Introduction to Infrared Gas Detector and Its Working Principle
Infrared gas detector is a portable gas detector that uses specialized infrared gas analysis technology and has the characteristics of high precision, high resolution, long service life, and easy maintenance. This type of infrared gas detection has been widely used 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 applied to the measurement of gas concentration, but also widely used to identify the structure of different molecules from 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 chambers open and close the optical path simultaneously or alternately at a certain period through a 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 entering the infrared receiving gas chamber through the measurement chamber. The higher the gas concentration, the less light flux enters the infrared receiving chamber; 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 measured gas, the greater the difference in luminous flux between 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 film several microns thick. The chamber is sealed with a gas component with a relatively high concentration, which can absorb all the incoming infrared rays within the absorption wavelength range, thereby transforming the pulsating light flux into a periodic change in temperature. Then, the temperature change can be converted into a change in pressure based on the gas state equation, and a capacitive sensor is used to detect it. After amplification, the concentration of the measured gas is indicated.
