Abstract: An oxygen sensor device is disclosed having a glass dome fluid-tightly connected at its circumferential base edge to one surface of an oxygen conductive solid electrolyte plate to form a diffusion chamber defined by the glass dome and the solid electrolyte plate. The diffusion chamber may be vacant, or may have a porous inorganic material packing layer fixedly disposed in the entire space thereof. Alternatively, the diffusion chamber may have a porous inorganic material semi-packing layer fixedly disposed in an upper portion thereof remote from the electrolyte plate, while leaving vacant the remainder of the chamber. The oxygen sensor device is advantageous from the viewpoints of miniaturization, power consumption saving and reliability.

Abstract: An oxygen sensor for determining the partial pressure of oxygen in a monitored gas environment includes a diffusion housing of zirconia based material having a gas diffusion aperture, an oxygen ion conductive plate of zirconia based material, a pair of electrode layers mounted on opposite sides of the conductive plate, and a sealing glass material sealingly bonding the conductive plate at one side to the housing to provide a diffusion chamber defined by the diffusion housing and the conductive plate. The electrodes are connectable to a power source for being supplied with an electric potential to pump oxygen ion out of the diffusion chamber through the conductive plate to flow a current through the electrodes which current is indicative of the partial pressure of the oxygen in the monitored gas environment. The sealing glass material contains SiO.sub.2, BaO, Na.sub.2 O and ZrO.sub.2.