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:
Sep. 28, 1999
Filed:
Jun. 30, 1997
William E Asher, Leominster, MA (US);
Richard H Clarke, Boston, MA (US);
Mohammad S Farahat, Westboro, MA (US);
Boston Advanced Technologies, Inc., Marlborough, MA (US);
Abstract
Methods for marking a liquid and methods and systems for identifying marked liquids. A liquid can be marked for identification purposes with at least a first marker and a second marker. Each of the markers is miscible with the liquid. The markers are mixed in the liquid so that the ratio of the concentration of the first marker to the concentration of the second marker is substantially equal to a predetermined value. Thus, when a system according to the invention measures the concentrations of the first and second markers, the system can compare the ratio of the measured concentration of the first marker to the measured concentration of the second marker with a look up table of the predetermined values to provide information concerning the identity of the liquid. In a preferred embodiment, the concentration of the markers is measured using an absorption spectrometer. When using an absorption spectrometer to measure the concentration of the markers, each of the markers has an absorbance spectrum with at least one wavelength range where the marker's absorbance is differentiable from the absorbance of the background liquid and any other marker in the liquid.