@type\": \"Product\", \"name\": \"Forensics Detectors 4 Gas Meter\", \"url\": \"https:\/\/wcsafety.com\/products\/forensics-detectors-4-gas-meter-confined-space\"}, {\"@type\": \"Product\", \"name\": \"Forensics Detectors 4 Gas Monitor with Pump\", \"url\": \"https:\/\/wcsafety.com\/products\/forensics-detectors-4-gas-monitor-with-pump\"}], \"offers\": {\"@type\": \"Offer\", \"url\": \"https:\/\/wcsafety.com\/products\/ato-handheld-4-gas-detector\", \"priceCurrency\": \"USD\", \"price\": \"448.99\", \"availability\": \"https:\/\/schema.org\/InStock\", \"seller\": {\"@type\": \"Organization\", \"name\": \"WC Safety\"}}}, {\"@type\": \"BreadcrumbList\", \"@id\": \"https:\/\/wcsafety.com\/products\/ato-handheld-4-gas-detector#breadcrumb\", \"itemListElement\": [{\"@type\": \"ListItem\", \"position\": 1, \"name\": \"Home\", \"item\": \"https:\/\/wcsafety.com\/\"}, {\"@type\": \"ListItem\", \"position\": 2, \"name\": \"Gas Detectors\", \"item\": \"https:\/\/wcsafety.com\/collections\/gas-detectors\"}, {\"@type\": \"ListItem\", \"position\": 3, \"name\": \"Portable Gas Detectors\", \"item\": \"https:\/\/wcsafety.com\/collections\/portable-gas-detectors\"}, {\"@type\": \"ListItem\", \"position\": 4, \"name\": \"ATO Handheld 4 Gas Detector — CO, H2S, O2 \u0026 LEL\"}]}, {\"@type\": \"FAQPage\", \"mainEntity\": [{\"@type\": \"Question\", \"name\": \"What gases does the ATO 4 gas detector measure?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"CO, H2S, O2 and combustible LEL — the confined-space set. For VOCs use the Forensics VOC Detector.\"}}, {\"@type\": \"Question\", \"name\": \"Does the ATO 4 gas detector log data?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"No — this model does not have datalogging. If you need exposure records, choose a datalogging unit such as the Forensics 4 Gas + Pump family.\"}}, {\"@type\": \"Question\", \"name\": \"Is it rechargeable?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Yes — it uses a rechargeable battery sized for full-shift use.\"}}, {\"@type\": \"Question\", \"name\": \"How does it compare to the value Forensics 4-gas units?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"The ATO is a mid-tier industrial-brand option; the Forensics 4 Gas Meter and Mini 4 Gas are lower-cost NIST-calibrated alternatives.\"}}, {\"@type\": \"Question\", \"name\": \"Can I use it for confined-space entry?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Yes for monitoring the four hazards. For pre-entry sampling of a sealed space, use a pump-equipped monitor.\"}}, {\"@type\": \"Question\", \"name\": \"Does it have a pump?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"No — it is diffusion. For remote sampling choose a pump monitor.\"}}, {\"@type\": \"Question\", \"name\": \"What alarms does it have?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Sound, light and vibration alarms trigger when any of the four gases exceeds its set point.\"}}, {\"@type\": \"Question\", \"name\": \"What does it not detect?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"VOCs, CO2 and specific toxics. For VOCs use the VOC Detector; for chlorine the Chlorine Analyzer.\"}}, {\"@type\": \"Question\", \"name\": \"How do I keep it accurate?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Bump-test before each day of use with four-gas calibration gas and calibrate on the manufacturer's schedule.\"}}, {\"@type\": \"Question\", \"name\": \"Is it in stock and how does it ship?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Use the Amazon buy button for current availability and delivery timing through our fulfillment partner.\"}}, {\"@type\": \"Question\", \"name\": \"Is ATO industrial grade?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"ATO is an industrial instrument supplier; this is a mid-tier 4-gas option. For managed-fleet docking automation, premium platforms still lead.\"}}, {\"@type\": \"Question\", \"name\": \"How long do the sensors last?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Electrochemical and catalytic sensors typically last two to three years; budget for replacement sensors and calibration gas.\"}}]}, {\"@type\": \"Organization\", \"@id\": \"https:\/\/wcsafety.com\/#org\", \"name\": \"WC Safety\", \"url\": \"https:\/\/wcsafety.com\", \"logo\": \"https:\/\/wcsafety.com\/cdn\/shop\/files\/logo.png\"}, {\"@type\": \"Person\", \"@id\": \"https:\/\/wcsafety.com\/#editor\", \"name\": \"Steven Eaton\", \"jobTitle\": \"Editorial Lead\", \"worksFor\": {\"@id\": \"https:\/\/wcsafety.com\/#org\"}, \"knowsAbout\": [\"industrial gas detection\", \"atmospheric monitoring\", \"personal protective equipment\"]}, {\"@type\": \"Brand\", \"name\": \"ATO\"}]}\n\u003c\/script\u003e","brand":"ATO","offers":[{"title":"Default Title","offer_id":44266961502296,"sku":"B09WVMPGDZ","price":448.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0594\/1900\/0920\/files\/510WkVH7EvL._AC_SL1000.jpg?v=1782133099"},{"product_id":"forensics-mini-4-gas-monitor","title":"Forensics Mini 4 Gas Monitor — Compact O2, CO, H2S \u0026 LEL (NIST)","description":"\u003c!-- PRODUCT B0GNQGL4NY | tag portable-gas-detector | TODO: add matching Product Review + best-of guide links when those silo layers exist --\u003e\n\n\u003cdiv style=\"background:#1a1a1a;border-left:4px solid #ff9800;padding:14px 18px;margin:0 0 18px 0;color:#f5e6d3;font-size:0.95em;\"\u003e\n\u003cstrong style=\"color:#ffb74d;\"\u003eEditor’s note:\u003c\/strong\u003e the Forensics mini 4 gas monitor is one of the instruments we curate in our \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"Portable Gas Detectors\"\u003ePortable Gas Detectors\u003c\/a\u003e buyer’s hub. Compare it with the \u003ca href=\"\/products\/forensics-voc-detector\" title=\"Forensics VOC Detector\"\u003eForensics VOC Detector\u003c\/a\u003e below before you order.\u003c\/div\u003e\n\n\u003ch2 id=\"top\"\u003eForensics Mini 4 Gas Monitor — Compact O2, CO, H2S \u0026amp; LEL\u003c\/h2\u003e\n\n\u003cp\u003eThe \u003cstrong\u003eForensics mini 4 gas monitor\u003c\/strong\u003e packs O2, CO, H2S and LEL into a compact, NIST-calibrated body — a \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"portable gas detector\"\u003eportable gas detector\u003c\/a\u003e for crews who want full four-gas coverage in the smallest, easiest-to-carry form, with a top 4.8-star rating.\u003c\/p\u003e\n\n\u003cp style=\"font-size:0.9em;color:#bdae9d;margin:10px 0 18px 0;\"\u003eJump to: \u003ca href=\"#features\" style=\"color:#ffb74d;\"\u003eFeatures\u003c\/a\u003e · \u003ca href=\"#specs\" style=\"color:#ffb74d;\"\u003eSpecs\u003c\/a\u003e · \u003ca href=\"#compatibility\" style=\"color:#ffb74d;\"\u003eWhat it detects\u003c\/a\u003e · \u003ca href=\"#comparison\" style=\"color:#ffb74d;\"\u003eComparison\u003c\/a\u003e · \u003ca href=\"#faq\" style=\"color:#ffb74d;\"\u003eFAQ\u003c\/a\u003e\u003c\/p\u003e\n\n\u003cp\u003eThe Forensics Mini 4 Gas Monitor is a compact, NIST-calibrated, USB-rechargeable confined-space monitor for O2, CO, H2S and combustible LEL.\u003c\/p\u003e\n\n\u003ch3 id=\"features\"\u003eKey features\u003c\/h3\u003e\n\n\u003cul\u003e\n\u003cli\u003eReads all four confined-space gases — O2, CO, H2S and LEL — in a compact body\u003c\/li\u003e\n\u003cli\u003eUSA NIST-traceable calibration for documented accuracy\u003c\/li\u003e\n\u003cli\u003eUSB-rechargeable for shift-long use\u003c\/li\u003e\n\u003cli\u003eSmaller and lighter than standard 4-gas meters for easy carry\u003c\/li\u003e\n\u003cli\u003eAudible, visual and vibration alarms\u003c\/li\u003e\n\u003cli\u003eStrong 4.8-star rating\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cdiv style=\"display:flex;gap:14px;flex-wrap:wrap;margin:18px 0;\"\u003e\n\u003cdiv style=\"flex:1;min-width:240px;background:#1b3a2a;border:1px solid #4caf50;border-radius:6px;padding:14px 18px;\"\u003e\n\u003cstrong style=\"color:#81c784;\"\u003ePros\u003c\/strong\u003e\u003cul style=\"margin:8px 0 0 0;\"\u003e\n\u003cli\u003eCompact, easy to carry\u003c\/li\u003e\n\u003cli\u003eNIST-calibrated\u003c\/li\u003e\n\u003cli\u003eUSB-rechargeable\u003c\/li\u003e\n\u003cli\u003eAffordable 4-gas\u003c\/li\u003e\n\u003cli\u003eExcellent 4.8-star rating\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"flex:1;min-width:240px;background:#3a1e1e;border:1px solid #ef5350;border-radius:6px;padding:14px 18px;\"\u003e\n\u003cstrong style=\"color:#e57373;\"\u003eCons\u003c\/strong\u003e\u003cul style=\"margin:8px 0 0 0;\"\u003e\n\u003cli\u003eDiffusion only (no pump)\u003c\/li\u003e\n\u003cli\u003eNo VOC\/PID coverage\u003c\/li\u003e\n\u003cli\u003eSmaller display than full-size units\u003c\/li\u003e\n\u003cli\u003eSensors need periodic replacement\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\n\u003ch3 id=\"specs\"\u003eSpecifications\u003c\/h3\u003e\n\n\u003cdiv style=\"overflow-x:auto;\"\u003e\u003ctable style=\"width:100%;border-collapse:collapse;background:#1a1a1a;margin:14px 0;\"\u003e\n\u003cthead\u003e\u003ctr style=\"background:#2a2a2a;\"\u003e\n\u003cth style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;text-align:left;\"\u003eSpecification\u003c\/th\u003e\n\u003cth style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;text-align:left;\"\u003eDetail\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eGases detected\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eO2, CO, H2S, LEL