Automatic Ratio Testers

  • Real 3 phase test voltage output
  • Up to 275 volts output for high accuracy
  • Optional tertiary winding channel
  • Fully automatic tap changer test mode
  • USB thumb drive & Ethernet ports
  • Easy cable management
  • Large color, sunlight readable, touch screen display

The ART-3D™ series of ratio meters are high precision instruments, designed to measure turn ratios, phase displacements, excitation currents of single phase and three phase power, distribution and instrument transformers in conformity to the IEEE C57.12.90 & IEC 60076.

With ART-3D’s™ intuitive menus, high contrast touch screen, convenient graphical test representation, highest test voltage on the market, long and flexible multipurpose test leads configuration, real 3-phase output, the widest range of applicable transformer types, it has never been so simple and easy to achieve high accuracy transformer turn ratio measurements.

The instrument’s rugged design is perfectly suited to tackle the most challenging field or manufacturing environments. The anti-induction mode strongly enhances the efficiency of the measurements by countering the unwanted effect of nearby induction interference. The large, high contrast, color, touch screen display offers easy menu navigation, creation of test plans and viewing of test files. The integrated LTC control terminal allows for manual or fully automatic testing sequence of on-load tap changers with configurable pulse duration and duty cycle. The additional tertiary winding channel of the ART-3Dx™ will save a great deal of time, with onetime test connections to primary, secondary and tertiary windings. One of the ART-3D’s™ key features is the colored and graphical way of displaying LTC test results for interpretation in seconds!

ART-3D connectors 001_SMALL
ART-3D küçük

With its real 3-phase test circuit, the ART-3D™ can address complex ratio measurements of PhaseShifting/ Regulating or irregular vector group type transformers, otherwise impossible to achieve with conventional ratio meters. Zigzag type transformers testing is very easy and will not require the installation of jumpers or the use of relay matrix circuits. The single or real 3 phase voltage output up to 275V contributes to higher magnetisation currents and therefore stronger flux for better signal reflection on secondary and/or tertiary windings allowing more accurate results. The ART-3D ™phase displacement measurements enables for simple detection of the transformer vector group.


  • Test Leads (15m / 50ft)
  • Tap Changer Cable
  • Ground Cable
  • Power Cable
  • PC Software for remote control
  • Calibration Certificate
  • Shipping Case (optional)
ART-3D instrument 004
Data Sheet
User Manual