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. 25, 2004
Filed:
Jun. 15, 2001
Klaus Bohnert, Oberrohrdorf, CH;
Hubert Brändle, Oberengstringen, CH;
ABB Research Ltd, Zurich, CH;
Abstract
The subject matter of the present invention is a fiber Bragg grating sensor which is suitable, in particular, for measuring differential pressures and flow rates v in oil drill holes. The sensor principle according to the invention is based on using a transducer with two pressure chambers , to convert a hydrostatic pressure difference between two liquid or gaseous media into a longitudinal fiber elongation or fiber compression and measuring it via the displacement of the Bragg wavelength &Dgr;&lgr; of at least one fiber Bragg grating . Exemplary embodiments are specified which have two fiber Bragg gratings which are sensitive to elongation in opposite senses and which have temperature-compensating transducers , and which have a plurality of transducers in a wavelength-division-multiplexing configuration. One embodiment relates to measuring a flow rate v with the aid of a venturi tube