Testing for the Cumulative Flashover Distribution

Methods for minimizing the error in an estimate of the voltage at a given probability of flashover (e. g., 3 sigma withstand) are presented. The variance in the estimate of a voltage is minimized with respect to the applied voltage and the number of applications of that voltage. It is shown that testing at approximately 5-percent and 95-percent probability of flashover yields maximum information about such quantities as 2 sigma and 3 sigma withstand voltages, and standard deviation.