Gas analysis should not be treated as a simple numerical snapshot. Readings must be interpreted together with temperature, flow rate, dew point, catalyst condition and sampling location.
Carbon monoxide — CO
CO is one of the active components of an endothermic atmosphere. An abnormal value may indicate an incorrect air-to-gas ratio, incomplete reaction or dilution with air.
Carbon dioxide — CO₂
CO₂ is highly sensitive to reaction quality and air infiltration. An increase can reduce carbon potential and may indicate excess air or leakage.
Residual methane — CH₄
Residual methane should not be interpreted in isolation. An increase may result from insufficient temperature, a degraded catalyst, excess natural gas or poor sampling.
The sampling point
Reliable measurement requires a clean sampling line free from condensation, leaks and air infiltration. Differences between two points in the same furnace may be real and depend on atmosphere circulation.
Recommended checks
- Allow the analyser to stabilise
- Check filters and tubing
- Check sample flow rate
- Compare with probe millivolts and furnace temperature