The Megohmmeter 3921 has been especially designed to take into consideration cable length during the test session. This provides a direct reading in Mohm x km on a large display mounted on a mobile support.
In the 1000m position, the 3921 unit is used as a conventional Megohmmeter. The output voltage is fixed at 500V DC.
The stability of the displayed value is ensured thanks to the triaxial cable which acts as a guard ring up to the connection of the cable to be tested. At the end of the test session, the cable is automatically discharged.