MMR-620 microohmmeter enables accurate measurements of both connections resistance (welded, soldered, bolted) and winding resistance of electrical motors.

• Measurements of objects resistive in nature:
  • welded and soldered connections, equipotential bondings, earthing conductors,
  • contacts, welds of rails, conductors and cables,
  • measurement according to the four-lead method.
• Measurements of objects inductive in nature:
  • motor windings,
  • low-resistance coils.

• Automatic or manual selection of measuring range (measurement of objects of an inductive nature).
• Selection of measurement mode according to the type of measured object:
  • fast measurement (3 seconds) for measurement of objects of a resistive nature,
  • extended measurement for testing of objects of an inductive nature (accelerated mode, with slightly worse accuracy, available); with automatic discharging of the object after measurement.
• Selection of measurement mode depending on application (including control of product series):
  • measurement in normal mode – triggered when the “START” button is pressed,
  • measurement in automatic mode – the instrument awaits connection of all four test leads to the object, after which it automatically start measurement in one or both directions and calculates the mean resistance value,
  • measurement in continuous mode – the meter repeats successive measurement cycles with breaks every 3 seconds (for objects of a resistive nature) or performs measurement continuously (for objects of an inductive nature)
• Window mode:
  • makes possible to set an upper and lower limit within the measurement result should remain; sound signal triggered when the result is beyond set range,
  • capability of performing measurements even under disturbances of a value five times greater than the measured signal.

    Resistance measurement

    Range	Resolution	Test current	Accuracy
    0…999 μΩ	1 μΩ	10 A	±(0.25% m.v. + 2 digits)
    1.000…1.999 mΩ	0.001 mΩ	10 A	±(0.25% m.v. + 2 digits)
    2.00…19.99 mΩ	0.01 mΩ	10 A	±(0.25% m.v. + 2 digits)
    20.0…199.9 mΩ	0.1 mΩ	1 A	±(0.25% m.v. + 2 digits)
    200…999 mΩ	1 mΩ	0.1 A	±(0.25% m.v. + 2 digits)
    1.000…1.999 Ω	0.001 Ω	0.1 A	±(0.25% m.v. + 2 digits)
    2.00…19.99 Ω	0.01 Ω	10 mA	±(0.25% m.v. + 2 digits)
    20.0…199.9 Ω	0.1 Ω	1 mA	±(0.25% m.v. + 2 digits)
    200…1999 Ω	1 Ω	0.1 mA	±(0.25% m.v. + 2 digits)

    m.v. – measured value