Problems Needing Attention When Using Gas Detectors
① Conduct regular calibration and testing.
Like other analytical instruments, toxic and harmful gas detectors adopt the relative comparison method for measurement. The instrument is first calibrated with zero gas and standard-concentration gas, and the standard curve is stored in the device. 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. Therefore, zeroing the instrument at any time and performing regular calibration are essential to ensure measurement accuracy. It should be noted that many gas detectors support replaceable sensors, but this does not mean one detector can be freely fitted with different sensor probes. Whenever the probe is replaced, the sensor requires a certain activation period, and the instrument must be recalibrated. In addition, it is recommended to conduct a response test with standard gas before using the instrument to ensure reliable protection.
② Watch out for detection interference between different sensors.
Generally, each sensor is designed for a specific target gas, yet no gas detector features absolute selectivity. Therefore, when selecting a gas sensor, users shall fully understand interference from other gases to guarantee 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 around three years; photoionization detectors can work for four years or longer; specific electrochemical gas sensors have a relatively 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 instruments have relatively larger sizes and longer sensor lifespans. Sensors shall be inspected regularly, used within their valid period, and replaced promptly once they fail.
④ Follow the concentration measuring range of the detector.
All types of toxic and harmful gas detectors have fixed detection ranges. Accurate measurement can only be guaranteed within the specified range. Long-term measurement beyond the detection range may cause permanent damage to the sensor.
