Â· 43 comments. in Facts. An intelligence quotient, or IQ, is a score derived from one of several standardized tests designed to assess intelligence. The abbreviation âIQâ comes from the German term Intelligenz-Quotient, originally coined by psychologist William Stern.
Lower explosive limit. Lower explosive limit (LEL): The lowest concentration (percentage) of a gas or a vapor in air capable of producing a flash of fire in presence of an ignition source (arc, flame, heat). The term is considered by many safety professionals to be the same as the lower flammable limit (LFL).
LEL sensors. For example, 100% of LEL methane (5% methane by. volume) produces much more heat than 100% of LEL turpentine. (0.8% turpen tine by volume). Because LEL sensors actually measure. the heat at which a gas or vapor burns, they can be âfooledâ by. vapors like turpentine that burn cool relative to methane.