产品名称：MRU-21系列接地电阻和电导测试仪

It allows to take the measurements of:

• earthing resistance using auxiliary electrodes,
• earthing resistance using auxiliary electrodes and clamp (for measurements of multiple earthing)
• earthing resistance using double clamps (for measurement of earthing when it is impossible to use auxiliary electrodes),
• ground resistivity (Wenner method),
• measurement of continuity of equipotential bondings and protective conductors (meeting the requirements of IEC 60364-6-61:2000 section 6.12.2) with auto-zero function – with current 200mA.
   

Additionally:

• measurement of resistance of auxiliary electrodes RS and RH,
• measurement of interference voltage,
• measurement of interference frequency,
• measurement in the presence of interference voltage in the power network with frequency 50Hz, 60Hz
• selection of maximum measuring voltage (25V and 50V)
• introducing the distance between the electrodes for the resistivity in metres (m),
• memory of 990 measurements (10 banks of 99 cells each),
• calibration of clamp used,
• real time clock (RTC),
• data transmission to the computer (USB, wireless),
• indication of battery state.

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

Rated operational conditions:
- operation temperature: -10...+50°C
- storage temperature: -20...+70°C
- humidity: 20...80%

Other technical data:
- LCD display: graphic, backlighted
- interface: USB, wireless
- number of measurements carried out of set of batteries: > 500
- warranty: 36 months

 

Measurement of interference voltage

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

• singnalling  overvoltage 24V or 40V rms
• measurement for DC and AC 45…65 Hz,

Measurement of earthing resistance (method 3- and 4-pole)
measurement range to IEC61557-5: 0,30Ω...19,9kΩ

Range	Resolution	Accuracy
0,00...19,99Ω	0,01Ω	±(2% m.v. + 2 digits)
20,0...199,9Ω	0,1Ω
200...1999Ω	1Ω
2,0k...9,99kΩ	0,01kΩ	±(5% m.v. + 4 digits)
10,0k...19,9kΩ	0,1kΩ

• measurement current: under short circuit >200mA,
• voltage on open terminals: selectable <25V AC or <50V AC,
• frequency of measurement current: 125 (for networks 50Hz) or 150Hz (for 60Hz),
 
Measurement of continuity of equipotential bondings and protective conductors (Rcont)
measurement range to IEC61557-5: 0,24Ω...19,9kΩ
 

Range	Resolution	Accuracy
0,00...19,99Ω	0,01Ω	±(2%  m.v. + 2 digits)
20,0...199,9Ω	0,1Ω
200...1999Ω	1Ω
2,0k...9,99kΩ	0,01kΩ	±(5%  m.v. + 2 digits)
10,0k...19,9kΩ	0,1kΩ

•voltage on open terminals: <24Vrms but >4Vrms,
• measurement current: under short circuit >200mA,
• frequency of measurement current: 125 (for networks 50Hz)  
  or 150Hz (for networks 60Hz), possible choice of measurement frequency in menu,
• auto-zero function measurement leads

Measurement of resistance of auxiliary electrodes R_H and R_S
 

Range	Resolution	Accuracy
0...999Ω	1Ω	±(5% (RS+RE+RH) + 8 digits)
1,00k...9,99kΩ	0,01kΩ
10,0k...19,9kΩ	0,1kΩ

Measurement of multiple earthing resistance with using the clamp and auxiliary electrodes (3p + clamp)
measurement range to IEC61557-5: 0,44Ω...1999Ω

Range	Resolution	Accuracy
0,00...19,99Ω	0,01Ω	±(8% m.v. + 3 cyfry)
20,0...199,9Ω	0,1Ω
200...1999Ω	1Ω

• voltage on open terminals: selectable <25V AC or <50V AC,
• measurement current: under short circuit > 200mA,
• frequency of measurement current: 125 (for networks 50Hz)
  or 150Hz (for 60Hz),


Measurement of multiple earthing resistance with using double clamps

Range	Resolution	Accuracy
0,00..19,99Ω	0,01Ω	±(10% m.v. + 3 digits)
20,0...149,9Ω	0,1Ω	±(20% m.v. + 3 digits)

• frequency of measurement current 125 (for networks 50Hz)
  or 150Hz (for networks 60Hz)

Measurement of ground resistivity
Measurement method: Wennera, ρ=2πLR_E
 

Range	Resolution	Accuracy
0,0...199,9Ωm	0,1Ωm	depending on measurement accuracy RE with 4p method, but not less than ±1 digit
200...1999Ωm	1Ωm
2,00k...19,99kΩm	0,01kΩm
20,0k...99,9kΩm	0,1kΩm
100k...999kΩm	1kΩm

L – distance between probes: 1...50m