Get Lel Of Natural Gas In Ppm US. If more than than one chemical is dispersed in the air, as is normally the case. The lower explosive limit (lel) is the minimal amount of concentration needed of a particular chemical to cause an explosion.
Lower limit of human perception is 53 ppm.
Lel sensors measure explosivity, not toxicity. But many other combustible vapors fall. Conversion of units in parts per million (ppm) to miligram per cubic meters and visa versa. The lel is the minimum concentration of combustible gas in a space at which combustion will occur given a source of ignition.