Specialty Gas Electrochemical Sensor Testing: These “Detail Pitfalls” Must Be Avoided

In fields such as industrial safety and environmental monitoring, SPECIALTY GAS ELECTROCHEMICAL SENSOR serve as sentinels safeguarding security by precisely detecting hazardous gases like HF, NH₃, and HCN. However, these gases often exhibit properties such as adsorption, corrosion, or even extreme toxicity. The slightest oversight during testing can lead to data inaccuracies, sensor failure, and in severe cases, safety risks. Practitioners must strictly adhere to the following critical precautions against specialty gas electrochemical sensor testing.

I. HF and HCl Sensors: Focus on Preventing Adsorption and Corrosion

HF and HCl gases exhibit strong adsorption and water solubility, easily adhering to equipment surfaces at low concentrations and interfering with testing.

1. Material Compatibility: Use corrosion-resistant stainless steel pressure regulators and flow meters. Select PTFE (polytetrafluoroethylene) for piping and calibration hoods, with pipe lengths ≤1 meter.

2. Pipeline Flushing: Before testing, flush pipelines with standard gas at a flow rate of 500–1000 ml/min for over 30 minutes. Lower concentrations require longer flushing times. After flushing, verify compliance using moistened pH paper; a red color indicates success.

3. Special Handling: If sensors show no significant response, extend flushing duration or remove the housing to test directly at the inlet with standard gas.

4. Safety and Environment: Maintain humidity below 80%. Wear protective gear including nitrile gloves, masks and goggles. Ensure adequate ventilation in the testing area.

II. NH₃, H₂, VOC Sensors: Simplified Flushing Sufficient

These gases exhibit weaker adsorption properties. Still require approximately 10 minutes of flushing before testing (flow rate 500–1000 ml/min). Extend flushing time appropriately for low concentrations.

III. HCN Sensor: Dual Focus on Failure Prevention and Toxicity Protection

HCN sensor electrodes contain special catalysts. Prolonged calibration with sulfur- or phosphorus-containing gases (e.g., H₂S, SO₂, PH₃) is strictly prohibited, as it causes sensor failure. Given HCN’s extreme toxicity, use low-concentration calibration gas and maintain full safety precautions throughout the process.

The specialty gas electrochemical sensor testing is essentially a “precise dialogue” with gas properties. From material compatibility to pipeline purging, from sensor protection to personal safety, every detail directly impacts data accuracy and equipment longevity. Adhering to these protocols ensures sensors function as reliable safety “eyes and ears,” fortifying risk prevention across all scenarios.