Development of a Reliable Methodology for the Measurement of the Electrical Properties of Insulating Oxide Coatings

Insufficiently defined measurement conditions are a major cause of the large scatter of values of electrical insulation properties of oxide coatings. In this contribution, methodological work on the development of an automated setup for measurements under defined conditions is presented. The strong influence of humidity requires conditioning and measurement in an isolated chamber. A defined contact pressure for a conductive rubber allows simple and reliable contacting. Furthermore, values for the electrical resistivity and the dielectric strength of APS- and HVOF-sprayed insulating coatings as a function of the applied voltage are reported.