Capacitive sensors

• Outstanding longevity and high process safety by non-contact sensing principle
  • Switching distance up to 30 mm and particularly flat design enable installation in a protected position and close to the process
• Reliable detection of many different object materials
  • Independent of color, gloss or  surface properties
  • Insensitive to dust and dirt
  • Sensors with flush installation are especially recommended for non-conductive (dielectric) media
  • Designs for non-flush installation are ideal for detecting conductive media and filling levels

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.