Introduction to the infrared gas detector and its operating principle
Infrared gas detector is a portable gas detector that uses specialized infrared gas analysis technology and features high precision, high resolution, long lifespan, and easy maintenance. This type of infrared gas detection has a wide range of applications in many industries, and the detection of the concentration of flammable and explosive gases, toxic and harmful gases has always been of great significance for safety production.
The infrared absorption spectrum is not only used for measuring gas concentration, but also widely used for identifying the structure of different molecules through characteristic absorption. And it has high sensitivity, fast response, can continuously indicate online, and can also form a regulating system. The detection part of infrared gas detectors commonly used in industry consists of two parallel optical systems with the same structure. One is the measurement room, and the other is the reference room. Two rooms open and close the optical path simultaneously or alternately at a certain period through a light cutting plate.
After introducing the measured gas into the measurement chamber, light with a unique wavelength of the measured gas is absorbed, thereby reducing the light flux that passes through the measurement chamber and enters the infrared receiving chamber. The higher the gas concentration, the less light flux enters the infrared receiving chamber; The light flux passing through the reference chamber is constant, and the light flux entering the infrared receiving chamber is also constant.
Therefore, the higher the concentration of the measured gas, the greater the difference in luminous flux passing through the measurement chamber and the reference chamber. This difference in luminous flux is projected onto the infrared receiving chamber with a certain amplitude of periodic vibration.
The receiving chamber is divided into two halves by a metal thin film several microns thick. The chamber is sealed with a high concentration of the tested component gas, which can absorb all the incoming infrared radiation within the absorption wavelength range, thereby transforming the pulsating light flux into a periodic change in temperature. The temperature change can then be converted into a change in pressure based on the gas state equation, and then detected by a capacitive sensor. After amplification processing, the concentration of the tested gas is indicated.
