AMRU

Grounding resistance and soil resistivity testers

MODELS 10, 11, 21, 120, 120 HD, 200 and 200 GPS

AMRU-10

Earthing resistance meter

• Basic measurements of earthing under all conditions

Tap resistance measurement of land

• Earthing resistances by the technical method (3p).
• Resistances by the bipolar method (2p).

Features

• Resistance measurements of auxiliary electrodes rh and rs.
• Disturbance voltage measurements up to 100 v.
• Indication of the status of batteries or accumulators.
• Choice of measuring voltage (25 v and 50 v) automatic switch-off function.

Descripción

MRU-10 is a simple meter that enables measurements by the technical method as well as the measurement of earthing resistance by the bipolar method. The device is characterised by ease of operation, high resistance to interference and high accuracy.

housing as well as the large, easy-to-read display make the device ideal for use in the field and in most working environments. The device stands out for its simple operation and intuitive handling. It is the best choice for electrical installation contractors, technicians and grounding measurement specialists.

MRU-10 is a simple to operate meter for earth resistance measurements. It is a basic device for testing the quality of the earthing circuit on the basis of the measurement result. Its ergonomic design, rugged and compact

Technical specifications

Standard accessories

Cable 2.2 m CAT III/1000 V CAT IV/600V (banana plugs) black

WAPRZ2X2BLBB

Black crocodile 1 kV 20 A WAKROBL20K01

Meter harness (type M1) WAPOZSZE4 Bracket - M1 hook for the meter WAPOZUCH1

15 m red cable for measuring earthing on reel (banana plugs) WAPRZ015REBBN

4 x 1.5 V AA battery, LR6

Case M6 WAFUTM6

30 m yellow cable for measurement reel grounding (banana plugs) WAPRZ030YEBBN

2 x soil penetration probe (25 cm) WASONG25 Certificate of calibration

Additional accessories

Cable 1.2 m (connectors type banana) black / blue / yellow WAPRZ1X2BLBB

Crocodile 1 kV 20 A red / blue / yellow WAKRORE20K02 WAKROBU20K02 WAKROYE20K02

25 / 30 m cable for measuring earth on reel (banana plug) red

15 m cable for measuring earth on reel (banana plugs) blue WAPRZ015BUBBSZ

WAPRZ025REBBSZ WAPRZ030REBBSZ

Cable on reel, red 75 m / 100 m / 200 m WAPRZ075REBBSZ WAPRZ100REBBSZ WAPRZ200REBBSZ

Cable on reel, blue 75 m / 100 m / 200 m

WAPRZ075BUBBSZ WAPRZ100BUBBSZ WAPRZ200BUBBSZ

Probe to be driven Screw clamp into the ground (banana plug) WASONG30 WAZACIMA1WASONG80

Reel for winding up the measuring cable WAPOZSZP1

Calibration certificate issued by accredited laboratory

1 kV tip probe (banana plug) black blue / yellow

WASONBUOGB1 WASONBLOGB1 WASONYEOGB1

50 m cable for measuring earth on reel (banana plugs) yellow

WAPRZ050YEBBSZ

Cable on reel, yellow 75 m / 100 m / 200 m WAPRZ075YEBBSZ WAPRZ100YEBBSZ WAPRZ200YEBBSz

Cover L3 WAFUTL3

AMRU-11

Earthing resistance meter and soil resistivity

• Easy way to measure wear grounding and resistivity

>20 mA soil resistivity without measuring conversion short-circuit current

Resistance measurement on the ground

• Soil resistivity.
• Earthing resistance by 3-wire and 4-wire method with auxiliary electrodes.
• Resistance of the test sample by means of the 2-wire.

Features

• Resistance of auxiliary electrodes Rh and Rs.
• Interference voltage measurement at 100 v.
• Battery status indication.
• Selection of maximum measuring voltage (25 v and 50 v).
• Automatic shutdown function.

Description

The MRU-11 is a simple meter that allows you to measure grounding using the technical method (3 and 4-wire) and soil resistivity using the Wenner method. The instrument is easy to operate, resistant to interference and highly accurate.

The MRU-11 is a basic device that allows the quality of the earthing system to be verified on the basis of the measurement result received. Its ergonomic shape, Its durable, sturdy housing and large, clear display make this instrument ideal for use in the field as well as in most working environments. The device is simple to operate and intuitive. It is the best choice for electrical installation contractors, technicians and professionals dealing with grounding measurements.

Technical specifications

Standard accessories

AMRU-21

Earthing resistance meter

• Basic measurements of earthing and continuity of connections

ρ aR Ω a Ωm

Soil resistivity without manual conversion

Measurement methods

Capacities

• 3-wire method – measuring earthing with auxiliary probes.
• 2-wire method – simplified measurement of earthing resistance.
• Resistance of earthing and compensatingconductors at current ≥200 mA with auto-zero function: complies with the requirements of EN 61557-4.

