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:
Mar. 13, 1990
Filed:
Jul. 15, 1987
Applicant:
Inventors:
Jun Usami, Aichi, JP;
Yuichi Sasaki, Nagoya, JP;
Assignee:
NGK Insulators, Ltd., Nagoya, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G01N / ;
U.S. Cl.
CPC ...
324711 ; 204406 ; 204425 ; 324446 ;
Abstract
A circuit is utilized for measuring a diffusion-limited current which flows through a diffusion-limited current element in proportion to an oxygen concentration which includes an output resistor connected in series with the element, a differential amplifier having a first input connected to a reference voltage supply source, a second input connected to ground, an output connected to the output resistor, and a feedback resistor connected between the first input of the differential amplifier and a point between the element and the output resistor, so that a bias voltage applied across the element is kept constant.