How gas detectors equipment work

User:JXCTUpload time:Jan 13 2023
Working principle of gas detector

The core technology of gas detector is sensor technology. Common gas sensors include electrochemical type, semiconductor type, ionization type, catalytic combustion type, infrared point type, etc. Sensors with different principles can form alarm detection devices of different types, different uses, and different gas detection purposes. How a gas leak detector works also depends on the type of sensor it uses.

gas sensor module
The working principle of the gas detector equipment

Now take the common infrared gas detector equipment as an example to illustrate the working principle of the gas detector.

The remote fixed gas detector can measure the absorption spectrum to determine the type of gas, and can measure the intensity of absorption to determine the concentration of the gas. Infrared detectors are widely used, not only to analyze gas components, but also to analyze the components of solutions. High sensitivity, rapid response, continuous on-line indication, can form an adjustment system. The detection part of the infrared gas detector equipment commonly used in industry is composed of two parallel optical systems with the same structure. The two optical systems are the measurement chamber and the reference chamber. The two chambers open and close the light path through the cutting plate simultaneously or alternately with a certain cycle.

Multi Gas detectors

After the measured gas is introduced into the measurement chamber, the light of the specific wavelength of the measured gas is absorbed, which reduces the light path from the measurement chamber to the infrared receiving chamber. The higher the gas concentration, the less luminous flux entering the infrared receiving chamber. And the luminous flux passing through the reference chamber is constant, and the luminous flux entering the infrared receiving chamber is also constant.

Therefore, the higher the concentration of the gas to be measured, the greater the difference in luminous flux between the measurement chamber and the reference chamber. The luminous flux is projected to the infrared receiving chamber through periodic vibration of a certain amplitude.

NDIR Flammable Modules CH4 Gas tester
The receiver air chamber is divided into two parts by a metal membrane a few microns thick

The receiver gas chamber is divided into two parts by a metal membrane a few microns thick. The measured gas is sealed in the chamber at a higher concentration. Can absorb absorption wavelength range of all incident infrared, change the light flux. A change in temperature translates into a change in pressure according to the gas equation. It is then detected by the capacitance detector.After amplification processing, the measured gas concentration is calculated.

In addition to capacitive detectors, the measurement room can also use quantum infrared detectors to directly detect infrared rays, and use infrared interference filters to select wavelengths, and use adjustable lasers as light sources to form a new all-solid-state infrared gas detector equipment. The detector uses only a light source, measuring chamber and infrared sensor to measure the gas concentration. In addition, the measurement uses filters equipped with multiple different wavelengths, which can simultaneously detect the concentration of multiple gases in a multi-component gas.

Application understanding of gas detector

Infrared gas detector is suitable for detecting various flammable and explosive gases such as carbon dioxide. It has high precision, good selectivity, high reliability, no poisoning, no dependence on oxygen, less environmental interference factors, and long service life. Now gradually become the mainstream of the future market.