Gas detector application

It is an instrument tool for detecting gas leakage concentration, which includes：Portable gas detectorHandheld gas detectors, fixed gas detectors, online gas detectors, etc. mainly utilizegas sensorTo detect the types of gases present in the environment，gas sensorIt is a sensor used to detect the composition and content of gases.

It is generally believed that the definition of gas sensors is based on the classification of detection targets, which means that any sensor used to detect gas composition and concentration is called a gas sensor, regardless of whether it uses physical or chemical methods. For example, sensors that detect gas flow are not considered gas sensors, but thermal conductivity gas analyzers are important gas sensors, although they sometimes use general detection principles.

Gas detector application

principle

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Taking the common infrared gas detector as an example, explain the principle of the gas detector:

Measuring this absorption spectrum can distinguish the type of gas; Measuring absorption intensity can determine the concentration of the gas being measured. The infrared detector has a wide range of applications, which can analyze not only gas components but also solution components. It has high sensitivity, rapid response, online continuous indication, 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 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. In addition to using capacitive sensors, quantum infrared sensors can also be used to directly detect infrared radiation. Infrared interference filters are used for wavelength selection and an adjustable laser is used as the light source to form a new all solid state infrared gas detector. This detector can measure gas concentration with only one light source, one measuring chamber, and one infrared sensor. In addition, if multiple filter discs with different wavelengths are used, the concentrations of various gases in multi-component gases can be measured simultaneously.