Patent ID: 8045154

Claim:
A method for measuring concentrations of fuel mixtures, comprising the steps of: (a) irradiating a sample container holding a sample fuel mixture with an excitation beam of ultraviolet radiation; (b) diverting an emission beam of fluorescent light emitted from the sample fuel mixture through a slit normal to the excitation beam, the slit being narrow relative to the sample container in order to test fluorescent light emitted from a thin layer of the sample fuel mixture at a discrete depth of penetration of the excitation light beam into the sample container; (c) generating an emission spectrum for at least one discrete depth; (d) generating a spectrum of fluorescent intensities at a single emission wavelength over a plurality of discrete depths; and (e) comparing the spectra to calibration curves generated from known concentrations of the fuel mixture in order to determine relative concentrations of components of the sample fuel mixture.