Statistical analysis of flashover data using a generalised likelihood method

In order to ensure consistency in the treatment of flashover data, it is desirable that a standard method of analysis of test results be established. Previous workers have suggested that the maximum likelihood method would be appropriate for estimating the parameters of the breakdown probability distribution, such as V50 and ¿¿ in the normal distribution. The present paper shows how this method may be applied in practice and can be extended to determine the confidence region associated with sets of parameters, and the confidence interval on a single parameter. It is also shown how other parameters, such as the voltage level corresponding to a specified probability of breakdown, may be determined. An example is given of the application of the method to a typical data set for flashover in air together with a listing of a suitable computer program in Fortran 77. It is recommended that this method be considered for adoption as a standard procedure.