A solid electrolyte sensor for trace gas analysis

Coulometric solid electrolyte sensors based on yttria-stabilized zirconia were characterized with respect to the electronic conductivity of the solid electrolyte and to their electrochemical activity of oxygen, hydrogen and hydrocarbon conversion. Sensor parameters like the temperature dependency of the electronic conductivity as well as the elevated noise of the coulometric cell at the working temperature determine the limit of detection of coulometric titration. Here we describe investigations on these parameters and approaches to shift the lower detection limit into the ppb-range. Furthermore, it is shown that a coulometric solid electrolyte sensor, positioned behind a gas chromatographic separation unit, allows simultaneous, calibration-free and long-term stable detection of different oxidizable components and oxygen.