The capacitive sensor basically functions like an open capacitor. An electrical field is formed between the measuring electrode and the GND electrode. If a material with a dielectric constant εr greater than air enters the electrical field, the capacity of the field increases depending on the εr of this material. The electronics measure this capacity increase, the generated signal is conditioned during subsequent signal processing and causes output switching at a corresponding magnitude.
Flush-mountable and non-flush mounting procedure
Flush mounting of flush-mountable capacitive sensors is possible in all materials. The minimum distance between the sensors must be observed. For non-flush mountable capacitive sensors, a free zone must be created around the sensor head which must not contain any damping material.
Flyer – Flat capacitive sensor CFDK 25
Catalog – Product Overview – Innovative Sensor Solutions
Application Report – Greater sensing distances for capacitive sensors