Collection: Helium Analyzer

A helium analyser measures the percentage of helium in a breathing gas mixture. It is an essential tool for technical divers using Trimix, a blend of oxygen, nitrogen, and helium, allowing them to verify the exact gas composition before a dive. Accurate helium measurement is critical for calculating safe depth limits, decompression schedules, and narcosis management.

Helium reduces the narcotic effect of nitrogen at depth, making it a key component in Trimix used for deep technical dives. If the helium percentage in a cylinder differs from the planned mix, it can result in incorrect decompression calculations, increased narcosis at depth, or oxygen toxicity risks. Verifying the gas mixture before every dive is a fundamental safety practice for all technical divers.

Yes. To fully characterise a Trimix gas blend, you need to know both the oxygen and helium percentages. Most technical divers use a helium analyser alongside an NRC O₂ Analyser (such as the Oxy Spy) to obtain a complete picture of their breathing gas. The nitrogen content is then calculated as the remainder (100% minus O₂% minus He%).

Calibration is typically performed using a known reference gas, either pure helium (100%) for a span calibration, or clean ambient air (which contains 0% helium) for a zero calibration. Follow the specific calibration procedure described in your analyser’s user manual. Always calibrate before use, particularly if the analyser has not been used for an extended period or if the sensor has recently been replaced.

You can order directly through our online shop at nrc-international.com/collections/helium-analyzer. If you need help choosing the right product for your application, our customer service team is always happy to assist.