A device which has a deliverable sensor, a container for receiving a liquid, a container environment and a signal processing circuit, the input side of which can be connected circuitry-wise to the sensor. The device is designed to perform a capacitive liquid level measurement in normal operation using the sensor, wherein a threshold value can be predefined for the signal processing circuit for normal operation. The device has a classification module which can be connected with an input side or line connection circuitry-wise to the sensor, is designed to make a capacitive measurement of the liquid in the container using the sensor and can be connected circuitry-wise to the signal processing circuit in order to trigger the specification of a threshold value using the sensor for capacitive measurement of the liquid.