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:
Dec. 17, 2002
Filed:
Dec. 19, 2000
Applicant:
Inventors:
Hiroshi Kataoka, Kariya, JP;
Yuji Honda, Okazaki, JP;
Assignee:
Denso Corporation, Kariya, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G01N 2/762 ; G01R 2/708 ;
U.S. Cl.
CPC ...
G01N 2/762 ; G01R 2/708 ;
Abstract
A gas concentration detector for detecting a concentration of pollutant gas such as NOx or SOx contained in ambient air is composed of an oxide-semiconductor gas sensor heated by a heater and a controller for determining the gas concentration by comparing a concentration level detected by the gas sensor with a calculated comparison level. The comparison level is calculated so that it follows the detected level with a certain delay. The degree of the delay is set shorter in an unstable region- of the gas sensor than in a stable region, thereby to effectively determine the gas concentration even in the unstable region.