The large, easy-to-read display shows resistance values and help information in all weather conditions. Additional warnings inform the user about irregularities during the measurement.

The IP54 protective housing ensures safety of use during severe weather conditions and lack of concern about splashing.

Additional features

• Resistance measurement of auxiliary electrodes RS and RH.
• Interference voltage measurement.
• Selection of maximum measuring voltage (25 V and 50 V).
• Resistance zeroing function of measuring conductors (RCONT zero) for electrical installation, technicians and specialists involved in earthing measurements.

Application

MRU-21 was designed to provide customers with a measuring instrument that is reliable in operation, technically advanced and at the same time easy to use. It works very well in testing in industrial plants as well as companies providing electrical measurement services. MRU-21 allows testing of single earth electrodes as well as multiple earthing systems.electrical, technicians and specialists engaged in earthing measurements.

The results can be stored in 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 Reader software for archiving or further analysis and research.

Technical data

AMRU-120

Earthing resistance meter and soil resistivity

200 mA

Measuring Soil resistivity without currentmanual conversion

Measurement methods

• 3-wire and 4-wire method – measurement of earthing with auxiliary probes.
• 3 wire clamp method – the measurement of multiple earthings.
• Soil resistivity – Wenner method.

Additional features

• Measuring current 200 mA – facilitates earth resistance measurements on difÏcult ground (sand, stony ground).
• Resistance measurement of auxiliary electrodes RS and RH.
• Interference voltage measurement.
• Measurement in the presence of interference voltage generated by mains systems with 50 Hz and 60 Hz frequencies.
• Selection of maximum measuring voltage (25 V and 50 V).
• Automatic calculation of soil resistivity at ohm metre (Ωm) and ohm foot (Ωft).
• Memory of 990 measurement results (10 banks of 99 cells).
• Calibration of clamp used.
• Real Time Clock (RTC).
• Data transmission to the computer.
• Battery indication.
• Resistance of earthing and compensating conductors at current ≥200 mA with self-zeroing function: complies with the requirements of EN 61557-4.

Application

MRU-120 was designed for the toughest working conditions. It generates a measuring current of more than 200 mA, which makes it possible to effectively measure the earthing of power installations, such as transformer stations or power plants.

Thanks to 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 working on objects exposed to weather conditions, where the connection elements sometimes corrode or tarnish.

The graphical user interface provides readings clear and explicit messages.

Protection and equipment

The housing of the MRU-120 enables safe working outside as well as inside buildings. The IP54 protection protects the device against water and solids in case of splashes or heavy dust. In addition, the housing provides excellent protection during transport and handling. The extensive standard equipment allows most measurements to be carried out without the need to purchase additional accessories. MRU-120 is a versatile solution offering complete grounding control.

Capacities

The measurement methods available in the device allow a comprehensive control of the working and protective earth connection. The calibration function of the test leads eliminates the influence of their resistance on the result. However, this is only the beginning.

• The four-wire method provides a very accurate measurement of the expected small resistance values: it eliminates the resistance of the test leads connecting the meter to ground.
• Continuity measurement of protective conductors and equipotential bondings with a current greater than 200 mA meets the requirements of EN 61557-4.
• Before performing the measurement, the meter checks whether the tested object is under excessive interference voltage, which may indicate additional problems.

Report and results

The results can be stored in 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 Reader software for archiving or further analysis and research.

Other functions of use

Integrated help – additional pictures show how to perform the measurement correctly for each method.

Connection correction - if the meter detects an error that does not allow a correct measurement to be made, it will signal this fact at the top of the display using the appropriate symbol of the measurement socket.

Measurement data set - in addition to measuring earth resistance, additional measurements of interference voltages and resistance of auxiliary probes are performed. The results contain information on the date and time of the test, which facilitates the creation of measurement documentation.

Technical data

AMRU-120HD

Grounding resistance and soil resistivity tester

200 mA Measuring Soil resistivity without currentmanual conversion

Measurement methods

• 3 and 4-wire method - grounding measurement with auxiliary probes.
• 3-wire clamp method - the measurement of multiple earthings.
• Two-clamp method - the measurement of earthing when auxiliary probes cannot be used.
• Soil resistivity - Wenner method
• Resistance of earthing and compensating conductors at current ≥200 mA with auto-zero function: complies with the requirements of EN 61557-4.

