Patent ID: 6239872
Filing Date: 2001-05-29
Classification: G01J,G01N

Abstract:
A method for high speed spectroscopic constituent verification comprising the following steps:illuminating a sample with broadband light;measuring reflected light in a first range of wavelengths .lambda..sub.1, said first wavelength range .lambda..sub.1 having been preselected as a baseline that is not significantly absorbed by a constituent of interest;measuring reflected light in a second narrow-range of wavelengths .lambda..sub.2, said second wavelength range .lambda..sub.2 having been preselected as a discriminant that is substantially absorbed by the constituent of interest;determining a first variable threshold measure for said baseline reflected light of wavelengths .lambda..sub.1 ;determining a second variable threshold measure for said discriminant reflected light of wavelengths .lambda..sub.2 based on the measured baseline reflected light of wavelengths .lambda..sub.1 ;outputting data indicative of the presence of constituent if the measured baseline reflected light of wavelengths .lambda..sub.1 exceeds the first variable threshold measure and the measure of the reflected discriminant wavelength .lambda..sub.2 exceeds the second variable threshold measure of reflected baseline light .lambda..sub.1.