Dielectric testing is the technical name for applying a high voltage to an object, usually to test for the insulating qualities. If the applied voltage doesn’t cause any arcing or excessive current flow, then the object is considered a good insulator. An example of an object that needs dielectric testing is rubber gloves used to protect someone when they are working on a live power line. In this case, there are different “Classes” of gloves that can be used at different working voltages. Each class is tested at a voltage that is higher than the working voltage to ensure that there is a safety margin for the user.
Items that get dielectric tested include gloves, sleeves (used over and above the gloves to protect a user’s arms), hard hats, rubber boots, safety blankets (spread over a live connection to protect from accidentally contacting the live line), boots (or covers) to cover a connection between 2 live power lines, and hot sticks.
Most items that are calibrated at Gulf Coast Calibration have standards (usually ASTM or ASME standards) that control the voltages and setups for doing this testing. We follow these standards when we do our testing. This is important as most of these products are life-safety devices: if not properly tested and used the user can be significantly (or even fatally) harmed.