Measure motor winding resistance and other low resistances

Possibility to measure objects of resistive and inductive nature with the use of versatile small resistance meter Sonel MMR-620.

We present a professional small resistance meter MMR-620, which ensures high measuring accuracy - the measurement resolution is 1 µΩ. With the use of this device it is possible to perform measurements of objects of both resistive and inductive nature (e.g. testing of transformers or motors). The meter provides a high measuring current for individual subranges and various operating modes, adjusted to the type of measured object - quick measurement mode (3 sec) for testing objects of resistive nature, as well as extended measurement mode for testing objects of inductive nature.

Product features

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.

Additional functions

• 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.

Weight and dimensions