Coriolis mass measuring device

US7040181B2 · kind B2 · utility

Assignee

• Endress+Hauser Flowtec AG · CH

Inventors

• Alfred Rieder · Landshut, DE
• Wolfgang Drahm · Erding, DE
• Michael Fuchs · Bad Wörishofen, DE
• Hans-Jörg Sprich · Schopfheim, DE
• Ibho Itin · Liestal, CH
• Samuel Wyss · Basel, CH

Key dates

• Filing date: Mar 21, 2005
• Grant date: May 9, 2006
• Expiry date: Mar 21, 2025

Classification

• Technology area (CPC G): Physics
• CPC primary: G01N11/162
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A Coriolis mass flow measuring device includes a vibratory measuring transducer having at least one measuring tube, which has medium flowing through it during operation. In operation, the measuring tube is caused by an exciter arrangement to undergo mechanical oscillations, especially bending oscillations. Additionally, the Coriolis mass flow measuring device includes a sensor arrangement for producing oscillation measurement signals (s1, S2) representing the inlet-end and outlet-end oscillations of the measuring tube. Measuring device electronics controlling the exciter arrangement produces an exciter current (iexc) and an intermediate value (X′m) derived from the oscillation measurement signals (s1, s2). This intermediate value represents an uncorrected mass flow. Derived from the exciter current and/or from a component of the exciter current (iexc), an intermediate value (X2) is produced, which corresponds to a damping of the oscillations of the measuring tube. This damping is especially a function of an apparent viscosity, and/or a viscosity-density product, of the medium guided in the measuring tube. Furthermore, a correction value (XK) is produced for the intermediate value (…