Capacitance Leakage Current Measurement Techniques Using the B2985A/87A
Notas de Aplicação
Introduction
Capacitor leakage current (IL ) is an important device parameter that can be alternatively expressed in terms of insulation resistance (Rp). These two parameters are related by the equation IL = Vw / Rp, where Vw is the working voltage specification of the capacitor.
When measuring capacitor leakage current, the capacitor must be fully charged and stable at its test voltage. In addition, any error currents caused by dielectric absorption or dielectric material soakage need to be removed. To eliminate these errors, all capacitor leakage current and insulation resistance measurements require some wait time after applying a test voltage. The required wait time depends on a given capacitor’s dielectric absorption characteristics.
There are a number of best practices you should follow when measuring the leakage current of a capacitor to maintain safety and to protect the measurement instruments from damage caused by electric charge stored in the capacitor.