Using LVDTs for Vibration Measurement

Written by transtek_admin on 05/28/2025

Linear Variable Differential Transformers (LVDTs) are precision sensors well known for their reliability in position measurement applications. While they are not the first choice for typical vibration measurement uses, LVDTs do offer advantages for specific applications when certain conditions exist. Typically, these are ones where measurement of both movement and vibration is required. Today, we’ll look at a few examples where LVDTs have proven to be a good choice for vibration measurement.

The LVDT Advantage

We’ll admit it: accelerometers excel at measuring high-frequency vibrations. They are great for monitoring rotating components in predictive maintenance applications and similar uses. However, accelerometers might not capture longer-stroke movements effectively. This is where LVDTs shine – when both vibration and significant displacement need to be monitored.

A great example of this is structural monitoring. For instance, TTI has supplied LVDTs to Mount Rushmore, where they monitor both immediate vibration, and also whether cracks are widening over time. Cracks are monitored by identifying significant positional changes in the rock face. It’s critical to have this data so that park managers can respond to significant changes, determine the source, and hopefully mitigate issues before significant damage occurs.

Structural Vibration Testing Applications

For earthquake monitoring, LVDTs have also proven invaluable. When testing scale models of skyscrapers, researchers use LVDTs to monitor both the high-frequency vibrations and the slower sway movements at the same time. It’s another example where the dual capability provides comprehensive data that single-purpose vibration sensors cannot deliver alone.

Another good structural example is bridge monitoring. Here, engineers need to track both vibration characteristics and structural shifting. LVDTs mounted between fixed and moving sections will capture data for both efficiently. Learning of these changes and responding to them early on could prevent costly damage or major catastrophes well in advance.

Automotive Vibration Testing

LVDTs are found in auto manufacturing for testing shock absorbers and tires. Cars on the road are subject to intense vibrations when traveling over rough pavement, or longer-stroke movements, such as hitting potholes. It’s important for auto manufacturers to test for these conditions on the factory floor so they can improve suspension systems for a safer and more comfortable ride.

With accelerated wear testing, manufacturers simulate thousands of miles of travel under various conditions in short periods of time. In this case, LVDTs help collect comprehensive data, combining high-frequency vibration information with displacement measurements to predict real-world performance and durability.

Harsh Environments

You’ve certainly heard us say it before, but here it is again: a key defining feature of an LVDTs is their ruggedness. They are analog devices with relatively simple construction, but in the case of specialty vibration scenarios, that is a major advantage. These characteristics are particularly beneficial for challenging environments where more sensitive electronics might fail.

Limitations

LVDTs do have some limitations when it comes to vibration measurement. The biggest one is frequency response. This means that for very small rapid movements, such as those found in turbines or generators for instance, an LVDT may not have sufficient response time. For these use cases, piezoelectric accelerometers or non-contact methods like laser-based alternatives are likely the better choice.

Conclusion

LVDTs certainly have their place in vibration measurement. This is particularly true when the application requires a combination of displacement tracking, durability in harsh conditions, and reliable performance over time.

Posted Under: LVTDs

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