Pd modified CO sensors with oscillatory response

In this paper, oscillatory changes in the conductance of Pd modified SnO/sub 2/ bead and Pd modified Pt coil in the presence of CO were investigated and compared. Changes in frequency were found for both sensors with varied CO concentrations. For the Pd modified SnO/sub 2/ sensor, the frequency of the waveform increased with increasing CO concentration, while for the Pd modified Pt coil, the frequency decreased. Influences of the surface temperature to CO responses were examined. The selectivity against H/sub 2/ was also tested.