Conventional insulation testers are highly susceptible to
damage when testing insulation resistance while voltage
is present on the measured object (whether ACV or DCV).
To safely prevent damage, this new line of testers has the
unique ability to sense voltage on a measured object. If
any voltage is sensed, the tester will automatically switch
to voltage detection mode and display the voltage finding
on the LCD screen. This allows the user to prevent damage
caused by attempting to measure insulation resistance
while voltage is present.