Combined Conductivity and Gravimetric Resonant Gas Sensor for High-Temperature Applications

A bulk acoustic wave gas sensor system based on high temperature stable piezoelectric transducers and thin metal oxide sensor films is developed. The simultaneous determination of changes in electrical and gravimetric properties of tin oxide (SnO
₂
), titanium oxide (TiO
₂
) and praseodymium doped ceria (PCO, Pr
_x
Ce
_1-x
O
₂
with x = 0.1 and 0.2) sensor films enables to distinguish methane and ethylene in inert gas atmospheres (argon) at temperatures up to 900 °C.