Trace Oxygen Analysis

Fuel-cell-grade hydrogen is generally held to a much tighter oxygen specification than hydrogen used for general industrial purposes, since oxygen contamination can gradually degrade fuel cell membrane performance. Exact limits vary by fuel cell type and application, so producers should confirm the specific purity requirement with their offtaker or the relevant fuel-cell hydrogen quality standard rather than relying on a single universal number.

The OMD-625 is typically installed downstream of the electrolyzer stack and any purification or drying equipment, giving a reading that reflects the hydrogen as it will actually reach storage, compression, or offtake. Some producers also add a second monitoring point earlier in the process, closer to the electrolyzer outlet, to separately track membrane performance before purification.

At the point where hydrogen changes ownership — such as a pipeline interconnect or a truck-loading station — a continuous trace oxygen reading gives both parties an objective, real-time record that the gas meets the agreed purity specification at the moment of transfer. This is more reliable than periodic manual sampling, since it captures any short-term purity excursions that a spot check could easily miss.