combustibles\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eForm\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eMini \/ compact\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eCalibration\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eUSA NIST-traceable\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003ePower\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eUSB-rechargeable\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eAlarms\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eAudible, visual \u0026amp; vibration\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eSensor\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eElectrochemical + catalytic\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003c\/div\u003e\n\n\u003ch3\u003eWhere the Forensics Mini 4 Gas Monitor fits\u003c\/h3\u003e\n\n\u003cul\u003e\n\u003cli\u003eConfined-space entry monitoring\u003c\/li\u003e\n\u003cli\u003eField and utility work\u003c\/li\u003e\n\u003cli\u003eMaintenance rounds\u003c\/li\u003e\n\u003cli\u003eBackup\/spare 4-gas in a kit\u003c\/li\u003e\n\u003cli\u003eGeneral multi-gas spot checks\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2 id=\"compatibility\"\u003eWhat the Forensics Mini 4 Gas Monitor detects (and what it doesn’t)\u003c\/h2\u003e\n\n\u003cp\u003eIt monitors \u003cstrong\u003eO2, CO, H2S and combustible LEL\u003c\/strong\u003e — not VOCs, CO2 or specific toxics. For VOCs use the \u003ca href=\"\/products\/forensics-voc-detector\" title=\"Forensics VOC Detector\"\u003eForensics VOC Detector\u003c\/a\u003e; for single toxics the \u003ca href=\"\/products\/forensics-chlorine-analyzer-cl2\" title=\"Chlorine\"\u003eChlorine\u003c\/a\u003e or \u003ca href=\"\/products\/forensics-ammonia-detector-nh3\" title=\"Ammonia\"\u003eAmmonia\u003c\/a\u003e analyzers. It is diffusion; for remote pre-entry sampling use the \u003ca href=\"\/products\/forensics-detectors-4-gas-monitor-with-pump\" title=\"Forensics 4 Gas + Pump\"\u003eForensics 4 Gas + Pump\u003c\/a\u003e. Compared with the \u003ca href=\"\/products\/forensics-detectors-4-gas-meter-confined-space\" title=\"4 Gas Meter\"\u003e4 Gas Meter\u003c\/a\u003e it is more compact. Bump-test before use.\u003c\/p\u003e\n\n\u003cp\u003eCross-shopping? This unit sits in our \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"Portable Gas Detectors\"\u003ePortable Gas Detectors\u003c\/a\u003e hub alongside \u003ca href=\"\/products\/forensics-voc-detector\" title=\"Forensics VOC Detector\"\u003eForensics VOC Detector\u003c\/a\u003e, \u003ca href=\"\/products\/amprobe-co2-100-carbon-dioxide-meter\" title=\"Amprobe CO2-100\"\u003eAmprobe CO2-100\u003c\/a\u003e, \u003ca href=\"\/products\/forensics-ammonia-detector-nh3\" title=\"Forensics Ammonia Detector\"\u003eForensics Ammonia Detector\u003c\/a\u003e, \u003ca href=\"\/products\/forensics-chlorine-analyzer-cl2\" title=\"Forensics Chlorine Analyzer\"\u003eForensics Chlorine Analyzer\u003c\/a\u003e. For other gas-detection form factors see \u003ca href=\"\/collections\/personal-gas-detectors\" title=\"Personal \u0026amp; Wearable Gas Detectors\"\u003ePersonal \u0026amp; Wearable Gas Detectors\u003c\/a\u003e, \u003ca href=\"\/collections\/fixed-gas-detection-systems\" title=\"Fixed Gas Detection Systems\"\u003eFixed Gas Detection Systems\u003c\/a\u003e, \u003ca href=\"\/collections\/area-gas-monitors\" title=\"Area \u0026amp; Transportable Gas Monitors\"\u003eArea \u0026amp; Transportable Gas Monitors\u003c\/a\u003e, or browse the full \u003ca href=\"\/collections\/gas-detectors\" title=\"Gas Detectors\"\u003eGas Detectors\u003c\/a\u003e range.\u003c\/p\u003e\n\n\u003ch2 id=\"comparison\"\u003ePortable 4-gas options compared\u003c\/h2\u003e\n\n\u003cdiv style=\"overflow-x:auto;\"\u003e\u003ctable style=\"width:100%;border-collapse:collapse;background:#1a1a1a;margin:14px 0;\"\u003e\n\u003ccaption style=\"color:#bdae9d;font-size:0.85em;text-align:left;padding:4px 0;\"\u003ePortable 4-gas options (O2, CO, H2S, LEL)\u003c\/caption\u003e\n\u003cthead\u003e\u003ctr style=\"background:#2a2a2a;\"\u003e\n\u003cth style=\"color:#ffb74d;padding:9px;border:1px solid #3a3a3a;text-align:left;\"\u003eModel\u003c\/th\u003e\n\u003cth style=\"color:#ffb74d;padding:9px;border:1px solid #3a3a3a;text-align:left;\"\u003eBrand\u003c\/th\u003e\n\u003cth style=\"color:#ffb74d;padding:9px;border:1px solid #3a3a3a;text-align:left;\"\u003eNotable\u003c\/th\u003e\n\u003cth style=\"color:#ffb74d;padding:9px;border:1px solid #3a3a3a;text-align:left;\"\u003eStreet price\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e\u003ca href=\"\/products\/forensics-mini-4-gas-monitor\" title=\"Forensics Mini 4 Gas\"\u003eForensics Mini 4 Gas\u003c\/a\u003e\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eForensics\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eCompact, NIST, USB\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e~$295\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e\u003ca href=\"\/products\/forensics-detectors-4-gas-meter-confined-space\" title=\"Forensics 4 Gas Meter\"\u003eForensics 4 Gas Meter\u003c\/a\u003e\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eForensics\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eLightest, NIST\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e~$199\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#2a2520;\"\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e\u003cstrong\u003e\u003ca href=\"\/products\/ato-handheld-4-gas-detector\" title=\"ATO 4 Gas Detector\"\u003eATO 4 Gas Detector\u003c\/a\u003e\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eATO\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eSound\/light\/vibration\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e~$449\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003c\/div\u003e\n\n\u003cul\u003e\n\u003cli\u003eChoose the \u003cstrong\u003eMini 4 Gas Monitor\u003c\/strong\u003e for the most compact NIST-calibrated four-gas at a low price.\u003c\/li\u003e\n\u003cli\u003eWant the lightest standard meter? See the \u003ca href=\"\/products\/forensics-detectors-4-gas-meter-confined-space\" title=\"Forensics 4 Gas Meter\"\u003eForensics 4 Gas Meter\u003c\/a\u003e.\u003c\/li\u003e\n\u003cli\u003eNeed a pump? Use the \u003ca href=\"\/products\/forensics-detectors-4-gas-monitor-with-pump\" title=\"Forensics 4 Gas + Pump\"\u003eForensics 4 Gas + Pump\u003c\/a\u003e.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2 id=\"faq\"\u003eFrequently asked questions\u003c\/h2\u003e\n\n\u003ch3\u003eWhat gases does the Forensics mini 4 gas monitor measure?\u003c\/h3\u003e\u003cp\u003eO2, CO, H2S and combustible LEL — the confined-space set. For VOCs use the \u003ca href=\"\/products\/forensics-voc-detector\" title=\"Forensics VOC Detector\"\u003eForensics VOC Detector\u003c\/a\u003e.\u003c\/p\u003e\n\u003ch3\u003eHow is it different from the standard 4 Gas Meter?\u003c\/h3\u003e\u003cp\u003eIt is more compact and USB-rechargeable; the \u003ca href=\"\/products\/forensics-detectors-4-gas-meter-confined-space\" title=\"Forensics 4 Gas Meter\"\u003eForensics 4 Gas Meter\u003c\/a\u003e is the lightest standard meter. Both are NIST-calibrated.\u003c\/p\u003e\n\u003ch3\u003eIs it NIST calibrated?\u003c\/h3\u003e\u003cp\u003eYes — USA NIST-traceable calibration. Bump-test before use and recalibrate on schedule.\u003c\/p\u003e\n\u003ch3\u003eIs it rechargeable?\u003c\/h3\u003e\u003cp\u003eYes — USB-rechargeable, sized for a full work shift.\u003c\/p\u003e\n\u003ch3\u003eCan I use it for confined-space entry?\u003c\/h3\u003e\u003cp\u003eYes for monitoring the four hazards. For pre-entry sampling, use the \u003ca href=\"\/products\/forensics-detectors-4-gas-monitor-with-pump\" title=\"Forensics 4 Gas + Pump\"\u003eForensics 4 Gas + Pump\u003c\/a\u003e.\u003c\/p\u003e\n\u003ch3\u003eDoes it have a pump?\u003c\/h3\u003e\u003cp\u003eNo — it is diffusion. For remote sampling choose the \u003ca href=\"\/products\/forensics-detectors-4-gas-monitor-with-pump\" title=\"pump model\"\u003epump model\u003c\/a\u003e.\u003c\/p\u003e\n\u003ch3\u003eWhat alarms does it have?\u003c\/h3\u003e\u003cp\u003eAudible, visual and vibration alarms trigger when any of the four gases exceeds its set point.\u003c\/p\u003e\n\u003ch3\u003eWhat does it not detect?\u003c\/h3\u003e\u003cp\u003eVOCs, CO2 and specific toxics. For VOCs use the \u003ca href=\"\/products\/forensics-voc-detector\" title=\"VOC Detector\"\u003eVOC Detector\u003c\/a\u003e; for chlorine the \u003ca href=\"\/products\/forensics-chlorine-analyzer-cl2\" title=\"Chlorine Analyzer\"\u003eChlorine Analyzer\u003c\/a\u003e.\u003c\/p\u003e\n\u003ch3\u003eWhy is it rated so highly?\u003c\/h3\u003e\u003cp\u003eIt pairs compact size, NIST calibration and USB charging at a low price, earning a strong 4.8-star rating.\u003c\/p\u003e\n\u003ch3\u003eIs it in stock and how does it ship?\u003c\/h3\u003e\u003cp\u003eUse the Amazon buy button for current availability and delivery timing through our fulfillment partner.\u003c\/p\u003e\n\u003ch3\u003eHow long do the sensors last?\u003c\/h3\u003e\u003cp\u003eElectrochemical and catalytic sensors typically last two to three years; budget for replacement sensors and calibration gas.\u003c\/p\u003e\n\u003ch3\u003eIs it a good backup unit?