| 摘要 |
The invention relates to a vibronic sensor (1) and to a method for operating a vibronic sensor for monitoring at least the density (ρ) and/or the viscosity (η) of a medium (2) in a container (3), said vibronic sensor at least comprising a unit (4) that can vibrate mechanically, a driving/receiving unit (5), and an electronic unit (6), wherein the driving/receiving unit (5) is designed to excite the unit (4) that can vibrate mechanically to mechanically vibrate by means of an electrical excitation signal (UA), and to receive the mechanical vibrations of the unit (4) that can vibrate mechanically, and to convert said mechanical vibrations into an electrical reception signal (UE), wherein the electronic unit (6) is designed to produce the excitation signal (UA) on the basis of the reception signal (UE) in such a way that a specifiable phase shift (φ 45, φ 90) exists between the excitation signal (UA) and the reception signal (UE), wherein the electronic unit (6) is designed to set at least a first specifiable phase shift (φ 90) and a second specifiable phase shift (φ 45), and to determine a first frequency (ω90) and a second frequency (ω135) corresponding to the respective specifiable phase shifts (φ 90, φ 45), and to determine from the two frequencies (ω90, ω135) the density (ρ) by means of a first analytical formula and the viscosity (η) of the medium (2) by means of a second analytical formula. |
