UT500 series insulation testers are used to measure the insulation resistance of electrical? equipment and household appliances. This is done by measuring the insulation resistance between electrical circuits or between circuits and ground. UT500 series can measure insulation resistance, AC Voltage, low resistance, PI (Polarization Index) and DAR (Dielectric Absorption). These are dieal? tools for ensuring transformers, genera-tors, high voltage motors, power capacitors, power cbles, arresters and other electrical equipment that can oprate in a safe and accurate manner.