Patent ID: 8362436

Claim:
A system for use in measuring a fluid characteristic, comprising: a source of optical energy; an optical waveguide slab in optical communication with the source of optical energy, the optical waveguide slab being at least partially filled with a material that fluoresces when illuminated by optical energy produced by the source of optical energy, and wherein the optical waveguide slab has an elongated body with first and second portions positioned for fluid contact in use, and wherein said first portion includes a reflective cover, and wherein said first portion is positioned closer to a light source entry point in said optical waveguide slab than said second portion, and said second portion provides for light transmission external to the optical waveguide slab into a fluid in contact with said second portion in use, and wherein said first portion extends longer than said second portion; a detector of optical energy in optical communication with the optical waveguide slab, wherein the detector of optical energy generates an output in response to the fluorescence of the fluorescent material; and a computing device communicatively coupled to the detector of optical energy, wherein the computing device stores input data, which input data is derived from an output of said optical waveguide slab, and wherein said computing device is preprogrammed with a plurality of relationships established relative to respective responses of the system to the presence of various types of fluids of known identity, with each fluid type also having been subjected to variations in temperature in the establishment of said plurality of relationships for the various types of fluid of known identity.