Fieldpiece Digital Megohm Meter SMG5

The maximum current output is <1mA. It can be used to determine the condition of insulation from winding to the ground in a motor, compressor, or transformer. Includes a case, alligator clip lead tip, and leads with removable tips.

To test resistance, a Digital Multi Meter supplies low voltage (<1V) to the test points and is capable of delivering only a few milliamps. It's not a high enough voltage to detect high resistance problems that might indicate moisture and other contaminants and it's not enough current to measure lower values of resistance. This is why a megger is a must-have tool for the HVAC tech.