Today I will talk about the calibration and calibration of gas detectors
All gas detectors need to be calibrated and calibrated before leaving the factory. In the actual measurement process of the gas detector, it is best to calibrate the gas detector every few months after a period of time. The calibration of the gas detector is as long as the standard gas is ventilated with the gas detector to measure and go through the calibration procedure.
The calibration of the gas detector requires sending the gas detector to the specified metrology institute to use professional equipment for measurement to see if the factory settings of the gas detector are within the error range stipulated by the state.
No matter what kind of gas detector, it will have an alarm function, mainly for the purpose of sending out an alarm when the instrument detects that the concentration of the target gas in the environment reaches a certain concentration. The accuracy of an instrument's detection results is an important condition for issuing a correct alarm, and the calibration of a gas detector is an important guarantee for this condition to be achieved. The calibration of a gas detector refers to placing the instrument in a test gas of a corresponding known concentration, and comparing the detection results of the gas detector with the gas concentration to know the accuracy of the gas detector. Generally speaking, each sensor corresponds to a specific detection gas, but any gas detector cannot be absolutely specific. Therefore, when selecting a gas sensor, it is necessary to understand the detection interference of other gases to the sensor as much as possible, so as to ensure its accurate detection of specific gases.
Like other analytical and testing instruments, the gas detector is measured by a relative comparison method: first, the instrument is calibrated with a zero gas and a gas with a standard concentration, and the standard curve is obtained and stored in the instrument. , the instrument compares the electrical signal generated by the gas concentration to be measured with the electrical signal of the standard concentration, and calculates an accurate gas concentration value.
Therefore, zeroing the instrument at any time and frequently calibrating the instrument are essential tasks to ensure the accuracy of the instrument measurement. It should be noted that many gas detectors can replace the detection sensor at present, but this does not mean that a detector can be equipped with different detector probes at any time.
Whenever the gas detector is replaced, in addition to a certain sensor activation and measurement instrument detection time, the instrument must be recalibrated when the probe is replaced. In addition, it is recommended to test the response of the standard gas used for the instrument before using the gas detector for various instruments to ensure that the instrument really plays a protective role. If this type of instrument is used as a safety alarm in an open place, 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. The fixed detector is generally a two-body type. The detection head composed of sensors and transmitters is installed on the detection site as a whole, and the secondary instrument composed of circuits, power supplies and display alarm devices is installed in a safe place as a whole, which is convenient for monitoring. The detection principle of the instrument calibration gas detector is the same as that described in the previous section, but it is more suitable for the continuous and long-term stability required by the fixed detection in the process ultra-clean instrument workbench calibration studio and technology. The 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, through testing and calibration, we can also judge whether the sensor of the gas detector has failed. Therefore, regular instrument calibration is very necessary. The general calibration is a very simple and convenient process, only two steps are required:
1. Reset the instrument to zero in "air" that does not contain the gas to be measured,
2. Put the instrument in a standard gas containing a known concentration for calibration. For small partners in the security industry, portable detectors must be accurate and reliable, and there is no room for sloppyness. Correct and regular calibration and maintenance of the detector is an essential method, which shows how important calibration is. In fact, both detector manufacturers and national regulations also have calibration regulations, which are usually divided into two categories: Equipment manufacturers will require regular calibration, usually within 2-6 months, to ensure that the instrument can work normally and effectively, The manufacturer recommends that qualified users, dealers or service personnel authorized by the manufacturer can carry out the calibration of the instrument. Metrology regulations require that the calibration frequency should not be less than once every 12 months, and this calibration must be carried out in the metrology department stipulated by the state, that is to say, it needs to be calibrated in a third-party metrology institute.
