Commonly used gas detector has a catalytic combustion type and semiconductor type, infrared type, electric chemical formula, photoionization detection principle (PID) type, etc.
Catalytic combustion type sensor using catalytic combustion reaction of combustible gas, make the internal coil heating up, cause the resistance changes to detect gas concentration.
The principle of catalytic combustion type sensor structure
By metal oxide semiconductor sensor membrane adsorption resistance change after the sample gas to measure the concentration of the gas.
The electric chemical formula principle of sensor structure
Infrared type gas sensor is using the infrared spectrum absorption principle, specific wavelength of infrared light through the comparison to the change of intensity of the sample gas after measuring the concentration of gas.
The principle of infrared sensor structure
PID type sensor use ultraviolet light to make gas ionization, by detecting ionized gas charge to measure gas concentration.
The principle of PID type sensor structure
Electric chemical formula micro electric current produced by electrochemical reaction detection of gas sensor to work.
The electric chemical formula principle of sensor structure
