An ohmmeter is effectively a low-voltage DC source, with measurement of current when the low-voltage source is applied to an electrical assembly—displaying resistance according to Ohm’s Law for the actual voltage and current.
Meg-o-meters are also resistance-measuring devices, but work at a much higher voltage, [250-5,000 VDC] to better stress insulation in an electrical assembly.
Meg-o-meter use often depends on policy of your employer or client. With experience, they can be indispensable for insulation testing.
