Dielectric Constant

The dielectric constant is an electrical parameter measured to understand the insulating properties of materials. The dielectric constant of any material or insulator is the ratio of capacitance induced between two metallic plates with the insulator between the plates to the capacitance with air or vacuum. The dielectric constant is a crucial property in the specification of any capacitor. It is also one of the metrics of measurement for characterizing polymeric materials, ceramics, solvents, biomaterials in aqueous media, etc.

Dissipation factor and loss tangent, which are used in lower and higher frequency applications, respectively, are other parameters measured along with dielectric constant to evaluate an insulator’s efficiency. Measurements are typically performed at room temperature to 500C, and 10Hz to 10Mhz frequencies depending on the testing standard followed (ASTM) and the application for which the material is tested.