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PRT & MRT range

PRT & MRT range


Measuring bridge or high accuracy digital ratiometer allowing the direct measurement of the ratio and the phase error of all types of power transformers and auto-transformers (single & three phase), as well as instrument transformers CT, PT, CVT.

Main caracteristics

- Test voltages: 4 single voltages and/or 3-phase voltages
- Ratios measurement: 0,1/1 to 20 000/1
- Accuracy of ratio measurement: <= 0,02 %
- Phase angle error: 0,00° to ± 180,00 °
- Angle index: 0-11 & ± 180,00 °

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Full description

After more than 80 years of design and manufacturing of bridges and measuring instruments of all types, Vettiner now offers two ranges of high precision measurement devices of transformation ratio and transformers phase shift.

Historically the PRT range that has made the reputation of Vettiner for over 80 years is based on a measuring bridge based on a Weatstone Bridge allowing accuracies never reached with the current digital ratiometers. Measurement uncertainty can be reduced to 0.02% with this type of measuring bridge, which identifies where applicable, a defective coil, more or less on a transformer primary can count eg 5000 turns.

On the other hand, Vettiner developed for twenty years a range of digital ratiometers, MRT range, based on a high accuracy vector measurement of voltage and current at the transformers primary and secondary. The MRT range precisely measures ratios and phase shifts with a measurement uncertainty of less than or equal to 0.05%, allowing the identification, where applicable, of a defective coil, on a transformer primary coil that can count eg 2000 turns.

One of the specificities of Vettiner is to have been able to develop customized solutions and control processors such as Digital Bridges measurement and ratiometers to identify not only the numbers of turns defects, connection / polarity in the windings, inversion of wrong connections of the switch for manufacturers and repair companies of transformers, but also open windings, short circuit between turns for operators and maintenance companies. Last but not least, a major benefit of Vettiner MRT measuring devices lies in the identification of abnormalities in new magnetic circuits or in operation, thanks to its sensitivity that of most other competitive ratiometers cannot offer.

The PRT and MRT lines are therefore dedicated to both power transformers and power auto-transformers manufacturers as well as repair or maintenance companies of national or local power networks (in-house industrial networks included). The range also allow for simple quick checks of transformation ratio of instrument transformers.