Patent ID: 6666098
Filing Date: 2003-12-23
Classification: G01F

Abstract:
A vibratory transducer for a fluid flowing in a pipe, said vibratory transducer defining a longitudinal axis and comprising:a curved flow tube for conducting the fluid, which vibrates in operation and communicates with the pipe via an inlet-side tube section and an outlet-side tube section of said curved flow tube; an antivibrator which in operation oscillates in a phase opposition to that of said curved flow tube and is mechanically connected with said curved flow tube by means of a first coupler on the inlet-side tube section and by means of a second coupler on the outlet-side tube section of said curved flow tube; an excitation system for vibrating said curved flow tube and said antivibrator at an excitation frequency; and a sensor system for sensing vibrations at said inlet-side tube section and said outlet-side tube section of said curved flow tube, wherein: an internal system formed by at least said curved flow tube, said antivibrator, said excitation system, and said sensor system, oscillating about said longitudinal axis of the transducer which is essentially in alignment with the inlet-side tube section, forces a torsion of said first and said second couplers about said longitudinal axis and an essentially torsional elastic deformation of at least parts of said inlet-side tube section and said outlet-side tube section; and in order to achieve a torsionally soft oscillation of said internal system, at least said first coupler, tuned to a torsional rigidity of said inlet-side tube section, and at least said second coupler, tuned to a torsional rigidity of said outlet-side tube section, are so dimensioned that an inlet-side inherent torsion eigenmode of said first coupler and of said inlet-side tube section has a natural frequency approximately equal to the excitation frequency, and an outlet-side inherent torsion eigenmode of said second coupler and of said outlet-side tube section has a natural frequency essentially equal to the natural frequency of said inlet-side inherent torsion eigenmode.