Description
Multifunctional earthing and soil resistivity meter
The Sonel MRU-200-GPS earth resistance and soil resistivity
meter is a versatile meter for earth resistance and soil
resistivity measurements. The device 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.
Sonel MRU-200-GPS XL3 comes with XL-3 hard carrying case..
Measurement methods
- Impulse method - measurement of
lightning protection systems with a measuring impulse ramp
of 4/10 μs, 8/20 μs, 10/350 μs
- >3-pole and 4-wire method -
measurement of earthing systems using auxiliary
probes
- 3-pole method with clamp - measurement
of earthing systems with multiple earth electrodes
- Two-clamp method - measurement of
earthing system when the auxiliary probes cannot be
used
- Earth resistivity - Wenner
method
- Resistance of earth and compensatory
conductors measured using current ≥200 mA with
auto-zero
function - meets the requirements of EN 61557-4
- Measurement of leakage current
Additional features
- Built-in GPS receiver - recording results
with location coordinates
- Measurement of resistance of auxiliary
electrodes RS and RH
- Measurement of interference voltage
- Measurement of interference frequency
- Measurement in the presence of interference
voltage generated by power networks with frequency of 16 2/3
Hz, 50 Hz, 60 Hz, 400 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 and mobile
devices
- Battery indication
Application
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.
Impulse method
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.
Compatible with ERP-1 adapter
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).
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.
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.
