Portable micro ohmmeter 1 A


NDB Technologie’s portable micro ohmmeter 1A is a device used to measure the resistance of electrical connections ranging from 1 μOhms to 200 Ohms.

The portable 1 A micro ohmmeter uses the principle of resistance measurement at four points which consists in injecting a current using two cables that are connected to each end of the part to be tested and to read the voltage on each side with two other cables. This eliminates any uncertainty related to contact resistances.

The advantage of the portable 1 A micro ohmmeter, compared to other devices on the market, comes from the injection of a current pulse of just a few hundred milliseconds to generate the current required for the measurement. Unlike a direct current technique of 10 or 100 Amps, the technique used by the 1 amp DRM-1A micro ohmmeter does not produce any local overheating which could vary the resistance as a function of time. In addition, it makes it possible to reduce the size of the power source while ensuring high operating autonomy.

The precision micro ohmmeter uses three intensities of current: 1 A for very low resistances, 100 mA for larger resistances and 5 mA for larger resistances. A special function, called winding mode for very small motors, allows this injection current to saturate the winding by extending the pulse duration to 1 second. This has the effect of eliminating the induction effect, which is detrimental to an accurate measurement.

The resolution of the device is 1 µOhms. It is equipped with a DSP processor which performs a selection of fully automatic measurement scales, that eliminate offsets and stray voltages. With its unique filtering system, the 1 amp DRM-1A micro ohmmeter can be used despite the presence of strong magnetic fields.

The portable 1 A micro ohmmeter is much lighter and easier to handle than other devices in its class, it is impact resistant and is particularly suitable for construction site applications. Its liquid crystal display with illumination allows the usage in dark places. A standard set of cables and alligator clips are supplied with the device, but other more specific probes are available.

The batteries used in the portable 1 A micro ohmmeter are not rechargeable. Ni-MH type batteries can be installed, but the user needs to have an external charger.

Please refer to the dedicated page of our supplier NDB Technology Inc. for the entire range.

Portable micro ohmmeter 1 A, resolution 1 µOhms, compact, precise, high resolution NDB Technologie
Portable micro ohmmeter 1 A, reference DRM-1A, compact, precise, high resolution NDB Technology


DRM-1A User’s Manual



  • Portable micro ohmmeter 1 A
  • NDB Technology manufacturer, made in Canada
  • Resolution 1 µOhms.
  • Measuring range 1 µOhms to 200 Ohms.
  • Measurement error 0.1%.
  • Scale error +/- 2 counts (LSB).
  • Four point measurement method.
  • Three measuring currents 1 A, 100 mA and 5 mA.
  • 200 ms measurement pulse.
  • 12,000 measurements at 1A.
  • Automatic switch-off of the device after 2 minutes of inaction.
  • Automatic switch-off of the rear lighting after 30 seconds
  • Display of results in large print.
  • Standard set of connection cables fitted with alligator-type clips.
  • Specific probes on request.
  • Reference resistance 9.5 µOhms and 500 µOhms.
  • Padded nylon protective case.
  • Transport case.


Reference: portable micro ohmmeter 1 A (DRM-1A)

Measuring range 1 μOhms to 200 Ohms
Precision +/- (0.1% of reading + 2 μOhms)
Resolution 1 μOhms
Operating temperature - 20 °C to + 50 °C
Storage temperature - 40 °C to + 50 °C
Humidity 0 to 95% non-condensing
Submersible, water resistant
Micro ohmmeter autonomy > 12,000 measurements at 1 A (for resistance < 50 mOhms)
> 10,000 measurements for other currents
Battery Type 6 non-rechargeable 'AA' type batteries
Display Type Backlit LCD, size 60 x 41 mm
2 brightness levels (100%, 50%)

Dimension (mm) 203 / 114 / 51
Weight 0,86 Kg