Norlab 4-Gas Calibration Gas Mix — Bump-Test & Calibrate Your Monitor

The Norlab 4-Gas Calibration Gas Mix is a 29-liter cylinder of 25 ppm H2S, 100 ppm CO, 50% LEL methane and 18% oxygen (balance nitrogen) for bump-testing and calibrating standard four-gas monitors — the calibration consumable that keeps a gas monitor accurate; it is not a detector or respiratory protection.

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Why the Norlab 4-Gas Calibration Gas keeps a monitor honest

A four-gas monitor is only trustworthy if it is bump-tested before use and calibrated on schedule — and that takes a cylinder of known gas. The Norlab 4-Gas mix is that consumable: 25 ppm H2S, 100 ppm CO, 50% LEL methane and 18% oxygen (balance nitrogen) in a 29-liter cylinder, the standard concentrations for verifying an O2/LEL/CO/H2S monitor, good for many bump tests per bottle. As gas detector calibration accessories go, this is the standard 4-gas cal-gas pick, and the gas detection guide and the best 4-gas monitor guide explain where it fits. It is the consumable behind every reliable four-gas monitor.

What the Norlab 4-Gas Calibration Gas listing documents

From the published specs: a four-gas mix for bump-testing and calibrating O2/LEL/CO/H2S monitors; standard concentrations of 25 ppm H2S, 100 ppm CO, 50% LEL methane, 18% O2 (balance nitrogen); a 29-liter cylinder for many tests; and compatibility with a standard 4-gas monitor and regulator. These are true 4-gas calibration gas and bump test gas credentials in a span gas cylinder. Confirm the concentrations, regulator, and expiration on the listing.

How the Norlab 4-Gas Calibration Gas fits your monitors

Use it to bump-test and calibrate a compact 2-year 4-gas like the BW Clip4, a datalogging workhorse like the GasAlertMicroClip XL, a compact certified unit like the RKI GX3R, a value color-screen 4-gas like the TopTes Guard-863Pro, or a confined-space meter like the Forensics 4-Gas Meter. The best 4-gas monitor guide and the 4-gas vs single-gas guide cover the monitors it services.

Choosing the right calibration gas

Match the gas mix and concentrations to the monitor and sensors you run. Browse the gas detectors, 4-gas monitors, and personal gas detectors collections; for the monitors it services, the portable gas detectors collection; and for the personal-monitor decision, the personal monitor guide, the calibration accessories collection, and the confined space equipment collection.

Where it fits by job and crew orders

The Norlab 4-Gas Calibration Gas suits any gas-detection program that runs O2/LEL/CO/H2S monitors and must bump-test before each use and calibrate on schedule — see the gas detection guide and the industrial CO guide for the monitors and programs it supports. Keeping cal gas on hand is what turns "we have monitors" into "our monitors are verified." Confirm the concentrations, the correct regulator, and the expiration date on the listing, and store the cylinder safely. 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.