Patent · US Expired

Fiber optic sensor for multiple variables

US5612778A · kind A · utility

14Cited by
5References
17Claims
0Family size

Assignee

Inventors

Key dates

Filing dateOct 18, 1995
Grant dateMar 18, 1997
Priority date
Expiry dateOct 18, 2015

Classification

  • Technology area (CPC A)Human Necessities
  • CPC primaryA61B5/0215
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

An optical device and method for sensing a plurality of ambient conditions (e.g., temperature and pressure) may include transmission of an optical flux through a fiber optic cable to a section of the cable that is placed where the ambient conditions are to be sensed. The section of cable includes a plurality of serially aligned sensors for reflecting the optical flux back through the cable, each of the sensors having semi-reflective surfaces at the two ends thereof for partially reflecting the optical flux. The distance between the two ends of each sensor varies primarily as a function of a different one of the ambient conditions. The optical flux is partially transmitted and partially reflected at each of the ends of the sensors and the optical flux reflected back through the cable includes an interference pattern that is a function of each sensor's end-to-end distance. A detector evaluates the interference pattern to determine the ambient conditions. The evaluation of the interference pattern may be simplified by properly selecting the reflectivity of the ends of the sensors.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.