How does a gas detector calibrate?
Whether it is a toxic gas detector or a combustible gas detector, they will have an alarm function, mainly to send out an alarm reminder when the instrument detects that the target gas concentration in the environment has reached a certain concentration. The accuracy of the detection results of an instrument is an important condition for issuing a correct alarm, and the calibration of a gas detector is an important guarantee for achieving this condition.
The calibration of a gas detector refers to placing the instrument in a test gas with a corresponding known concentration, and comparing the detection results of the gas detector with the gas concentration to determine the accuracy of the gas detector. For example, n-hexane will burn and explode at 1.1% VOL, and when a 10% alarm is set on the hexane detector, an alarm will sound when the hexane concentration reaches 0.1%. For catalytic combustion sensors, this concentration is quite low. The alarm value of toxic gases is much lower than that of combustible gases, taking chlorine gas as an example, its threshold alarm value is only 0.5ppm.
The calibration of gas detectors is an important way to detect instrument sensitivity and restore instrument accuracy. At the same time, through testing and calibration, we can also determine whether the sensor of the gas detector has failed. Therefore, regular instrument calibration is very necessary. Generally, calibration is a simple and convenient process that only requires two steps:
1, Zero the instrument in air that does not contain the gas to be measured.
2, Place the instrument in a standard gas with a known concentration for calibration.
For security industry partners, portable detectors must be reliable and cannot tolerate any carelessness. The correct and regular calibration and maintenance of the testing instrument is a method, which shows how important calibration is. In fact, both detector manufacturers and national regulations have calibration regulations, which are usually divided into two categories:
The equipment manufacturer will require regular calibration, usually once every 2-6 months, to ensure that the instrument can work normally and effectively. The manufacturer recommends that qualified users, distributors, or authorized service personnel from the manufacturer can carry out instrument calibration work.
The metrology regulations require that the number of calibrations must not be less than once every 12 months, and this calibration must be carried out by the national metrology department, which means it needs to be carried out at a third-party metrology institute.
