What is an LVDT?

LVDT (Linear Variable Differential Transformer) is a type of electrical transformer used for measuring linear displacement (position). It is known for its high precision, robustness, and frictionless operation.

How it Works

It consists of three coils placed end-to-end around a tube. A ferromagnetic core attached to the object being measured moves inside this tube.

Primary Coil: Excited by an AC source.
Secondary Coils: The movement of the core changes the induced voltage in the secondary coils.

The difference in voltage between the two secondary coils is proportional to the position of the core.

Advantages

Friaction-free: Non-contact measurement means infinite mechanical life.
High Resolution: Can measure movements down to micrometers.
Robustness: Resistant to shock and vibration.

LVDTs are often used with precision conditioners or Data Acquisition Systems to monitor structural health or machine geometry.