Ensure proper insulation and ground wire continuity in new or repaired drills, circular saws, grinders, and other hand tools. Also known as a hi-pot tester, it checks the quality of a tool's insulation by applying voltage and measuring how much current leaks from the tool.

The analog display works well for measuring rapidly changing values because you can see the magnitude and rate of change more easily than on a digital display.

The calibration certificate with test data is traceable to NIST and includes the test measurements that confirm the tester's accuracy.