How much do you know about the sensors commonly used in gas detectors
The sensor is the main detection component of the gas alarm. The sensor is a device or device that can sense the specified measurement and convert it into an available output signal according to a certain rule.
Liye Detector: How much do you know about the sensors commonly used in gas detectors
A gas sensor is a sensor used to detect the composition and content of a gas. Generally speaking, the definition of a gas sensor is based on the classification of the detection target. That is to say, any sensor used to detect the composition and concentration of a gas is called a gas sensor. , no matter it is by physical method or chemical method.
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 roughly the same detection principle. From its principle, we can divide it into the following three categories:
1. Gas sensors using physical and chemical properties: such as semiconductors, catalytic combustion, solid heat conduction, photoionization, etc.;
2. Gas sensors using physical properties: such as thermal conductivity, light interference, infrared absorption, etc.;
3. Electrochemical gas sensors: current type, potential type.
Catalytic combustion sensor;
It belongs to the high temperature sensor, and its working principle is that the gas-sensitive material (such as Pt electric heating wire, etc.) is oxidized and burned under the action of a catalyst when the gas-sensitive material (such as Pt heating wire, etc.) is oxidized and burned under the action of a catalyst. .
electrochemical sensor
A precision sensor, electrochemical sensors work by reacting with a target gas and generating an electrical signal proportional to the gas concentration. A typical electrochemical sensor consists of a sensing electrode (or working electrode) and a counter electrode.
semiconductor sensor
It is a broad-spectrum sensor, and its working principle is that the resistance of the metal oxide semiconductor surface changes after absorbing gas.
infrared sensor
Belonging to the precision sensor, it has quite good measurement pertinence. At present, it mainly detects low carbon chain hydrocarbons and CO2.
