Ngk Spark Plug Company, Limited

Tomohiro Mabuchi

Hiroyuki Hayashi

Yoshiaki Kuroki

Shinya Awano

Kunio Yanagi

Satoshi Teramoto

Shigeki Mori

Takeshi Kawai

A sensor element including an insulative base (), a heating resistor (), an oxygen pump cell (), an oxygen detection cell (), and a diffusion-chamber-forming member () having a rate-controlling introduction portion () and defining a diffusion chamber () in cooperation with electrodes (), wherein these components have been subjected to simultaneous firing (i.e., cofiring) to form a unitary sensor element. A partition wall (), which extends from the diffusion-chamber-forming member and is made of alumina, is joined to a surface of a solid electrolyte () between two electrodes () of an Ip cell. Preferably, a region within 20 &#x3bc;m from the plane of junction joining the partition wall () to the solid electrolyte () contains no portion whose amount of non-alumina substances exceeds by 2% by mass (by weight) or more the amount of non-alumina substances of the diffusion-chamber-forming member ().

Gas sensor element having at least two cells

A multi-layer gas sensor element is described which comprises a solid electrolytic member, a substrate, and a porous member, wherein each of the substrate and the porous member has a thickness larger than that of the solid electrolytic member with respect to a lamination direction; the substrate and the porous member face each other and sandwich the solid electrolytic member; a ceramic component constituting the substrate in the highest volume percent is the same as the ceramic component constituting the porous member in the highest volume percent thereof; and the volume percent (R2) of the ceramic component contained in the porous member is 80% or more the volume percent (R1) of the ceramic component contained in the substrate.

Multi-layer gas sensor element and gas sensor comprising the same

A method of stabilizing pump current in a gas sensor through suppression of oscillations of the pump current which result from pulsations of measured gas is provided. The gas sensor includes an oxygen pump element, an oxygen concentration cell element and a measurement gap between the oxygen pump element and the oxygen concentration cell element, and is operative to control the pump current through the oxygen pump element so that an output voltage of the oxygen concentration cell element is constant in order that an oxygen concentration in the measurement gap is maintained constant and detect an oxygen concentration in the measured gas on the basis of the pump current. The method comprising adjusting an activity of electrodes of an oxygen pump element so as to change a responsiveness in control of the pump current and thereby reduce an amplitude of the oscillations of the pump current. There is also provided the above described type gas sensor wherein the activity of the electrodes of the oxygen pump element is adjusted so as to change a responsiveness in control of the pump current and thereby reduce the oscillations of the pump current.

Method of stabilizing pump current in gas sensor

Growing community of inventors

Aichi, Japan

Tomohiro Mabuchi