Application of CNTs Gas Sensor in Online Monitoring of SF6 Insulated Equipment

The detection and analysis of SF6 decomposition components are of great significance in online condition assessment and fault diagnosis of GIS. Considering the shortcomings of general detection methods, carbon nanotubes (CNTs) gas sensor was studied to detect the SF6 decomposition components because of its advantages in large surface activity and abundant pore structure, et al. The large surface area has a strong adsorption and desorption capacity. In this chapter, SF6 decomposed gases, namely SO2F2, SOF2, SO2, H2S and CF4 are chosen as probe gases because they are the main by-products in the decomposition of SF6 under partial density (PD). First, the properties and preparation methods of CNTs are introduced to verify the advantages of CNTs for SF6 decomposition components detection. Then, both theoretical calculation and sensing experiment were adopted to study the microadsorption mechanism and macrogas-sensing properties. Based on the intrinsic CNTs, study for SF6 decomposition components adsorption, Pd, Ni, Al, Pt and Au metal doping CNTs and plasma-modified CNTs are discussed in order to enhance the gas sensing and selectivity of CNTs.