Oscillatory response of Pt-based CO sensors

In this paper, the investigation of oscillatory changes in the conductance of coil-structured platinum sensors in the presence of carbon monoxide is presented. Both period and amplitude of the oscillation waveform increased with the increasing CO concentration. The annealing temperature has an influence on oscillation regions, with lower concentrations of CO leading to oscillatory response as the annealing temperature increases. The sensors are selective towards CO, with no oscillatory behaviour being observed in the presence of H2 gas. The sensitivity of the device was improved by modifying the platinum surface with palladium. The partial pressure of oxygen in the gas mixture plays an important role in oscillation performance. The response of a Pt thin film was also tested.