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.

New earth resistance and ground resistivity meter - Sonel MRU-30

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 U _N (RMS)

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

• 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)

• 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 R _H i R _S

Measurement of multiple earthing resistance with using double clamps

• 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=2πLR _E

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,
• measurement 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.