The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 30, 2000
Filed:
Feb. 12, 1998
Senta Tojo, Kariya, JP;
Makoto Saito, Okazaki, JP;
Keigo Mizutani, Okazaki, JP;
Hiroshi Mori, Ichinomiya, JP;
Yushi Fukuda, Chita-gun, JP;
Denso Corporation, , JP;
Nippon Soken, Inc., , JP;
Abstract
A gas sensor using oxygen-ion-conductive solid electrolyte layers measures a concentration of a constituent gas such as NOx in a gas mixture such as an exhaust gas mixture of an internal combustion engine. The gas sensor includes a pair of oxygen pumping cells and a sensor cell. Before the constituent gas concentration is measured by the sensor cell, oxygen gas contained in the gas mixture has to be purged because the oxygen gas adversely affects the measurement of the constituent gas concentration. Two pumping cells disposed to face a chamber, into which the gas mixture is introduced, pump out the oxygen gas contained in the gas mixture so that the oxygen concentration is reduced substantially zero. Then, the gas mixture is diffused to the sensor cell where the constituent gas concentration is measured without the adverse influence of the oxygen gas. A marginal ion current which is proportional to the constituent gas concentration is measured by the sensor cell with a high accuracy and sensitivity.