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:
Aug. 01, 1989
Filed:
Mar. 11, 1988
John P Dakin, Hampshire, GB;
Plessey Overseas Limited, Illford, GB;
Abstract
An optical fibre sensing system for monitoring and/or measuring temperatures or pressures distributed around an optical fibre sensing loop. Light source and coupler are provided for applying continuous wave light to the loop so that the light propagates simultaneously in opposite directions around the loop with the resultant light output from the loop being detected by a detector. Light pulse generating source and coupler cause light pulses to propagate in one direction only around the loop and by so doing produce transient variations in the propagation constant along the looped fibre in dependence upon the distributed temperature or pressure around the loop. The detector detects the phase changes occurring in the continuous wave light received from the sensing loop due to variations in temperature or pressure around the loop.