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Forensics Detectors 4 Gas Monitor — USB-Rechargeable, O2/CO/H2S/LEL
$225.45
Final price set by Amazon · may vary
EDITORIAL REVIEW: 4.6/5 — WC Safety Review of the Forensics Detectors 4 Gas Monitor, the USB-rechargeable base model. Editorial assessment by Steven Eaton, WC Safety editor, based on published Forensics Detectors sp...
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EDITORIAL REVIEW: 4.6/5 — WC Safety Review of the Forensics Detectors 4 Gas Monitor, the USB-rechargeable base model.
Editorial assessment by Steven Eaton, WC Safety editor, based on published Forensics Detectors specifications and category fit. We did not laboratory-test this product.
Editorial assessment by Steven Eaton, WC Safety editor, based on published Forensics Detectors specifications and category fit. We did not laboratory-test this product.
Read the full Forensics Detectors 4 Gas Monitor review →
The Forensics Detectors 4 Gas Monitor is the USB-rechargeable member of the Forensics family — a NIST-certified electrochemical instrument reading oxygen, combustible LEL, carbon monoxide and hydrogen sulfide with triple alarms, built for portable confined-space and field monitoring — a monitoring device, not respiratory protection.
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Why the Forensics Detectors 4 Gas Monitor keeps charging simple
A four-gas monitor that charges from any USB source removes a small daily friction — no proprietary dock or disposable cells to manage. This Forensics base model does exactly that: a USB-rechargeable, NIST-certified four-gas instrument reading O2, LEL, CO and H2S, with triple alarms, built for portable confined-space and field monitoring and backed by a long, well-reviewed track record. As 4-gas monitors go, this is the simple USB-charging pick, and the gas detection guide and the best 4-gas monitor guide explain where it fits. It covers four gases with the least charging fuss.
Safety first: a gas detector alarms; it does not protect. In an IDLH or oxygen-deficient atmosphere you must evacuate and use supplied-air or an SCBA — a monitor warns of the hazard, it is not a substitute for respiratory protection. This is a diffusion model, so use a pump-equipped instrument for remote pre-entry testing of a confined space; bump-test before each use, calibrate on the manufacturer schedule, and confirm the sensor configuration and alarm setpoints on the listing.
What the Forensics Detectors 4 Gas Monitor listing documents
From the published specs: a NIST-certified electrochemical four-gas instrument (O2, CO, H2S, LEL); a USB-rechargeable battery; triple alarms; and a portable body for confined-space and field use. These are true usb rechargeable 4-gas monitor and nist calibrated gas detector credentials in a confined space gas monitor. Confirm the sensor configuration and alarm setpoints on the listing.
How the Forensics Detectors 4 Gas Monitor compares to other gas detectors
For the compact version of the same platform, the Forensics Mini 4-Gas; for a handheld pre-entry pump monitor, the Forensics 4-Gas with Pump; for a transportable datalogging monitor, the Forensics FD-600; for a datalogging wearable 4-gas, the GasAlertMicroClip XL; and for a value color-screen 4-gas, the TopTes Guard-101. The Forensics meter vs pump guide and the 4-gas vs single-gas guide help you choose.
Choosing the right gas monitor
Match the charging, gases, and sampling method to your hazard. Browse the gas detectors, personal gas detectors, and portable gas detectors collections; for sampling, the diffusion vs pump guide; and for the personal-monitor decision, the best personal gas detector guide, the 4-gas monitors collection, and the calibration accessories collection.
Where it fits by job and crew orders
The Forensics Detectors 4-Gas suits construction, utilities, and field crews that want a simple USB-charging four-gas monitor with a NIST certificate — see the confined-space kit guide and the area gas monitors collection for related equipment. USB charging means it tops up from any laptop or wall adapter between jobs, which suits crews that travel light and cannot carry a proprietary dock. The NIST certificate documents its accuracy for a compliance program. Confirm the sensor configuration and alarm setpoints on the listing, bump-test before use, and calibrate on schedule. For crew orders, quantity purchasing runs through a free Amazon Business account — volume pricing, PO numbers at checkout, and tax-exempt eligibility for qualifying organizations, with the walkthrough linked in our footer.
Brand / Vendor
Forensics Detectors
Model / SKU
FD-4A
Product Type
Portable Gas Detector
Price
$225.45 (Amazon)
Rating
4.88 / 5 — 8 reviews
Availability
Check current availability on Amazon
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Verified Buyer Reviews
Customer Reviews
★★★★☆4.4 / 5· 123 ratings on Amazon
★★★★★
Customer service came through!
