Use of statistics opens the door for enhancing bushing power factor / capacitance analysis. The tool, in¬formed by a database with more than 6 million tests, tailors the diagnostic limits by determining what is sta¬tistically normal for a specific type, manufacturer, and voltage rating of a bushing. More precisely, it com¬putes deviations of power factor and capacitance from a benchmark. It then determines the probability dis¬tribution that best fits the resulting dataset. Once the data is mathemat¬ically characterized, the mean and standard deviations are computed. In the end, the bushing in question is assessed based on how it statistical¬ly compares to the rest
