... by Polarization Index (PI), Dielectric Absorption Ratio (DAR), step voltage measures, temperature compensation, current leakage,log test (up ... to 8 hours), average value, etc..Step voltage test: to check the insulation resistance changes ... 30 seconds to 30 minutes.Large and clear LCD with multiple data and bar graph display and ... (red, black, blue),each for one. 5KV Digital Insulation Tester