The RMO-A is a portable micro-ohmmeter designed for contact resistance measurements of switchgear during the manufacturing, commissioning, and maintenance stages. This micro-ohmmeter is widely used by medium and high-voltage circuit breakers manufacturers. Other typical applications are the testing of disconnecting switches, high-current bus bar joints, cable splices, and different high-current links. It accurately measures not only in factory environments but also in high-induction fields and substations

The RMO-A series contains 6 models, rated from 100 A (RMO100A) to 600 A (RMO600A). The RMO500A (formerly CPM500) is our best-seller, with a 500 A ripple-free current, and weighs only 8 kg.

Although placed in a very portable and lightweight metal housing, RMO-A micro-ohmmeters have very high output power capabilities. They can generate 600 A test current continuously for up to 20 s. You can test with current up to 100 A without a rest time. High output voltage enables a wider measurement range at the highest test currents, as well as the use of thinner/longer test cables. For testing with 100 A, 20 m test leads can be provided with only 16 mm2 cross-sections.

RMO-A micro-ohmmeter generates a true DC ripple-free (less than 1 %) current with automatically regulated test ramps. During a test, the RMO-A ramps up with increasing current before measuring and decreasing current after the measurement. This significantly decreases magnetic transients and ensures great accuracy.

An additional option is a built-in High Precision module suitable for measurement of very low resistances, ranging from 1 to 30 µΩ, with 0,01 µΩ resolution.

These instruments can store up to 500 measurements in internal memory. A built-in thermal printer is available as an option.

Our free DV-Win software communicates with the RMO-A micro-ohmmeters via USB or RS232 interface. It allows you to run the test remotely from a PC, as well as to download test results, analyze them, and generate fully configurable test reports.