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:
Jul. 02, 1991
Filed:
Jul. 02, 1990
Applicant:
Inventors:
Assignee:
NGK Insulators, Ltd., , JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G01M / ;
U.S. Cl.
CPC ...
731181 ; 436160 ;
Abstract
A method of evaluating properties of an oxygen sensor used for detecting air-fuel ratio of exhaust gas from internal combustion engine comprises steps of preparing a burnt gas having a predetermined excess air ratio, supplying additional oxidation gas and/or reduction gas into the burnt gas, and detecting an output from the sensor exposed to the mixed gas flow. The supply amount of the additional gas is increased and decreased with a frequency of at least 10 Hz, and a ratio of a supply increasing period to a supply decreasing period is changed to change the supply amount of the additional gas, so that an excess air ratio .lambda. can be controlled similarly to exhaust gas from an actual engine.