Sivananda Automatic Ratio Meter is the first automatic ratio meter in the country giving digital display of ratio directly;The instrument without any need of balancing precisely & accurately measures the voltage transformation ratio of single phase/3-phase delta or star connected transformers, CTs 8. PTs, Power Transformers.

Test Voltage

The Instrument provides test voltages of 48V & 4.8V,which enable the testing of both power transformers & Cts..


4 line LCD displays the ratio i.e. ratio of high voltage winding to low voltage winding at low flux in the core. Ratio range 0.8 to 20000 is displayed in by auto ranging.

Principle of Operation

This Instrument uses ratio~metric circuit in which the ratio of test specimen is compared with known internal standard.


Instrument is protected against any wrong connection across the transformer. Fast acting VBO trips in case of stepping up of test voltage

Keypad & LCD Display

This is provided for displaying keyboard selected parameter,error/warning messages like incorrect connection, accidental step up misconnection,for user friendly functioning etc.

We Also Offer

C & Tan delta Bridge with High Voltage Power Supply uptc 12K\/..SF6 gas filled Standard Capacitors 100pf/1000 pf upto 20 K\/.,Oscillographic Null Detectors, High Voltage Insulation Testers upto 5KV (Solid State), Precision Current Transformers for range extension of C & Tan D Bridge etc. For detailed information & product catalogue please write to us.

  • 1. Fully auto operation, No balancing is required.

  • 2. Measures and displays transformer ratio, Phase Angle Deviation & Excitation Current.

  • 3. LCD Display

  • 4. True 4 terminal measurement.

  • 5. Fully protected against any wrong connections.

  • 6. TResolution of 0.001 in the range10.

  • 1. Power Supply: 230V AC, 50Hz,± 10% Single phase.

  • 2. Test Voltage : 48 V & 4.8 V **

  • 3. Ratio Range : 0.8 to 20000 **

  • 4. Excitation Cur. : 2Amp

  • 5. Indication : 4 line LCD display

  • 6. Phase Angle : Range ± 90.0°/ Resolution ± 0.01° /Accuracy ± 0.5°

  • 7. Polarity: Facility to change polarity from instrument

  • 8. Displays: Ratio / Excitation Current /Phase Angle Deviation

Automatic Transformer Ratio Meter Model : ATRM-1M

Autoamtic Transformer Ratio Meter