Selection principles of harmful gas detection alarm

Clarify the purpose of detection and select the instrument category

In short, the detection of harmful gases has two purposes, the first is explosion detection, and the second is poison detection. The so-called explosion detection is to detect the content of combustible gas in dangerous places, and alarm when it exceeds the standard to avoid explosion accidents; poison detection is to detect the content of toxic gas in dangerous places, and alarm when it exceeds the standard to avoid poisoning of workers. The range of explosion detection is 0~100%LEL, and the range of poison detection is 0~tens (or hundreds) of ppm, which is very different.

There are three types of harmful gases in dangerous places. First, non-toxic (or low-toxic) flammable, second, non-flammable and toxic, and third, flammable and toxic. The first two situations are easy to determine, the first is explosion detection, the second is poison detection, and the third situation is if there are people exposed to poison detection, if there are no people exposed, explosion detection can be performed.

Choose a combustible gas detection alarm for explosion detection, and a toxic gas detection alarm for poison detection.

2. Clarify the purpose of detection and select the type of instrument (portable or fixed).

For long-term leakage detection in production or storage positions, use fixed detection alarm instruments; for other inspections such as maintenance detection, emergency detection, entry detection and patrol detection, use portable (or pocket) instruments. The instrument model includes three main contents: manufacturer, functional indicators and detection principle.

3. Clarify the detection object and select the best instrument model.

The following principles should be considered when selecting the instrument model:

① The manufacturer is honest, reputable, and has guaranteed production quality. It has passed the ISO9002 quality system certification, has a CMC production license issued by the technical supervision department, and has fire protection and explosion-proof certificates.

② The detection principle of the instrument should adapt to the requirements of the detection object and the detection environment.