MRU-30     

Catalog index: WMGBMRU30

Earth Resistance and Resistivity Meter

 

   

The Sonel MRU-30 uses most known methods of earth resistance measurements.

Tests can be performed using the 3-pole, 4-pole, 3-pole with auxiliary clamp and also, additionally, the MRU-30 employs the two clamp method of measurement, without the use of auxiliary test rods which can’t be used in some situations.

Complementary features of the MRU-30 are measurements of soil resistivity, continuity measurement of protective and equipotential

conductors and, using clamps, leakage currents and interference voltages.

  • Robust and weatherproof (IP65) – no ingress of dust, water protected by a nozzle against enclosure from any direction.
  • Ergonomic casing – small and handy casing to make the measurements more convenient than before.
  • Built-in rechargeable battery – saving time to replace flat batteries; can be recharged from Power Bank and Cigarette Lighter Socket!
  • Clear on-screen notes – displayed on screen before and after the measurement to alert user of possible dangers and irregularities.
  • Many measurement methods available in a small, portable casing.

It allows to take the measurements of:

  • earthing resistance using auxiliary electrodes,
  • earthing resistance using auxiliary electrodes and clamp (for measurements of multiple earthing),
  • earthing resistance using double clamps (for measurement of earthing when it is impossible to use auxiliary electrodes),
  • ground resistivity (Wenner method),
  • continuity of equipotential bondings and protective
  • conductors (meeting the requirements IEC 60364) with auto-zero function – with current 200mA.

Additionally:

  • measurement of resistance of auxiliary electrodes RS and RH,
  • measurement of interference voltage,
  • measurement in the presence of interference voltage in the power network
  • with frequency 50Hz, 60Hz,
  • selection of maximum measuring voltage (25V and 50V),
  • 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,
  • data transmission to the computer (USB),
  • indication of battery state.

Measurement of interference voltage UN (RMS)

Range Resolution Accuracy
0…100 V 1 V ±(10% m.v. + 1 digit)

Measurement of continuity of equipotential bondings and protective conductors (Rcont)
measurement range to IEC 61557-4:2007: 0,13 Ω…1999 Ω

Range Resolution Accuracy
0,00…9,99 Ω 0,01 Ω ±(2% m.v. + 3 digits)
10,0…99,9 Ω 0,1 Ω
100…1999 Ω 1 Ω

• measurement current: under short circuit >200mA
• frequency of measurement current: 125 Hz (for networks 50 Hz) and 150 Hz (for networks 60 Hz)

Measurement of earthing resistance (method 3- and 4-pole)
measurement range to IEC 61557-5:2007: 0,53 Ω…9999 Ω (dla 50 V)

Range Resolution Accuracy
0,00…19,99 Ω 0,01 Ω ±(3% m.v. + 3 digits)
20,0…199,9 Ω 0,1 Ω
200,0…1999 Ω 1 Ω ±5% m.v.
2000…9999 Ω 1 Ω ±8% m.v.

• measurement current: under short circuit >20 mA,
• voltage on open terminals: selectable 25 V AC or 50 V AC,
• frequency of measurement current: 125 Hz (for networks 50 Hz) or 150 Hz (for 60 Hz).

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

Range Resolution Accuracy
0,00…19,99 Ω 0,01 Ω ±(3% m.v. + 3 digits)
20,0…199,9 Ω 0,1 Ω
200…1999 Ω 1 Ω ±5% m.v.
2000…9999 Ω 1 Ω ±8% m.v.

• voltage on open terminals: selectable 25 V AC or 50 V AC,
• measurement current: under short circuit >20 mA,
• frequency of measurement current: 125 Hz (for networks 50 Hz) and 150 Hz (for networks 60 Hz)
Measurement of resistance of auxiliary electrodes RH i RS

Range Resolution Accuracy
0…999 Ω 1 Ω ±(5% m.v.+ 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 double clamps

Range Resolution Accuracy
0,00…19,99 Ω 0,01 Ω ±(10% m.v. + 8 digits)
20,0…99,9 Ω 0,1 Ω ±(20% m.v. + 3 digits)

• frequency of measurement current: 125 Hz (for networks 50 Hz) and 150 Hz
(for networks 60 Hz)

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

Range Resolution Accuracy
0,00…9,99 Ωm 0,01 Ωm depending on measurement
accuracy RE with 4p method,
but not less than ±1 digit
10,0…99,9 Ωm 0,1 Ωm
100…999 Ωm 1 Ωm
1,00…9,99 kΩm 0,01 kΩm
10,0…99,9 kΩm 0,1 kΩm
100…999 kΩm 1 kΩm

L – distance between probes: 1…50 m.. or 1…150 ft

Electric security:

  • type of insulation: double, according to EN 61010-1 i IEC 61557,
  • mesurement category: CAT III 300V wg EN 61010-1,
  • protection class acc. to EN 60529: IP65,

Rated operational conditions:

  • operation temperature: -10…+55°C,
  • storage temperature: -20…+80°C,
  • humidity: 20…90%,

Other technical data:

  • LCD display: segment, backlit,
  • dimensions: 200x150x74 mm.

Data Sheet                                      

User Manual                                   

Declarations of conformity          

Firmware for MRU-30                   

Firmware for MRU-30                   

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