Introduction to how to calibrate gas detectors
Gas detectors, like other analytical instruments, are measured using a relative comparison method: first, the instrument is calibrated with a zero gas and a standard concentration gas to obtain a standard curve, which is stored in the instrument. During the measurement, the instrument compares the electrical signal generated by the concentration of the gas to be measured with the electrical signal of the standard concentration to calculate the accurate gas concentration value. Therefore, zeroing the instrument at any time and regularly calibrating the instrument are essential tasks to ensure accurate measurement. It should be noted that many gas detectors currently have replaceable detection sensors, but this does not mean that a detector can be equipped with different detector probes at any time.
Whenever replacing the probe of a gas detector, in addition to requiring a certain sensor activation time, the instrument must also be recalibrated. In addition, it is recommended to perform response testing on the standard gas used in various instruments before using the gas detector to ensure that the instrument is truly protective. If this type of instrument is used as an alarm in an open environment, such as an open workshop, a portable diffusion gas detector can be used because it can continuously, real-time, and accurately display the concentration of toxic and harmful gases on site. Fixed detectors are generally two-piece, with a detection head composed of sensors and transmitters installed as a whole at the detection site, and a secondary instrument composed of circuits, power supplies, and display alarm devices installed as a whole at the site for easy monitoring. The detection principle of the gas detector is as described in the previous section, but it is more suitable for the continuous and long-term stability required for fixed detection in terms of process and technology.
Generally, each sensor corresponds to a specific gas being detected, but no gas detector can be particularly effective. Therefore, when choosing a gas sensor, it is important to understand as much as possible the detection interference of other gases on the sensor to ensure accurate detection of specific gases.
