The megaohm measures high electrical resistance, equivalent to one million ohms. It is primarily used to specify the insulation resistance of cables, motor windings, and printed circuit boards. High values indicate good isolation and prevent dangerous leakage currents. Technicians verify these values using a specialized high-voltage tester called a megohmmeter.
Heard on the job
The insulation test on that stator winding showed over 500 megaohms, so it's safe to energize.
Insider tip
In the field, this is almost universally pronounced and spelled as megohm rather than megaohm, and engineers often shorten it to just megs when calling out readings.
Also heard as
- megohm