Description
Heavy-duty earthing and soil resistivity meter
The Sonel MRU-120HD earth resistance and soil resistivity
meter is a robust and functional device characterised by
particular resistance to difficult working conditions. It is not
afraid of dust or mud and performs excellently even in areas where
there is an increased risk of splashing.
With the use of the Sonel MRU-120HD meter it is possible to perform
earth resistance measurements using the 3-pole and 4-wire method.
The instrument also allows measurements to be made using additional
clamps (multiple earthing - without the need to disconnect the
monitoring connections) and measurements using the two-clamp method.
In some cases, the measurement can be done without the use of
auxiliary probes driven into the ground. Sonel MRU-120HD is a tool
designed especially for earthing measurements in the power industry.
Measuring range (measurements in accordance with EN 61557) from 0.30
Ω.
Other practical functions of the device are the ability to measure
the resistivity of the ground and the continuity of protective and
equalising connections.
Cechy dodatkowe
- Outstanding resistance to harsh
environmental conditions – the suitcase housing
protects against the ingress of
dust and water and protects against the effects of
falls
- Measurement of resistance of auxiliary
electrodes RS and RH
- Measurement of interference voltage
- Measurement in the presence of interference
voltage generated by power networks with frequency of 50 Hz
or 60 Hz
- Selection of maximum measuring voltage (25 V
and 50 V)
- Automatic calculation of soil resistivity in
ohm-meters (Ωm) and ohm-feet (Ωft)
- Memory of 990 measurement results (10 banks
of 99 cells each)
- Calibration of clamp used
- Real time clock (RTC)
- Data transmission to the computer
- Battery indication
Application
MRU-120HD 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.
Transport and security
It doesn't matter if you take measurements while wading in the mud
or if you act in the sand amongst clouds of dust. The MRU-120HD
meter is ready and will not disappoint. IP67 protection degree when
the cover is closed ensures dust-tightness and prevents water
ingress – even when the housing is immersed briefly! When measuring,
the tightness is still high (IP54), providing protection against
dust and water splashes from any direction.
Capabilities
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 four-lead method provides very
accurate measurement of the expected small values of
resistance – eliminates the resistance of the test leads
connecting the meter to grounding.
- Measurement of the continuity of
protective connections and equipotential bondings with a
current
exceeding 200 mA meets the requirements of EN 61557-4
standard.
- Before performing the measurement, the meter
checks whether the tested object is a subject
to excessive interference voltage, which may indicate
additional problems.
Memory and results
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.
