Double resonating beam force transducer with reduced longitudinal pumping

US4724351A · kind A · utility

Assignee

• Quartex, Inc. · US

Inventors

• Errol P. EerNisse · Salt Lake City, US
• Walter P. Kistler · Bellevue, US

Key dates

• Filing date: Nov 14, 1984
• Grant date: Feb 9, 1988
• Expiry date: Nov 14, 2004

Classification

• Technology area (CPC G): Physics
• CPC primary: G01L1/162
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A double resonator beam force transducer configured to minimize longitudinal pumping by making the beams vibrate symmetrically. This can be accomplished by making the boundary conditions of the beams symmetrical or, if the boundary conditions are nonsymmetric, then by biasing the beams inwardly or outwardly to compensate for the nonsymmetrical boundary conditions of the beams. In the nonsymmetrical case where the beams would bow outwardly at their fundamental resonant frequency or an odd overtone thereof, an inward bias is provided to minimize longitudinal pumping. In the nonsymmetrical case where the beams would bow inwardly at an even overtone of the fundamental resonant frequency, an outward bias is provided to minimize longitudinal pumping. The inward or outward bias is provided in various embodiments by bowing the beams inwardly or outwardly, placing masses on the inner or outer edges of the beams, or tapering the inner or outer edges of the beams so that the width of the beams increase toward their midpoints.