\u003c\/h3\u003e\u003cp\u003eYes — its compact size and low price make it a popular spare\/backup 4-gas to keep in a kit or truck.\u003c\/p\u003e\n\n\u003cdiv style=\"background:#1a1a1a;border:1px solid #3a3a3a;border-radius:6px;padding:16px 18px;margin:22px 0;\"\u003e\n\u003cp style=\"margin:0 0 10px 0;color:#f5e6d3;\"\u003eReady to order the \u003cstrong\u003eForensics mini 4 gas monitor\u003c\/strong\u003e? Add it to your cart above, or check the current Amazon price below. Compare it against the rest of our \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"Portable Gas Detectors\"\u003ePortable Gas Detectors\u003c\/a\u003e lineup before you buy.\u003c\/p\u003e\n\u003cp style=\"display:flex;gap:10px;flex-wrap:wrap;align-items:center;margin:0;\"\u003e\u003ca href=\"https:\/\/www.amazon.com\/dp\/B0GNQGL4NY?tag=wcsafety04-20\" rel=\"sponsored nofollow noopener\" target=\"_blank\" style=\"display:inline-block;background:#FFD814;color:#0F1111;padding:13px 26px;text-decoration:none;font-weight:bold;border-radius:4px;border:1px solid #FCD200;\"\u003eCHECK PRICE ON AMAZON →\u003c\/a\u003e\u003cspan style=\"font-size:0.8em;color:#bdae9d;\"\u003eAs an Amazon Associate, WC Safety earns from qualifying purchases.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/div\u003e\n\n\u003cdiv style=\"background:#1a2733;border:1px dashed #4fc3f7;padding:16px 20px;margin:30px 0 18px 0;color:#cfd8dc;font-size:0.92em;\"\u003e\n  \u003cstrong style=\"color:#4fc3f7;\"\u003eWhy trust this Forensics Detectors page?\u003c\/strong\u003e WC Safety is an independent industrial safety-equipment retailer serving safety managers, procurement teams and field supervisors. The specifications here are taken from the manufacturer’s published listing for Forensics Mini 4 Gas Monitor and framed against \u003ca href=\"https:\/\/www.osha.gov\/laws-regs\/regulations\/standardnumber\/1910\/1910.146\" rel=\"noopener\" target=\"_blank\" style=\"color:#4fc3f7;\"\u003eOSHA 29 CFR 1910.146\u003c\/a\u003e and \u003ca href=\"https:\/\/www.osha.gov\/annotated-pels\" rel=\"noopener\" target=\"_blank\" style=\"color:#4fc3f7;\"\u003eOSHA Permissible Exposure Limits\u003c\/a\u003e. Disclosed: WC Safety earns Amazon affiliate commissions on outbound clicks; that does not influence the specs shown or our lineup.\n\u003c\/div\u003e\n\u003cdiv style=\"background:#1a2733;border-left:4px solid #4fc3f7;padding:18px 22px;margin:18px 0;color:#cfd8dc;font-size:0.92em;\"\u003e\n  \u003cstrong style=\"color:#4fc3f7;\"\u003eBy Steven Eaton, WC Safety Editorial\u003c\/strong\u003e — Industrial safety-equipment desk · specialization: atmospheric monitoring, gas detection and instrument selection.\u003cbr\u003e\n  \u003cstrong\u003eLast updated:\u003c\/strong\u003e \u003ctime datetime=\"2026-06-22\"\u003eJune 22, 2026\u003c\/time\u003e · \u003cstrong\u003eSources reviewed:\u003c\/strong\u003e manufacturer product listing \u0026amp; specifications, OSHA 29 CFR 1910.146, OSHA Annotated PEL tables, ACGIH Threshold Limit Values.\u003cbr\u003e\n  \u003cstrong\u003eEditorial standard:\u003c\/strong\u003e \u003cem\u003eZero sponsored listings. No manufacturer input. Specs verified against the manufacturer’s published data.\u003c\/em\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"background:#1a2733;border-left:4px solid #4fc3f7;padding:16px 20px;margin:18px 0;color:#cfd8dc;font-size:0.92em;\"\u003e\n  \u003cstrong style=\"color:#4fc3f7;\"\u003eHow this page is maintained.\u003c\/strong\u003e Specifications and pricing are reviewed against the manufacturer’s current listing and re-checked whenever the lineup changes. Gas-detection guidance follows \u003ca href=\"https:\/\/www.osha.gov\/laws-regs\/regulations\/standardnumber\/1910\/1910.146\" rel=\"noopener\" target=\"_blank\" style=\"color:#4fc3f7;\"\u003eOSHA 1910.146\u003c\/a\u003e and \u003ca href=\"https:\/\/www.osha.gov\/annotated-pels\" rel=\"noopener\" target=\"_blank\" style=\"color:#4fc3f7;\"\u003eOSHA PELs\u003c\/a\u003e, cross-referenced with ACGIH TLVs.\n\u003c\/div\u003e\n\u003cdiv style=\"background:#2a2520;border-left:4px solid #ff9800;padding:16px 20px;margin:18px 0;color:#f5e6d3;font-size:0.92em;\"\u003e\n  \u003cstrong style=\"color:#ffb74d;\"\u003eDisclosure.\u003c\/strong\u003e WC Safety participates in the Amazon Associates Program and earns commissions on qualifying purchases through outbound links on this page (tag wcsafety04-20). We are not sponsored by any instrument manufacturer. This page is buyer guidance, not medical, legal or regulatory advice — confirm gas-detection requirements for your site against the applicable OSHA standard and, for commercial monitoring programs, a Certified Industrial Hygienist (CIH).\n\u003c\/div\u003e\n\n\u003cscript type=\"application\/ld+json\"\u003e\n{\"@context\": \"https:\/\/schema.org\", \"@graph\": [{\"@type\": \"Product\", \"@id\": \"https:\/\/wcsafety.com\/products\/forensics-mini-4-gas-monitor#product\", \"name\": \"Forensics Mini 4 Gas Monitor — Compact O2, CO, H2S \u0026 LEL (NIST)\", \"description\": \"Forensics mini 4 gas monitor — compact, NIST-calibrated O2, CO, H2S \u0026 LEL detector with USB recharge for confined-space and field use. Order at WC Safety.\", \"sku\": \"B0GNQGL4NY\", \"mpn\": \"FD-Mini4\", \"image\": [\"https:\/\/wcsafety.com\/cdn\/shop\/products\/forensics-mini-4-gas-monitor.jpg\"], \"brand\": {\"@type\": \"Brand\", \"name\": \"Forensics Detectors\"}, \"category\": \"Portable Gas Detector\", \"isPartOf\": {\"@type\": \"CollectionPage\", \"@id\": \"https:\/\/wcsafety.com\/collections\/portable-gas-detectors#collection\", \"name\": \"Portable Gas Detectors\", \"url\": \"https:\/\/wcsafety.com\/collections\/portable-gas-detectors\"}, \"isRelatedTo\": [{\"@type\": \"Product\", \"name\": \"Forensics VOC Detector\", \"url\": \"https:\/\/wcsafety.com\/products\/forensics-voc-detector\"}, {\"@type\": \"Product\", \"name\": \"Amprobe CO2-100 Carbon Dioxide Meter\", \"url\": \"https:\/\/wcsafety.com\/products\/amprobe-co2-100-carbon-dioxide-meter\"}, {\"@type\": \"Product\", \"name\": \"Forensics Ammonia (NH3) Detector\", \"url\": \"https:\/\/wcsafety.com\/products\/forensics-ammonia-detector-nh3\"}, {\"@type\": \"Product\", \"name\": \"Forensics Chlorine (Cl2) Analyzer\", \"url\": \"https:\/\/wcsafety.com\/products\/forensics-chlorine-analyzer-cl2\"}, {\"@type\": \"Product\", \"name\": \"Forensics Sulfur Dioxide (SO2) Analyzer\", \"url\": \"https:\/\/wcsafety.com\/products\/forensics-sulfur-dioxide-analyzer-so2\"}, {\"@type\": \"Product\", \"name\": \"ATO Ozone (O3) Gas Detector\", \"url\": \"https:\/\/wcsafety.com\/products\/ato-ozone-gas-detector-o3\"}, {\"@type\": \"Product\", \"name\": \"ATO Handheld 4 Gas Detector\", \"url\": \"https:\/\/wcsafety.com\/products\/ato-handheld-4-gas-detector\"}, {\"@type\": \"Product\", \"name\": \"Forensics Detectors 4 Gas Meter\", \"url\": \"https:\/\/wcsafety.com\/products\/forensics-detectors-4-gas-meter-confined-space\"}, {\"@type\": \"Product\", \"name\": \"Forensics Detectors 4 Gas Monitor with Pump\", \"url\": \"https:\/\/wcsafety.com\/products\/forensics-detectors-4-gas-monitor-with-pump\"}], \"offers\": {\"@type\": \"Offer\", \"url\": \"https:\/\/wcsafety.com\/products\/forensics-mini-4-gas-monitor\", \"priceCurrency\": \"USD\", \"price\": \"295.00\", \"availability\": \"https:\/\/schema.org\/InStock\", \"seller\": {\"@type\": \"Organization\", \"name\": \"WC Safety\"}}}, {\"@type\": \"BreadcrumbList\", \"@id\": \"https:\/\/wcsafety.com\/products\/forensics-mini-4-gas-monitor#breadcrumb\", \"itemListElement\": [{\"@type\": \"ListItem\", \"position\": 1, \"name\": \"Home\", \"item\": \"https:\/\/wcsafety.com\/\"}, {\"@type\": \"ListItem\", \"position\": 2, \"name\": \"Gas Detectors\", \"item\": \"https:\/\/wcsafety.com\/collections\/gas-detectors\"}, {\"@type\": \"ListItem\", \"position\": 3, \"name\": \"Portable Gas Detectors\", \"item\": \"https:\/\/wcsafety.com\/collections\/portable-gas-detectors\"}, {\"@type\": \"ListItem\", \"position\": 4, \"name\": \"Forensics Mini 4 Gas Monitor — Compact O2, CO, H2S \u0026 LEL (NIST)\"}]}, {\"@type\": \"FAQPage\", \"mainEntity\": [{\"@type\": \"Question\", \"name\": \"What gases does the Forensics mini 4 gas monitor measure?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"O2, CO, H2S and combustible LEL — the confined-space set. For VOCs use the Forensics VOC Detector.\"}}, {\"@type\": \"Question\", \"name\": \"How is it different from the standard 4 Gas Meter?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"It is more compact and USB-rechargeable; the Forensics 4 Gas Meter is the lightest standard meter. Both are NIST-calibrated.\"}}, {\"@type\": \"Question\", \"name\": \"Is it NIST calibrated?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Yes — USA NIST-traceable calibration. Bump-test before use and recalibrate on schedule.\"}}, {\"@type\": \"Question\", \"name\": \"Is it rechargeable?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Yes — USB-rechargeable, sized for a full work shift.\"}}, {\"@type\": \"Question\", \"name\": \"Can I use it for confined-space entry?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Yes for monitoring the four hazards. For pre-entry sampling, use the Forensics 4 Gas + Pump.\"}}, {\"@type\": \"Question\", \"name\": \"Does it have a pump?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"No — it is diffusion. For remote sampling choose the pump model.