Capacitance of the Capacitive Transducers
The capacitance C between the two plates of capacitive transducers is given by:
C = εo x εr x A/ d
Where C is the capacitance of the capacitor or the variable capacitance transducer
εo is the absolute permittivity
εr is the relative permittivity
The product of εo & εr is also called as the dielectric constant of the capacitive transducer.
A is the area of the plates
D is the distance between the plates
It is clear from the above formula that capacitance of the capacitive transducer depends on the area of the plates and the distance between the plates. The capacitance of the capacitive transducer also changes with the dielectric constant of the dielectric material used in it.
Thus the capacitance of the variable capacitance transducer can change with the change of the dielectric material, change in the area of the plates and the distance between the plates. Depending on the parameter that changes for the capacitive transducers, they are of three types as mentioned below.