The MPK-105x high-current micro-ohmmeter is a portable, microprocessor-controlled instrument. Has optimized filters and protections for measurements in electrical substations. Can be used to accurately measure very low contact resistances of high voltage circuitbreakers and switches, busbars, etc., with test currents up to 100A. It employs the 4 terminals-method (U/I measuring principle) to avoid errors caused by test leads and their contact resistances.