Lower Explosive Limit in combustible gas detection
When the concentration of flammable gas in the air reaches its Lower Explosive Limit, we call the explosion risk of the flammable environment in this place 100%, that is, 100% LEL. If the flammable gas content only reaches 10% of the lower explosion limit, we call the flammable environment explosion risk of this site at 10% LEL; the monitoring of flammable gas in the ambient air often gives the danger degree of flammable gas directly. Therefore, this Lower Explosive Limit is important in combustible gas detection.
Besides, in environments with combustible gas hazards, it is important to know long before the gas concentration reaches the LEL. Typical safety standards require that a gas detection unit give warnings at 10 – 20% of the LEL. Do not confuse the alarm level with the volume of gas required to reach the LEL. The lower explosion limit is referred to as "LEL", which is a technical term for combustible gases. For example: Methane has an LEL of 5% by volume in air. For a gas detector to give an alarm at 10% of the LEL, it must trigger when it detects 0.5% by volume. The detector for this application would most likely be calibrated for the range from 0% to 5% gas by volume, but display the reading as 0 – 100% LEL.