A statistical method for predicting dielectric breakdown

High voltage testing of insulated wire and cable for extended periods of time is injurious even though the insulation does not fail. This deterioration of the product in testing can be avoided if testing of valid samples to destruction is acceptable. Also by testing samples to destruction, an appraisal of the quality of the material can be made which is much more discriminating than the common procedure of carrying out tests on all of the material at a level below the failure voltage. A proposed procedure and statistical treatment of data is given for destructive tests on small samples of insulated wire.