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. 05, 2002
Filed:
Jan. 15, 1999
Tessho Yamada, Aichi, JP;
Noboru Ishida, Gifu, JP;
Toshitaka Matsuura, Aichi, JP;
Yoshiro Noda, Gifu, JP;
Nobuhiro Hayakawa, Aichi, JP;
Norihiko Nadanami, Aichi, JP;
Satoshi Sugaya, Aichi, JP;
Takaki Otsuka, Tokyo, JP;
Masashi Ando, Aichi, JP;
Takafumi Oshima, Aichi, JP;
NGK Spark Plug Co., Ltd., Nagoya, JP;
Abstract
An apparatus and method using a two-serial space sensor (having first and second internal spaces ) for accurately measuring NOx concentration in gas, e.g., exhausted from an internal combustion engine. Both NOx (nitrogen oxide) and oxygen are forced to be partially dissociated in the first space to an oxygen concentration level of 2×10 to 2×10 atm by pumping out oxygen from the first space . The NOx concentration is determined based on the second current measured in the second space and based on the NO dissociation percentage in the first chamber which is 0.5-50%, or preferably 2-20%. The NOx measurement accuracy is further improved when the above oxygen concentration level is maintained from 2×10 to 2×10 and the temperature drift of the sensor is maintained within ±5° C. under a sensor temperature range of 700-900° C.