Inductance-Type Transducers:

The inductance-type transducer consists of three categories: a coil, a movable magnetic core, and a pressure sensing element. The components are attached to the core, and as pressure varies, the components cause the core to move within the coil. An AC voltage is applied to the coil, and, as the core moves, the inductance of the coil changes. A current by the coil will rise as the inductance decreases. For increased sensitivity, the coil could be separated into two coils through utilizing a center tap, as display in Figure. As the core moves inside the coils, the inductance of one coil will raise, although the other will decrease.

Figure: Inductance-Type Pressure Transducer Coil