Additional features

• Excellent resistance to harsh environmental conditions: case shell protects against dust and water ingress and drop protection.
• Resistance measurement of auxiliary electrodes RS and RH.
• Interference voltage measurement.
• Measurement at the presence of the interference voltage generated by mains systems with 50 Hz or 60 Hz frequencies.
• Selection of maximum measuring voltage (25 V and 50 V).
• Automatic calculation of soil resistivity at ohm metre (Ωm) and ohm foot (Ωft).
• Memory of 990 measurement results (10 banks of 99 cells).
• Calibration of clamp used.
• Real Time Clock (RTC).
• Data transmission to the computer.
• Battery indication.

Application

MRU-120HD was created for the most difÏcult working conditions. It generates a measuring current in excess of 200 mA, which provides effective measurements of the grounding of power objects such as transformer stations and power plants.

a very tedious operation. This plays a special role when working on objects exposed to weather conditions, where the connecting elements sometimes corrode or tarnish.

Graphical user interface provides clear readings and explicit messages.

Thanks to the methods using clamps, it is not necessary to disconnect the control connectors, which s sometimes

Transport and security

It doesn’t matter if you take measurements while walking in the mud or working in the sand amidst clouds of dust. The MRU-120HD meter is ready and will not disappoint.

The IP67 protection rating when the cover is closed ensures dust tightness and prevents water ingress, even when the case is briefly submerged.

Capacities

The measurement methods available in the device enable comprehensive control of the working and protective earth connection. The calibration function of the test leads eliminates the influence of their resistance on the result. However, this is only the beginning.

The four-wire method provides a very accurate measurement of the expected small resistance values:

it eliminates the resistance of the test leads connecting the meter to earth.

Measuring the continuity of protective conductors and equipotential bonding with a current greater than 200 mA meets the requirements of EN 61557-4. Before performing the measurement, the meter checks whether the tested object is under excessive interference voltage, which may indicate additional problems.

Report and results

The results can be stored in 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 Reader software for archiving or further analysis and research.

Datos técnicos

AMRU-200 / 200 GPS

Earthing resistance meter and soil resistivity

Measurement methods

• Impulse method - lightning protection measurement with measuring impulse with 4/10 μs, 8/20 μs, 10/350 μs flank.
• 3 and 4 wire method - measurement of earthing with auxiliary probes.
• 3 wire clamp method - the measurement of multiple earthings.
• Two-clamp method - the measurement of earthing when auxiliary probes cannot be used.
• Soil resistivity - Wenner method.
• Resistance of earthing and compensating conductors with current ≥200 mA with auto-zero function: meets the requirements of EN 61557-4.
• Measurement of leakage current.

Additional features

• Built-in GPS receiver - saves result and location coordinates (AMRU-200-GPS)
• Resistance measurement of auxiliary electrodes RS and RH.
• Interference voltage measurement.
• Interference frequency measurement.
• Measurement in the presence of interference voltage generated by mains systems 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 at ohm metre (Ωm) and ohm foot (Ωft).
• Memory of 990 measurement results (10 banks of 99 cells).
• Calibration of clamp used.
• Real Time Clock (RTC).
• Data transmission to computer and mobile devices.
• Battery indication.
• Memory of 990 measurement results (10 banks of 99 cells).

Application

The MRU-200 and MRU-200-GPS meters are designed for harsh working conditions. They generate current measurement in excess of 200 mA, which makes it possible to effectively measure the earthing of power installations, such as transformer stations or power plants. Thanks to the clamp-on methods, there is no need to disconnect the control connectors, which is sometimes a very tedious operation. The graphical user interface provides clear readings and explicit messages.

Method of drive

With MRU-200 and MRU-200-GPS it is possible to examine lightning protection earthing, as the meters can simulate lightning strike conditions: they generate currents which are characterised as follows for the standardised sudden rise and time to half-peak. Pulse shapes with 4/10 μs, 8/20 μs, 10/350 μs edge are available.

Works with ERP-1 adapter

The ERP-1 adapter makes it possible to examine earth connections with the flexible clamp. This is particularly useful e.g. in case of electricity masts because it is not necessary to deactivate the lines or to disconnect the control joints. A special algorithm makes it possible to check the current direction for individual measurements and makes it easier to find damage, e.g. a rusty strap.

Capacities

The measurement methods available in the device enable comprehensive control of the working and protective earth connection. The calibration function of the test leads eliminates the influence of their resistance on the result. However, this is only the beginning.

The four-wire method provides a very accurate measurement of the expected small resistance values: it eliminates the resistance of the test leads connecting the meter to ground.

Continuity measurement of protective conductors and equipotential bondings with a current greater than 200 mA meets the requirements of EN 61557-4.

Before performing the measurement, the meter checks if the tested object is under excessive interference voltage, which may indicate.

Report and results

The results can be stored in 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 Reader software for archiving or further analysis and research.

Bluetooth wireless communication interface allows measurement results to be sent to the computer and mobile with the AMRU Mobile app. This means not only the possibility to archive the data, but also to send it directly from the measurement site as an e-mail.

Technical data