Vibrator damping flow meter

US4493215A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Theodor Gast · Berlin, DE
• Kurt Binder · Stuttgart, DE
• Gunter Honig · Ditzingen, DE

Key dates

• Filing date: Jun 16, 1982
• Grant date: Jan 15, 1985
• Expiry date: Jun 16, 2002

Classification

• Technology area (CPC G): Physics
• CPC primary: G01F1/00
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

An electromagnetically excited vibrator with arms carrying baffle members at their ends that are immersed in the flow to be measured is mounted at one or more vibration nodes to reduce loss of vibratory energy to the casing of the flow meter. A flat magnetically conducting cross shape can be mounted at a node in the middle, provided each cross beam of the cross is vibrated in flexure, and the two cross beams vibrate in phase opposition (counter stroke). Such a vibrator is excited by a similarly crossed pair of E-shaped cores with exciter and secondary windings on the middle legs of the cores, or by a coaxial re-entrant core with permanent magnet wafers set in the rim at respective locations separated by an air gap from the arms of the cross. In each case the vibrator can be firmly affixed to the central leg or legs of the core. A two-ended rod system can be excited by magnetostriction, operating differentially on a split middle portion of the core, while the latter is supported at two nodes located between the split middle portion and the respective ends that carry baffle members. Evaluation circuits in all cases measure the vibration damping caused by fluid flow.