The LEL in the gas detector actually refers to the concentration value of the gas alarm.

is the lowest content of combustible gas that can cause an explosion called the lower explosive limit Low Explosion - Level(LEL).

LEL It is not a unit, it refers to a value, generally refers to the volume ratio of explosive gas in the air. LEL this value is not detected by the instrument, it is the national standard for different gases have different values. The data displayed by the gas detection instrument only indicates the concentration of combustible gas in the air to make an alarm. Generally, there is a mark on the quantitative analysis instrument to detect what gas. If it is a qualitative analysis instrument, it cannot show what kind of gas it is.

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%, that is, 100 LEL. If the content of combustible gas only reaches 10% of its lower explosion limit, we call the explosion risk of combustible gas environment in this place 10% LEL; The monitoring of combustible gas in ambient air often directly gives the risk of combustible gas environment, that is, the content of combustible gas in air and the percentage of its lower explosion limit are expressed:[%LEL]

In other words, when the detector value reaches the "100 LEL" alarm point, it is equivalent to the "5%" volume ratio of methane at this time. When the value of the combustible gas detector reaches the "25% LEL" alarm point, it is equivalent to the "1.25%" volume ratio of methane at this time.However, 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 some 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.