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:
Nov. 22, 1994
Filed:
Nov. 24, 1993
Lloyd C Bobb, Horsham, PA (US);
The United States of America as represented by the Secretary of the Navy, Washington, DC (US);
Abstract
A method of measuring the position of a liquid surface within a vessel is scribed. An optical fiber is provided which has first and second ends and has an energy-absorbing element of a predetermined length disposed upon a portion of the cladding thereof such that there is a thermal interface between the energy-absorbing element and the cladding. The optical fiber is then positioned in the vessel so that the energy-absorbing element disposed thereon extends a known distance into the vessel along a known depth gradient of the vessel and so that the energy-absorbing element will intersect the liquid surface over the anticipated range of positions thereof. Single-frequency, coherent light is then transmitted through the core of the optical fiber by launching it into the first end of the optical fiber. A pulse of energy is applied across the entire length of the energy-absorbing element to heat it, and then the transmitted light is received from the second end of the optical fiber. The change in phase of the transmitted light resulting from applying the pulse of energy is then measured, and the position of the liquid surface is then determined in accordance with the change in phase.