Precise meter for oxygen concn. in gas - with complex oxide between solid electrolyte vessel and sintered iron-ferrous oxide core

摘要

Oxygen concn. meter for use in waste gases has a solid electrolyte vessel of ZrO2 together with Y2O3, CaO and/or MgO and a sintered mass of Fe-FeO inside the vessel. There is a complex oxide layer of vessel material and Fe-FeO on the interface between the sintered mass and the vessel and that a porous metal film on the outside of the vessel and the sintered mass form the poles of the meter. The meter is produced by filling the vessel with fine Fe and FeO powder and sintering at 600-1400 degrees C, with formation of the complex oxide layer, and applying Pt paste to the outside and baking to form the metal film, which pref. is coated with porous alumina for protection. The meter is precise, functions at low temp., reacts immediately to temp. changes and can be miniaturised. It is suitable for continuous operation at 400-1000 degrees C.