"LEL" refers to the lower explosive limit, which is a technical term for flammable gases. The lowest concentration of flammable gas in the air when it encounters an open flame is called the lower explosion limit - referred to as "LEL". English: Lower Explosive Limit.
When the concentration of flammable gas in the air reaches its lower limit of explosion, we call the explosion danger of the flammable environment in this place as 100%, that is, 100% LEL. If the combustible gas content only reaches 10% of its lower explosion limit, we call the explosion hazard of the combustible environment at this time 10% LEL; the monitoring of combustible gas in the ambient air often directly gives the danger of combustible environment Degree, that is, the percentage of the content of the combustible gas in the air and its lower explosion limit: [%LEL]; therefore, this kind of monitoring is sometimes called "explosion test", and the monitoring instrument used is also called "explosion tester" .
