Sensing of decomposition products in SF6 by use of a corner cube prism coated with a dye film as an optical sensor head

A very sensitive optical sensing method for detecting a small quantity of gaseous decomposition products generated by an electric discharge in SF6 was developed. A sensor head is prepared using a corner cube prism of which three total reflection planes are coated with a thin film of methyl orange dye deposited by a vacuum evaporation method. The methyl orange dye is a color reaction reagent for detection of SF6 gas decomposition products such as HF gas, which is generated due to discharge induced in a glass container filled with FB gas. The sensor head connected to a halogen lamp through an optical fiber is placed in the container. This optical sensing method can be used to detect in real time problems or failure occurring in gas-insulated equipment.