Ultraviolet Absorption Spectroscopy Measurement of Gas Mixture of SF6 Decomposition Components SO2 and CS2

SO ₂ and CS ₂ are both characteristic gas components that represent the internal insulation state of SF ₆ insulated electrical equipment. Their accurate quantification is of great significance for judging the type and severity of internal insulation faults of SF ₆ electrical equipment. The ultraviolet (UV) differential absorption spectroscopy system for trace gas detection was built. The UV absorption spectral of single SO ₂ , CS ₂ and their mixture were collected by using the system. Then through the analysis of UV absorption spectral data of SO ₂ and CS ₂ , the quantitative detection method of SO ₂ and CS ₂ mixed gas was proposed and verified. The results show that the method can achieve the hybrid quantitative detection of SO ₂ and CS ₂ , and the maximum absolute detection error of CS ₂ is less than 3.2nL/L. The research results laid the foundation for the application of UV differential absorption spectroscopy to the on-line monitoring of SF ₆ characteristic decomposition components and the fault diagnosis of SF ₆ electrical equipment.