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).
For instance, if the LEL alarm is set at 10% LEL, when instrument starts out at -3% LEL it will take 13% LEL gas to cause the instrument to go into alarm. When the display is digitally locked on zero the user is unaware of the need to fresh air zero adjust the instrument.or instance, some brands of instruments equipped with miniaturized pellistor type LEL sensors have a dead-band that stretches all the way from -3% to +3% LEL. In other words, in the presence of a rising concentration of gas, the first reading displayed is 4% LEL.