\"}}, {\"@type\": \"Question\", \"name\": \"What alarms does it have?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Audible, visual and vibration alarms trigger when any of the four gases exceeds its set point.\"}}, {\"@type\": \"Question\", \"name\": \"What does it not detect?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"VOCs, CO2 and specific toxics. For VOCs use the VOC Detector; for chlorine the Chlorine Analyzer.\"}}, {\"@type\": \"Question\", \"name\": \"Why is it rated so highly?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"It pairs compact size, NIST calibration and USB charging at a low price, earning a strong 4.8-star rating.\"}}, {\"@type\": \"Question\", \"name\": \"Is it in stock and how does it ship?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Use the Amazon buy button for current availability and delivery timing through our fulfillment partner.\"}}, {\"@type\": \"Question\", \"name\": \"How long do the sensors last?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Electrochemical and catalytic sensors typically last two to three years; budget for replacement sensors and calibration gas.\"}}, {\"@type\": \"Question\", \"name\": \"Is it a good backup unit?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Yes — its compact size and low price make it a popular spare\/backup 4-gas to keep in a kit or truck.\"}}]}, {\"@type\": \"Organization\", \"@id\": \"https:\/\/wcsafety.com\/#org\", \"name\": \"WC Safety\", \"url\": \"https:\/\/wcsafety.com\", \"logo\": \"https:\/\/wcsafety.com\/cdn\/shop\/files\/logo.png\"}, {\"@type\": \"Person\", \"@id\": \"https:\/\/wcsafety.com\/#editor\", \"name\": \"Steven Eaton\", \"jobTitle\": \"Editorial Lead\", \"worksFor\": {\"@id\": \"https:\/\/wcsafety.com\/#org\"}, \"knowsAbout\": [\"industrial gas detection\", \"atmospheric monitoring\", \"personal protective equipment\"]}, {\"@type\": \"Brand\", \"name\": \"Forensics Detectors\"}]}\n\u003c\/script\u003e","brand":"Forensics Detectors","offers":[{"title":"Default Title","offer_id":44266961600600,"sku":"B0GNQGL4NY","price":295.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0594\/1900\/0920\/files\/71mdaKWdgnL._AC_SL1500.jpg?v=1782133103"},{"product_id":"bw-gasalertclip-extreme-h2s-monitor","title":"BW GasAlertClip Extreme H2S Monitor — 2-Year Disposable Single-Gas","description":"\u003c!-- PRODUCT B00APKZWRG | tag personal-gas-detector | TODO: add matching Product Review + best-of guide links when those silo layers exist --\u003e\n\n\u003cdiv style=\"background:#1a1a1a;border-left:4px solid #ff9800;padding:14px 18px;margin:0 0 18px 0;color:#f5e6d3;font-size:0.95em;\"\u003e\n\u003cstrong style=\"color:#ffb74d;\"\u003eEditor’s note:\u003c\/strong\u003e the BW GasAlertClip Extreme H2S is one of the instruments we curate in our \u003ca href=\"\/collections\/personal-gas-detectors\" title=\"Personal \u0026amp; Wearable Gas Detectors\"\u003ePersonal \u0026amp; Wearable Gas Detectors\u003c\/a\u003e buyer’s hub. Compare it with the \u003ca href=\"\/products\/toptes-guard-633-h2s-detector\" title=\"TopTes Guard-633 H2S\"\u003eTopTes Guard-633 H2S\u003c\/a\u003e below before you order.\u003c\/div\u003e\n\n\u003ch2 id=\"top\"\u003eBW GasAlertClip Extreme H2S Monitor — 2-Year Disposable Clip\u003c\/h2\u003e\n\n\u003cp\u003eThe \u003cstrong\u003eBW GasAlertClip Extreme H2S\u003c\/strong\u003e is a 2-year disposable single-gas clip for hydrogen sulfide — a set-and-forget \u003ca href=\"\/collections\/personal-gas-detectors\" title=\"personal gas detector\"\u003epersonal gas detector\u003c\/a\u003e you turn on once and wear for two years with no battery or sensor service.\u003c\/p\u003e\n\n\u003cp style=\"font-size:0.9em;color:#bdae9d;margin:10px 0 18px 0;\"\u003eJump to: \u003ca href=\"#features\" style=\"color:#ffb74d;\"\u003eFeatures\u003c\/a\u003e · \u003ca href=\"#specs\" style=\"color:#ffb74d;\"\u003eSpecs\u003c\/a\u003e · \u003ca href=\"#compatibility\" style=\"color:#ffb74d;\"\u003eWhat it detects\u003c\/a\u003e · \u003ca href=\"#comparison\" style=\"color:#ffb74d;\"\u003eComparison\u003c\/a\u003e · \u003ca href=\"#faq\" style=\"color:#ffb74d;\"\u003eFAQ\u003c\/a\u003e\u003c\/p\u003e\n\n\u003cp\u003eThe BW GasAlertClip Extreme H2S is a 2-year disposable, electrochemical single-gas personal monitor for hydrogen sulfide with audible, visual and vibrating alarms.\u003c\/p\u003e\n\n\u003ch3 id=\"features\"\u003eKey features\u003c\/h3\u003e\n\n\u003cul\u003e\n\u003cli\u003eWorn in the breathing zone to alarm on hydrogen sulfide (H2S) exposure\u003c\/li\u003e\n\u003cli\u003e2-year disposable design — turn it on and run it with no battery or sensor service\u003c\/li\u003e\n\u003cli\u003eAudible, visual and vibrating alarms\u003c\/li\u003e\n\u003cli\u003eSet-and-forget simplicity; no docking infrastructure required\u003c\/li\u003e\n\u003cli\u003eStrong 4.3-star, 97-review track record\u003c\/li\u003e\n\u003cli\u003eAn alternative to the BW Clip for the same H2S hazard\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cdiv style=\"display:flex;gap:14px;flex-wrap:wrap;margin:18px 0;\"\u003e\n\u003cdiv style=\"flex:1;min-width:240px;background:#1b3a2a;border:1px solid #4caf50;border-radius:6px;padding:14px 18px;\"\u003e\n\u003cstrong style=\"color:#81c784;\"\u003ePros\u003c\/strong\u003e\u003cul style=\"margin:8px 0 0 0;\"\u003e\n\u003cli\u003e2-year run with zero maintenance\u003c\/li\u003e\n\u003cli\u003eSet-and-forget, no docking needed\u003c\/li\u003e\n\u003cli\u003eTriple alarm modes\u003c\/li\u003e\n\u003cli\u003eLow cost per worker\u003c\/li\u003e\n\u003cli\u003eProven review base\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"flex:1;min-width:240px;background:#3a1e1e;border:1px solid #ef5350;border-radius:6px;padding:14px 18px;\"\u003e\n\u003cstrong style=\"color:#e57373;\"\u003eCons\u003c\/strong\u003e\u003cul style=\"margin:8px 0 0 0;\"\u003e\n\u003cli\u003eSingle gas only — H2S\u003c\/li\u003e\n\u003cli\u003eDisposable (replace at end of life)\u003c\/li\u003e\n\u003cli\u003eStill needs bump testing\u003c\/li\u003e\n\u003cli\u003eNo data export\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\n\u003ch3 id=\"specs\"\u003eSpecifications\u003c\/h3\u003e\n\n\u003cdiv style=\"overflow-x:auto;\"\u003e\u003ctable style=\"width:100%;border-collapse:collapse;background:#1a1a1a;margin:14px 0;\"\u003e\n\u003cthead\u003e\u003ctr style=\"background:#2a2a2a;\"\u003e\n\u003cth style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;text-align:left;\"\u003eSpecification\u003c\/th\u003e\n\u003cth style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;text-align:left;\"\u003eDetail\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eGas detected\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eHydrogen sulfide (H2S)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eSensor\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eElectrochemical\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eService life\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003e2 years, disposable\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eAlarms\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eAudible, visual \u0026amp; vibrating\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eCalibration\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eFactory-set; bump test recommended\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eMaintenance\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eNone — no battery or sensor service\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eForm\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eCompact breathing-zone clip\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003c\/div\u003e\n\n\u003ch3\u003eWhere the BW GasAlertClip Extreme fits\u003c\/h3\u003e\n\n\u003cul\u003e\n\u003cli\u003eOil-and-gas and wellsite work\u003c\/li\u003e\n\u003cli\u003eWastewater and sewer entry\u003c\/li\u003e\n\u003cli\u003eRefineries and pulp\/paper\u003c\/li\u003e\n\u003cli\u003eTank and vessel work with H2S\u003c\/li\u003e\n\u003cli\u003eOne clip per worker across a crew\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2 id=\"compatibility\"\u003eWhat the BW GasAlertClip Extreme detects (and what it doesn’t)\u003c\/h2\u003e\n\n\u003cp\u003eIt detects \u003cstrong\u003ehydrogen sulfide (H2S) only\u003c\/strong\u003e — not CO, O2 or combustibles. For multi-gas wear use a 4-gas unit like the \u003ca href=\"\/collections\/personal-gas-detectors\" title=\"Personal \u0026amp; Wearable Gas Detectors\"\u003ePersonal \u0026amp; Wearable Gas Detectors\u003c\/a\u003e hub’s GasAlertMicroClip XL; for the maintenance-free serviceable alternative see the \u003ca href=\"\/products\/honeywell-bw-clip-h2s-monitor-bwc2-h\" title=\"Honeywell BW Clip H2S\"\u003eHoneywell BW Clip H2S\u003c\/a\u003e. It is a personal exposure monitor — confined-space entry still needs pre-entry testing with a \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"Portable Gas Detectors\"\u003ePortable Gas Detectors\u003c\/a\u003e instrument. Bump-test with H2S calibration gas before use.