## Capacitive transducer

In this article we explain the capacitive transducer, the transducer is a device used to convert one form of energy to another form, the transducer is called the convertors and in some cases, they are used to measure the quantities by using the conversion action.

The capacitive transducer is the device used to measure many quantities using the variable capacitance.

We try to explain some of the pieces of information about the capacitive transducer, which includes the working and applications of capacitive transducer.

## Capacitive transducer is used for

The capacitive transducer is used for measuring the quantities like distance, volume, density, water level and……etc.

The main principle behind the capacitive transducer is the variations in capacitance.

## The capacitive transducer works on the principle of

The figure shows the model of the capacitive transducer, so from the figure, we get a basic idea of its working principle.

• The capacitive transducer work with a principle called a variable capacitor.
• As per the above structure, the transducer has two parallel metal plates which will have a proper distance between them and also they separate with a dielectric material.
• This means the distance between two metal plates varies the capacitance.
• The only difference the capacitive transducer makes with the common capacitor is that the general capacitor has fixed plates.
• But at the capacitive transducer, the parallel plates are movable, which makes it a variable capacitor.

C = εo εr A/ d

C= indicate the capacitance

εo= indicate the permittivity of free space

εr= indicate the relative permittivity

A= indicate the area of the plate

D= indicate the distance between the plates

• This capacitance formula shows the factor responsible for the change.
• From the formula, we can see the distance is inversely proportional to the capacitance.

## Application of capacitive transducer

• Measure humidity in the gas
• Measure volume
• Measure liquid level
• Measure density
• The measure of linear angular displacement
• Measure brake disc
• Dynamic at turbines or engine measure with it
• Thickness measure
• Measure for force or pressure
• Measure the weight
• Measure the temperature

## Capacitive transducer displays

The capacitive transducer screen displays or called the capacitive sensor, at projected capacitive touch or (PCT) technology utilizes the capacitance property.

The pressure variations at the screen due to the sensations of touch will be used to make touch screens.