Hydrogen Sulfide (H2S) Sensor Calibration: Best Practices

Hydrogen sulfide detection is one of the most safety-critical applications in gas monitoring — H2S is toxic at low concentrations, and it's common in wastewater treatment, oil and gas, and confined-space work. That makes sensor accuracy non-negotiable.

Why H2S sensors need extra attention

Electrochemical H2S sensors are sensitive to their environment: high humidity, temperature swings, and repeated exposure to elevated concentrations can all accelerate drift. In continuous-monitoring environments like wastewater plants, sensors work harder and may need calibration checks more frequently than the manufacturer's baseline interval.

Calibration tips

• Calibrate near your alarm setpoint, not just at an arbitrary reference concentration — accuracy matters most exactly where the alarm will trigger.
• Bump test daily before use, especially in confined-space entry work where a false negative has serious consequences.
• Watch for signs of sensor poisoning or degradation (slow response, failure to return to zero) and don't wait for the scheduled interval if you see them.

ACD's H2S source is available in 10-, 50-, and 100-hour capacities to match your calibration volume. Shop H2S calibration gas.