Eristysjännitearvona

Eristysjännitearvona, often translated as "dielectric strength" or "insulation strength" in English, refers to the maximum electric field strength that a material can withstand without breaking down. When an electric field is applied across an insulating material, the charge carriers within the material experience a force. If this force becomes too large, it can overcome the forces holding the material together, causing a sudden increase in conductivity. This phenomenon is known as dielectric breakdown.

The dielectric strength is typically measured in volts per unit of distance, commonly expressed as kilovolts per millimeter (kV/mm) or megavolts per meter (MV/m). A higher dielectric strength value indicates a better insulating capability for a material. This property is crucial in many electrical and electronic applications, such as the insulation used in power cables, transformers, capacitors, and electronic components.

Different materials have vastly different dielectric strengths. For example, air has a relatively low dielectric strength compared to materials like porcelain, glass, or certain polymers. The dielectric strength of a material can be influenced by factors such as temperature, humidity, the presence of impurities, and the duration of voltage application. Understanding and utilizing the dielectric strength of materials is essential for ensuring the safe and reliable operation of electrical systems.