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:
Apr. 02, 1985
Filed:
Feb. 14, 1984
Applicant:
Inventor:
Sai Sakai, Osaka, JP;
Assignee:
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G01N / ;
U.S. Cl.
CPC ...
338 34 ; 73 23 ; 73 2 / ; 422 98 ;
Abstract
A gas sensor comprising an electric resistor of noble metal and a sintered piece of a metal oxide covering the resistor and serving as a semiconductor. The ratio of the combined resistance Ro of the resistor and the semiconductor to the resistance ro of the resistor, Ro/ro, is within the range of 0.45<Ro/ro<0.95. The sintered piece may be prepared from a mixture of SnO.sub.2 powder of usual particle sizes and a superfine powder of SnO.sub.2 by sintering the mixture at about 600.degree. C. to about 800.degree. C.