Quantitative Approaches to Evaluating the Chalking Layer on Silicone Rubber

Silicone rubber (SR) insulators are continuously affected by various kinds of environmental factors. Thus, the aging characteristics are of great significance for long-term operation. Chalking, which is a typical feature of aging, is often reported from areas with high temperature and humidity. However, the description of chalking level is still qualitative, leaving the quantitative evaluation approach uninvestigated. Therefore, in this paper, weight loss measurement is introduced, in order to quantitatively characterizing the chalking level of SR insulators. It indicates that the upper surface of insulator shed is more easily to get chalked, while the influence of electric field distribution is negligible. Subsequently, for the convenience of measurement on site, weight gain measurement is proposed, which is non-destructive. It is confirmed to have close results to the weight loss measurement.