The sulfur(IV)–cobalt(II)–azide system and its application to the investigation of the decomposition of sulfur hexafluoride under electrical discharges

Abstract

A wet chemical procedure is described that is suitable for investigating the degradation of sulfur hexafluoride (SF₆), used as an insulating medium in high-voltage and ultra-high-voltage power equipment. It is based on the alkaline hydrolysis of S^IV species present in aged SF₆ and subsequent spectrophotometric determination of sulfite through its capability to accelerate the autoxidation of Co^II to Co^III in aqueous azide solution. Results showing the ageing of SF₆ as a function of time are presented.