Dielectric strength describes the resistance of a material to internal breakdown or its ability to provide electrical insulation. To be more precise, it describes the field strength that may at most exist for there to be no voltage breakdown by means of a spark or arc. However, this is only a guideline, since the dielectric strength of a material depends on many factors, such as the material itself and its purity, the type of electrical current, the temperature, the period in which the voltage acts on the component and the size and shape of the electrodes used. The temperature of the workpiece plays a crucial role. Long dwell times and high field strengths causes the temperature inside an insulator to rise. As the temperature rises, however, the conductivity of the insulator also increases, which in turn leads to a decrease in the dielectric strength.