Abstract: Flow sensors for, and a method of monitoring, a condensate drain. The method includes a) providing a flow sensor for detecting flow properties in a pipe and/or fitting carrying a medium, b) detecting a vibration behavior by means of a vibration converter at a measurement location provided on the flow sensor, and c) electronically evaluating the vibration behavior of a vibration body, wherein at the measurement location vibrations of a first region of the vibration body and a second region of the vibration body are recorded. The first region of the vibration body is provided at least partially in or adjacent to the flow of the medium, and the second region of the vibration body is outside the flow.

Abstract: Method of testing the functionality of condensate dischargers. Any ultrasonic vibrations present in the condensate discharger are picked up with an ultrasonic vibration sensor and transformed into an electric output signal. The latter is compared in an evaluation unit with stored data. A test result is then formed based on predetermined decision criteria. The test is carried out over a predetermined test duration, within which instantaneous values of the ultrasonic vibrations are picked up at predetermined times and, if need be, smoothed. The test result is based on the instantaneous values.