Introduction to infrared gas detector and introduction to its working 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 infrared gas detection has a wide range of applications in many industries, and the detection of concentrations of flammable, explosive, 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 from characteristic absorption. And it has high sensitivity, rapid response, can indicate continuously online, and can also form a regulating system. The detection part of the infrared gas detector 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. The two rooms open and close the light path simultaneously or alternately at a certain period through a light cutting plate.
After introducing the measured gas into the measurement chamber, light with the unique wavelength of the measured gas is absorbed, thereby reducing the amount of light passing through the measurement chamber and entering the infrared receiving 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 measuring 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 few microns thick metal film, and the chamber is sealed with a high concentration of the measured component gas. Within the absorption wavelength range, all the incoming infrared rays can be absorbed, thereby converting the pulsating luminous flux into a periodic change in temperature. Then, the temperature change can be converted into a pressure change according to the gas equation, and a capacitive sensor can be used to detect it. After amplification processing, the measured gas concentration is indicated.
