The energy dissipated by corona or spark discharge is lower than that by arc discharge.The type and status of the low energy discharge are necessary to be estimated before the discharge develops into high energy discharge and causes damages.This paper summarizes the SF6 decomposition mechanisms under different conditions

and outlines how SF6 decomposes when low energy discharge such as corona or spark discharge takes place.The needle-plate electrode and the sphere-plate electrode with metallic particles on its plate are adopted to simulate corona and spark discharge.By analyzing the types and concentration of gaseous by products

it is suggested that the increment of S2OF10 be a criterion for estimating the occurrence of low energy discharge

and the correlation between S2OF10 and SO2 concentrations be another criterion for estimating the type of low energy discharge.