Accession Number : ADD016316

Title :   A Refractive Index-Based Sensor for the Discrimination of Chlorinated Hydrocarbons from Groundwater.

Descriptive Note : Patent Application, Filed 28 Mar 94,

Corporate Author : DEPARTMENT OF THE NAVY WASHINGTON DC

Personal Author(s) : Ewing, Kenneth H ; Nau, Gregory ; Bilodeau, Thomas ; Schneider, Irwin ; Aggarwal, Ishwar

Report Date : 28 Mar 1994

Pagination or Media Count : 22

Abstract : A refractive index-based sensor uses a light source and an optical fiber to direct an optical beam towards a sensor/ environment face at a specific angle. The sensor has a predetermined shape selected such that the light directed into the sensor will have a specific angle of incidence designed to detect a plurality of liquids. A second optical fiber carries the light reflected off the sensor/environment face to a photodetector. The optical beam will either be transmitted through or reflected off the sensor/environment face based upon the refractive indices of the sensor and the environment and upon the angle of incidence of the optical beam. The amount of light reflected is indicative of the refractive index of the material in a given area of the sensor/environment face and, thus, the type of material. By adjusting the angle at which the light is directed to the sensor/environment face, the photodetector response can be calibrated to identify the type of liquid present at the sensor/environment face.

Descriptors :   *FIBER OPTICS, *OPTICAL DETECTORS, *PATENT APPLICATIONS, *HAZARDOUS WASTES, ANGLES, LIGHT SOURCES, PHOTODETECTORS, REFRACTIVE INDEX, NAVAL RESEARCH, CHLORINATED HYDROCARBONS, LIQUID PHASES, CHLOROFORM, TRICHLOROETHYLENE, CARBON TETRACHLORIDE, GROUND WATER, CHEMICAL VAPOR DEPOSITION, SITE INVESTIGATIONS, CONTAMINATION, SOIL POLLUTION, WATER POLLUTION, SOIL SURVEYS

Subject Categories : Fiber Optics and Integrated Optics
      Solid Wastes Pollution and Control

Distribution Statement : APPROVED FOR PUBLIC RELEASE