Capacitive

Capacitive proximity sensors are non-contact sensors that can detect metallic and non-metallic targets through changes in capacitance between the sensor and target material. Capacitive sensors require the target to be relatively close <50mm and come in shielded or unshielded housings to be mounted flush (embedded) or non-flush (non-embedded) in metal. Capacitive proximity sensor is designed to monitor levels of liquids and dry bulk material in nonmetallic tanks. It can detect both conductive and non-conductive materials, but is most commonly used for sensing plastics, liquids, powders and granular materials. It does not require contact with the medium being monitored.