Patent ID: 9709475
Date: 2017-07-18
CPC Classifications: G01F,G01N

Claim:
1. An apparatus for determining and/or monitoring at least viscosity of a medium, comprising: at least one mechanically oscillatable unit; and at least one evaluation unit, which supplies said mechanically oscillatable unit with an exciter signal with oscillations of the mechanically oscillatable unit and receives a received signal from said mechanically oscillatable unit, wherein said evaluation unit is embodied to ascertain and/or monitor the eigenfrequency of the mechanically oscillatable unit and/or the phase relationship between the exciter signal and the received signal, wherein said evaluation unit is embodied to deduce a change in viscosity from changes in the eigenfrequency and/or from changes in the phase relationship between the exciter signal and the received signal, with oscillations of the mechanically oscillatable unit at the resonance frequency, and/or wherein said evaluation unit is embodied to ascertain the viscosity, based on dependencies of the oscillations of the mechanically oscillatable unit on the viscosity of the medium, from the eigenfrequency and/or the phase relationship between the exciter signal and the received signal, with oscillations of the mechanically oscillatable unit at the resonance frequency; and wherein said mechanically oscillatable unit is embodied in such a manner, that the geometry of the mechanical oscillatable unit is optimized such that effects of changes in density on the mechanical oscillations of said mechanically oscillatable unit are negligible.