Mass flow gauge for flowing media with devices for determination of the Coriolis force

US5052231A · kind A · utility

Assignee

• Rheometron AG · CH

Inventors

• Herbert Christ · Reutlingen, DE
• Mike Kellaway · Little Thetford, GB
• Wolfgang Stumm · Erbach, DE

Key dates

• Filing date: Dec 29, 1989
• Grant date: Oct 1, 1991
• Expiry date: Dec 29, 2009

Classification

• Technology area (CPC G): Physics
• CPC primary: G01F1/8472
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

In a Coriolis mass flow gauge, the signal from each sensor is digitized and converted into digital measuring values by one or more analog/digital converters operating with a specific digital sampling frequency. Then, using a microcomputer, each digital measuring value thus obtained is multiplied, on the one hand, with the sine value of the phase angle at the point of sampling of the alternating signal or another scanning signal with the same frequency as the alternating voltage signal, but phase-shifted against that signal and, on the other hand, with the corresponding cosine value. The sine-multiplication values thus obtained are summed over a predetermined time interval to form one Cartesian coordinate of a corresponding sum vector, whereas the cosine multiplication values thus obtained are summed over that time interval to form the other Cartesian coordinate of the sum vector, and from the Cartesian coordinates of the sum vectors of both lateral sensors, the measuring value describing the mass flow through the loop is calculated directly.