\u003c\/p\u003e\n\n\u003cp\u003eCross-shopping? This unit sits in our \u003ca href=\"\/collections\/personal-gas-detectors\" title=\"Personal \u0026amp; Wearable Gas Detectors\"\u003ePersonal \u0026amp; Wearable Gas Detectors\u003c\/a\u003e hub alongside \u003ca href=\"\/products\/toptes-guard-633-h2s-detector\" title=\"TopTes Guard-633 H2S\"\u003eTopTes Guard-633 H2S\u003c\/a\u003e, \u003ca href=\"\/products\/honeywell-bw-clip-h2s-monitor-bwc2-h\" title=\"Honeywell BW Clip H2S\"\u003eHoneywell BW Clip H2S\u003c\/a\u003e. For other gas-detection form factors see \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"Portable Gas Detectors\"\u003ePortable Gas Detectors\u003c\/a\u003e, \u003ca href=\"\/collections\/fixed-gas-detection-systems\" title=\"Fixed Gas Detection Systems\"\u003eFixed Gas Detection Systems\u003c\/a\u003e, \u003ca href=\"\/collections\/area-gas-monitors\" title=\"Area \u0026amp; Transportable Gas Monitors\"\u003eArea \u0026amp; Transportable Gas Monitors\u003c\/a\u003e, or browse the full \u003ca href=\"\/collections\/gas-detectors\" title=\"Gas Detectors\"\u003eGas Detectors\u003c\/a\u003e range.\u003c\/p\u003e\n\n\u003ch2 id=\"comparison\"\u003eHoneywell BW personal H2S monitors compared\u003c\/h2\u003e\n\n\u003cdiv style=\"overflow-x:auto;\"\u003e\u003ctable style=\"width:100%;border-collapse:collapse;background:#1a1a1a;margin:14px 0;\"\u003e\n\u003ccaption style=\"color:#bdae9d;font-size:0.85em;text-align:left;padding:4px 0;\"\u003eHoneywell BW personal H2S monitors\u003c\/caption\u003e\n\u003cthead\u003e\u003ctr style=\"background:#2a2a2a;\"\u003e\n\u003cth style=\"color:#ffb74d;padding:9px;border:1px solid #3a3a3a;text-align:left;\"\u003eModel\u003c\/th\u003e\n\u003cth style=\"color:#ffb74d;padding:9px;border:1px solid #3a3a3a;text-align:left;\"\u003eService model\u003c\/th\u003e\n\u003cth style=\"color:#ffb74d;padding:9px;border:1px solid #3a3a3a;text-align:left;\"\u003eRun time\u003c\/th\u003e\n\u003cth style=\"color:#ffb74d;padding:9px;border:1px solid #3a3a3a;text-align:left;\"\u003eNotable\u003c\/th\u003e\n\u003cth style=\"color:#ffb74d;padding:9px;border:1px solid #3a3a3a;text-align:left;\"\u003eStreet price\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e\u003ca href=\"\/products\/honeywell-bw-clip-h2s-monitor-bwc2-h\" title=\"BW Clip H2S (BWC2-H)\"\u003eBW Clip H2S (BWC2-H)\u003c\/a\u003e\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eMaintenance-free\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e2 years sealed\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eNo sensor\/battery service\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e~$125\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#2a2520;\"\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e\u003cstrong\u003e\u003ca href=\"\/products\/bw-gasalertclip-extreme-h2s-monitor\" title=\"GasAlertClip Extreme H2S\"\u003eGasAlertClip Extreme H2S\u003c\/a\u003e\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eDisposable\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e2 years\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003eSet-and-forget, no docking needed\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:9px;border:1px solid #3a3a3a;\"\u003e~$124\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003c\/div\u003e\n\n\u003cul\u003e\n\u003cli\u003eChoose the \u003cstrong\u003eGasAlertClip Extreme\u003c\/strong\u003e for a simple 2-year disposable H2S clip with no docking needed.\u003c\/li\u003e\n\u003cli\u003ePrefer the same maker’s maintenance-free line? See the \u003ca href=\"\/products\/honeywell-bw-clip-h2s-monitor-bwc2-h\" title=\"BW Clip H2S\"\u003eBW Clip H2S\u003c\/a\u003e.\u003c\/li\u003e\n\u003cli\u003eFor a lower-cost rechargeable H2S clip, see the \u003ca href=\"\/products\/toptes-guard-633-h2s-detector\" title=\"TopTes Guard-633\"\u003eTopTes Guard-633\u003c\/a\u003e.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2 id=\"faq\"\u003eFrequently asked questions\u003c\/h2\u003e\n\n\u003ch3\u003eWhat gas does the BW GasAlertClip Extreme detect?\u003c\/h3\u003e\u003cp\u003eHydrogen sulfide (H2S) only, with audible, visual and vibrating alarms. For several gases on one worker, use a 4-gas wearable.\u003c\/p\u003e\n\u003ch3\u003eHow long does it last?\u003c\/h3\u003e\u003cp\u003eTwo years from activation, then you replace the whole unit — it is a disposable design with no battery or sensor service in between.\u003c\/p\u003e\n\u003ch3\u003eHow is it different from the BW Clip H2S?\u003c\/h3\u003e\u003cp\u003eBoth are 2-year H2S clips; the \u003ca href=\"\/products\/honeywell-bw-clip-h2s-monitor-bwc2-h\" title=\"BW Clip H2S\"\u003eBW Clip H2S\u003c\/a\u003e is the current maintenance-free line, while the GasAlertClip Extreme is the established disposable model. Either covers the same H2S hazard.\u003c\/p\u003e\n\u003ch3\u003eDoes it need docking or calibration?\u003c\/h3\u003e\u003cp\u003eNo docking is required — it is set-and-forget. You should still bump-test with H2S gas before use to confirm response.\u003c\/p\u003e\n\u003ch3\u003eWhere should it be worn?\u003c\/h3\u003e\u003cp\u003eIn the breathing zone, clipped to the collar or upper chest within about 12 inches of the nose and mouth.\u003c\/p\u003e\n\u003ch3\u003eIs it rechargeable?\u003c\/h3\u003e\u003cp\u003eNo — it is a sealed 2-year disposable. For a rechargeable H2S clip, see the \u003ca href=\"\/products\/toptes-guard-633-h2s-detector\" title=\"TopTes Guard-633\"\u003eTopTes Guard-633\u003c\/a\u003e.\u003c\/p\u003e\n\u003ch3\u003eWhat alarms does it have?\u003c\/h3\u003e\u003cp\u003eAudible, visual and vibrating alarms trigger when H2S crosses the set point.\u003c\/p\u003e\n\u003ch3\u003eCan one unit cover a crew?\u003c\/h3\u003e\u003cp\u003eNo — issue one per worker. For area coverage use a \u003ca href=\"\/collections\/area-gas-monitors\" title=\"Area \u0026amp; Transportable Gas Monitors\"\u003eArea \u0026amp; Transportable Gas Monitors\u003c\/a\u003e monitor; for pre-entry a \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"Portable Gas Detectors\"\u003ePortable Gas Detectors\u003c\/a\u003e instrument.\u003c\/p\u003e\n\u003ch3\u003eIs it good for oil and gas?\u003c\/h3\u003e\u003cp\u003eYes — H2S clips are standard PPE in oil and gas, wellsite, refinery and wastewater work where H2S is the dominant hazard.\u003c\/p\u003e\n\u003ch3\u003eIs it in stock and how does it ship?\u003c\/h3\u003e\u003cp\u003eUse the Amazon buy button for current availability and delivery timing through our fulfillment partner.\u003c\/p\u003e\n\u003ch3\u003eDoes it detect anything besides H2S?\u003c\/h3\u003e\u003cp\u003eNo. For CO use the \u003ca href=\"\/collections\/carbon-monoxide-alarms-detectors\" title=\"Carbon Monoxide Alarms \u0026amp; Detectors\"\u003eCarbon Monoxide Alarms \u0026amp; Detectors\u003c\/a\u003e range; for multi-gas a 4-gas wearable in the \u003ca href=\"\/collections\/personal-gas-detectors\" title=\"Personal \u0026amp; Wearable Gas Detectors\"\u003ePersonal \u0026amp; Wearable Gas Detectors\u003c\/a\u003e hub.\u003c\/p\u003e\n\u003ch3\u003eDo I still need pre-entry testing?\u003c\/h3\u003e\u003cp\u003eYes — a personal clip supplements but does not replace pre-entry atmospheric testing with a \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"Portable Gas Detectors\"\u003ePortable Gas Detectors\u003c\/a\u003e instrument.\u003c\/p\u003e\n\n\u003cdiv style=\"background:#1a1a1a;border:1px solid #3a3a3a;border-radius:6px;padding:16px 18px;margin:22px 0;\"\u003e\n\u003cp style=\"margin:0 0 10px 0;color:#f5e6d3;\"\u003eReady to order the \u003cstrong\u003eBW GasAlertClip Extreme H2S\u003c\/strong\u003e? Add it to your cart above, or check the current Amazon price below. Compare it against the rest of our \u003ca href=\"\/collections\/personal-gas-detectors\" title=\"Personal \u0026amp; Wearable Gas Detectors\"\u003ePersonal \u0026amp; Wearable Gas Detectors\u003c\/a\u003e lineup before you buy.\u003c\/p\u003e\n\u003cp style=\"display:flex;gap:10px;flex-wrap:wrap;align-items:center;margin:0;\"\u003e\u003ca href=\"https:\/\/www.amazon.com\/dp\/B00APKZWRG?tag=wcsafety04-20\" rel=\"sponsored nofollow noopener\" target=\"_blank\" style=\"display:inline-block;background:#FFD814;color:#0F1111;padding:13px 26px;text-decoration:none;font-weight:bold;border-radius:4px;border:1px solid #FCD200;\"\u003eCHECK PRICE ON AMAZON →\u003c\/a\u003e\u003cspan style=\"font-size:0.8em;color:#bdae9d;\"\u003eAs an Amazon Associate, WC Safety earns from qualifying purchases.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/div\u003e\n\n\u003cdiv style=\"background:#1a2733;border:1px dashed #4fc3f7;padding:16px 20px;margin:30px 0 18px 0;color:#cfd8dc;font-size:0.92em;\"\u003e\n  \u003cstrong style=\"color:#4fc3f7;\"\u003eWhy trust this Honeywell BW page?\u003c\/strong\u003e WC Safety is an independent industrial safety-equipment retailer serving safety managers, procurement teams and field supervisors. The specifications here are taken from the manufacturer’s published listing for BW GasAlertClip Extreme and framed against \u003ca href=\"https:\/\/www.osha.gov\/laws-regs\/regulations\/standardnumber\/1910\/1910.146\" rel=\"noopener\" target=\"_blank\" style=\"color:#4fc3f7;\"\u003eOSHA 29 CFR 1910.146\u003c\/a\u003e and \u003ca href=\"https:\/\/www.osha.gov\/annotated-pels\" rel=\"noopener\" target=\"_blank\" style=\"color:#4fc3f7;\"\u003eOSHA Permissible Exposure Limits\u003c\/a\u003e. Disclosed: WC Safety earns Amazon affiliate commissions on outbound clicks; that does not influence the specs shown or our lineup.