Amprobe AMB-50 [3730288] Industrial High-Voltage Insulation Tester. The Amprobe AMB-50 High-Voltage Insulation Tester has the necessary features for professional insulation diagnostics. The AMB50 features calculation of PI, and DAR parameters. The pass/fail comparison function helps to improve testing productivity. Readings are clearly displayed on a large backlit LCD display. Windows compatible PC Software and USB communications port serve for connecting the instrument to the PC and management of the recorded test data.