Temperature dependence of Co detection by SnO/sub 2/: Pd sensitive films gas sensors

The electrical response to CO partial pressure in dry and wet synthetic air was investigated in the range Of 200-650/spl deg/C, for SnO/sub 2/ and SnO/sub 2/-Pd thick films. Two peaks of sensitivity where found at 200, respectively 500/spl deg/C in the case of CO interaction with the surface of SnO/sub 2/ exposed to dry atmosphere. The presence of water vapours induced an extra peak of sensitivity at 300/spl deg/C for pure SnO/sub 2/ sensors. The influence of Pd catalyst on CO detection has been studied in wet at humid atmosphere versus temperature.