Sonel MRU-200-GPS Earthing Resistance and Soil Resistivity Meter: 马来西亚的首选 Sonel

The Sonel MRU-200-GPS earth resistance and soil resistivity meter allows the use of all known earth resistance measurement methods. This renders it an unrivalled measuring instrument in its category and definitely makes it stand out from other devices of its kind. Sonel MRU-200-GPS allows you to perform tests with the 3-pole and 4-wire method, using additional clamps (multiple earthing), as well as the two-clamp method and impulse method (earth impedance measurement).

The application of the two-core measurement method allows, under certain conditions, to perform earth resistance measurements without the use of auxiliary probes which are driven into the ground. The impact method, on the other hand, is used for diagnosing lightning protection earthing, but can also be used to measure extensive, multiple and connected earthing (including underground) without interfering with the circuit. With the use of the impact method it is possible to carry out measurements in accordance with EN 62305 - the need to measure earth impedance. It is worth noting that the instrument also has a built-in GPS receiver, which allows for recording the result along with the coordinates of the location. An additional function of the meter is the possibility of carrying out measurements of soil resistivity, continuity of protective and equalising connections and, with the use of clamps, also leakage or fault currents.

The high class of the device is confirmed by the excellent accuracy of the result it produces. The meter makes measurements in accordance with the EN 61557 standard starting from 0.100 Ω.

MRU-200-GPS meter was created for the most difficult working conditions. It generates a measuring current exceeding 200 mA, which provides effective measurements of grounding of energy objects such as transformer stations and power stations.

Thanks to the methods using clamps, it is not necessary to disconnect the control connectors, which is sometimes a very tedious operation. This plays a special role when performing works on objects exposed to weather conditions, where the connecting elements are sometimes corroded or tarnished.

The graphical user interface provides clear readings and explicit messages. This translates into quick, trouble-free service.

MRU-200-GPS may be used to test earthing of lightning protection systems, as this meter is able to simulate the conditions occurring during a lightning strike – it generates current with a standardized pulse leading edge and a time to half-peak. Available impulse ramps include 4/10 μs, 8/20 μs, 10/350 μs.

ERP-1 adapter allows user to test earthing systems using flexible clamps. This is particularly useful, e.g. in case of lattice towers – there is no need to switch off the line or disconnect control connectors. Proprietary algorithm allows user to check the current direction in the individual measurements and facilitates damage detections, e.g. corroded steel strip (hoop).

The measuring methods available in the device allow for comprehensive control of working and protective grounding. The calibration function of the test leads eliminates the influence of their resistance on the result. However, this is just the beginning.

The results can be saved to the device’s memory. It is divided into 10 banks of 99 cells, each corresponding to one measurement. These results can be easily transferred to the Sonel Reader software for archiving or subsequent analysis and research.

Bluetooth wireless interface may be used to transfer measurement results to PC software or to a mobile phone with dedicated app – Sonel MRU Mobile. This provides not only data archiving function, but further data transfer – directly from the measurement site via an e-mail.

Measurement functions	Measurement range	Display range	Resolution	Accuracy
Interference voltage	0 V…100 V	0 V…100 V	1 V	±(2% m.v. + 3 digits)
Resistance of earth connection and equipotential bonding	0.045 Ω…19.99 kΩ acc. to EN 61557-4	0.00 Ω…19.9 kΩ	from 0.001 Ω	from ±(2% m.v. + 2 digits)
Earth resistance
3-pole and 4-wire method	0.100 Ω…19.99 kΩ acc. to EN 61557-5	0.00 Ω…19.9 kΩ	from 0.001 Ω	from ±(2% m.v. + 2 digits)
3-pole + clamp method	0.120 Ω…1999 Ω acc. to EN 61557-5	0.00 Ω…1999 Ω	from 0.001 Ω	±(8% m.v. + 3 digits)
two-clamp method	0.00 Ω…149.9 Ω	0.00 Ω…149.9 Ω	from 0.01 Ω	from ±(10% m.v. + 3 digits)
impulse method 4/10 μs, 8/20 μs, 10/350 μs pulse	0.0 Ω…300 Ω	0.0 Ω…300 Ω	from 0.1 Ω	±(2.5% m.v. + 3 digits)
auxiliary electrodes resistance	0 Ω…19.9 kΩ	0 Ω…19.9 kΩ	from 1 Ω	±(5% (R_E +R_H+R_S) + 8 digits)
Earth resistivity	0.0 Ωm…999 kΩm	0.0 Ωm…999 kΩm	from0.1 Ωm	Depends on the accuracy of the R_E 4p measurement, but not less than ±1 digit
Leakage current	0.1 mA…300 A	0.1 mA…300 A	from 0.1 mA	from ±(5% m.v. + 5 digits)

“m.v.” - measured value

Parameter	Value
Net weight (kg)	1.4
Package weight (kg)	8
Package width (cm)	50
Package height (cm)	19
Package length (cm)	32