TVS plus torsional vibration sensorThe TVS™ and TVS+™ systems accurately measure speed and torsional vibration in rotating machinery.  They can be used for temporary measurement or for permanent installation.  Additionally, our sensors measure torque and the TVS+™ product also measure axial displacement of the coupling.

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

Torsional vibration, speed, and torque measurements can be achieved several ways, but the greatest advantages of our optical system approach are:

  • Portability - The instruments can be used as quick troubleshooting tools or permanently installed to the machinery for condition monitoring of torque and torsional vibration.
  • Ease of Installation - Our optical sensors are easy to install, with very little to no modification to the shaft.  One version of our product, called TVS+™, only requires a rugged label to be affixed in two places on the shaft.  The other version, simply called TVS™, does not require any marking or change to the shaft.
  • Intrinsically Safe - 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.
  • Non-Contact - 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.
  • Easy Retrofit - Installation of the sensor 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.

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, 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 vibrations 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.  This can be performed in a single plane with a single sensor; however, a 2-plane, 2-sensor arrangement will give more accurate data, allowing differentiation between synchronous speed changes and actual torsional vibration.

Torsional vibration amplitude is determined by measuring the twist angle between two locations on the shaft.  This requires a dual-plane, dual-probe sensor.  Knowledge of amplitude is a critical factor in determining if a torsional vibration poses a high cycle or low cycle fatigue problem or if the vibration is benign for the sizing of 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.  Failures in other components, although not as frequent, also happen.

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.

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.

Product Details

TVS™ Product Family

TVS™ Torsional Vibration Measurement System

TVS+™ Torque and Torsional Vibration System