Type semiconductor gas sensor: since 1962, metal oxide semiconductor ceramic gas sensor, the semiconductor gas sensor has become the most common application today, the most practical type of gas sensor. It has low cost, simple manufacture, high sensitivity, fast response, long life, low sensitive to humidity and simple circuit etc. Deficiency is must work under high temperature, poor selectivity of gas or smell, disperse element parameters, the stability is not ideal, high power.

Electrochemical gas sensors, electrochemical gas sensor is by measuring electric current to detect the concentration of the gas, can be divided into primary cell type without power supply and controlled potential electrolysis type need power supply, the current can detect many toxic gas and oxygen, which can detect the oxygen concentration in the blood. The main advantage of the electrochemical sensor is a high sensitivity and good selectivity of gases. Deficiencies have limited life of the general for two years.

Solid electrolyte gas sensor: as the name implies, a solid electrolyte is based on solid ion conductive chemical battery electrolyte. It's between the semiconductor and electrochemical. Selectivity, sensitivity is higher than the semiconductor and life longer than electrochemical, so also got a lot of application, deficiency is the response time is too long.

Contact: combustion type gas sensor can only measure the combustible gas combustion type gas sensors. Is divided into direct contact with the combustion and catalytic combustion type contact, the principle is the gas sensitive material in the condition of electricity, combustible gas on the surface or under the effect of catalyst combustion, due to the burning gets sensitive material temperature and resistance to change. The latter because of the catalyst is widely put application more widely.