Transformer Winding Resistance Meter is designed to measure the winding resistance of transformers, Inductors, generators and motor windings, Tap Changers, Bus Bar contacts,Power Cables etc


It is specially designed for Highly Inductive objects like 765kV/400kV/220kV. This is only indigenous TWRM which gives very fast readings for 3Phase Star -Delta any combination Transformers. The built in open circuit Features Voltage of DC Supply ensures that core of the transformer is saturated for fast measurements to be taken.Care is taken to absorb the Back emf of such transformers. For user safety, Indication for discharge is provided on front panel,if the current through winding under measurement is disturbed/discontinued.


Instrument has built in 10A regulated and highly stable specifical current surce with current seletion of 10A,5A,1A,0.1A Power supply 100mA & 10mA Instrument uses ratio -metric circuit where the resistance of specimen is compared with known internal standard and 4 1/2 digit LCD display is provided for resistance measurement in microohm, milliohms and in ohms.


  • 1. Regulated and highly stable 50V.25Amp, 10A, 5A, 1A, 0.1A & 0.01A current source.

  • 2. 4½ digit LCD display , 19999 counts.

  • 3. Simultaneous measurements of voltage & current.

  • 4. True four terminal measurement.

  • 5. Resolution of 0.1 micro ohm.

  • 6. Protection against inductive kickback and discharge.

  • 7. Current Vs Time plot for OLTC

  • 8. Visual Indication For discharge.

  • 9. Line voltage interference suppression making instrument most suitable for field application.

  • 10. Automatic Discharge.

  • 11. Thermally Protected Power Supply.

  • 12. Light weight carrying case & with 20 meter leads.

  • 13. Temperature compensated value for copper and aluminium..

  • 14. RS 232 port to Data acquisition software Windows Based.

  • 1. POWER SUPPLY : 230V AC ±10%,50Hz ±5%, single phase.

  • 2. TEST CURRENT : 50A,25A,10A,1A,0.1A,10mA.

  • 3. RANGE : 100micro to 2000‎Ω ( Auto Ranging )

  • 4. INDICATION : 4 ½ Digit on coloured LCD ( 19999 counts)

  • 5. RESOLUTION : 0.1μΩ at 500μΩ range.

  • 6. ACCURACY : ± 0.2% ± 2 count.

  • 7. DC POWER SUPPLY 50VDC,50Amp

  • 8. KEYPAD : Touch Screen

  • 9. CABLES : Test cables,Ground Cable, Power Chord & Cable Bag.

  • 10. SAFETY SPECS : Complied IEC61010

  • 11. EMI/EMC SPECS : Complied IEC61326

  • 12. WEIGHT : < 15Kg( Without Leads )

  • 13. OPERATING TEMP : 0°C to +50°C

  • 14. OPERATING HUMIDITY : Max 90% NonCondensing

  • 15. CHANNELS : 2 Channels.

  • 16. PORTS : RS 232 Port,USB

  • 17. MEMORY 30 sets of readings.

  • 18. SOFTWARE Windows based software for data downloading,Report Generation, Temperature Compensation in External Laptop supplied with Kit.

Transformer Winding Resistance Meter Model :50AμP

TWRM