Key Considerations for Operating Gas Detectors
① Conduct regular calibration and testing Like other analytical instruments, toxic and hazardous gas detectors adopt the relative comparison method for measurement. The instrument is calibrated with zero gas and standard-concentration gas to generate a standard curve stored inside. During measurement, the instrument compares the electrical signal generated by the target gas with that of the standard gas to calculate the accurate gas concentration value. Therefore, zeroing at any time and regular calibration are essential to guarantee measurement accuracy. It should be noted that many gas detectors support replaceable sensors, but this does not mean one detector can be equipped with arbitrary sensor probes at will. Whenever the probe is replaced, the sensor requires a certain activation period, and the instrument must be recalibrated. In addition, it is recommended to perform a response test with calibration gas before use to ensure the detector provides reliable protection.
② Watch out for detection interference between different sensors Generally, each sensor is designed for a specific gas, yet no gas detector is completely free from cross-interference. When selecting a gas sensor, users shall fully understand interference from other gases to ensure accurate detection of the target gas.
③ Pay attention to the service life of various sensors All gas sensors have a limited service life. For portable instruments, LEL sensors usually last about three years; photoionization detectors can work for four years or longer; dedicated electrochemical gas sensors have a shorter lifespan of one to two years; oxygen sensors have the shortest service life of approximately one year. The service life of electrochemical sensors depends on the evaporation of internal electrolyte. If not used for a long time, sealing and storing them in a low-temperature environment can extend their service life to a certain extent. Fixed detectors feature relatively longer sensor service life due to larger overall size. Sensors shall be inspected regularly, used within their valid period, and replaced promptly once they fail.
④ Mind the concentration measuring range of the detector Every toxic and hazardous gas detector has a fixed detection range. Accurate measurement can only be guaranteed within the specified range. Long-term over-range measurement may cause permanent damage to the sensor.
