MRU-21 Earth resistance meter

MRU-21 is designed as a reliable measuring instrument, which is both technically advanced and easy to use. It is suitable for tests in industrial plants and in companies providing electrical measurement services. MRU-21 allows user to test individual earth electrodes and systems with multiple earthing electrodes.

Manufacturer: SONEL S.A. (Poland).

Description

Features

Measurement of resistance of auxiliary electrodes RS and RH
Measurement of interference voltage
Selection of maximum measuring voltage (25 V and 50 V)
Auto-zero function for the resistance of measurement leads (RCONT zero)

Technical specifications

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)
Connection and equipotential bonding resistance	0.13 Ω…199 Ω	0.00 Ω…199 Ω	from 0.01 Ω	±(2% m.v. + 3 digits)
Earth resistance 2-wire method	0.00 Ω…1.99 kΩ	0.00 Ω…1.99 kΩ	from 0.01 Ω	±(2% m.v. + 3 digits)
Earth resistance 3-wire method	0.50 Ω…1.99 kΩ	0.00 Ω…1.99 kΩ	from 0.01 Ω	±(2% m.v. + 3 digits)
Earth resistance auxiliary electrodes resistance	0 Ω…50.0 kΩ	0 Ω…50.0 kΩ	from 1 Ω	±(5% (RE+RH+RS) + 3 digits)
Safety and work conditions
Measuring category according to EN 61010		III 600 V / IV 300 V
Ingress protection		IP54
Type of insulation according to EN 61010-1 and IEC 61557		double
Dimensions		288 x 223 x 75 mm
Weight		ca. 1.4 kg
Operating temperature		-10…+55°C
Storage temperature		-20…+70°C
Humidity		20…90%
Nominal temperature		23 ± 2°C
Reference humidity		40%…60%
Memory and communication
Memory of measurement results		990 results
Data transmission		USB

Complete set

Standard accessories:

MRU-21
Test lead 15 m on a reel, banana plugs, blue
Test lead 30 m for earth resistance measurements on a reel, red
2 x earth contact test probe (30 cm)
L-4 carrying case
Test lead 1.2 m (banana plugs) blue
Test lead 2.2 m (banana plugs) black
USB cable
Hanging straps
Crocodile clip 1 kV 20 A blue
Crocodile clip 1 kV 20 A black
Battery pack 4xLR14
4 x R14 alkaline battery

Optional accessories:

Test lead on a reel red 75 m / 100 m / 200 m
Test lead on a reel blue 75 m / 100 m / 200 m
Test lead on a reel yellow 75 m / 100 m / 200 m
Test lead 25 / 30 m on a reel, banana plugs, red
Test lead 15 / 25 m on a reel, banana plugs, blue
Test lead 50 m for earth resistance measurements (banana plugs) yellow
Pin probe 1 kV (banana socket) black / red / blue / yellow
Test lead 1.2 m (banana plugs) black / red / blue / yellow
Crocodile clip 1 kV 20 A red / blue / yellow
Cramp with banana socket
Earth contact test probe 25 cm / 80 cm
L-3 carrying case (for 80 cm test probes)
Test wire reel

Documentation

MRU-21 Datasheet.pdf