Glossary · Sensors and measurement
Capacitive sensor
German: Kapazitiver Sensor
In measurement technology, a capacitive sensor is a sensor that converts a change in electrical capacitance into a signal. The capacitance changes with the distance between electrodes, their overlap or the dielectric material between them.
- Sensors
In one sentence
A capacitive sensor turns a change in capacitance, caused by distance, overlap or material, into a signal for detection or measurement.
Example
A capacitive level probe in a tank measures the continuous level of a non-conductive liquid from the change in capacitance between the probe and the tank wall.
How it applies
- Engineering: Capacitive sensors appear as proximity switches, level probes, displacement sensors and inside MEMS accelerometers, pressure and humidity sensors. The choice depends on whether a switching output or a continuous value is needed.
- Commissioning: Capacitive measurements depend on the dielectric constant of the medium. A change of product, temperature or moisture can shift the reading, so adjustment is done with the real medium.
- Documentation: For each capacitive measuring point, record the medium it was adjusted for. Change procedures should trigger a check when the medium changes.
Capacitive sensor vs. capacitive proximity sensor
Capacitive sensor names the physical principle. A Capacitive proximity sensor is one kind that detects objects and usually has a switching output. Capacitive level probes and displacement sensors are other kinds that deliver a continuous value.