... 10 seconds 1) Detecting principle: catalytic combustion2) Detected gas: combustible gas3) Measurement range: 0-100% LEL (LEL ... Explosion Level - the lowermost concentration of combustible gas to generate an explosion in air when meeting a ... used, etc., such as chemical, petroleum, metallurgy, oil depot, LPG (Liquefied Petroleum Gas) station , pharmaceutical, gas transmission and distribution, etc. to ...