Dielectric strength is the resistivity of insulators to electrical sparkover. The value is highly dependent on the material thickness, and this must consequently also be specified.
- Type of electrodes and applied voltage
- Thickness, homogeneity and moisture content of the specimen
- Type of environment (medium, temperature, pressure, etc.)
In the case of plastics filled with carbon black, particular care over the dielectric strength must be taken for thin-walled components, as carbon black can substantially reduce the dielectric strength of a plastic.