The TVS™ and TVS+™ systems accurately measure speed, torque, and torsional vibration.

Torsional Vibration Measurement

Torsional vibration measurements help you avoid downtime and surprises.

Torsional vibration is the angular vibration of a shaft about its axis of rotation.  It can be induced by variations in shaft load, unbalance, or bearing degradation, or other undesirable characteristics of the drivetrain. 

For example, Variable Frequency Drives (VFD) are notorious for generating torsional vibration in the coupled shaft.  More generally, the dynamic behavior of the whole drivetrain consisting of the driving force (turbine, VFD or other motor), the coupling shaft, and the driven load (such as compressor, alternator, or pump) generates torsional vibration at given speed and acceleration conditions.

Other phenomena such as fluctuations in the available electrical power can also generate swings which induce torsional vibration.

Torsional vibration frequency is assessed by measuring variations in shaft speed at high resolution.  Torsional vibration amplitude is determined by measuring the twist angle between two locations on the shaft.

Torsional vibration is usually not monitored continuously, resulting in unplanned failure.  Common failures happen in the coupling shaft. Both disc couplings and diaphragm couplings have experienced torsional failures.

Torsional vibration measurements help identify issues in rotating equipment in lieu of scheduled maintenance intervals or prior to catastrophic failure.  Foreknowledge of a problem before failure and avoiding premature maintenance, results in less down-time and lower maintenance costs.

Torsional vibration on a piece of equipment can occur as a transient phenomenon during ramp up or ramp down while crossing specific speeds and frequencies of rotation.  It is essential for the operator to know where the torsional vibration frequencies are, to determine a safe range of operation and to avoid running for prolonged durations at damaging speeds.

Our TVS™ and TVS+™ systems measure torsional vibration of your equipment optically.


Torque Measurement

Torque measurement helps you plan your machine preventive maintenance intelligently.

Accurate torque measurement is critical to understanding the health of the rotating system. Torque monitoring over time can alert the user to system degradation.  For example, wear in pump seals decrease the pump efficiency over time; these show as a variation in torque over time.  Monitoring changes in torque through continuous measurement of shaft twist is a reliable way to alert an operator to the need of preventive or corrective maintenance.

Continuous torque monitoring is also a reliable way to detect system aberrations or over-torque conditions that are leading indicators of system failure.  Setting alarms based on detection of these anomalous torque events allows operators to perform inspection of the machinery, avoiding further degradation of the equipment.

Additionally, combining the TVS+™ torque and speed measurement results in a high accuracy measurement of shaft power and enables precise calculation of system efficiency.


Accurate shaft speed measurement

Hold your system accountable to the speed limits.  Speed measurement helps you ensure that your system is operating as intended.  Speed is critical in a variety of applications across industries.

  • In power generation speed changes can lead to fluctuations in frequency of the AC power produced.
  • In films and paper manufacturing variations in roller speed can lead to inconsistent product dimensions and scrap.
  • In automotive and industrial environments variation in speed can be an identifier of unbalance in the system.

Taking accurate real time speed measurements can allow you to automate system shut down before failure, identify out of tolerance product, and account for variation in your manufacturing system.  Our TVS™ system accurately measures speed and speed variation of your rotating assembly.


Using TVS™ to Measure Speed, Torque, and Torsional Vibration

These measurements can be achieved several ways, but the greatest advantages of our optical system approach are that:

  • Optical systems are intrinsically safe and immune to electromagnetic interference.  The optical probes can be located in any ATEX zone.  Long optical leads allow the instrumentation to be located remotely, away from the hazardous area.  Instrumentation can also be enclosed in an ATEX rated enclosure.
  • The sensor does not need to make contact with the shaft in order to give high accuracy measurement. Rotating systems are sensitive to balance and loading conditions, by opting for a non-contact sensor you avoid these potential risks.
  • Optical sensors are easy to install, with very little to no modification to the shaft.  One version of our product does not require any marking or change to the shaft. Another version only requires a rugged label to be affixed in two places on the shaft.
  • Installation of the system can be done both retroactively on existing systems or designed into the system upon conception.

The ease of installation combined with the minimally invasive aspect of the sensor system makes it an ideal measurement tool for a variety of applications and environments.


Product Details

TVS™ Product Family

TVS™ Torsional Vibration Measurement System

TVS+™ Torque and Torsional Vibration System