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.

Date of Patent:
Mar. 06, 1990

Filed:

May. 30, 1989
Applicant:
Inventors:

Toyohei Nakajima, Saitama, JP;

Yasushi Okada, Saitama, JP;

Toshiyuki Mieno, Saitama, JP;

Nobuyuki Ohno, Saitama, JP;

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G01N / ; F02D / ;
U.S. Cl.
CPC ...
123479 ; 123489 ; 204401 ; 204410 ; 204412 ; 204425 ;
Abstract

A device for detecting and measuring the concentration of a gas in a mixture of gas such as oxygen in the exhaust gas of an internal combustion engine and circuits for using that measurement to control the air-fuel ratio supplied to the engine. The detecting device has two separate gas residence chamber with different diffusion resistance openings for each chamber and separate pairs of electrodes for each chamber whereby the measurement can be separately made in each chamber. The particular chamber selected for measurement may be done on the basis of whether the air-fuel ratio is lean or rich whereby a substantially linear reading results for all ratios or on the basis of the transition-state or steady-state operating condition of the engine to provide either more rapid or more accurate readings. Further, by using the cells from both chambers to compare their readings and standards, the actual readings can be corrected for abnormalties that may occur after a period of use or to indicate the detector has become defective.


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