Patent · US Expired

Fiber optic liquid leak detector

US5058420A · kind A · utility

11Cited by
6References
3Claims
0Family size

Assignee

Inventors

Key dates

Filing dateApr 20, 1990
Grant dateOct 22, 1991
Priority date
Expiry dateApr 20, 2010

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG01M3/3245
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

A precision liquid leak detector 10 free of mechanical moving parts is disclosed herein. The liquid leak detector 10 of the present invention is disposed to measure the rate of change of the volume of a liquid within a container 14. The leak detector 10 includes a light guide 16, implemented as an optical fiber, which is disposed within the container 14 and at least partially immersed in the liquid. The optical fiber 16 includes a fiber core circumscribed by a fiber cladding selected such that evanescent wave loss occurs as a result of immersion of the cladding within the liquid. The optical fiber 16 is positioned in optical alignment with a laser source 26, which injects optical energy therein. The leak detector 10 of the present invention further includes an arrangement 24 for measuring the decrease in the intensity of the injected optical energy occurring over a length of the fiber 16 immersed in the liquid. The measuring arrangement 24 then generates an intensity loss signal indicative of this intensity decrease. The inventive leak detector 10 also includes a network 36 and 38 for measuring the rate of change of the intensity loss signal and for calculating the rate of change o…

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