The UT513 (or UT513A) is a professional high-voltage digital insulation resistance tester or megohmmeter from the UNI-T brand. Use it to ensure the safety of insulation in power plants, transformers, electric motors, and high-voltage cables. Test Voltage: Five adjustable voltage ranges—250V, 500V, 1000V, 2500V, and 5000V. Insulation Resistance Range: Measure insulation resistance from 0.5 MΩ up to 1000 GΩ or 1 TΩ. Short-Circuit Current: >3 mA. Diagnostic Test: Automatically calculate Polarization Index (PI) and Dielectric Absorption Ratio (DAR). Display: Large LCD with backlight.