What Is an LVDT Displacement Transducer?

A linear variable differential transformer, or LVDT, is a type of transducer used for measuring linear displacement. Known as one of the most robust, reliable sensors available on the market, LVDTs from Cooper Instrument & Systems are long-term solutions with a virtually infinite lifespan.


How Do They Work?


An LVDT displacement transducer is made up of one primary and two secondary coils. A magnetic core (armature) controls the transfer of current between the primary coil and the secondary coils. The two secondary coils are connected in opposition and, because they are equal, read zero on the sensor output. As the armature moves away from center, one of the position sensors increases and the other decreases. The result is an output from the measurement sensor.


What Are LVDTs Used for?


Because of their durability and accuracy, LVDTs are used for a variety of applications. There is a long list of common uses, but some of the most popular include testing soil strength, controlling pill production, inspecting assembly lines, and monitoring fluid levels.


Why Choose LVDTs?


The biggest strength of the LVDT sensor is its ability to function with no electrical interaction across the transducer position sensing element. The result is clean data and infinite resolution. Other benefits include an unlimited mechanical life, single-axis sensitivity, environmentally-strong construction, and fast response times. All of these features combine to make an LVDT sensor a sound investment for the future.


At Cooper Instruments & Systems, we offer two types of LVDTs. Both the AC/AC and DC/DC versions can be purchased with captive, unguided, or spring return armatures. Click here to view LVDTs in our catalog.


As always, if you have any questions related to this material, our support staff at Cooper Instruments is available to help. Contact them by calling (800) 344-3921 or emailing


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