PROMET - High-Precision Ohm Meters

The PROMET 600 ohm meter is based on state-of-the-art power electronics and generates a freely adjustable test current of up to 600 A which is fully independent of the supply voltage. The resistance is determined by measuring the voltage drop using four-wire measuring technology. Both the test current and the voltage drop are measured via high-accuracy measurement inputs. Because the device can output currents for an unlimited period of time, it can also be used as a current source

PROMET ohm meters are operated and controlled using four function keys and a jog dial. Measurements can also be controlled with an optional remote control unit. The freely adjustable current is switched on and off via automatic ramps. This prevents the occurrence of transient signals which could cause indirect releases to trip falsely, for example.The resistance value determined by a PROMET ohm meter is displayed on the LCD screen and can be saved with a time and date stamp in the internal memory.


PROMET ohm meters are ideal for high-precision resistance measurements in the μΩ range. Typical applications include measuring the contact resistance of circuit breakers or disconnectors, testing bus bars and checking welded joints and earth connections.

Interface to ACTAS

PROMET ohm meters feature an interface for connection to the circuit breaker test systems of the ACTAS product range for the specific purpose of measuring contact resistance. Using the ACTAS testing software it is then easy to integrate static resistance measurement in circuit breaker tests. Resistance values determined in this way can also be included as results in test reports.

Remote control unit

Once the test current has been set, up to 250 measurements can be carried out with the remote control unit which has its own measurement inputs. Visual and acoustic signals indicate the status of the measurement currently in progress.

PROMET software

A PC or laptop computer can also be connected directly to the ohm meters of the PROMET range. Downloading and managing the data saved in the device is made easy by the user-friendly software. The measurement results are displayed in a clearly structured form and can also be exported to an Excel spreadsheet or test report.

Contact resistances

Contact resistance measurement provides information on the condition of the contact system of switchgear devices in the heavy electrical engineering sector. The contact resistance has a direct influence on the power loss which arises in connection with switchgear devices carrying currents. Measuring the contact resistance can also point to the existence of eroded contacts or loose connections in the contact system. Regular checks make it possible to identify maintenance requirements at an early stage keeping unplanned equipment down times to a minimum.