Capacitive sensor

Capacitive sensors are non-contact and non-contact electrical sensors that work against metals and often non-metals.
These sensors are suitable for level control in tanks filled with powder, liquid and granular materials.

They can also be used as pulse generators to control the program status of machines for counters and to detect almost all metallic and non-metallic materials.
Capacitive sensors are another type of proximity sensor.
These sensors are very similar to induction sensors.
The main differences of this induction sensor are that the induction sensor produces an electromagnetic field.

As a result, the induction sensor is only capable of detecting metallic materials, but the capacitive sensor, in addition to metallic materials, is also capable of detecting non-metallic materials such as glass, paper, plastic, liquids and fabrics.

These sensors are usually made in the form of cylinders in diameters of 30-18-12-6 mm or plastic or metal bodies, and of course in some special cases are made in the form of cubes as well as other shapes.

Capacitor sensors are based on measuring the change in capacitance of a capacitor in an RC resonance circuit due to the proximity of metal or non-metal components.

The main part of the oscillator consists of two metal parts, the position of these parts in relation to each other is such that it creates a capacitive capacity.

Whenever a component with a dielectric constant approaches the sensitive plate, it changes the capacitance between the metal parts, which changes the output amplitude of the oscillator by the demodulator compared to the apparent reference value.

Whenever the amplitude of the oscillator is greater than the reference value, the sensor output is activated.