Vibration-type measuring device

US8396674B2 · kind B2 · utility

Assignee

• ABB TECHNOLOGY AG · CH

Inventors

• Jörg Gebhardt · Mainz, DE
• Rene Friedrichs · Göttingen, DE
• Beat Kramer · Windisch, CH
• Frank Kassubek · Rheinfelden (Baden), DE
• Steffen Keller · Konstanz, DE

Key dates

• Filing date: Jul 8, 2009
• Grant date: Mar 12, 2013
• Expiry date: Apr 2, 2031

Classification

• Technology area (CPC G): Physics
• CPC primary: G01F1/8436
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A vibration-type measuring device includes an exciter arrangement which exerts a time-dependent force with at least one sinusoidal component at an adjustable excitation frequency on a measuring tube, through which a medium can flow, and causes the measuring tube to oscillate. The measuring device includes first and second sensors which are fitted to the measuring tube at different locations. The first and second sensors output first and second measurement signals, respectively. The measuring device includes an evaluation unit which determines a first phase shift between the first and second measurement signals and uses the determined phase shift to determine a measurement variable of the medium. The measuring device includes a phase comparator, which determines a second phase shift between the force and the average value of the first and second measurement signals, and a frequency generator which sets the excitation frequency on the basis of the second phase shift.