Theory of Equalization of Thermal Ageing Processes of Electrical Insulating Materialsin Thermal Endurance Tests I: Review of Theoretical Basis of Test Methods and Chemical and Physical Aspects of Ageing

In this series of three papers, the theory of equalized ageing processes is presented, to provide a wider theoretical basis than the conventional methods for accelerated thermal endurance tests of electrical insulating materials. In Paper I, the chemical and physical aspects of ageing are reviewed. The present methods for thermal endurance testing are critically assessed. Basic principles of the equalized ageing processes are presented and a comparison is made of its theory with that of the conventional methods. Papers II and III, the detailed theory of equalized ageing processes is presented with practical application to ageing tests of materials. Comparative test results with critical evaluation of the equality of the ageing processes in the accelerated physical ageing tests completes this series of papers.