Patent ID: 8955377
Filing Date: 2015-02-17
Classification: G01F

Abstract:
1. A method for determining or monitoring a predetermined fill level, a phase boundary or a density of a medium in a container with an oscillatable unit, comprising the steps of: placing the oscillatable unit at the height of the predetermined fill level; exciting the oscillatable unit to oscillate by means of a frequency scanning operation within a predeterminable frequency band in the working range of the oscillatable unit successively with discrete exciter frequencies following one another; receiving the corresponding oscillations of the oscillatable unit in the form of received signals; ascertaining the exciter frequency in the frequency scanning operation, at which the oscillatable unit oscillates with an oscillation frequency, which has a predetermined phase shift between the transmission signal and the received signal; and the transmitting/receiving unit excites the oscillatable unit to oscillate with the oscillation frequency ascertained or wherein a subsequent frequency scanning operation is started, wherein: the oscillation frequency at the predetermined phase shift between the transmission signal and the received signal is ascertained by evaluating amplitudes of the received signals received by the transmitting/receiving unit or by evaluating phase shift between the transmission signal and the received signal.