Capacitive Proximity Sensors

Capacitive proximity sensors are a type of sensor that can detect metallic and non-metallic materials. They can detect and measure materials that are conductive or have a greater dielectric constant than air. They are able to detect materials in solid form, in powder form or in granulate.
How do they work?
Capacitive sensors use an electrical field to detect objects. Any changes in capacitance in the sensing area are detected by the sensor, which then changes state.
What are they used for?
Capacitive proximity sensors are incredibly versatile as they are able to sense both ferrous and non-ferrous materials. These sensors are frequently found within the automotive industry, in the food industry and within storage and conveyor systems. Capacitive proximity sensors can be used to detect liquid through non-ferrous materials such as glass or plastic. Typical applications include the induction moulding process, liquid level detection and material level control.
Things to consider
Capacitive proximity sensors are ideal for sensing all sorts of materials, but you must keep them away from non-target materials. Non-target materials can potentially interfere with the sensor, and provide inaccurate or incorrect readings.
Capacitive proximity sensors have an excellent life span and are highly reliable. They are resistant to fault and contaminants such as dust and spray particles have very little impact on them. However, you should bear in mind that they can be a little slower to provide a reading that inductive sensors.