HOW HUMAN ARE ELECTRONIC NOSES

Characterization of odours in olfactometry is usually done by trained persons. The basic problem in an objective characterisation results from the fact that general odours and smells cannot be composed by basis vectors of individual components. Our present understanding of the biochemical and physiological background in odour sensation is still limited. As a result it is not possible to use individual components of this complex system in any technical hybrid sensor system. Electronic noses based upon the signal evaluation of individual sensors by means of pattern recognition are therefore used to produce signal pattern They are subsequently correlated with subjectively characterised odours of test persons. Typical examples illustrate possibilities and limitations in the use of electronic noses for olfactometry today.