DV Power RMO300 High DC Current Resistance MicroOhmMeter


Call for Price

RMO300 is a micro-ohmmeter based on state of the art technology, using the most advanced switch mode technique available today. RMO300 generates true DC current with automatically regulated test ramps. During the test RMO300 ramps with increasing current before measuring and decreasing current after the measurement. This eliminates magnetic transients.

After the test current has been set, the automatic test procedure is started by pressing the Ω-button. The test result is displayed as R=U/I.  There is enough memory in RMO300 to store 100 measurements. All measurements are time and date stamped. They can also be exported to a PC with RMO-Win software. The software connects a PC to RMO300 with a RS232 cable. The RMO-Win makes it easy to report and analyse all results.

RMO300 has very high ability to cancel electrostatic and electromagnetic interference in high HV electric fields. It is achieved by very efficient filtration. The filtration is made utilizing appropriate hardware and software.

Output Ratings

The full output is available from the RMO300 for a 230V+10%-15% supply. A reduced output is available from lower supply voltages.

Supply Voltage            Output Current            Full Load Voltage
230 V AC                        300 A DC                        5,8 V DC
                                        200 A DC                        6,0 V DC
115 V AC                        300 A DC                        5,0 V DC
                                        200 A DC                        6,0 V DC

Output current is filtered and has a ripple of less then 1%.


RMO300 can generate DC current continuously using the CONT menu. In this menu the current can be chosen the same way like in the SINGLE menu, but the duration of the test can be preset. The test is started pressing the Ω-button. During the test, a new result is shown on the display and stored into the PC (RMOWin) each second. Using RMOWin the result can be printed like an Excel table which later can be shown as a diagram and used for a report.

Typical application is measuring resistance of:
  • high, middle and low voltage circuit breakers
  • high, middle and low voltage disconnecting switches
  • high-current bus bar joints
  • cable splices
  • welding joints
The Good:

The Bad:

The Bottom Line:

Full Review

  • Lightweight - only 7 kg           
  • Powerful - 5A-300A DC         
  • Measuring range 0 - 999 mΩ         
  • Resolution to 0,1 Ω         
  • SINGLE/CONT Mode         
  • Mechanical protection IP54
1 Mains Power Supply
Connection     according to IEC/EN60320-1; UL498, CSA 22.2
Mains supply     from 90 V to 264 V AC; 50-60 Hz

2 Output data

Test current     5 A - 300 A DC
Measuring range     Resolution
   0,1Ω - 999,9Ω     0,1 Ω
   1,000mΩ - 9,999mΩ     1 Ω
   10,00mΩ - 99,99mΩ     10 Ω
   100,0mΩ - 999,9mΩ     0,1 mΩ
Typical accuracy     (0,2% rdg + 0,2% FS)

3 Environment conditions

Operating temperature     -10C - +50C / 14F - +122F
Storage and transportation     -25C - +70C / -13F - +158F
Humidity     5% - 95% relative humidity, non condensing

4 Dimensions and Weight

Dimensions     198 mm x 255 mm x 380 mm (7,8 in x 10 in x 15 in) (W x H x D) without handle
Weight     7,5 kg/16,5 lb

5 Mechanical protection     IP54

6 Warranty     two years

7 Safety Standards

European standards     EN 61010-1
International standards     IEC 61010-1
UL 3111-1
CAN/CSA-C22.2 No 1010.1-92

8 Electromagnetic Compatibility (EMC)

CE conformity     EMC standard 89/336/EEC
Emission     EN 50081-2, EN 61000-3-2/3
Interference Immunity     EN 50082-2
No user reviews available.

Have a Question?

Do you have a question for us? Can't find what you're looking for? We're glad to help you. Fill out the simple form below and we'll get back to you as soon as possible.

In order to prevent spam through the form, please enter the passcode word displayed below. If you cannot read the word clearly, you can change the passcode image.

Enter Passcode: