These values were readily used in polluted insulator simulation in seeking the statistics of tangential electric field along composite insulator, which drives the leakage current. The effects of those conductivities in each contamination layer on the leakage current density on insulator surface were sought.
As an example, Fig. 2a shows the leakage current density distribution over the creepage distance for a 1 mm contaminating layer thickness and with 284.9 μS/cm contaminant conductivity. By surface integrating current densities, the overall surface leakage current was found to be 54.6 mA.