Dielectric material is a material that does not conduct electricity. Examples include plastics and other resins, rubber, ceramics, glass, pure water, insulating oil (transformer oil), and fluorine-based inert liquids. To evaluate insulation performance, it is necessary to apply a high voltage and measure the amount of electricity flowing to obtain the insulation resistance.

Matsusada Precision manufactures and sells high-voltage power supplies that are indispensable for evaluating insulation performance. Care must be taken when handling high voltage.