How do LEL monitors work?
The most common LEL sensor is known as a Catalytic Bead Combustible sensor. It detects gas through a process of catalytic oxidation. As detectable gas is introduced, the active bead heats up even more causing a measurable change in electrical resistance. This linear response becomes the LEL% reading on the gas monitor.
What is LEL in safety?
Atmospheres with a concentration of flammable vapors at or above 10 percent of the lower explosive limit (LEL) are considered hazardous when located in confined spaces. However, atmospheres with flammable vapors below 10 percent of the LEL are not necessarily safe. Such atmospheres are too lean to burn.
What does an LEL sensor detect?
An LEL Detector or LEL Meter detects dangerous levels of a combustible gas or solvent vapor in air, expressed in percent Lower Explosive Limit, or LEL. An LEL Detector is an integral part of a complete gas detection system and can be referred to as a Gas Detector or just a fixed gas detection system.
What is LEL and UEL in safety?
Lower explosive limit (LEL): the lowest concentration of gas or vapour which will burn or explode if ignited. Upper explosive limit (UEL): the highest concentration of gas or vapour which will burn or explode if ignited.
What is the difference between LEL and PPM?
LEL stands for the Lower Explosive Limit of a gas. It is the minimal concentration of the gas required for the gas to ignite. It is normally expressed as a percentage of the total air. PPM stands for parts per million.
What is a safe LEL level methane?
Methane, for example, has an LEL of 5% vol and a UEL of 15% vol. Methane combustion is possible when the gas level is at or above 5%, but below 15%. Here is a list of common combustible gases and their lower explosive limits.
What is the safe oxygen level for confined space?
19.5 %
19.5 % Minimum acceptable oxygen level. 15 – 19% Decreased ability to work strenuously.
What is the difference between LEL and LFL?
Lower flammability limit (LFL): The lowest concentration (percentage) of a gas or a vapor in air capable of producing a flash of fire in the presence of an ignition source (arc, flame, heat). The term is considered by many safety professionals to be the same as the lower explosive level (LEL).
What are upper and lower flammability limits?
The upper flammability limit is defined as the concentration of the most concentrated mixture that is flammable and the lower flammability limit as the concentration of the most dilute fuel-air or fuel-diluent mixture that is flammable.
Can you convert LEL to ppm?
Multiply the LEL percentage number by 10,000 to get PPM.
What is the LEL of carbon monoxide?
CO is a colorless, odorless, tasteless and combustible gas with a lower explosive limit (LEL) of 12.5% or 125,000 parts per million (propane has an LEL of 2.2% or 22,000 ppm). Its specific gravity is slightly less than that of air – so it will stratify throughout a living space.
What are LEL levels?
LEL, short for “Lower Explosive Limit“, is defined as the lowest concentration (by percentage) of a gas or vapor in air that is capable of producing a flash of fire in presence of an ignition source (arc, flame, heat, etc.).