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:
Feb. 24, 2004
Filed:
Jun. 07, 2000
Masashi Ando, Nishikasuga-gun, JP;
Noboru Ishida, Kakamigahara, JP;
Satoshi Sugaya, Inuyama, JP;
Takafumi Oshima, Nagoya, JP;
Norihiko Nadanami, Kasugai, JP;
Takaki Ootuka, Komaki, JP;
Yoshikuni Sato, Nagoya, JP;
Tatsuo Okumura, Gujyo-gun, JP;
NGK Spark Plug Co., Ltd., Aichi, JP;
Abstract
Method and sensor for measuring accurate measurement of NOx concentration in an exhaust gas containing O ,H O, CO and NOx and a NOx gas concentration sensor. A first oxygen pump cell sufficiently pumps out oxygen in a measurement gas such as not to decompose NOx. A pair of electrodes is provided on an inner side and an outer side of a second measurement chamber into which the gas is introduced from a first measurement chamber via a diffusion resistance. A voltage is impressed across the paired electrodes for decomposing NOx in the second measurement chamber to dissociate oxygen which causes the current to flow in a second oxygen ion pump cell. The NOx gas concentration is measured for this current. The voltage impressed across the paired electrodes of the second oxygen ion pump cell is set so as not to dissociate H O and CO present in the second measurement chamber.