Product Video

Portable resistance tester that’s ideal for low-resistance measurement and testing of large transformers and motors

This resistance tester features a portable design that’s easy to use when performing maintenance work in the field. You can wear the instrument over your neck with the included strap, leaving both hands free to hold the clip-type leads while making measurements. The instrument can be powered by eight AA alkaline batteries for about 10 hours of measurement. (Operating time varies with measurement conditions.)

Reduce the effects of thermoelectromotive force with the offset voltage correction

Thermoelectromotive force refers to the potential difference that occurs at junctions between different metals (see figure). Specifically, the phenomenon occurs where measurement probes and measurement targets come into contact, and at connections between measuring instruments and measurement leads. The magnitude of this thermoelectromotive force varies with the temperature of the measurement environment, increasing as the temperature difference grows. The RM3548 includes an offset voltage correction function that applies the measurement current in both the positive and negative directions and then uses the resulting detected voltages to eliminate the effects of thermoelectromotive force.

Correct resistance values, which vary with temperature, to a reference temperature with the temperature correction function

Temperature correction functions can convert readings to resistance values at a user-specified reference temperature and display the results, even for materials such as copper wire whose resistance varies with temperature. The RM3548’s temperature correction function converts the measured resistance value Rt at the current temperature t to the resistance value Rt0 at the reference temperature t0, as shown in the figure. The Temperature Sensor Z2002 (which comes with the RM3548) is used to perform temperature correction.