Earth Resistance Testers » EARTH RESISTANCE TESTER MRU-21


EARTH RESISTANCE TESTER MRU-21

Possible measurements:

  • earth resistance measurment with 3-pole method,
  • measurement of continuity of equipotential bondings and protective conductors with auto-zero function - with current 200 mA,
  • resistance measurement using 2-pole method.

Measurement of earthing resistance 
measurement range to IEC61557 - 5:
0,50 Ω...1,99 kΩ for Un=50 V;
0,68 Ω...1,99 kΩ for Un=25 V;

Range Resolution Accuracy
0,00...9,99 Ω 0,01 Ω
±(2% m.v. + 3 digits)
10,0...99,9 Ω 0,1 Ω
100...999 Ω 1 Ω
1,00k...1,99 kΩ 0,01 kΩ

• measurement current: under short circuit >20 mA,
• voltage on open terminals: selectable <25 V AC or <50 V AC,
• frequency of measurement current: 125 Hz

Measurement of interference voltage UN (RMS)

Range Resolution Accuracy
0...100 V 1 V ±(2% m.v. + 3 digits)

• measurement for DC and AC 45…65 Hz

Measurement of resistance of auxiliary electrodes RH i RS

Range Resolution Accuracy
0...999 Ω 1 Ω
±(5% (RS+RE+RH) + 3 digits)
1,00k...9,99 kΩ 0,01 kΩ
10,0k...50,0 kΩ 0,1 kΩ

Measuremet of continuity of equipotential bondings and protective conductors 
measurement range to IEC61557 - 4: 0,13 Ω...199 Ω

Range Resolution Accuracy
0,00...9,99 Ω 0,01 Ω
±(2% m.v. + 3 digits)
10,0...99,9 Ω 0,1 Ω
100...199 Ω 1 Ω
  • measuring method: technical 2-pole method,
  • max. voltage on open terminals: 13 V,
  • measurement current: under short circuit >200 mA,
  • auto-zero function for measurement leads

Electric security:

  • type of insulation: double, according to EN 61010 - 1and IEC 61557
  • measurement category: CAT IV 300 V acc. to EN 61010 - 1
  • protection class acc. to EN 60529: IP54

Rated operational conditions:

  • operation temperature: -10...+55°C
  • storage temperature: -20...+70°C
  • humidity: 20...80%

Other technical data:

  • LCD display: segment, backlit
  • interface: USB,
  • number of measurements carried out of set of batteries: > 1000 (5 Ω, 2 meas./min.)
  • warranty: 2 years
  • dimentions: 288 x 223x75 mm
  • weigth: 1,4 kg