The MMR-620 Series meters are professional portable instruments for measuring very low resistances. Due to their special measurement algorithm they can be used for both resistive and inductive type of a specimen that makes MMR-620 a perfect instrument for electricianstesting electrical junctions, motors and power transformers windings.The results can be stored in the internal memory and send to a computer via serial interface. A quick PASS/FAIL test function with results displayed and acoustically indicated simplifies measurements considerably. The MMR-620 meter can also be used for testing the quality of the junctions in a production process via the interface.
- Measurement of resistive object type:
- welded and soldered connections, equipotential bonding, earth wire,
- terminals and connectors, rail welded joints, cables and wires,
- measurement 4-pole method. - Measurement of inductive object type:
- coils (motors and transformers), low resistance coils. - Range selection autoranging or manual (measurement of inductive object type).
- Selectable measurement mode adjusted to object type:
- for resistive objects - fast mode (3 seconds),
- for inductive objects - long mode with automatic discharge after measurements (or with lower accuracy - shorter mode). - Selectable measurement mode adjusted to application:
- normal mode - after pushing „START” button,
- automatic mode - since test leads are connected to the object meters automatically starts measurement with dual direction current flow and gives average result - what eliminates eventual DC voltage on tested object,
- continuous mode - every 3 seconds for resistive objects or continuous measurement for inductive objects. - Window mode:
- this option enables setting an upper and a lower limit between which the average measurement result is bound to appear. The results outside of this range will be indicated by two long audible signals and the symbols. - Memory store for up to 990 results and a communications facility for transferring data from the device to a PC.
Electric security:
- type of insulation: double, according to EN 61010-1 and IEC 61557
- measurement category: CAT III 300V acc. to EN 61010-1
- protection class acc. to EN 60529: IP54
Other technical data:
- meter’s power supply: battery package SONEL/Ni-MH 4,8V
- battery charging time: approx. 2,5 hours
- number of measurements with the current of 10A: 300
- auto-off time: 120 seconds
- immunity to interference: additional error ≤1% for voltage 50 Hz ≤100mV RMS
- maximum leads resistance for the 10A current: 0,1Ω
- maximum inductance of the tested object: 40H
- accuracy of the test current: ±10%
- resistance measurement time:
- with the selected resistive object type with the bidirectional current: 3 seconds
- with the selected inductive object type, dependant on the resistance
and inductance of the object: a few minutes (max. 10)
- dimensions: 295 x 222 x 95 mm
- weight: approx. 1,7 kg
Rated operational conditions:
- operation temperature: 0...+40°C
- storage temperature: -20...+60°C
MMR-620 microohmmeter conforms the following directives
or standards according to CE requirements.
Directive:
Low Voltage Directive (LVD) 73/23/EEC, 93/68/EEC.
Standards:
EN 61010-1:2001 Safety requirements for electrical equipment for measurement, control and laboratory use. General requirements .
EN 61010-031:2002: Safety requirements for electrical equipment for measurement, control and laboratory use. Safety requirements for hand-held probe assemblies for electrical measurement and test.
Directive:
Electromagnetic compatibility (EMC) 89/336/EEC, 92/31/EEC, 93/68/EEC.
Standards:
EN 61326:1997+A1:1998+A2:2001 Electrical equipment for measurement, control and laboratory use - EMC requirements.
Resistance measurement
MMR-620 | Current | Voltage for the full scale | Accuracy | |
Range | Resolution | |||
0...999μΩ | 1μΩ | 10A | 20mV | ±(0,25%m.v. + 2 digits) |
1,000...1,999mΩ | 0,001mΩ | |||
2,00...19,99mΩ | 0,01mΩ | 200mV | ||
20,0...199,9mΩ | 0,1mΩ | 1A | ||
200...999mΩ | 1mΩ | 0,1A | ||
2,00...19,99Ω | 0,01Ω | |||
20,0...199,9Ω | 0,1Ω | 1mA | ||
200...1999Ω | 1Ω | 0,1mA |
- input impedance of the voltmeter: ≥200kΩ
„m.v.” - measured value.