What is lel gas detector?

The lel gas detector is a device that detects the concentration of combustible gases in the air. lel stands for Lower Explosive Limit, which is the value of the gas concentration at which the gas is able to form the smallest combustible mixture with oxygen. In the following, we will describe the immediate content of the LEL gas detector.

lel gas detector for natural gas storage
lel gas detector for natural gas storage

Detection principle of the LEL gas detector

The detection principle of the LEL gas detector is based on the reaction principle of combustible gases (e.g. methane, ethane, propane, etc.) with oxygen. When a combustible gas is present in the air, the LEL detector draws it into the instrument and reacts with the sensors in it to produce an electrical signal. This signal is processed by a circuit and is displayed on the instrument’s screen. It is important to note here that LEL detectors can only detect the concentration value of combustible gases, not their type.

4 in1 Gas Detector FS11301

Application Scenarios

LEL gas detector is commonly used in industrial production, mining, environmental monitoring and other fields. Its application scenarios include but are not limited to the following:

1.Detecting combustible gases in the air when mining coal and metal minerals;

2.Oil and gas mining, storage, transportation, processing, and other fields, to detect the combustible gas concentration in the field of underground mining and other links;

3.Industrial production, chemical industry, construction, printing and other places, for the detection of flammable gases, liquids, gases and solid substances.

FS10201 (1)
Industrial Gas Detector FS10201

Important features

As a specialized instrument, LEL detector has the following key features:

1.High sensitivity

LEL detector adopts advanced Combustible Sensor, which can monitor, control and alarm the concentration of combustible gas with high precision. Therefore, the sensitivity of LEL detector is quite high.

2.Flexible and portable

LEL detectors are usually handheld, portable or belt-type, which are lightweight and small in size, and can be carried or operated at any time to facilitate the application.

3.Easy to operate

LEL detector is easy to operate, you can adjust and set the instrument through the buttons or menus on the instrument, you can start testing.

4.Intelligent Alarm

LEL detector can collect feedback information according to the concentration of combustible gases, and alarm the user at the right time to ensure the personal safety of the user.

5.Durable and high quality

LEL detector shell materials are mostly engineering plastics or stainless steel materials, the surface covered with a protective layer, with good waterproof, dustproof performance. At the same time, the instrument accepts the sensor and circuitry and other components have been strictly protected design, can be in the harsh environment of continuous, stable operation.

FS01200B (1)
Catalytic Combustion Methane Sensor FS01200B

The following points should be noted when using the LEL detector

Calibrate before use: calibrating the instrument can improve the accuracy of the test and ensure the reliability of the test results.

Prevent damage to the instrument: avoid contact with strong acids, strong alkalis and other chemicals, and should also be careful to avoid damage to the machine by sun exposure, impact and drop.

Avoid false alarms: LEL detector is usually interfered by environmental factors, so be careful to avoid false alarms when using.


As a professional detection tool, LEL detector can accurately and reliably detect the concentration of combustible gases in the air in industrial production, mining, environmental protection monitoring and other fields. This article introduces the LEL detector’s key features, use scenarios, detection principle and other aspects of the content, and the use of precautions are explained.