No matter what kind of gas detector, it will have an alarm function, mainly because when the instrument detects that the target gas concentration in the environment reaches a certain concentration, the gas detector can issue an alarm reminder. The accuracy of the test results of an instrument is an important condition for the correct alarm, and the calibration of the gas detector is an important guarantee for this condition.

The calibration of a gas detector means that the instrument is placed in a test gas of a corresponding known concentration, and the accuracy of the gas detector is known by comparing the results of the gas detector with the gas concentration. For example, n-hexane will burn and explode at 1.1% VOL, and when a 10% alarm is set on the hexane detector, the alarm should be issued when the hexane concentration reaches 0.1%. For catalytic combustion sensors, this concentration is quite low. The alarm value of toxic gas is much lower than that of combustible gas. For example, the threshold alarm value of chlorine gas is only 0.5ppm.

The difference between the measurement result of the recalibrated gas detector and the measured gas concentration is generally not more than 10%, then this instrument can be used without calibration. For example, if an ammonia tester detects 50ppm standard ammonia gas, if the measurement result of the instrument is 46ppm, then the detection accuracy of this ammonia tester can be considered qualified without recalibration, because 46ppm is at 50 ± 10% X50 The result is between 45 ~ 55ppm. Similarly, if the detection result of this ammonia detector is 44ppm, then this detector needs to be recalibrated before it can be used.

Calibration of the gas detector is an important way to detect the sensitivity of the instrument and restore the accuracy of the instrument. At the same time, we can also determine whether the sensor of the gas detector has failed through testing and calibration. Therefore, it is necessary to calibrate the instrument regularly. The general calibration is a very simple and convenient process, which only requires two steps: one, zero the instrument with “air” that does not contain the gas to be measured, and two, place the instrument in a standard gas with a known concentration Correction.

For the small partners in the security industry, portable detectors must be accurate and reliable, and must not be sloppy. The correct and regular calibration of the maintenance detector is an indispensable method, which shows how important the calibration is. In fact, both the tester manufacturer and national regulations also have calibration requirements, which are usually divided into two categories:

Equipment manufacturers will require regular calibration, usually once every 2-6 months, to ensure that the meter can work normally and effectively. The manufacturer recommends that qualified users, dealers or manufacturers authorized service personnel can perform the calibration of the meter.

The measurement regulations require that the number of calibrations cannot be less than once every 12 months, and this time the calibration must be performed in the metrology department specified by the state, that is to say, the calibration must be performed in a third-party metrology institute.

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