Vorrichtung zur Feststellung und/oder Überwachung eines vorbestimmten Füllstands in einem Behälter
摘要
The device for finding and/or monitoring a predetermined level of contents of a container comprises a sensor for the level of the contents of the container to be monitored which contacts the contents when the predetermined level is reached. An exciting arrangement causes the sensor to vibrate mechanically at its natural resonant frequency. An assessment circuit is used to trigger display and/or switching processes depending upon whether the frequency of the mechanical vibrations of the sensor exceeds or lies below a switching frequency. The sensor is associated with an electrical component having a characteristic bearing a definite relationship to the natural resonant frequency of the sensor. The switching frequency is set in the assessment circuit according to the value of the characteristic of the electrical component. The assessment circuit is thus automatically matched to sensors with different natural resonant frequencies. The electrical component is preferably a resistor, the resistance of which is the characteristic.