Analysis of spark decomposition products of SF6 using multivariate mid-infrared spectrum evaluation

Infrared spectroscopy is a powerful tool for the analysis of gaseous by-pro ducts generated from electrical discharges in sulfur hexafluoride gas. The spark decomposition of SF6 was studied under pressures of 250 kPa and 300 k Pa, which were provided for the insulating gas inside a discharge chamber c onstructed from stainless steel and Teflon. The sparks were generated betwe en a point-plane configuration by discharging a capacitor. The spark energi es were in the range between 0.15 and 1.0 J/spark. The electrode materials used were copper, aluminium and silver. Quantification was carried out usin g classical least-squares with spectral data from selected intervals. The m ain-products found were the sulfuroxyfluorides SOF4 and SOF2 with concentra tions correlated to the spark energy. Moreover, we were able to measure HF at spark energies in the upper range. The experimental conditions and pract ical aspects for reliable quantitative analysis of reactive sulfurfluoride species are discussed. (C) 1999 Elsevier Science B.V. All rights reserved.