The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 23, 2002
Filed:
Dec. 06, 1999
Mark R. Fernald, Enfield, CT (US);
Timothy J. Bailey, Longmeadow, MA (US);
Matthew B. Miller, Glastonbury, CT (US);
James M. Sullivan, Manchester, CT (US);
James R. Dunphy, South Glastonbury, CT (US);
Michael A. Davis, Glastonbury, CT (US);
Christopher J. Wright, Amston, CT (US);
Alan D. Kersey, South Glastonbury, CT (US);
Martin A. Putnam, Cheshire, CT (US);
Robert N. Brucato, Waterbury, CT (US);
Paul E. Sanders, Madison, CT (US);
Weatherford/Lamb, Inc., Houston, TX (US);
Abstract
A fiber grating pressure sensor includes an optical sensing element which includes an optical fiber having a Bragg grating impressed therein which is encased within and fused to at least a portion of a glass capillary tube and/or a large diameter waveguide grating having a core and a wide cladding and which has an outer transverse dimension of at least 0.3 mm. Light is incident on the grating and light is reflected from the grating at a reflection wavelength &lgr; The sensing element may be used by itself as a sensor or located within a housing When external pressure P increases, the grating is compressed and the reflection wavelength &lgr; changes. The shape of the sensing element may have other geometries, e.g., a “dogbone” shape, so as to enhance the sensitivity of shift in &lgr; due to applied external pressure and may be fused to an outer shell At least a portion of the sensing element may be doped between a pair of gratings to form a compression-tuned laser or the grating or gratings may be constructed as a tunable DFB laser. Also, the axial ends of element where the fiber exits the tube may have an inner tapered region and/or a protruding tapered (or fluted) axial section to provide strain relief or improved pull strength for the fiber A temperature grating may be used to measure temperature and allow for a temperature-corrected pressure measurement. The sensor may be suspended within an outer housing by a fluid, spacers, or other means. The invention may also be used as a force transducer.