Abstract: An oxygen sensor particularly useful for detecting oxygen concentration in exhaust gas of internal combustion engine is principally made up of a solid electrolyte tube which is closed at one end, anode and cathode electrode layers respectively formed on the outer and inner surfaces of the electrolyte tube and a tubular metal shell which tightly receives therein the electrolyte tube, leaving a closed end portion of the electrolyte tube protruded from the shell. To protect the protruded portion of the electrolyte tube against a direct exposure to a high velocity hot gas stream to be measured and a collision with any external article, without obstructing a rapid and uniform heating of the electrolyte tube by the gas stream, a hood in the shape of a cylindrical tube with a closed end is fixed at its open end portion to the shell to enclose therein the closed end portion of the electrolyte tube.

Abstract: A solid electrolyte tube closed at one end and two porous electrode layers respectively coated on the outer and inner surfaces of the electrolyte tube constitute a known oxygen concentration cell. A tubular metal shell encloses the electrolyte tube partly such that a closed end portion of the tube protrudes from the shell and that the outer electrode coating is locally in contact with the inside of the shell, and a metal tube is partly and fixedly inserted into the bore of the electrolyte tube to serve both as an inner conductor and as an air admitting conduit. To protect the open end of the electrolyte tube against splashing of water during use, an annular ceramic pad is placed on the open end face of the electrolyte tube allowing the metal tube to pass therethrough, and a tubular cap which is shaped to tightly sheathe the ceramic pad is fixed at one end to the shell to prevent the ceramic pad from parting from the end face of the electrolyte tube.

Abstract: An oxygen sensor comprises an electrolyte which is shaped into a conical tube having a closed end of small diameter and an open end of large diameter. The wall thickness of the electrolyte is gradually decreased toward the closed end from the open end and that of the closed end is 0.3 to 1.0 mm so as to provide a high sensitivity.

Abstract: The specification discloses a first and a second rotary disk fixed together, each disk having a magnetic pole on its circumference, which disks rotate in the vicinity of a fixed magnetic head; the fixed magnetic head provides an electrical output signal each time a magnetic pole passes near it and, thus, said electrical output signal indicates a rotational angle and/or the number of rotations of said disk. Said magnetic head operates on a new principle developed from parametric excitation.