Sulfur hexafluoride gas leakage detection mainly uses electrochemical technology,electrical breakdown technology and infrared spectroscopy absorption technology.

　　1.Electrochemical technology:The principle of electrochemical technology is that the detected gas touches the surface of the catalyst at a high temperature of about 200°C,and reacts with sulfur hexafluoride gas accordingly,resulting in the change of electrical signal,so as to discover the detected gas.

　　2.Electrical breakdown technology:Electrical breakdown technology is evolved from the typical application of SF6 gas in power--as an insulating gas applied in GIS switchgear.Its working principle is based on the characteristics of sulfur hexafluoride gas insulation,from the change of voltage between the high voltage electrode in the detected air to determine whether the air contains SF6 gas.

　　3,usually used in the infrared spectrum absorption technology(also known as laser technology)principle is SF6 as a greenhouse gas,the specific band of infrared light has very strong absorption characteristics.

　　In addition,it is necessary to understand that the online monitoring and alarm system of sulfur hexafluoride gas leakage is an intelligent gas alarm system that detects environmental data such as high-purity sulfur hexafluoride concentration,oxygen content,temperature and humidity on site,and makes control and alarm through a large number of data analysis and processing.