| The breakdown phenomenon in insulators occurs due to conduction of electrical current, through the insulating medium, either permanently or temporarily. Dielectric strength is the voltage gradient at which dielectric failure of an insulating material occurs under specific conditions of test.;An environmental chamber has been designed and manufactured according to our specifications. The measurements were carried out on two different thickness (75 mum and 125 mum) of NOMEXRTM (an aramid paper produced by E.I. Dupont Inc.) with DC voltages. For the sake of comparison AC voltages were also used on same samples over the entire range of temperature. The analysis yielded results with regard to (a) Dependence of dielectric strength on thickness; (b) Comparison between the AC and DC results; (c) Comparison between Weibull and normal distributions regarding the changes of shape parameter beta in Weibull distribution; (d) The optimum number of measurement points. (Abstract shortened by UMI.)... |
