In the marine and offshore industries, accurate gas detection saves lives and ensures compliance with global safety standards. Whether you’re testing for flammable gases, toxic exposure, or ensuring scrubber systems are working, the right calibration gas matters.
Here’s a breakdown of commonly used gases in calibration cylinders—including scrubber gases and a standard quad mix used for multi-gas detectors onboard vessels.
⚗️ Key Calibration Gases Explained
- H₂S – Hydrogen Sulphide
➤ Toxic and flammable. Found in crude oil tanks, sewage, and confined spaces. Calibration ensures your H₂S detectors respond accurately to dangerous levels. - CH₄ – Methane
➤ Highly flammable. Used as the standard for LEL (Lower Explosive Limit) testing. Essential in explosive gas detection. - SO₂ – Sulphur Dioxide
➤ Toxic and corrosive. Commonly found in emissions from engines or as part of scrubber gas calibration mixtures to meet MARPOL regulations. - CO – Carbon Monoxide
➤ Colorless, odorless, and toxic. Present in engine exhaust and poorly ventilated areas. Accurate detection is critical for crew safety. - NO / NO₂ – Nitric Oxide / Nitrogen Dioxide
➤ Used in environmental monitoring and scrubber performance testing. Part of emissions control compliance. - O₂ – Oxygen
➤ Low or high O₂ levels are hazardous. Oxygen sensors ensure confined space entry is safe and atmospheres are breathable. - CO₂ – Carbon Dioxide
➤ Detected in cargo holds, engine spaces, and enclosed environments. Also part of scrubber emission checks. - NH₃ – Ammonia
➤ Used in SCR (Selective Catalytic Reduction) systems to reduce NOx emissions. Requires precise calibration to prevent overexposure. - CL₂ – Chlorine
➤ Highly toxic. Detected in water treatment systems onboard. Must be monitored carefully. - HCl – Hydrogen Chloride
➤ Found in scrubber discharge or exhaust gases. Highly corrosive and toxic.
🔹 QUAD MIX GASES (Standard 4-Gas Mixture)
One of the most common calibration gas blends used for portable multi-gas detectors onboard ships and offshore platforms:
✔ H₂S + CO + Combustible Gas (usually CH₄ or pentane at LEL) + O₂ (balance N₂)
✅ Used to calibrate 4-gas meters for confined space entry, engine room safety, and tank inspections.
✅ N₂ acts as the balance gas, keeping the mixture stable and inert.
🌍 Scrubber Gas Calibration Mixtures
Scrubber calibration mixtures typically include combinations of:
SO₂, NO, CO₂, O₂, and N₂
Used to verify exhaust gas cleaning systems are functioning correctly and complying with IMO 2020 sulphur caps and MARPOL Annex VI.
At Marine Gas Supplies, we supply standard and custom gas blends—single, dual, quad, or more—and handle the entire DG process for global delivery.
📦 Safe. Certified. Worldwide.