Dual gas sensor having solid electrolyte contained in an oxide matrix

Claim 1

A solid electrolyte dual gas sensor for measuring two selected component gases of a monitored gas environment by generating electrical signals on the basis of a difference in the partial pressure between (a) the two selected component gases of the monitored gas environment at first and second monitor electrodes in contact with the monitored gas environment and solid electrolyte, and (b) corresponding component reference gases at reference electrode means in contact with a reference gas environment and solid electrolyte; comprising a single reference electrode surrounded by a first solid electrolyte and a separate second solid electrolyte and being isolated from the monitored gas environment, the reference electrode being physically contacted by both electrolytes, the first electrolyte being oxygen ion conductive, and the second electrolyte having a composition conductive to sodium or potassium ions, one monitor electrode contacting the first solid electrolyte and, the other monitor electrode contacting the second solid electrolyte, where the second solid electrolyte is a single component composition disposed within a separate, ceramic oxide, interconnected skeletal matrix having a melting point greater than 1,600° C. and pores therein having approximate diameters of up to 150 micrometers, which is 35% to 95% porous prior to electrolyte impregnation, which matrix contains continuous interconnected pores filled with the second solid electrolyte, allowing a continuous ionic conduction path through the second solid electrolyte within the matrix, which second solid electrolyte is adapted upon heating to dissociate and provide the sole source of constant partial pressures of self-generated reference gases, at the reference electrode corresponding to the selected component gases to be measured in the monitored gas environment, to provide a unitary, dual gas sensor.