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:
Jun. 06, 1989
Filed:
Dec. 28, 1987
Applicant:
Inventors:
Assignee:
NGK Spark Plug Co., Ltd., Nagoya, JP;
Primary Examiner:
Int. Cl.
CPC ...
G01N / ;
U.S. Cl.
CPC ...
204410 ; 204412 ; 204425 ;
Abstract
An air-fuel ratio sensor in which the temperature dependence as well as the pressure dependence of a detection signal obtained by the air-fuel ratio sensor are suppressed to thereby improve the accuracy in air-fuel ratio by the air-fuel ratio sensor, which is not influenced by deposits in an exhaust gas and which is high in durability. The suppression is achieved by using a gas-diffusion limiting portion having such critical parameters as 10-30% porosity, 1-3 micrometers mean pore size and 200-1000 micrometers thickness. Alternatively the parameters may be 15-25% porosity, 0.1-7 micrometers pore size and 400-800 micrometers thickness.