\n\u003c\/div\u003e\n\u003cdiv style=\"background:#1a2733;border-left:4px solid #4fc3f7;padding:18px 22px;margin:18px 0;color:#cfd8dc;font-size:0.92em;\"\u003e\n  \u003cstrong style=\"color:#4fc3f7;\"\u003eBy Steven Eaton, WC Safety Editorial\u003c\/strong\u003e — Industrial safety-equipment desk · specialization: atmospheric monitoring, gas detection and instrument selection.\u003cbr\u003e\n  \u003cstrong\u003eLast updated:\u003c\/strong\u003e \u003ctime datetime=\"2026-06-22\"\u003eJune 22, 2026\u003c\/time\u003e · \u003cstrong\u003eSources reviewed:\u003c\/strong\u003e manufacturer product listing \u0026amp; specifications, OSHA 29 CFR 1910.146, OSHA Annotated PEL tables, ACGIH Threshold Limit Values.\u003cbr\u003e\n  \u003cstrong\u003eEditorial standard:\u003c\/strong\u003e \u003cem\u003eZero sponsored listings. No manufacturer input. Specs verified against the manufacturer’s published data.\u003c\/em\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"background:#1a2733;border-left:4px solid #4fc3f7;padding:16px 20px;margin:18px 0;color:#cfd8dc;font-size:0.92em;\"\u003e\n  \u003cstrong style=\"color:#4fc3f7;\"\u003eHow this page is maintained.\u003c\/strong\u003e Specifications and pricing are reviewed against the manufacturer’s current listing and re-checked whenever the lineup changes. Gas-detection guidance follows \u003ca href=\"https:\/\/www.osha.gov\/laws-regs\/regulations\/standardnumber\/1910\/1910.146\" rel=\"noopener\" target=\"_blank\" style=\"color:#4fc3f7;\"\u003eOSHA 1910.146\u003c\/a\u003e and \u003ca href=\"https:\/\/www.osha.gov\/annotated-pels\" rel=\"noopener\" target=\"_blank\" style=\"color:#4fc3f7;\"\u003eOSHA PELs\u003c\/a\u003e, cross-referenced with ACGIH TLVs.\n\u003c\/div\u003e\n\u003cdiv style=\"background:#2a2520;border-left:4px solid #ff9800;padding:16px 20px;margin:18px 0;color:#f5e6d3;font-size:0.92em;\"\u003e\n  \u003cstrong style=\"color:#ffb74d;\"\u003eDisclosure.\u003c\/strong\u003e WC Safety participates in the Amazon Associates Program and earns commissions on qualifying purchases through outbound links on this page (tag wcsafety04-20). We are not sponsored by any instrument manufacturer. This page is buyer guidance, not medical, legal or regulatory advice — confirm gas-detection requirements for your site against the applicable OSHA standard and, for commercial monitoring programs, a Certified Industrial Hygienist (CIH).\n\u003c\/div\u003e\n\n\u003cscript type=\"application\/ld+json\"\u003e\n{\"@context\": \"https:\/\/schema.org\", \"@graph\": [{\"@type\": \"Product\", \"@id\": \"https:\/\/wcsafety.com\/products\/bw-gasalertclip-extreme-h2s-monitor#product\", \"name\": \"BW GasAlertClip Extreme H2S Monitor — 2-Year Disposable Single-Gas\", \"description\": \"BW GasAlertClip Extreme H2S monitor — 2-year disposable single-gas hydrogen sulfide clip, no sensor or battery service. Order at WC Safety.\", \"sku\": \"B00APKZWRG\", \"mpn\": \"GAXT-H2S\", \"image\": [\"https:\/\/wcsafety.com\/cdn\/shop\/products\/bw-gasalertclip-extreme-h2s-monitor.jpg\"], \"brand\": {\"@type\": \"Brand\", \"name\": \"Honeywell BW\"}, \"category\": \"Personal Gas Detector\", \"isPartOf\": {\"@type\": \"CollectionPage\", \"@id\": \"https:\/\/wcsafety.com\/collections\/personal-gas-detectors#collection\", \"name\": \"Personal \u0026 Wearable Gas Detectors\", \"url\": \"https:\/\/wcsafety.com\/collections\/personal-gas-detectors\"}, \"isRelatedTo\": [{\"@type\": \"Product\", \"name\": \"TopTes Guard-633 H2S Detector\", \"url\": \"https:\/\/wcsafety.com\/products\/toptes-guard-633-h2s-detector\"}, {\"@type\": \"Product\", \"name\": \"Honeywell BW Clip H2S Monitor (BWC2-H)\", \"url\": \"https:\/\/wcsafety.com\/products\/honeywell-bw-clip-h2s-monitor-bwc2-h\"}], \"offers\": {\"@type\": \"Offer\", \"url\": \"https:\/\/wcsafety.com\/products\/bw-gasalertclip-extreme-h2s-monitor\", \"priceCurrency\": \"USD\", \"price\": \"124.00\", \"availability\": \"https:\/\/schema.org\/InStock\", \"seller\": {\"@type\": \"Organization\", \"name\": \"WC Safety\"}}}, {\"@type\": \"BreadcrumbList\", \"@id\": \"https:\/\/wcsafety.com\/products\/bw-gasalertclip-extreme-h2s-monitor#breadcrumb\", \"itemListElement\": [{\"@type\": \"ListItem\", \"position\": 1, \"name\": \"Home\", \"item\": \"https:\/\/wcsafety.com\/\"}, {\"@type\": \"ListItem\", \"position\": 2, \"name\": \"Gas Detectors\", \"item\": \"https:\/\/wcsafety.com\/collections\/gas-detectors\"}, {\"@type\": \"ListItem\", \"position\": 3, \"name\": \"Personal \u0026 Wearable Gas Detectors\", \"item\": \"https:\/\/wcsafety.com\/collections\/personal-gas-detectors\"}, {\"@type\": \"ListItem\", \"position\": 4, \"name\": \"BW GasAlertClip Extreme H2S Monitor — 2-Year Disposable Single-Gas\"}]}, {\"@type\": \"FAQPage\", \"mainEntity\": [{\"@type\": \"Question\", \"name\": \"What gas does the BW GasAlertClip Extreme detect?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Hydrogen sulfide (H2S) only, with audible, visual and vibrating alarms. For several gases on one worker, use a 4-gas wearable.\"}}, {\"@type\": \"Question\", \"name\": \"How long does it last?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Two years from activation, then you replace the whole unit — it is a disposable design with no battery or sensor service in between.\"}}, {\"@type\": \"Question\", \"name\": \"How is it different from the BW Clip H2S?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Both are 2-year H2S clips; the BW Clip H2S is the current maintenance-free line, while the GasAlertClip Extreme is the established disposable model. Either covers the same H2S hazard.\"}}, {\"@type\": \"Question\", \"name\": \"Does it need docking or calibration?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"No docking is required — it is set-and-forget. You should still bump-test with H2S gas before use to confirm response.\"}}, {\"@type\": \"Question\", \"name\": \"Where should it be worn?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"In the breathing zone, clipped to the collar or upper chest within about 12 inches of the nose and mouth.\"}}, {\"@type\": \"Question\", \"name\": \"Is it rechargeable?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"No — it is a sealed 2-year disposable. For a rechargeable H2S clip, see the TopTes Guard-633.\"}}, {\"@type\": \"Question\", \"name\": \"What alarms does it have?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Audible, visual and vibrating alarms trigger when H2S crosses the set point.\"}}, {\"@type\": \"Question\", \"name\": \"Can one unit cover a crew?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"No — issue one per worker. For area coverage use a Area \u0026 Transportable Gas Monitors monitor; for pre-entry a Portable Gas Detectors instrument.\"}}, {\"@type\": \"Question\", \"name\": \"Is it good for oil and gas?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Yes — H2S clips are standard PPE in oil and gas, wellsite, refinery and wastewater work where H2S is the dominant hazard.\"}}, {\"@type\": \"Question\", \"name\": \"Is it in stock and how does it ship?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Use the Amazon buy button for current availability and delivery timing through our fulfillment partner.\"}}, {\"@type\": \"Question\", \"name\": \"Does it detect anything besides H2S?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"No. For CO use the Carbon Monoxide Alarms \u0026 Detectors range; for multi-gas a 4-gas wearable in the Personal \u0026 Wearable Gas Detectors hub.\"}}, {\"@type\": \"Question\", \"name\": \"Do I still need pre-entry testing?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Yes — a personal clip supplements but does not replace pre-entry atmospheric testing with a Portable Gas Detectors instrument.\"}}]}, {\"@type\": \"Organization\", \"@id\": \"https:\/\/wcsafety.com\/#org\", \"name\": \"WC Safety\", \"url\": \"https:\/\/wcsafety.com\", \"logo\": \"https:\/\/wcsafety.com\/cdn\/shop\/files\/logo.png\"}, {\"@type\": \"Person\", \"@id\": \"https:\/\/wcsafety.com\/#editor\", \"name\": \"Steven Eaton\", \"jobTitle\": \"Editorial Lead\", \"worksFor\": {\"@id\": \"https:\/\/wcsafety.com\/#org\"}, \"knowsAbout\": [\"industrial gas detection\", \"atmospheric monitoring\", \"personal protective equipment\"]}, {\"@type\": \"Brand\", \"name\": \"Honeywell BW\"}]}\n\u003c\/script\u003e","brand":"Honeywell BW","offers":[{"title":"Default Title","offer_id":44266968121432,"sku":"B00APKZWRG","price":124.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0594\/1900\/0920\/files\/71nPCQpUbqL._SL1360.jpg?v=1782133291"},{"product_id":"toptes-guard-633-h2s-detector","title":"TopTes Guard-633 H2S Detector — Clip-On Single-Gas Monitor (7-Day Battery)","description":"\u003c!-- PRODUCT B0DHGC7547 | tag personal-gas-detector | TODO: add matching Product Review + best-of guide links when those silo layers exist --\u003e\n\n\u003cdiv style=\"background:#1a1a1a;border-left:4px solid #ff9800;padding:14px 18px;margin:0 0 18px 0;color:#f5e6d3;font-size:0.95em;\"\u003e\n\u003cstrong style=\"color:#ffb74d;\"\u003eEditor’s note:\u003c\/strong\u003e the TopTes Guard-633 H2S detector is one of the instruments we curate in our \u003ca href=\"\/collections\/personal-gas-detectors\" title=\"Personal \u0026amp; Wearable Gas Detectors\"\u003ePersonal \u0026amp; Wearable Gas Detectors\u003c\/a\u003e buyer’s hub. Compare it with the \u003ca href=\"\/products\/bw-gasalertclip-extreme-h2s-monitor\" title=\"BW GasAlertClip Extreme H2S\"\u003eBW GasAlertClip Extreme H2S\u003c\/a\u003e below before you order.