Electronic noses based on metal oxide gas sensors: the problem of selectivity enhancement

Metal oxide gas sensors (MOX) are widely used in olfactory systems for their high sensitivity and low-cost. These sensors vary their conductivity in presence of oxidizing and reducing gases and their performance is strictly dependant on the measurement technique adopted. In this paper the authors present results concerning the selectivity enhancement of an electronic nose based on MOX sensors, proposing also a gray-box model to describe the sensor response in presence of oxygen and CO during sensor temperature modulation.