Pressure Transducers

A pressure transducer is a measuring device which converts an applied pressure into an electrical signal. Generally, a pressure transducer consists of two parts, an elastic material which deforms under the application of pressure and an electrical part which detects this deformation.

How low pressure transducers work

Depending on the range of pressures to be measured the elastic material is given different shapes and sizes, such as bourdon tube, piston, diaphragm, and bellows. Most common among them is the diaphragm.

Three different types of electrical device can be attached to this elastic material to make pressure transducers. These include resistive, capacitive and inductive types.

• Resistive pressure transducers uses strain gauges, which are bonded the deformable material. Any change in the deformation causes the change in the electrical resistance of each strain gauge which can be measured by a Wheatstone bridge.
• In the capacitance type pressure transducers, change in pressure is measured change in capacitance between two capacitance plates. One plate bonded to the deformable side of the elastic material while other one is bonded to the unpressurized surface.
• In inductive pressure transducer the deformation of the elastic material is used to provide linear movement of a ferromagnetic core. This linear movement will vary the induced AC current.