As we all know, the combustible gas detected by the combustible gas detector contains alkanes (such as methane, ethane, propane, isobutane, etc.), hydrocarbons (such as polyalkanes), alcohols (such as methanol, ethanol, etc.), aldehydes (such as formaldehyde, etc.), benzene (such as toluene, xylene, etc.), acetylene, volatile organic compounds, etc. In the process of detecting these combustible gases, we usually involve some professional terms, such as Lel. Do you know what lel means in Combustible Gas Detector ? The following is a brief introduction by yi yun Tian:

lel in combustible gas detector refers to the lower explosive limit of gas, which is a technical word for combustible gas.

when the concentration of combustible gas in the air reaches its lower explosion limit, we call the explosion risk of the combustible gas environment in this place 100%, I .e. 100 LEL.

if the content of combustible gas reaches only 10% of its lower explosion limit, we call the explosion risk of combustible gas environment in this place 10% LEL at this time. The monitoring of combustible gas in ambient air often directly gives the hazard of combustible gas environment, that is, the content of the combustible gas in the air and the percentage of its lower explosive limit to express: [%LEL].

when combustible gas and combustible liquid vapor (or combustible dust) are mixed with air and reach a certain concentration, an explosion will occur when encountering a fire source. this concentration range that can explode is called the explosion limit.

The lower explosive limit of each gas is different. For example, the explosion limit of hydrogen: the lower limit is 4.0, the upper limit is 74.2, and combustion and explosion occur when air and open flame are encountered. 4.0% is the low volume fraction of hydrogen that encounters open fire explosion, which is less than this bottom line. If open fire does not burn, it will not explode. 74.2% is the highest limit (or upper limit) of high volume fraction. When the volume fraction is higher than this limit, it can burn safely in air and open flame, and there will be no explosion. In short, the volume fraction below or below the explosion limit range, the case of open fire will not explode.

Therefore, you don't have to worry about whether there will be danger at any time after the combustible gas detector alarms. It is still a certain distance from reaching the explosion. Take appropriate measures immediately, such as opening the exhaust fan or cutting off 1 valves or opening the spray system, the danger of explosion will not appear. There is still a big gap from the lower explosion limit where danger is really possible to give an alarm, so that it will play the role of alarm prompt.