Application of Excimer Lamp in Quantitative Detection of SF₆ Decomposition Component SO₂

Accurate quantitative detection for trace gas has long been the center of failure diagnosis for gas-insulated equipment. An absorption spectroscopy-based detection system was developed for trace SF₆ decomposition SO₂ detection in this paper. In order to reduce interference from other decomposition, ultraviolet spectrum of SO₂ was selected for detection. Firstly, an excimer lamp was developed in this paper as the excitation of the absorption spectroscopy compared with regular light sources with electrodes, such as electrodeless lamps that are more suitable for long-term monitoring. Then, based on the developed excimer lamp, a detection system for trace SO₂ was established. Next, a proper absorption peak was selected by calculating spectral derivative for further analysis. Experimental results indicated that good linearity existed between the absorbance and concentration of SO₂ at the chosen absorption peak. Moreover, the detection limit of the proposed detection system could reach the level of 10^-7. The results of this paper could serve as a guide for the application of excimer lamp in online monitoring for SF₆-insulated equipment.