The engineering approach to selection and application of insulating materials

Twenty years ago a paper entitled “Functional Evaluation of Insulating Materials”¹ proposed a philosophy that only evaluation techniques based upon functional needs are truly significant in the selection and application of insulating materials. Since that time, the idea has gained momentum with many contributions from many individuals. Last year at the ei* conference in Chicago, the complexity of the evaluation problem was emphasized by a paper² which described how service variables so greatly affect just three dielectric properties - voltage breakdown, restivity and dielectric loss.