Torsion & Twist

Torsional vibration measurement and analysis

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The Instantaneous angular Velocity Converter (IVC) provides instantaneous angular velocity signal to be analyzed.


  • Integrated Frequency to Voltage converter
  • Cross Phase Tracking: the order cross-phase relatively to a reference channel for torsional resonances at specific orders identification
  • Virtual inputs compute the static and dynamic twist from 2 tachometers’ signals

Main Features

  • No additional hardware to the standard 3-Series analyzers
  • Up to 6 torsional inputs per analyzer
  • Up to 1,024 pls/rev and 30,000 RPM (with a 5° resolution)
  • High accuracy with 6.4 MHz over-sampling
  • Record and analyze synchronously with standard AC/DC/ICP inputs
  • Real-time and post-processing
  • Torsional vibrations export (UFF, MAT, txt, SDF, wav, etc..)
  • Spectral, order, time domain, overall, waterfall analyses of the torsional channels
  • Missing pulses management
  • Angle, angular velocity and angular acceleration with integration and differentiation filters

Integrated frequency to voltage converters

The 3-Series analyzers integrate the frequency to voltage converters based on the existing external synch. inputs, used for the measurement of torsional vibration. The Instantaneous angular Velocity Converter software option converts it in an instantaneous angular velocity signal available for the analysis plug-ins. With NVGate, the software platform for OROS 3-Series analyzers, the analyses can be real-time and/or post-processed.


The instantaneous angular velocity can be converted to angular position or to angular acceleration using the digital integration and differentiation filters. The obtained angular signal is processed as any other input (or recorded track) of the analyzer. The typical analysis modes are FFT, the order tracking, time domain analysis and waterfall/color spectrogram.

Shaft View and Cross Phase Tracking

Some special features are available for the analysis of this angular signal:

  • The shaft view shows the instantaneous angular signal along one or multiple revolution.
  • The cross-phase tracking extracts the cross-phase order by order between one reference channel and all the others. It is useful for the identification of torsional resonances at specific orders and the evaluation of their amplitudes.

Torsion & Twist sensor

An interference-free and non contact high speed optical fiber sensor providing up to to 260k pulses/sec from an optical fiber probe is the perfect tool for measurement.

  • Optical fiber sensor
  • Accurate
  • Conditioning, cables and accessories included


Application-oriented for your Efficiency

  • Marine propulsion certification and maintenance
  • Wind turbines, gearboxes and transmissions monitoring and maintenance
  • Electric power generators maintenance
  • Engine service belt drive (alternators, compressors, pumps) R&D
  • Aircraft propellers engines and transmissions R&D
  • Industrial drive train tests, monitoring, maintenance and noise diagnostics

All our software solutions are customizable to be integrated in your environment. Please contact our the OROS Customer Care Department and visit the customization services webpage.