How to Select and Purchase Hazardous Gas Detectors
At present, our understanding of toxic and hazardous gases is mostly focused on detectors for combustible gases, acutely toxic gases (such as hydrogen sulfide and hydrocyanic acid), certain common toxic gases (carbon monoxide), oxygen, etc.
Based on hazards, toxic and hazardous gases are divided into two major categories: combustible gases and toxic gases. Due to their different properties and hazards, different detection methods are adopted.
In China, due to historical factors and cognitive limitations, there are quite a few problems in the selection of various gas detectors, which are specifically reflected in: ① More emphasis is placed on combustible gas detection than toxic gas detection. ② Greater attention is given to gases that may cause acute poisoning than those that may lead to chronic poisoning.
Lessons learned from numerous explosion accidents caused by combustible gas leaks have made people attach great importance to combustible gas detectors. In petrochemical and chemical plants, the majority of hazardous gas detectors are LEL detectors. However, relying solely on LEL detectors is far from sufficient to truly protect workers' safety and health.
When selecting a suitable toxic and hazardous gas detector, it is necessary to confirm the types and concentration ranges of gases to be detected. Different production departments encounter different types of gases, and all potential scenarios shall be considered during detector selection. If methane and other low-toxicity alkanes predominate, an LEL detector is undoubtedly the most appropriate option.
It is undeniable that most volatile hazardous gases are combustible. Nevertheless, catalytic combustion combustible gas detectors (LEL) are not the optimal choice for detecting all combustible gases. They are designed specifically for methane and deliver poor detection performance for other substances. Hence, the lower limit concentration of combustible gases (other than methane) that they can detect is far higher than their permissible exposure limits.
