Generation of low-frequency oscillations in gas sensors based on indium-doped SnO2 films in the course of heterogeneous reactions

Generation of regular periodic signals was discovered in the course of investigation of noise properties of gas sensors based on a series of indium-doped SnO 2 films. The signals arose after injecting CO (0.03...0.2%) and CH 4 (0.03%) into the air chamber. This phenomenon is associated accompanied by the periodic processes of adsorption and dissociation of oxygen molecules with the formation of ions O - 2 and O - and their subsequent reaction with the molecules of recovering gases in relaxation regions (relaxators) on the sensor surface.