How to choose toxic and harmful gas detectors

At present, with the development of manufacturing technology, portable multi-gas (compound) detectors are also a new choice for us. Since this detector can be equipped with multiple gas (inorganic/organic) detection sensors on a host computer, it has the characteristics of small size, light weight, corresponding rapidity, and simultaneous multi-gas concentration display. More importantly, the price of pumped composite gas detectors is lower than that of multiple single diffusion gas detectors and is more convenient to use. It should be noted that when selecting such detectors, it is best to select an instrument that has the ability to switch each sensor individually to prevent the use of one sensor from affecting other sensors. At the same time, in order to avoid clogging of the suction pump due to water ingress, it is also safer to select a smart pump design with a pump stop alarm.

Problems to be aware of when using gas detectors:

First, pay attention to the regular calibration and detection of toxic and harmful gas detectors are the same as other analytical testing instruments, are measured by a comparative method: first calibrate the instrument with a zero gas and a standard concentration of gas, The calibration curve is stored in the instrument. During the measurement, the instrument compares the electrical signal generated by the gas concentration to be measured with the electrical signal of the standard concentration to calculate the accurate gas concentration value. Therefore, zero calibration of the instrument at any time, and regular calibration of the instrument is an indispensable task to ensure accurate measurement of the instrument. It should be noted that at present, many gas detectors can replace the detection sensors. However, this does not mean that one detector can be equipped with different detector probes at any time. Whenever a probe is replaced, the instrument must be recalibrated in addition to a certain sensor activation time. In addition, it is recommended to respond to the standard gas of the instrument before using it to ensure that the instrument really protects the instrument.

Second, pay attention to the detection of interference between various sensors In general, each sensor corresponds to a specific detection gas, but any kind of gas detector can not be absolutely special effects. Therefore, when selecting a gas sensor, it is necessary to know as much as possible the interference of other gases to the sensor, so as to ensure accurate detection of the specific gas.

Third, pay attention to the life of various types of sensors All kinds of gas sensors have a certain useful life, that is, life. Generally speaking, in portable instruments, LEL sensors have a long life, generally about three years; photoionization detectors have a life expectancy of four years or more; electrochemical specific gas sensors have a relatively short life span, and generally In one year to two years, the oxygen sensor has the shortest life span of about one year. The life of the electrochemical sensor depends on the dryness of the electrolyte, so if it is not used for a long time, sealing it in a lower temperature environment can prolong the service life. Because of the relatively large size of the stationary instrument, the life of the sensor is longer. Therefore, it is necessary to detect the sensor at any time and use it within the effective period of the sensor as soon as possible. If it fails, replace it in time.

Fourth, pay attention to the measuring instrument concentration measurement range:

Various toxic and harmful gas detectors have their fixed detection range. Only when the measurement is completed within its measurement range can the instrument be accurately measured. However, measuring over a long period of time may cause permanent damage to the sensor.

For example, if the LEL detector is inadvertently used in a 100% LEL environment, it may burn the sensor completely. Toxic gas detectors can also cause damage if used for a long time at higher concentrations. Therefore, if a fixed-type instrument emits an over-limit signal during use, the measurement circuit must be turned off immediately to ensure the safety of the sensor.