The how and why of electronic noses

An electronic nose is a system consisting of three functional components that operate serially on an odorant sample, a sample handler, an array of gas sensors, and signal processing systems. The output of the electronic nose can identify the odorant, an estimate of the concentration of the odorant, or the characteristic properties of the odor as might be perceived by a human. Fundamental to the artificial nose is the idea that each sensor in the array has different sensitivity. Each sensor in the array has a unique response profile to the spectrum of odorants under test. The pattern of response across all sensors in the array is used to identify and/or characterize the odor.