Spectral detection of contaminants in containers

摘要

To spectrally detect a contaminant in a moving container, a set of reference spectral information related to one or more containers having known contents is stored. Thereafter, radiant energy is directed at liquid near the bottom of the container so that the radiant energy is modified by the contents of the container and travels through the contents of the container in multiple paths of varying length. Spectral information from detected portions of the modified radiant energy is obtained, and is compared to the stored set of reference spectral information using correlation techniques. Based on the relationship between this spectral information and the stored set of reference spectral information, the presence or absence of a contaminant is indicated.