The digital insulation resistance meter I’m using displayed “OF.”
QWhat does this mean?
A“OF” means “overflow,” and it is equivalent to an infinite result on an analog insulation resistance meter. Digital Megaohm HiTesters display “OF” when the measured value is greater than or equal to the resistance display range. As a rule, this indicates extremely good insulation, although you should short the test lead tips on a regular basis to verify that there are no broken connections causing this result.