Breakdown voltage

All insulators will conduct heat and electricity if subjected to extremely high voltages. At very high voltages, the material's composition will lose its insulating abilities; the voltage at which this change occurs is known as the breakdown voltage. Breakdown voltage, sometimes also called dielectric strength or striking voltage, is the quantity of electrical force required to transform the electrical properties of an object. It is defined as the maximum voltage required to produce a dielectric breakdown through the material and is expressed as Volts per unit thickness. A higher breakdown voltage represents a better quality of insulator.

As an example, consider air, normally an excellent insulator. Lightning passes through air because its very high voltage overwhelms, or breaks down, air's ability to insulate. Different insulators have different breakdown voltages, and are used for different purposes. For example, plastic may be used as an insulator in households where the voltage is not very high, but it cannot be used for industrial purposes. Ceramic is one of the best insulators in such applications, as it has a very high breakdown voltage.

breakdown voltage of a pressure sensor is the highest AC or DC voltage, which can be applied across the insulation portion of a sensor without arcing or conduction above a specific current value.