The ohmmeter RMO30T is designed for resistance measurement of inductive test objects. RMO30T generates true, filtered DC current. Both injection of current and discharge of energy from the inductance is automatically regulated. RMO25W injects current with a voltage as high as 50V at a start. This ensures that the duration of test is as short as possible, and that the desired test current is reached as soon as possible. The test result is displayed as R=U/I. Two independent channels enable testing of two series windings, or primary and secondary windings. There is enough memory within RMO30T instrument to store 100 measurements. All measurements are time and date stamped. Using RMOWin-W the result can be printed like an Excel table which later can be shown as a diagram and used for a report. The RMO25W has very high ability to cancel electrostatic and electromagnetic interference in high HV electric fields. It is achieved by very efficient filtration. The filtration is made utilizing appropriate hardware and software.