The capacitive transducer works on the principle of change of capacitance which may be caused by a change in

1. Dielectric constant

2. The overlapping area of plates

3. Distance between the plate

• Capacitive transducers are used for the measurement of displacement, pressure, and other physical quantities.

• It works on the principle of variable capacitances.
• The schematic diagram of a parallel plate capacitive transducer is shown in the figure:

The capacitance of a parallel plate is mathematically defined as:

\(C = \frac{{\varepsilon A}}{d}\)

Observations:

From the given formula, we observe that the capacitance of the capacitive transducer can change because of the following:

1. The overlapping area of plates
2. Change in the distance between the plates and
3. Dielectric constant

ϵ = dielectric constant

A = area of plates.

d = distance between the plates