Gas Detector Calibration
Gas detector calibration keeps your monitors reading accurately so they protect workers in confined spaces and hazardous areas. This guide explains the difference between a bump test and a span calibration, which calibration gas to use for your detector, and how to calibrate step by step.
What is gas detector calibration?
Gas detector calibration is the process of exposing a gas detector to a known concentration of calibration gas and adjusting the instrument so its reading matches that value. It ensures the detector responds correctly to real hazards. Trigas USA cylinders are NIST traceable, blended in an ISO 17025 certified lab to a ±2% tolerance, with a standard C-10 connection.
Bump test vs. span calibration
| Bump test | Span calibration | |
|---|---|---|
| What it does | Confirms sensors and alarms respond to gas | Adjusts the reading to a known concentration |
| How often | Before each day's use | Periodically, per the manufacturer |
| Gas needed | Calibration gas cylinder | Calibration gas cylinder |
Which calibration gas does your detector need?
| Detector / use | Recommended gas |
|---|---|
| 4-gas confined space monitor | 4-Gas mix (CO, H₂S, LEL, O₂) |
| Carbon monoxide | CO 25–300 ppm |
| Hydrogen sulfide | H₂S 10–40 ppm |
| Combustibles (LEL) | Methane / pentane / propane |
| Oxygen | O₂ 0.4–20.9% |
Find your exact match by detector brand
Trigas USA offers NIST-traceable equivalents for every major detector brand. Find your OEM part number on our cross-reference pages:
- MSA calibration gas cross-reference
- BW Technologies / Honeywell cross-reference
- Dräger cross-reference
- Industrial Scientific cross-reference
- RAE Systems cross-reference
- RKI Instruments cross-reference
- See all OEM cross-references
Or use the Cross-Reference Search to find your Trigas USA equivalent by OEM part number.
How to calibrate a gas detector
- Attach the correct calibration gas cylinder to a C-10 demand-flow or fixed-flow regulator.
- Put the detector into calibration mode (see your device manual).
- Apply the gas and let the readings stabilize.
- Confirm the bump test response, then perform the span calibration so the reading matches the cylinder's stated concentration.
- Record the date and results; recalibrate per the manufacturer's schedule.
Shop calibration gas
Browse disposable calibration gas cylinders — 4-gas mixes, single gases and reactive gases, NIST traceable and shipping Division 2.2 across the USA.
Frequently asked questions
What is gas detector calibration?
It is exposing a detector to a known gas concentration and adjusting it so its reading is accurate.
What is the difference between a bump test and a calibration?
A bump test confirms the sensors and alarms react to gas; a span calibration adjusts the reading to match a known concentration.
How often should I calibrate my gas detector?
Bump test before each use and perform a full span calibration on the schedule set by the detector manufacturer (commonly every 3–6 months).
Which calibration gas do I need for a 4-gas monitor?
A 4-gas mix containing carbon monoxide (CO), hydrogen sulfide (H₂S), a combustible (LEL, e.g. methane or pentane) and oxygen (O₂).
What is a span calibration?
Applying a known concentration of calibration gas and adjusting the detector so its reading equals that value.