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:
Jul. 31, 1995
Filed:
Mar. 27, 1994
Kenneth J Ewing, Bowie, MD (US);
Gregory Nau, Alexandria, VA (US);
Thomas Bilodeau, Alexandria, VA (US);
Irwin Schneider, Alexandria, VA (US);
Ishwar Aggarwal, Fairfax Station, VA (US);
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.