vibration sensors selection guide      vibration sensors selection guide    vibration sensors selection guide

Image credit: PCB Piezotronics | Electro-Sensors, Inc. | Dytran Instruments

 

Vibration sensors are sensors for measuring, displaying, and analyzing linear velocity, displacement and proximity, or acceleration.

 

Purpose of Vibration Measurement

Vibration — however subtle and unnoticed by human senses — is a telltale sign of machine condition. Abnormal vibration indicative of problems with an industrial machine can be detected early and repaired before the event of machine failure; because such a failure is potentially costly in terms of time, cost, and productivity, vibration measurement allows industrial plants to increase efficiency and save money. Therefore, vibration analysis is used as a tool to determine equipment condition as well as the specific location and type of problems.

 

The video below describes the construction and use of a typical vibration sensor. (This particular sensor is a switch and features an adjustable actuation point, as shown.) The ISO 10816 referenced in the video is one of the most important vibration measurement standards and is described in more detail below.

 

Video credit: IFM

 

Vibration Severity

The severity of machine vibration is standardized by the International Standards Organization (ISO) in the ISO 10816 publication. The standard describes acceptable vibration levels for four different classes of machines. This data, as laid out in the chart below, proves useful as a reference point when analyzing vibration measurements.

 

vibration sensors selection guide

Guide to vibration severity per ISO 10816. Image credit: Reliability Direct


Form Factor and Construction

This page classifies various devices — including sensors (or transducers), transmitters, and switches for vibration measurement — under the blanket term "vibration sensor." Many devices which are not nominally considered vibration sensors can be used for vibration measurement; for example, accelerometers are frequently used to measure vibration as well as acceleration. Basic vibration sensor types are described below.

 

  • Vibration sensors are simply packaged as a raw sensor. Vibration transducers are slightly more complex sensors which output a voltage or current signal.
  • Vibration transmitters are sensors packaged with the means (such as integral signal conditioners) to transmit a more complex output.
  • Vibration switches use an integral sensor to make or break contact when certain vibration levels are detected.

vibration sensors selection guide

A typical raw vibration sensor. This device would include a connector to allow transmission of an output signal.

Image credit: Carleton University

 

Applications and Industries

The table below describes the industries which commonly use vibration measurement, as well as the product traits for sensors designed for each. The unique characteristics of each industry determine ideal sensor characteristics; for example, the very slow rotation of turbines in the mining and wind power industries results in the use of a vibration sensor with a very low frequency response of around 1 Hz or less. In contrast, the oil and gas industry requires high frequency (greater than 10 Hz - 10 kHz) sensors to cope with the faster rotation of turbines and gears.

 

 

Industry

Frequency

Physical considerations

Special features

Food and beverage

Low

Small size and profile

Must be resistant to corrosion from chemicals and cleaning fluids; able to withstand frequent washdown.

Metalworking

Low

Robust (to withstand flying debris)

Corrosion-resistant; high signal-to-noise ratio for detecting defective bearings.

Mining

Very low

Robust

Corrosion-resistant; high signal-to-noise ratio.

Oil and gas

High

Varies

Suitable for hazardous area use; precise monitoring; integral RFI shielding.

Paper

Low

Varies

Temperature-resistant; high signal-to-noise ratio; fluid-resistant.

Portable (specialized)

Varies

Small and durable for portability

Features vary depending on frequency and application.

Power generation

Higher

Varies

Measures both velocity and acceleration; precise sensitivity; RFI shielding for high voltage environments; heat-resistant.

Wind power

Very low

Small and compact

Integral cable and standardized package to simplify installation on many different turbines.

 

 

Standards

Standards related to vibration measurement are published and maintained by numerous standards bodies. Examples of these include:

 

  • BS 7385 (Evaluation and measurement for vibration in buildings)
  • SAA AS 2625.1 (Evaluation of machine vibration by measurements on non-rotating parts)
  • ISO 10816 (Evaluation of mechanical vibration on non-rotating parts)

 

References

 

National Instruments - Vibration Sensors

 

Read user Insights about Vibration Sensors

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