MRU-200
Index: WMGBMRU200
Earth Resistance and Resistivity Meter
Description
Technical Specification
Files
  • Description

    MRU-200 is the only meter in the market which uses all measurement methods.

    Possible measurements:
    • earth resistance measurment with 2-pole, 3-pole,4-pole method,
    • impulse earth impedance measurement, three kinds of measuring impulse 4/10μs, 8/20μs, 10/350μs,
    • earth resistance measurement without disconnecting measured earths (using clamp),
    • two clamps earth resistance measurement without auxiliary test probs,
    • earth resistivity measurement,
    • continuity measurement,
    • leakage current measurement.

  • Technical Specification

    It allows to take the measurements of:

    • earth resistance using auxiliary electrodes,
    • earth resistance using auxiliary electrodes and clamp (for measurements of multiple earthing)
    • earth resistance using double clamps for measuring multiple earthing without underground connections,
    • impulse earth impedance (without disconnecting measured earthing),
    • ground resistivity (Wenner method),
    • current using the clamp (e.g. leakage) and flexible clamp (Rogowsky coil),
    • 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 16 2/3 Hz, 50 Hz, 60 Hz and 400 Hz (with automatic selection of proper frequency of measuring signal or with manual selection),
    • selection of maximum measuring voltage (25 V and 50 V)
    • introducing the distance between the electrodes for the resistivity in metres (m) and feet (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 and Bluetooth*,
    • indication of battery state.

    *Bluetooth communication from serial number E30001

    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: IP54

    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
    • number of measurements carried out of set of batteries: > 1200
    • warranty: 24 months

    Measurement of interference voltage

    Range Resolution Accuracy
    0...100 V 1 V ±(2% m.v. + 3 digits)

    Measurement of interference frequency

    Range Resolution Accuracy
    15...450 Hz 1 Hz ±(1% m.v. + 2 digits)

    Measurement of earthing resistance (method 3- and 4-pole)
    measurement range to IEC61557 - 5: 0,100 Ω...19,9 kΩ

    Range Resolution Accuracy
    0,000...3,999 Ω 0,001 Ω ±(2% m.v. + 4 digits)
    4,00...39,99 Ω 0,01 Ω ±(2% m.v. + 2 digits)
    40,0...399,9 Ω 0,1 Ω
    400...3999 Ω 0,001 kΩ
    4,00k...19,99 kΩ 0,01 kΩ ±(5% m.v. + 2 digits)


    Measurement of continuity of equipotential bondings and protective conductors (Rcont)
    measurement range to IEC61557 - 4: 0,045 Ω...19,99 kΩ

    Range Resolution Accuracy
    0,000...3,999 Ω 0,001 Ω ±(2% m.v. + 4 digits)
    4,00...39,99 Ω 0,01 Ω ±(2% m.v. + 2 digits)
    40,0...399,9 Ω

    0,1 Ω

    400...3999 Ω 0,001 kΩ
    4,00k...19,99 kΩ 0,01 kΩ ±(5% m.v. + 2 digits)

    Measurement of resistance of auxiliary electrodes RH and RS

    Range Range Accuracy
    0...999 Ω 1 Ω
    ±(5% (RS+RE+RH) + 8 digits)
    1,00k...9,99 kΩ 0,01 kΩ
    10,0k...19,9 kΩ 0,1 kΩ

     

    Measurement of multiple earthing resistance with using the clamp and auxiliary
    electrodes (3p + clamp)

    Range Resolution Accuracy
    0,000...3,999 Ω* 0,01 Ω ±(8% m.v. + 4 digits)
    10,0...99,9 Ω 0,01 Ω ±(8% m.v. + 3 digits)
    100...999 Ω 0,1 Ω
    1,00k...1,99 kΩ 1 Ω

    * - in range 0,000…0,045 Ω the accuracy is not specified.

    Measurement of multiple earthing resistance with using double clamps

    Range Resolution Accuracy
    0,00...19,99 Ω 0,1 Ω ±(10% m.v. + 3 digits)
    20,0...149,9 Ω 0,1 Ω ±(20% m.v. + 3 digits)

    Measurement of ground resistivity Measurement method: Wennera, ρ=2πLRE

    Range Resolution Accuracy
    0,0...199,9 Ωm 0,1 Ωm depending on measurement
    accuracy RE with 4p method,
    but not less than ±1 digit
    200...1999 Ωm 1 Ωm
    2,00k...19,99 kΩm 0,01 kΩm
    20,0k...99,9 kΩm 0,1 kΩm
    100k...999 kΩm 1 kΩm

    L – distance between probes: 1...50 m
     

    Measurement of AC current (leakage)

    Range Resolution Accuracy
    0,1...99,9 mA 1 0,1 mA
    ±(8% m.v. + 5 digits)
    100...999 mA 1 1 mA ±(8% m.v. + 3 digits)
    1,00...4,99 A 1,2 0,01 A ±(5% m.v. + 5 digits)1
    unspecified 2
    5,00...9,99 A 1,2 0,01 A ±(5% m.v. + 5 digits)
    10,0...99,9 A 1,2 0,1 A
    100...300 A 1,2 1 A

    1 – receiving clamp (diameter 52 mm) – C-3
    2 – flexible clamp (Rogowsky coil) with diameter 400 mm – F-1


    Measurement of dynamic earthing resistance (RD) with impulse wave method (4p )

    Range Resolution Accuracy
    0,0...99,9 Ω 0,1 Ω
    ±(2,5% m.v. + 3 digits)
    100...199 Ω 1 Ω

    choice impulse edges: 4/10μs, 8/20μs, 10/350μs

    „m.v.”- measured value

  • Files
    • Firmware MRU-200-GPS

      Changes in 2.24 version:

      • Improved user interface;
      • Added user interface languages: French, Spanish, Italian, Norwegian;
      • Improved multiple earthing resistance measurement using clamp.

      Changes in 2.22 version:

      • Improved user interface errors.
      • Improved measurement procedure using an adapter ERP-1.
      • Improved language errors.

      Changes in 2.21 version:
      Update recommended for users of ERP-1 adapter.

      • Update measurement mode 3P + clamp and current measurement.
      • Adding the possibility of using an adapter measuring ERP-1.
      • Improved stability measuring leakage currents.

      Changes in 2.18 version:

      • Improvement of current measurement function.
      • Improvement of user interface.
      • Improvement of function for indicating measurement place GPS location.

      Changes in v 2.17 version:

      • Improved function of indicating the geographical coordinates

      For PC proper communication with meter the latest PC software is required.

    • Changelog:

      • English (US) language has been added to the user interface.
      • Bluetooth wireless communication has been added.
      • The user interface has been improved.

      This firmware is dedicated for MRU-200 meters from the serial number E30001. Before updating, it is recommended to save data from the meter to your computer. This update may delete the saved data in the device memory and restore the factory settings.

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