H₂S Sensor Failures
H₂S sensors are consumables. Most failures are caused by overexposure, moisture, and false expectations.
Field rule:
If an H₂S sensor lasts “too long” in harsh service,
it is probably lying.
Failure Symptoms
- Slow response or no response
- Zero offset or stuck readings
- Frequent calibration failures
- Short sensor life
Main Causes
- Exposure above sensor range
- Moisture ingress
- Poisoning by solvents or hydrocarbons
- Lack of rest periods
- Using process analyzers as safety detectors
Correct Use Guidelines
- Match sensor range to worst-case H₂S
- Install moisture protection upstream
- Separate safety detection from process control
- Plan regular sensor replacement
Calibration Reality
Over-calibration accelerates sensor aging.
Use calibration to verify, not to force readings.