Capacitive Transducers Construction and Working Principle, Application in Electronic Instrumentation

Capacitive Transducer used to measure displacement, pressure and other several physical quantities so as per its construction these are having two parallel pates which are maintaining the distance. and In between them, dielectric medium such as air or oil can be filled. So, the distance between these two metal plates can change its capacitance value. and also capacitance varied due to change in dielectric medium. so here capacitance value can be measured by above formula. here A indicates the area of the plates and D indicates the distance between the plates. So according to this formula, the variable capacitance value is dependent on four important parameters. They are the distance between the plates, area of plates, permittivity of free space, relative permittivity, and dielectric material. These parameters can be vary capacitance value. and here dielectric medium and area of the plates are kept constant. but, When the plates are moving then distance is varied and this results in changing of capacitance value of capacitive transducer and it requires external power to operate. so in this way we can measure displacement with the help of Capacitive Transducer