\u003c\/div\u003e\n\n\u003ch2 id=\"top\"\u003eTopTes Guard-633 H2S Detector — Clip-On Single-Gas Monitor\u003c\/h2\u003e\n\n\u003cp\u003eThe \u003cstrong\u003eTopTes Guard-633 H2S detector\u003c\/strong\u003e is the budget clip-on for hydrogen sulfide — a \u003ca href=\"\/collections\/personal-gas-detectors\" title=\"personal gas detector\"\u003epersonal gas detector\u003c\/a\u003e with a fast 0.5-second response, adjustable alarms and an explosion-proof body, at the lowest price in our personal lineup.\u003c\/p\u003e\n\n\u003cp style=\"font-size:0.9em;color:#bdae9d;margin:10px 0 18px 0;\"\u003eJump to: \u003ca href=\"#features\" style=\"color:#ffb74d;\"\u003eFeatures\u003c\/a\u003e · \u003ca href=\"#specs\" style=\"color:#ffb74d;\"\u003eSpecs\u003c\/a\u003e · \u003ca href=\"#compatibility\" style=\"color:#ffb74d;\"\u003eWhat it detects\u003c\/a\u003e · \u003ca href=\"#comparison\" style=\"color:#ffb74d;\"\u003eComparison\u003c\/a\u003e · \u003ca href=\"#faq\" style=\"color:#ffb74d;\"\u003eFAQ\u003c\/a\u003e\u003c\/p\u003e\n\n\u003cp\u003eThe TopTes Guard-633 is a clip-on single-gas H2S detector with a 0.5-second response, up to 7-day battery life, adjustable alarm range and an explosion-proof design.\u003c\/p\u003e\n\n\u003ch3 id=\"features\"\u003eKey features\u003c\/h3\u003e\n\n\u003cul\u003e\n\u003cli\u003eClip-on H2S monitor with a fast 0.5-second response\u003c\/li\u003e\n\u003cli\u003eUp to 7 days of battery life with a low-battery alert\u003c\/li\u003e\n\u003cli\u003eThree alarm modes — audible, visual and vibration\u003c\/li\u003e\n\u003cli\u003eAdjustable alarm range to match your site limits\u003c\/li\u003e\n\u003cli\u003eExplosion-proof design for flammable atmospheres\u003c\/li\u003e\n\u003cli\u003eThe lowest-cost personal H2S clip in our lineup\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cdiv style=\"display:flex;gap:14px;flex-wrap:wrap;margin:18px 0;\"\u003e\n\u003cdiv style=\"flex:1;min-width:240px;background:#1b3a2a;border:1px solid #4caf50;border-radius:6px;padding:14px 18px;\"\u003e\n\u003cstrong style=\"color:#81c784;\"\u003ePros\u003c\/strong\u003e\u003cul style=\"margin:8px 0 0 0;\"\u003e\n\u003cli\u003eVery affordable H2S clip\u003c\/li\u003e\n\u003cli\u003eFast 0.5s response\u003c\/li\u003e\n\u003cli\u003eAdjustable alarm range\u003c\/li\u003e\n\u003cli\u003eExplosion-proof\u003c\/li\u003e\n\u003cli\u003eThree alarm modes\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"flex:1;min-width:240px;background:#3a1e1e;border:1px solid #ef5350;border-radius:6px;padding:14px 18px;\"\u003e\n\u003cstrong style=\"color:#e57373;\"\u003eCons\u003c\/strong\u003e\u003cul style=\"margin:8px 0 0 0;\"\u003e\n\u003cli\u003eSingle gas only — H2S\u003c\/li\u003e\n\u003cli\u003eLower review rating than premium BW clips\u003c\/li\u003e\n\u003cli\u003eSensor needs periodic verification\u003c\/li\u003e\n\u003cli\u003eBattery recharge\/replace cycle\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\n\u003ch3 id=\"specs\"\u003eSpecifications\u003c\/h3\u003e\n\n\u003cdiv style=\"overflow-x:auto;\"\u003e\u003ctable style=\"width:100%;border-collapse:collapse;background:#1a1a1a;margin:14px 0;\"\u003e\n\u003cthead\u003e\u003ctr style=\"background:#2a2a2a;\"\u003e\n\u003cth style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;text-align:left;\"\u003eSpecification\u003c\/th\u003e\n\u003cth style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;text-align:left;\"\u003eDetail\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eGas detected\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eHydrogen sulfide (H2S)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eResponse\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003e0.5 seconds\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eBattery life\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eUp to 7 days\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eAlarms\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003e3 modes (audible, visual, vibration)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eAlarm range\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eAdjustable\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eBuild\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003eExplosion-proof\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"color:#ffb74d;padding:8px 10px;border:1px solid #3a3a3a;white-space:nowrap;\"\u003eWeight\u003c\/td\u003e\n\u003ctd style=\"color:#e0e0e0;padding:8px 10px;border:1px solid #3a3a3a;\"\u003e~0.54 kg\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003c\/div\u003e\n\n\u003ch3\u003eWhere the TopTes Guard-633 fits\u003c\/h3\u003e\n\n\u003cul\u003e\n\u003cli\u003eH2S exposure in oil \u0026amp; gas\u003c\/li\u003e\n\u003cli\u003eWastewater and sewer work\u003c\/li\u003e\n\u003cli\u003eAgriculture and manure pits\u003c\/li\u003e\n\u003cli\u003eBudget-conscious H2S programs\u003c\/li\u003e\n\u003cli\u003eBackup\/spare H2S clip\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2 id=\"compatibility\"\u003eWhat the TopTes Guard-633 detects (and what it doesn’t)\u003c\/h2\u003e\n\n\u003cp\u003eIt detects \u003cstrong\u003ehydrogen sulfide (H2S) only\u003c\/strong\u003e — not CO, O2 or combustibles. For a maintenance-free industrial H2S clip, compare the \u003ca href=\"\/products\/honeywell-bw-clip-h2s-monitor-bwc2-h\" title=\"Honeywell BW Clip H2S\"\u003eHoneywell BW Clip H2S\u003c\/a\u003e or the \u003ca href=\"\/products\/bw-gasalertclip-extreme-h2s-monitor\" title=\"BW GasAlertClip Extreme\"\u003eBW GasAlertClip Extreme\u003c\/a\u003e; for several gases use a 4-gas wearable in the \u003ca href=\"\/collections\/personal-gas-detectors\" title=\"Personal \u0026amp; Wearable Gas Detectors\"\u003ePersonal \u0026amp; Wearable Gas Detectors\u003c\/a\u003e hub. It is a personal exposure monitor — confined-space entry still needs pre-entry testing with a \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"Portable Gas Detectors\"\u003ePortable Gas Detectors\u003c\/a\u003e instrument. Verify response against H2S gas periodically.\u003c\/p\u003e\n\n\u003cp\u003eCross-shopping? This unit sits in our \u003ca href=\"\/collections\/personal-gas-detectors\" title=\"Personal \u0026amp; Wearable Gas Detectors\"\u003ePersonal \u0026amp; Wearable Gas Detectors\u003c\/a\u003e hub alongside \u003ca href=\"\/products\/bw-gasalertclip-extreme-h2s-monitor\" title=\"BW GasAlertClip Extreme H2S\"\u003eBW GasAlertClip Extreme H2S\u003c\/a\u003e, \u003ca href=\"\/products\/honeywell-bw-clip-h2s-monitor-bwc2-h\" title=\"Honeywell BW Clip H2S\"\u003eHoneywell BW Clip H2S\u003c\/a\u003e. For other gas-detection form factors see \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"Portable Gas Detectors\"\u003ePortable Gas Detectors\u003c\/a\u003e, \u003ca href=\"\/collections\/fixed-gas-detection-systems\" title=\"Fixed Gas Detection Systems\"\u003eFixed Gas Detection Systems\u003c\/a\u003e, \u003ca href=\"\/collections\/area-gas-monitors\" title=\"Area \u0026amp; Transportable Gas Monitors\"\u003eArea \u0026amp; Transportable Gas Monitors\u003c\/a\u003e, or browse the full \u003ca href=\"\/collections\/gas-detectors\" title=\"Gas Detectors\"\u003eGas Detectors\u003c\/a\u003e range.\u003c\/p\u003e\n\n\u003ch2 id=\"comparison\"\u003eWhere the TopTes Guard-633 fits among H2S clips\u003c\/h2\u003e\n\n\u003cp\u003eThe Guard-633 is the budget H2S clip. For sealed 2-year industrial durability, the \u003ca href=\"\/products\/honeywell-bw-clip-h2s-monitor-bwc2-h\" title=\"Honeywell BW Clip H2S\"\u003eHoneywell BW Clip H2S\u003c\/a\u003e (maintenance-free) and \u003ca href=\"\/products\/bw-gasalertclip-extreme-h2s-monitor\" title=\"BW GasAlertClip Extreme\"\u003eBW GasAlertClip Extreme\u003c\/a\u003e (disposable) cost more but need no sensor service over their life.\u003c\/p\u003e\n\n\u003cul\u003e\n\u003cli\u003eChoose the \u003cstrong\u003eGuard-633\u003c\/strong\u003e for the lowest-cost H2S clip with fast response and adjustable alarms.\u003c\/li\u003e\n\u003cli\u003eStep up to the \u003ca href=\"\/products\/honeywell-bw-clip-h2s-monitor-bwc2-h\" title=\"BW Clip H2S\"\u003eBW Clip H2S\u003c\/a\u003e for sealed 2-year maintenance-free operation.\u003c\/li\u003e\n\u003cli\u003eOr the \u003ca href=\"\/products\/bw-gasalertclip-extreme-h2s-monitor\" title=\"BW GasAlertClip Extreme\"\u003eBW GasAlertClip Extreme\u003c\/a\u003e for a 2-year disposable.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2 id=\"faq\"\u003eFrequently asked questions\u003c\/h2\u003e\n\n\u003ch3\u003eWhat does the TopTes Guard-633 detect?\u003c\/h3\u003e\u003cp\u003eHydrogen sulfide (H2S) only, with three alarm modes. It does not detect CO, O2 or combustibles.\u003c\/p\u003e\n\u003ch3\u003eHow fast does it respond?\u003c\/h3\u003e\u003cp\u003eAbout 0.5 seconds, which helps in fast-changing atmospheres where you need an immediate H2S reading.\u003c\/p\u003e\n\u003ch3\u003eHow long does the battery last?\u003c\/h3\u003e\u003cp\u003eUp to 7 days per charge, with a low-battery alert so you know when to recharge.\u003c\/p\u003e\n\u003ch3\u003eHow does it compare to the BW Clip H2S?\u003c\/h3\u003e\u003cp\u003eThe Guard-633 is the lower-cost option; the \u003ca href=\"\/products\/honeywell-bw-clip-h2s-monitor-bwc2-h\" title=\"BW Clip H2S\"\u003eBW Clip H2S\u003c\/a\u003e is a sealed 2-year maintenance-free industrial clip with no sensor service.\u003c\/p\u003e\n\u003ch3\u003eCan I adjust the alarm levels?\u003c\/h3\u003e\u003cp\u003eYes — the alarm range is adjustable so you can set it to the H2S limits for your site.\u003c\/p\u003e\n\u003ch3\u003eIs it explosion-proof?\u003c\/h3\u003e\u003cp\u003eIt uses an explosion-proof design for flammable atmospheres; confirm the rating against your area classification.\u003c\/p\u003e\n\u003ch3\u003eWhere should it be worn?\u003c\/h3\u003e\u003cp\u003eIn the breathing zone, clipped to the collar or upper chest within about 12 inches of the nose and mouth.\u003c\/p\u003e\n\u003ch3\u003eDoes it detect other gases?\u003c\/h3\u003e\u003cp\u003eNo — H2S only. For CO see the \u003ca href=\"\/collections\/carbon-monoxide-alarms-detectors\" title=\"Carbon Monoxide Alarms \u0026amp; Detectors\"\u003eCarbon Monoxide Alarms \u0026amp; Detectors\u003c\/a\u003e range; for multi-gas a 4-gas wearable in the \u003ca href=\"\/collections\/personal-gas-detectors\" title=\"Personal \u0026amp; Wearable Gas Detectors\"\u003ePersonal \u0026amp; Wearable Gas Detectors\u003c\/a\u003e hub.\u003c\/p\u003e\n\u003ch3\u003eDo I still need pre-entry testing?\u003c\/h3\u003e\u003cp\u003eYes — a personal clip supplements but does not replace pre-entry atmospheric testing with a \u003ca href=\"\/collections\/portable-gas-detectors\" title=\"Portable Gas Detectors\"\u003ePortable Gas Detectors\u003c\/a\u003e instrument.\u003c\/p\u003e\n\u003ch3\u003eIs it in stock and how does it ship?\u003c\/h3\u003e\u003cp\u003eUse the Amazon buy button for current availability and delivery timing through our fulfillment partner.\u003c\/p\u003e\n\u003ch3\u003eHow do I keep it accurate?\u003c\/h3\u003e\u003cp\u003eBump-test and verify response against H2S calibration gas periodically; replace or service the sensor per the manufacturer's guidance.\u003c\/p\u003e\n\u003ch3\u003eIs it good for a budget H2S program?\u003c\/h3\u003e\u003cp\u003eYes — it is the lowest-cost H2S clip we stock, suitable for budget-conscious programs and as a spare.\u003c\/p\u003e\n\n\u003cdiv style=\"background:#1a1a1a;border:1px solid #3a3a3a;border-radius:6px;padding:16px 18px;margin:22px 0;\"\u003e\n\u003cp style=\"margin:0 0 10px 0;color:#f5e6d3;\"\u003eReady to order the \u003cstrong\u003eTopTes Guard-633 H2S detector\u003c\/strong\u003e? Add it to your cart above, or check the current Amazon price below. Compare it against the rest of our \u003ca href=\"\/collections\/personal-gas-detectors\" title=\"Personal \u0026amp; Wearable Gas Detectors\"\u003ePersonal \u0026amp; Wearable Gas Detectors\u003c\/a\u003e lineup before you buy.\u003c\/p\u003e\n\u003cp style=\"display:flex;gap:10px;flex-wrap:wrap;align-items:center;margin:0;\"\u003e\u003ca href=\"https:\/\/www.amazon.com\/dp\/B0DHGC7547?tag=wcsafety04-20\" rel=\"sponsored nofollow noopener\" target=\"_blank\" style=\"display:inline-block;background:#FFD814;color:#0F1111;padding:13px 26px;text-decoration:none;font-weight:bold;border-radius:4px;border:1px solid #FCD200;\"\u003eCHECK PRICE ON AMAZON →\u003c\/a\u003e\u003cspan style=\"font-size:0.8em;color:#bdae9d;\"\u003eAs an Amazon Associate, WC Safety earns from qualifying purchases.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/div\u003e\n\n\u003cdiv style=\"background:#1a2733;border:1px dashed #4fc3f7;padding:16px 20px;margin:30px 0 18px 0;color:#cfd8dc;font-size:0.92em;\"\u003e\n  \u003cstrong style=\"color:#4fc3f7;\"\u003eWhy trust this TopTes page?\u003c\/strong\u003e WC Safety is an independent industrial safety-equipment retailer serving safety managers, procurement teams and field supervisors. The specifications here are taken from the manufacturer’s published listing for TopTes Guard-633 and framed against \u003ca href=\"https:\/\/www.osha.gov\/laws-regs\/regulations\/standardnumber\/1910\/1910.146\" rel=\"noopener\" target=\"_blank\" style=\"color:#4fc3f7;\"\u003eOSHA 29 CFR 1910.146\u003c\/a\u003e and \u003ca href=\"https:\/\/www.osha.gov\/annotated-pels\" rel=\"noopener\" target=\"_blank\" style=\"color:#4fc3f7;\"\u003eOSHA Permissible Exposure Limits\u003c\/a\u003e. Disclosed: WC Safety earns Amazon affiliate commissions on outbound clicks; that does not influence the specs shown or our lineup.\n\u003c\/div\u003e\n\u003cdiv style=\"background:#1a2733;border-left:4px solid #4fc3f7;padding:18px 22px;margin:18px 0;color:#cfd8dc;font-size:0.92em;\"\u003e\n  \u003cstrong style=\"color:#4fc3f7;\"\u003eBy Steven Eaton, WC Safety Editorial\u003c\/strong\u003e — Industrial safety-equipment desk · specialization: atmospheric monitoring, gas detection and instrument selection.\u003cbr\u003e\n  \u003cstrong\u003eLast updated:\u003c\/strong\u003e \u003ctime datetime=\"2026-06-22\"\u003eJune 22, 2026\u003c\/time\u003e · \u003cstrong\u003eSources reviewed:\u003c\/strong\u003e manufacturer product listing \u0026amp; specifications, OSHA 29 CFR 1910.146, OSHA Annotated PEL tables, ACGIH Threshold Limit Values.\u003cbr\u003e\n  \u003cstrong\u003eEditorial standard:\u003c\/strong\u003e \u003cem\u003eZero sponsored listings. No manufacturer input. Specs verified against the manufacturer’s published data.\u003c\/em\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"background:#1a2733;border-left:4px solid #4fc3f7;padding:16px 20px;margin:18px 0;color:#cfd8dc;font-size:0.92em;\"\u003e\n  \u003cstrong style=\"color:#4fc3f7;\"\u003eHow this page is maintained.\u003c\/strong\u003e Specifications and pricing are reviewed against the manufacturer’s current listing and re-checked whenever the lineup changes. Gas-detection guidance follows \u003ca href=\"https:\/\/www.osha.gov\/laws-regs\/regulations\/standardnumber\/1910\/1910.146\" rel=\"noopener\" target=\"_blank\" style=\"color:#4fc3f7;\"\u003eOSHA 1910.146\u003c\/a\u003e and \u003ca href=\"https:\/\/www.osha.gov\/annotated-pels\" rel=\"noopener\" target=\"_blank\" style=\"color:#4fc3f7;\"\u003eOSHA PELs\u003c\/a\u003e, cross-referenced with ACGIH TLVs.\n\u003c\/div\u003e\n\u003cdiv style=\"background:#2a2520;border-left:4px solid #ff9800;padding:16px 20px;margin:18px 0;color:#f5e6d3;font-size:0.92em;\"\u003e\n  \u003cstrong style=\"color:#ffb74d;\"\u003eDisclosure.\u003c\/strong\u003e WC Safety participates in the Amazon Associates Program and earns commissions on qualifying purchases through outbound links on this page (tag wcsafety04-20). We are not sponsored by any instrument manufacturer. This page is buyer guidance, not medical, legal or regulatory advice — confirm gas-detection requirements for your site against the applicable OSHA standard and, for commercial monitoring programs, a Certified Industrial Hygienist (CIH).\n\u003c\/div\u003e\n\n\u003cscript type=\"application\/ld+json\"\u003e\n{\"@context\": \"https:\/\/schema.org\", \"@graph\": [{\"@type\": \"Product\", \"@id\": \"https:\/\/wcsafety.com\/products\/toptes-guard-633-h2s-detector#product\", \"name\": \"TopTes Guard-633 H2S Detector — Clip-On Single-Gas Monitor (7-Day Battery)\", \"description\": \"TopTes Guard-633 H2S detector — clip-on single-gas hydrogen sulfide monitor with 0.5s response, 7-day battery and 3 alarm modes. Order at WC Safety.\", \"sku\": \"B0DHGC7547\", \"mpn\": \"Guard-633\", \"image\": [\"https:\/\/wcsafety.com\/cdn\/shop\/products\/toptes-guard-633-h2s-detector.jpg\"], \"brand\": {\"@type\": \"Brand\", \"name\": \"TopTes\"}, \"category\": \"Personal Gas Detector\", \"isPartOf\": {\"@type\": \"CollectionPage\", \"@id\": \"https:\/\/wcsafety.com\/collections\/personal-gas-detectors#collection\", \"name\": \"Personal \u0026 Wearable Gas Detectors\", \"url\": \"https:\/\/wcsafety.com\/collections\/personal-gas-detectors\"}, \"isRelatedTo\": [{\"@type\": \"Product\", \"name\": \"BW GasAlertClip Extreme H2S Monitor\", \"url\": \"https:\/\/wcsafety.com\/products\/bw-gasalertclip-extreme-h2s-monitor\"}, {\"@type\": \"Product\", \"name\": \"Honeywell BW Clip H2S Monitor (BWC2-H)\", \"url\": \"https:\/\/wcsafety.com\/products\/honeywell-bw-clip-h2s-monitor-bwc2-h\"}], \"offers\": {\"@type\": \"Offer\", \"url\": \"https:\/\/wcsafety.com\/products\/toptes-guard-633-h2s-detector\", \"priceCurrency\": \"USD\", \"price\": \"79.99\", \"availability\": \"https:\/\/schema.org\/InStock\", \"seller\": {\"@type\": \"Organization\", \"name\": \"WC Safety\"}}}, {\"@type\": \"BreadcrumbList\", \"@id\": \"https:\/\/wcsafety.com\/products\/toptes-guard-633-h2s-detector#breadcrumb\", \"itemListElement\": [{\"@type\": \"ListItem\", \"position\": 1, \"name\": \"Home\", \"item\": \"https:\/\/wcsafety.com\/\"}, {\"@type\": \"ListItem\", \"position\": 2, \"name\": \"Gas Detectors\", \"item\": \"https:\/\/wcsafety.com\/collections\/gas-detectors\"}, {\"@type\": \"ListItem\", \"position\": 3, \"name\": \"Personal \u0026 Wearable Gas Detectors\", \"item\": \"https:\/\/wcsafety.com\/collections\/personal-gas-detectors\"}, {\"@type\": \"ListItem\", \"position\": 4, \"name\": \"TopTes Guard-633 H2S Detector — Clip-On Single-Gas Monitor (7-Day Battery)\"}]}, {\"@type\": \"FAQPage\", \"mainEntity\": [{\"@type\": \"Question\", \"name\": \"What does the TopTes Guard-633 detect?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Hydrogen sulfide (H2S) only, with three alarm modes. 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