How to Select Toxic and Hazardous Gas Detectors
At present, our understanding of toxic and harmful gases is mainly focused on combustible gases, gases that can cause acute poisoning (hydrogen sulfide, hydrogen cyanide, etc.), as well as some common toxic gases (carbon monoxide), oxygen and other detection devices.
According to the hazards, we classify toxic and harmful gases into two categories: combustible gases and toxic gases. Due to their different properties and hazards, their detection methods also vary.
In China, due to historical and cognitive reasons, there are still many problems when choosing various gas detectors, specifically reflected in: 1) the detection of flammable gases is more important than the detection of toxic gases. 2) The detection of gases that may cause acute poisoning is more important than the detection of gases that may cause chronic poisoning.
Due to the lessons learned from numerous explosion accidents caused by combustible gas leaks, people attach great importance to combustible gas detectors. It can be said that in any petrochemical or chemical plant, the vast majority of hazardous gas detectors are LEL detectors. However, equipping only with LEL detectors is still far from enough to truly protect the safety and health of workers.
When choosing a suitable toxic and harmful gas detector, attention should be paid to confirming the type and concentration range of the gas to be detected: the gas types encountered by each production department are different. When choosing a gas detector, all possible scenarios should be considered. If methane and other less toxic hydrocarbons are predominant, choosing an LEL detector is undoubtedly the most suitable.
It cannot be denied that most volatile hazardous gases are combustible gases, but catalytic combustion combustible gas detectors (LELs) are not the best choice for detecting all combustible gases. It is specifically designed for detecting methane, but its detection performance for other substances is relatively poor. So, the lower limit concentration of combustible gases other than methane that they can detect is much higher than their allowable concentration.
