Reference Gas Fault — ABB AZ10

This alarm indicates a problem with the reference gas supply reaching the zirconia sensor. Accurate oxygen measurement depends on a stable and clean reference gas path.

Recommended Diagnostic Sequence

1) Check reference gas cylinder pressure and confirm the regulator is set to the correct outlet pressure.
2) Inspect reference gas tubing for leaks, kinks, condensation, or blockages.
3) Verify that reference gas flow reaches the sensor and that flow is within the manufacturer’s recommended range.
4) Check reference gas filters (if fitted) for clogging or contamination.
5) If the fault persists, replace the regulator or tubing and re-test the system.
Technician note: Reference gas faults are often caused by empty cylinders, blocked tubing, or incorrect regulator settings — not sensor failure.