Novel Solid State Galvanic Cell Gas Sensors

Abstract

Solid electrolytes transduce the ratio of the activities of the electroactive component at both electrodes directly into an electrical voltage. Oxygen ion conductors such as zirconia are commercially successfully employed on this basis as sensors for oxygen partial pressures in automobile exhaust systems, in molten steel and for food packing. It is of considerable practical interest to expand this technique to the detection of other gases and to operate the galvanic cells at lower temperatures. There are, however, severe restrictions at the present time with regard to the available materials. Especially, it may be hardly expected that fast solid ionic conductors may ever be found for heteroatomic gas molecules such as CO_x, NO_x or SO_x.