Product Description
4-Gas Calibration Gas – 25 PPM H2S / 50 PPM CO / Methane (CH₄) 2.5% (50% LEL) / 19.5% O2 – 66L C-10 Cylinder
This 4-gas calibration gas blend is engineered for routine bump testing and full calibration of portable multi-gas monitors used in confined space entry and industrial safety programs.
Unlike atmospheric baseline blends containing 20.9% oxygen, this mixture contains 19.5% oxygen, the OSHA-defined oxygen-deficiency threshold. This allows technicians to verify low-oxygen alarm setpoints while simultaneously calibrating toxic and combustible sensors.
Concentration profile:
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25 PPM Hydrogen Sulfide for toxic exposure sensor validation
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50 PPM Carbon Monoxide for conservative CO alarm verification
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2.5% Methane (50% LEL) for combustible sensor accuracy
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19.5% Oxygen to simulate oxygen-deficient conditions
This blend is commonly specified for confined space entry programs where validation of oxygen alarm functionality is critical.
Gas Concentrations
| Component | Concentration |
|---|---|
| Hydrogen Sulfide (H₂S) | 25 PPM |
| Carbon Monoxide (CO) | 50 PPM |
| Methane (CH₄) | 2.5% (50% LEL) |
| Oxygen (O₂) | 19.5% |
| Balance | Nitrogen |
Cylinder Specifications
| Property | Value |
|---|---|
| Cylinder Size | 66L (2.3 ft³) |
| Pressure | 1150 psi |
| Cylinder Specification | C-10 |
| Cylinder Material | Aluminum |
| Gas Reactivity | Reactive |
Reactive multi-gas blends should be stored and used with compatible C-10 regulators to maintain concentration stability and calibration precision.
Applications & Detector Compatibility
This 4-gas calibration gas supports most major portable multi-gas monitors used for toxic, combustible, and oxygen detection, including models from BW, MSA, Industrial Scientific, RAE Systems, and Dräger.
Common applications include:
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Low-oxygen alarm verification
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Confined space compliance testing
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Routine bump testing
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Scheduled multi-sensor calibration
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OSHA-aligned safety audits
The 66L cylinder format balances portability with sufficient calibration volume for field service programs.
Need a Different Concentration or Cylinder Size?
If you do not see the exact gas mixture, ppm level, oxygen percentage, LEL value, or cylinder size required for your application, contact our calibration gas specialists. We can supply custom multi-gas blends built to your detector model, regulatory requirements, or site-specific hazard profile.
