Method for determining and/or monitoring a predeterminable filling level of a medium in a container by means of a vibronic sensor , with at least one sensor unit with a mechanically vibrating unit comprising the following method steps: - Excitation of the mechanically vibrating unit to mechanical vibrations by means of an excitation signal (U A ) and reception of the mechanical vibrations in the form of a reception signal (U E ), - Determine an amplitude (A) and a frequency (f) of the received signal (U E ), - comparing the frequency (f) and the amplitude (A) of the received signal (U E ) with a predeterminable frequency limit value (f ref ) and a predeterminable amplitude limit value (A ref ), and - Determining whether the predeterminable fill level has been reached by comparing the frequency (f) and the amplitude (A) of the received signal (U E ) with the predeterminable frequency limit value (f ref ) and the predeterminable amplitude limit value (A ref ), characterized in that that in the event of a change in amplitude (A), it is concluded that the vibrating unit is covered by a foam or that a sediment is present in the medium in the area of the vibrating unit , that in the event of a change in amplitude (A) and in the event of a constant frequency (f), the presence of the sediment in the medium in the region of the oscillating unit and that in the event of a change in the amplitude (A) and in the event of a change in the frequency (f), whereby the predeterminable frequency limit value (f ref ) is not exceeded or undershot, the presence of the sediment in the medium in the region of the oscillating unit or the coverage by the foam is concluded. with at least one sensor unit with a mechanically vibrating unit comprising the following method steps: - Excitation of the mechanically vibrating unit to mechanical vibrations by means of an excitation signal (U A ) and reception of the mechanical vibrations in the form of a reception signal (U E ), - Determine an amplitude (A) and a frequency (f) of the received signal (U E ), - comparing the frequency (f) and the amplitude (A) of the received signal (U E ) with a predeterminable frequency limit value (f ref ) and a predeterminable amplitude limit value (A ref ), and - Determining whether the predeterminable fill level has been reached by comparing the frequency (f) and the amplitude (A) of the received signal (U E ) with the predeterminable frequency limit value (f ref ) and the predeterminable amplitude limit value (A ref ), - Excitation of the mechanically vibrating unit to mechanical vibrations by means of an excitation signal (U A ) and reception of the mechanical vibrations in the form of a reception signal (U E ), - Determine an amplitude (A) and a frequency (f) of the received signal (U E ), - comparing the frequency (f) and the amplitude (A) of the received signal (U E ) with a predeterminable frequency limit value (f ref ) and a predeterminable amplitude limit value (A ref ), and - Determining whether the predeterminable fill level has been reached by comparing the frequency (f) and the amplitude (A) of the received signal (U E ) with the predeterminable frequency limit value (f ref ) and the predeterminable amplitude limit value (A ref ), characterized in that that in the event of a change in amplitude (A), it is concluded that the vibrating unit is covered by a foam or that a sediment is present in the medium in the area of the vibrating unit , that in the event of a change in amplitude (A) and in the event of a constant frequency (f), the presence of the sediment in the medium in the region of the oscillating unit and that in the event of a change in the amplitude (A) and in the event of a change in the frequency (f), whereby the predeterminable frequency limit value (f ref ) is not exceeded or undershot, the presence of the sediment in the medium in the region of the oscillating unit or the coverage by the foam is concluded. <EOS>