Effects on implemented pre-heated foamed ceramic filters

We report the use of a pre-heated catalytic filter to improve the stability and cross sensitivity of metal oxide gas sensors (MOS). For characterization a pure and gold coated Al2O3 foamed ceramic is integrated into a newly designed chamber. When heating up the foamed ceramic, the Pd/SnO22 sensor shows a significant sensitivity to acetone. The sensor signal decreases on methane, acetaldehyde and carbon monoxide. Furthermore, a temperature dependency to the ambient gas concentration and an adsorption on the ceramic filter is observed. Due to the fact that the heated filter is independent of the sensor heater, it is possible to operate the sensor at its ideal operating temperature for the target gases along with the additional opportunity of indirect gas determinations.