The transducer using the change in distance between the plates.
Variable area capacitance displacement sensor.
The conducting surfaces forming the capacitor are insulated.
The permittivity of the air is ε 0 8.
In the variable area type capacitive sensor taking the parallel plate capacitor as an example when the upper plate moves the relative coverage area between the two plates changes thereby causing a change in capacitance.
The capacitive transducer or sensor is nothing but the capacitor with variable capacitance.
Measuring displacement using capacitive sensor.
For the measurement of object displacement one plate of the capacitance transducer is kept fixed while the other plate is connected to the object.
The capacitor transducers are used for the measurement of linear and angular displacement.
A variable dielectric capacitive displacement sensor consists of two square metal plates of side 5 cm separated by a gap of 1 mm.
Capacitive displacement sensors are used in a wide variety of applications including semiconductor processing assembly of precision equipment such.
Capacitance of a parallel plates capacitor is determined by the formula c ε a d where a is the plate square d is a distance between plates and ε is a permittivity of the material between the plates.
They are also able to measure the thickness or density of non conductive materials.
A sheet of dielectric material 1 mm thick and of the same area as the plates can be slid between them as shown in the figure.
This uses the concept of change of capacitance by a change in overlapping area and distance between the capacitor plates.
2 variable area capacitive sensor.
854 10 12 f m.
In the typical capacitor the distance between the two plates is fixed but in variable capacitance transducers the distance between the two plates.
Applications for capacitive sensors.
This post answers the question how capacitive displacement sensor works.
A variable capacitance sensor is constructed with its capacitance plates connected at their center.
Capacitive displacement sensors are non contact devices capable of high resolution measurement of the position and or change of position of any conductive target.
A transducer using the change in the area of plates.
The capacitive transducer comprises of two parallel metal plates that are separated by the material such as air which is called as the dielectric material.
The change in capacitance producted by a displacement in response to supplied pressure or force is increased by maximizing the displacement at peripheral regions having the largest area.
