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Title: Fiber optic moisture sensor with moisture-absorbing reflective target

A method and apparatus for sensing moisture changes by utilizing optical fiber technology. One embodiment uses a reflective target at the end of an optical fiber. The reflectance of the target varies with its moisture content and can be detected by a remote unit at the opposite end of the fiber. A second embodiment utilizes changes in light loss along the fiber length. This can be attributed to changes in reflectance of cladding material as a function of its moisture content. It can also be affected by holes or inserts interposed in the cladding material and/or fiber. Changing light levels can also be coupled from one fiber to another in an assembly of fibers as a function of varying moisture content in their overlapping lengths of cladding material.
Authors:
 [1]
  1. (Richland, WA)
Publication Date:
OSTI Identifier:
866104
Report Number(s):
US 4634856
DOE Contract Number:
AC06-76RL01830
Resource Type:
Patent
Research Org:
BATTELLE MEMORIAL INSTITUTE
Country of Publication:
United States
Language:
English
Subject:
fiber; optic; moisture; sensor; moisture-absorbing; reflective; target; method; apparatus; sensing; moisture; changes; utilizing; optical; fiber; technology; embodiment; reflective; target; optical; fiber; reflectance; target; varies; moisture; content; detected; remote; unit; opposite; fiber; embodiment; utilizes; changes; light; loss; fiber; length; attributed; changes; reflectance; cladding; material; function; moisture; content; affected; holes; inserts; interposed; cladding; material; fiber; changing; light; levels; coupled; fiber; assembly; fibers; function; varying; moisture; content; overlapping; lengths; cladding; material; remote unit; embodiment utilizes; moisture content; moisture content; moisture content; fiber optic; optical fiber; optical fiber; cladding material; cladding material; cladding material; light loss; reflective target; reflective target; moisture sensor; utilizing optical; light level /250/73/