gas detectorIt plays an important role in industrial safety production, and in Chinese production enterprises,gas detectorFrom scratch to more and more widely used, the sensor, the core component of gas detector, plays an increasingly important role. Sensors are divided into semiconductor, catalytic combustion, electrochemical sensors according to spectral analysis measurement Infrared photoionization type A new generation of sensors graphene sensors are about to be born, which have many advantages that traditional sensors cannot match. Semiconductor sensors have been used since 1962, mainly to measure flammable gas, and are relatively early, using the current or voltage of gas-sensitive components to change with the change of gas content to measure the gas concentration. This sensor is poorly selective and is rarely used now. The detection of flammable gas is now mostly catalytic combustion, and the platinum wire coated with catalyst material causes resistance changes and current changes when flammable gas is burned at high temperatures, so as to measure the gas concentration.
Characterized by stability. Electrochemical sensors are mainly used to measure toxic gas, including oxygen. The gas concentration is calculated by performing a redox reaction through the gas to be measured coated with a platinum wire catalyst film, and then calculating the gas concentration by electrolyzing the current generated by the circuit acquisition system Measured gases in the instrument. High sensitivity, good selectivity, simple structure, and use at room temperature. Infrared sensors use the changes of the spectra of measured gases after infrared irradiation to measure the concentration of flammable gases, which are highly selective and sensitive. Higher price photoionization sensor is to use gas after ultraviolet irradiation to ionize gas molecules into positive and negative ions, and the ultraviolet spectrum changes to measure the gas concentration, mainly to measure volatile organic compounds. High sensitivity, good selectivity, and high price. The new generation of sensors Graphene sensors are starting to emerge due to their unique advantages. It is the adsorption of gas molecules by graphene to change the resistance, so as to measure the gas concentration.