Liquid soiling level determination device detects damping of oscillator coupled to measuring sensor with inductive-capacitive oscillation circuit

摘要

The soiling level determination device uses a measuring sensor (1) with an inductive-capacitive oscillation circuit, coupled to an oscillator (2) with a frequency tuning device (3), a measuring and evaluation circuit (4) determining the damping of the oscillator for providing a signal representing the soiling level. The measuring sensor is provided by a single conductor with a contactless energy coupling between the oscillator and the measuring sensor.