The MRU-120HD device enables assistance in measuring earth resistance:

  • earth resistance measurment with 3-pole,4-pole method,
  • earth resistance measurement without disconnecting measured earths (using clamp),
  • two clamps earth resistance measurement without auxiliary test probes,
  • continuity of equipotential bondings and protecting conductors,
  • earth resistivity measurement.

The device is dedicated to earth measurements in the power industry – range of measurement in accordance with IEC 61557-5: 0,30 Ω... 19,9 kΩ.


The HD version of the MRU-120 meter means intended for difficult conditions, where there is no place for compromises. Is designed everywhere where instruments must be resistant to impact, splashing, mud and dust.

Sonel -MRU-120HD -Earth Resistance and Resistivity Meter, -10...+50°C Tester

$1,609.00Price
  • Please allow 4-5 weeks for this product to arrive. 

    This product comes with a 2 year manufacturer warranty.

  • Please see photos and description for full specifications.

    It allows to take the measurements of:

    • earth resistance using auxiliary electrodes,
    • earth resistance using auxiliary electrodes and clamp (for measurements of multiple earth)
    • earth resistance using double clamps for measuring multiple earthing without underground connections,
    • ground resistivity (Wenner method),
    • measurement of continuity of equipotential bondings and protective conductors (meeting the requirements of IEC 60364 - 6-61:2000 section 6.12.2) with auto-zero function – with current 200 mA.

    Additionally:

    • measurement of resistance of auxiliary electrodes RS and RH,
    • measurement of interference voltage,
    • measurement of interference frequency,
    • measurement in the presence of interference voltage in the power network with frequency 50 Hz, 60 Hz
    • selection of maximum measuring voltage (25 V and 50 V)
    • introducing the distance between the electrodes for the resistivity in metres (m) and foot (ft),
    • memory of 990 measurements (10 banks of 99 cells each),
    • calibration of clamp used,
    • real time clock (RTC),
    • data transmission to the computer USB,
    • indication of battery state.

    Electric security:

    • type of insulation: double, according to EN 61010 - 1 and IEC 61557
    • measurement category: CAT IV 300 V acc. to EN 61010 - 1
    • protection class acc. to EN 60529: case protection rating in acc. with  EN 60529: IP54 (IP67 - with lid closed)


    Rated operational conditions:

    • operation temperature: -10...+50°C
    • storage temperature: -20...+70°C
    • humidity: 20...80%

    Other technical data:

    • LCD display: graphic, backlighted
    • interface: USB, wireless
    • number of measurements carried out of set of batteries: > 500
    • warranty: 24 months