My original review is below. The first unit I received had a bad 02 sensor. Sarah reached out to me and within a few days I received a replacement unit. No issue with the replacement, customer service was willing to help and now everything is all good. Thanks Sarah and all at Forensics Detectors. I am sure that I will be purchasing other equipment in the future.I have no idea if this device is easy to use or not. Value for the money certainly does not seem to be there, and accuracy gets a 0% from me right now. The unit I received went into alarm mode when turned on for the first time and will not reset or clear. Display indicates 02 level at 0.0%, which I have to assume indicates a sensor failure or some issue with the equipment. I have sent emails, but so far I have received NO response at all. I understand that equipment fails sometimes, but with 0 time on the equipment? I am not sure that is an acceptable time between failure. Hopefully this company will reply within the next couple of days and this can be resolved.Update on this issue. Customer Support contacted me and is shipping a new unit to me, I will advise further when new item is received.
Verified Purchaser · February 1 · ✓ Amazon Verified Purchase
★★★★★
Good Monitor
Works as intended and included the certificate!
Verified Purchaser · December 3 · ✓ Amazon Verified Purchase
★★★★★
Great Value
This was purchased to replace a broken, very expensive, industrial model. It works just as well and is very accurate, for a fraction of the price....as a matter of fact, this was dropped in water and stopped working. After drying it out, it worked like a charm at the same great level of accuracy. No complaints!
Verified Purchaser · February 7 · ✓ Amazon Verified Purchase
★★★★☆
Several Concerns… However
Update: After learning of my concerns, FD reached out directly and offered to help me resolve my issues. With so many companies hiding behind layer upon layer of automation when trying to get ahold of someone with any customer care issues, it is refreshing to see that FD actually concerns themselves with customers’ experiences, and aims for resolve them promptly. This is commendable. Based on this fact, I felt necessary to revisit my review to highlight that each concern received the attention it deserved.Initial review below:I have some concerns with this detector. The display has that “not made in the USA” font often associated with a quantity over quality approach to production originating in another specific country. Furthermore, the quick reference guide contains grammatical and spelling errors which should be addressed.Upon unboxing, I moved to fresh air before ever turning it on to ensure a proper baseline was established. Out the box, the detector’s alarm was incessantly beeping with an EX indication of 4 percent, and an O2 reading of 18.1 percent. My neighbor’s industrial detector, which costs more than ten times what this unit does detected zero percent EX and 20.1 percent O2. I am confident his was accurate and that this detector somehow came from the manufacturer with a fault of some sort. The paperwork states it is calibrated and ready to use out the box.The user interface could be more intuitive. The O2 it picked up outdoors in fresh air also triggered an alarm, which by default is set to 19.5 percent for low O2. This was a bit confusing, as I hadn’t immediately realized that, in fact, two alarm triggers had been met simultaneously (EX present, and low O2). Additionally, please note that FD states you should recalibrate this detector every 12 months. This is important because this step requires the introduction of various gases, in addition to an optional device and hose. Like most, I do not have these gases or additional gadgets just lying around.
Verified Purchaser · January 4, · ✓ Amazon Verified Purchase
★★★★★
Did what it was supposed to do.
Back then, when purchased, it worked as advertised. In Mexico, we never got sick in an old mine shaft. Luckily, we're still okay.
Verified Purchaser · September · ✓ Amazon Verified Purchase
★★★★★
Good Gas Sniffer
I’ve bought 8 of these, much cheaper than some of the alternates but this still has all of the good stuff to go in confined spaces
Verified Purchaser · April 25, · ✓ Amazon Verified Purchase
★★★★★
4 gas personal monitor
USA NIST Calibrated 4 Gas Monitor by Forensics | O2, CO, H2S, LEL | USB Recharge |Excellent value (cheaper) when compared to other personal monitors. Slightly bulkier than other monitors, other than that I'm happy with it. I suppose I won't know how accurate it is until I dont come back!
Verified Purchaser · September · ✓ Amazon Verified Purchase
★★★★★
Nice
I’ve had this for just over a year, and it has performed flawlessly. It’s important that safety devices work all the time. I wish more companies sold quality products like this one.
Verified Purchaser · January 8, · ✓ Amazon Verified Purchase
Showing 8 of 123 Amazon reviews.
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