Winding Resistance Meter TRM 25


Product: Winding Resistance Meter
Model: TRM 25
Manufacturer: SCOPE


  • Designed to measure DC winding resistance of highly inductive test objects - Transformers, Generators, Motors etc. for field testing as well as for factory testing
  • Designed to work reliably under live EHV switchyard conditions ensuring operator's safety and repeatability of results
  • Winding Resistance Meter designed for large transformers up to 500MVA
  • Quick stabilization of reading even on large test objects by deploying high open circuit voltage
  • Quick & simple tool to check the condition of OLTC - discontinuity during tap change, if any
  • Direct display of Resistance values
  • Available for continuous testing - powerful, truly continuous DC source with excellent heat management through forced cooling
  • Total instrument and human safety ensured through automatic & quick back-emf discharge after test completion
  • Discharge possible through either voltage or current lead in case of accidental lead disconnection - operator risk is minimized


  • Injects test current of 25A DC for measuring winding resistance as high as 800mΩ
  • Has three voltage input (resistance) channels, one temperature input channel and one test current channel
  • Saves down time, measurement of resistance of 3 windings simultaneously
  • In-built stable DC source and direct display of resistance value
    • Single compact instrument
    • No need to spend time in bridge balancing
    • No need of manual calculation
  • Backlit graphic LCD with a user-friendly menu sets up the instrument for the test
  • Configuration
    • Permits enable / disable of measuring channels
    • Automatic Temperature correction settings
    • Winding material selection
    • Selection of print / download intervals
    • RTC setting etc.
    • Test setup: Current range selection, enable / disable of printing, downloading, alarms etc.
    • Record handling: Save, print, download and recall.
  • Easy to use - self guided operation through interactive menu and keyboard
  • Can be operated in standalone mode or controlled through external PC/Laptop
  • No need to compensate lead resistance as Kelvin's Four wire measurement method is used
  • Authentic data management through onboard memory, PC connectivity & downloading software
  • Tamperproof test results through Inbuilt Thermal Printer
  • Displays, prints and stores test reports in the form of text header and tabulated test results
  • Housed in rugged case enhancing transport-worthiness


Resistance Channel


Temperature Channel


Current Range

25A, 10A, 5A, 1A, 100mA & 10mA Selectable

Resistance Range

800µâ?¦, 2mâ?¦, 4mâ?¦, 8mâ?¦, 20mâ?¦, 40mâ?¦, 80mâ?¦, 200mâ?¦, 400mâ?¦, 800mâ?¦, 2â?¦, 4â?¦, 20â?¦, 200â?¦ & 2000â?¦

Best Resolution



Value ± 0.5% ± 2 Digits

Display Resolution

Resistance : 4½ Digit (1 count in 19999 counts), Current : 3½ Digit (1 count in 1999 counts)

Open Circuit Voltage

50V DC


Back EMF, Over Temperature, Accidental Disconnection of Lead





Temperature Correction


Instrument Display

256 X 128 pixel, backlit graphic LCD.


5000 results

Inbuilt Printer


PC Connectivity


Power Supply

230V AC ± 15%, 50Hz ± 10%, 1 Phase


585 x 480 x 195mm

Instrument Weight


Models & Accessories

  • Standard Accessories
    • Test Cables 15m long, with CK clamps, 75mm opening - Set
    • Shorting lead, 10m long, with 75mm CK clamps - 1 Set
    • Master Earthing Cable, 7m long - 1 Set
    • Mains Cord, 3m long - 1 No
    • RTD sensor with 10m long lead and connectors - 1 No
    • Spare fuses - 1 Set
    • Carrying Case for Instrument - 1 No
    • Carrying Case for Test Lead Set - 1 No
    • Paper Roll - 1 No
    • Operation cum Instruction Manual - 1 No
    • Factory test & Calibration Certificate
    • Warranty Certificate
  • Optional Accessories
    • C Trans : Communication, Operation & Data Downloading Software in CD media - 1 No
    • PC Communication cable - 1 No
    • A box of paper rolls containing 10 rolls of thermal paper - 1 Set
    • Test Cables 15m long, with CK clamps of 100mm opening - 1 Set
    • Test Cables 15m long, with CK clamps of 150mm opening - 1 Set
    • Test Cables 20m long, with CK clamps of 75mm opening - 1 Set
    • Test Cables 20m long, with CK clamps of 100mm opening - 1 Set
    • Test Cables 20m long, with CK clamps of 150mm opening - 1 Set