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:
May. 13, 2003
Filed:
Aug. 25, 2000
Klaus Bohnert, Oberrohrdorf, CH;
Hubert Brändle, Oberengstringen, CH;
Patrick Bodor, Gippingen, CH;
ABB Research Ltd., Zurich, CH;
Abstract
The subject-matter of the present invention is a wavelength-coded fiber Bragg grating pressure sensor which is suitable, in particular, for use in the case of high pressures and temperatures in oil drill holes. The sensor principle according to the invention is based on the fact that the hydrostatic pressure of a liquid or gaseous medium is converted with the aid of a transducer into a longitudinal fiber elongation or fiber compression. The transducer comprises a measuring or pressure cylinder which exchanges pressure with the medium and a reference cylinder which is shielded from the medium or oppositely pressure-loaded. Temperature-compensated transducers with a temperature-independent Bragg wavelength &lgr; can be realized by introducing a suitable temperature dependence of the mechanical prestressing of the pressure sensor fiber by selecting the materials, lengths and arrangements of the fiber holder supports A fiber Bragg grating temperature sensor can be provided, in addition. Also specified are transducers with other cylinder arrangements and a wavelength-division multiplex configuration with several transducers