Pattern Analysis of Odors by Multiple Metal Oxide Semiconductors: Odor Analyzer with Human Sense of Smell

Abstract

To carry out a pattern analysis of odors, we used an odor analyzer with a human sense of smell; this analyzer indicates not only the odor quality, i.e., pleasantness and unpleasantness in the pattern, but also the odor intensity. Conventional systems indicate only the intensity level of an odor, irrespective of its quality. This newly developed system can discriminate offensive from inoffensive odors by the shapes of graphic patterns. From a hexagonal radar pattern made by six unique semiconductor sensors, odor quality and intensity are obtained, the sharpness of radar pattern indicating the odor quality, while the area indicates odor intensity. An odor map can then be made from the odor quality and intensity obtained. Thus, various odors can be visually identified, and this procedure, rather than the human sense of smell, can be applied to classify various types of odors.