High-precision Portable Resistance Meter Measures
from µΩ to MΩ
Hioki DC resistance meters measure a broad range of resistance values at
a high level of precision. The RM3548 is a high-precision, portable
resistance meter capable of measuring resistance levels from microohms
to megaohms, and is ideal for the testing and maintenance of large
equipment, for example, measuring the winding and weld resistances in
large motors and stators for hybrid and electric vehicles.

Model No. (Order Code)


Key Features

• 0.02 % basic accuracy, 1 μΩ max. resolution, 300 mA max. measurable current
• Measure from 0.000 mΩ (testing current 300 mA) to 3.5 MΩ
• Probe for guard jack use and increased measurement current yield an instrument that’s more resistant to noise
• Optional LED COMPARATOR ATTACHMENT and high-volume judgment tones combine to ensure PASS/FAIL judgments are communicated reliably in the noisy environment of the production floor
• EXT I/O interface with NPN/PNP support can accommodate a variety of automated production lines (-01 model)

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.

Basic specifications (Accuracy guaranteed for 1 year, Post-adjustment accuracy guaranteed for 1 year)

Resistance range3 mΩ (3.5000 mΩ display Max., 0.1 µΩ resolution) to 3 MΩ range (3.5000 MΩ display Max., 100 Ω resolution), 10 steps
Measurement accuracy: ±0.020 % rdg. ±0.007 % f.s.
Testing current[at 3 mΩ range] 1 A DC to [at 3 MΩ range] 500 nA DC
Open-terminal voltage5.5 V DC max.
Temperature measurement-10.0 to 99.9°C, accuracy: ±0.50°C (Temperature Sensor Z2002 and RM3548 combined accuracy)
Measurement speedFixed
Display refresh rateWithout OVC: approx. 100ms, With OVC: approx. 230ms
FunctionsTemperature correction, temperature conversion, offset voltage compensation (OVC), comparator (ABS/REF%), length conversion, judgment sound setting, auto hold, auto power save (APS),
Averaging, panel store/panel load, USB communication interface (RM3548 internal memory is recognized as a mass storage device when connected to a PC)
Memory storageNumber of recordable data points: (manual/auto) Up to 1,000, (interval) Up to 6,000; Interval: 0.2 to 10.0s (0.2s steps); Acquisition of data from memory: display, USB mass storage (CSV, TXT files)
Power supplyLR6 (AA) Alkaline batteries ×8, Continuous use: 10 hours (Under our company’s conditions), Rated power consumption: 5 VA max.
Dimensions and mass192 mm (7.56 in) W × 121 mm (4.76 in) H × 55 mm (2.17 in) D, 770 g (27.2 oz)
AccessoriesClip type lead L2107 ×1, Temperature sensor Z2002 ×1, LR6 Alkaline battery ×8, Instruction manual ×1, USB Cable(A-to-mini B type) ×1, Strap ×1, Spare fuse ×1
Catalog: RESISTANCE METER RM3544, RM3548Download PDF  [4MB]English

For more information, click here