34-liter calibration or bump-test gas cylinder for BW Monitor (20ppm H2S, 60ppm CO, 15%O2, 1.45% vol. CH4)
CA$199.99
34-liter calibration (or bump-test) gas cylinder (2.5% (50%LEL) CH4, 18%O2, 25ppm H2S, 100ppm CO) | BW (Honeywell)
Description:
This is a 34-litre (34 L) disposable (or non-refillable) calibration gas cylinder, containing a quad-gas mixture tailored for bump testing and calibration of four-gas portable gas detectors. The blend includes methane (CH4), oxygen (O2), hydrogen sulfide (H2S), and carbon monoxide (CO), with nitrogen (N) as the balance gas.
Methane (CH4) is present at 2.5% by volume, which corresponds to about 50% of the Lower Explosive Limit (LEL) for methane. This means the gas mixture can test the combustible or LEL sensor on a gas detector.
Oxygen (O2) is at 18%, which is lower than ambient “normal air” (~20.9%) — this helps simulate oxygen-depleted environments while still being safe to handle.
Hydrogen Sulfide (H2S) is at 25 ppm, a low but hazardous concentration often used in calibration, especially for detectors measuring very toxic gases.
Carbon Monoxide (CO) is present at 100 ppm, enabling calibration of CO sensors as well.
The rest of the gas volume is typically nitrogen (N), which acts as a diluent / balance gas.
These cylinders are used to bump-test (perform a functional test) or span-calibrate multi-gas detectors. During a bump test, the detector’s sensors are exposed to this known concentration, and the instrument must respond within expected limits — verifying correct sensor operation. For calibration, the device is adjusted (if necessary) to read accurately for that gas mixture.
The 34 L size gives a good balance: enough gas for many calibration or bump-test cycles, while remaining compact and portable. These cylinders typically have a C-10 (5/8″-18 UNF) valve (or equivalent), compatible with standard demand-flow or fixed-flow regulators used in field calibration.
Because the gas mix includes flammable CH4, plus toxic CO and H2S, these cylinders are handled under hazardous-gas (HAZMAT) precautions, and come with a Certificate of Analysis (CoA) for quality assurance. The cylinders may also have a limited shelf life (often 12–24 months, depending on supplier) to ensure gas stability
Cylinder Material
Usually aluminum (for lightweight, portable use)
Valve Type / Connection
Commonly C-10 (5/8″-18 UNF)
Pressure
Depending on the manufacturer, but common for similar 34 L gas cylinders is ~500 psi / 35 bar for non-refillable
Shelf Life
Often 12–24 months, depending on the supplier and storage conditions. Example: Cal-gas 34L 2.5% CH4 / 25 ppm H2S cylinder has 24 months shelf life
Accuracy / Certification
Supplied with a Certificate of Analysis (CoA), often NIST- or ISO-traceable, depending on manufacturer. (For example, Cal-gas version provides NIST-traceable CoA.)
Use Case / Application
- Bump-testing portable gas detectors (especially 4-gas detectors)
- Span-calibration of multi-gas sensors
- Verifying sensor response for LEL, O2, H2S, CO
- Safety / maintenance / calibration labs in industrial, petrochemical, confined-space environments
Safety Considerations
- Gas is flammable due to CH4 component.
- Toxic components (CO, H2S) require proper ventilation, safety handling.
- Use with proper regulator and flow control device.
- Storage and transport may need to follow hazardous-gas cylinder norms.
Advantages & Benefits
Multi-gas calibration: Because it has four gases (combustible, toxic, oxygen), it’s very efficient for calibrating 4-gas detectors in one go.
Compact & portable: 34 L size provides a good number of tests while staying manageable to carry to field locations.
Reliable response: The concentrations are chosen to give a meaningful test for both flammable and toxic sensors.
Traceable quality: With a CoA, you can be confident in the accuracy of the gas mix for calibration/audit purposes.
Limitations / Drawbacks
Limited life: Shelf life means you need to use or replace before expiration.
Gas consumption: If performing many calibrations, the 34 L volume may run out; higher-volume cylinders may be needed.
Safety risk: Toxic and flammable gases mean stricter handling procedures.
Regulator compatibility: You need compatible regulators (demand-flow or fixed-flow) that can deliver the correct flow rate for your detectors.