How does the DMEG3 work?
Insulation resistance testers apply a higher voltage and look for a very small current. The resistance they are able to read on much higher than read with a standard DMM. An example is the DMEG3 will display up to 2000M ohm, while a standard DMM will only display to 40M ohm. Also, DMM's test with voltage closer to 3V, and weak insulation is strong enough to completely block this voltage and will result in a reading of infinity. Insulation resistance testers allow testing at working voltage and above, and can determine the condition of insulation where multimeters can not.
Is DMEG3 digital and what is warranty length?
Yes it is digital and has a 3 year limited warranty.