Electric field probes may always distort when measuring the electric field intensity distribution on the insulator surface. To measure the field intensity distribution on insulator surface more accurately

based on the electroluminescence effect of ZnS:Cu

a novel non-contact test method was proposed. In this method

an epoxy resin coating mixed with ZnS:Cu electroluminescent powder is sprayed on the surface of the insulator. Its luminescence under different high electric field is photographed. The distribution of electric field intensity on the surface of the insulator is deduced by image processing. Firstly

the feasibility is verified on the disc insulator with a simple structure

and measurements with an average error of 3% are achieved over most areas of the disc insulator. Then

the method is extended to the basin-type insulator. Consistently the measured results are in good agreement with the simulation results. This method provides a new idea which the electroluminescence effect is utilized for measuring the surface electric field intensity distribution of insulators without distorting it.