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. 16, 2006
Filed:
Feb. 13, 2004
Klaus Bohnert, Oberrohrdorf, CH;
Philippe Gabus, Nussbaumen, CH;
Hubert Brandle, Oberengstringen, CH;
Klaus Bohnert, Oberrohrdorf, CH;
Philippe Gabus, Nussbaumen, CH;
Hubert Brandle, Oberengstringen, CH;
ABB Research LTD, Zurich, CH;
Abstract
The invention relates to a fiberoptic current or magnetic field sensor having a plurality of sensor heads, and to a corresponding measurement method. The sensor has a light source: N≧2 sensor heads; at least one phase modulation unit; a detector; a control and evaluation unit. The at least one phase modulation unit is connected to at least one of the sensor heads. Lightwaves can be differentially phase-modulated in a non-reciprocal fashion by means of the at least one phase modulation unit. Modulation amplitudes φand modulation frequencies vare selected as a function of modulation-relevant optical path lengths l.