OPTIMUM DESIGN OF LIFE TESTS FOR INSULATING MATERIALS, SYSTEMS AND COMPONENTS

The accuracy of the results of life tests performed on insulating materials, systems or components may be influenced significantly by the organization of the tests. The choice of the number of stress levels, values of applied stresses, size of samples subjected to each life test, as well as the type of life test procedure, all affect the accuracy of the estimates of the life-model parameters and the failure-time percentiles. In this paper a procedure is suggested which allows the life test to be performed economically for any selected error level, using the inverse-power model and the Weibull distribution function. A worked example is included, which permits an evaluation of the effectiveness of the proposed procedure.