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:
Aug. 07, 1990
Filed:
Jan. 30, 1986
Applicant:
Inventor:
Karl-Heinz Pannwitz, Lubeck, DE;
Assignee:
Dragerwerk Aktiengesellschaft, Lubeck, DE;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G01N / ;
U.S. Cl.
CPC ...
422 60 ; 422 83 ; 422 86 ; 422 88 ; 436126 ; 436902 ;
Abstract
A colorimetric gas diffusion testing tube is disclosed that is to be opened at one end and that contains a granular indicator layer. The testing tube detects a gas that does not directly change the color of the indicator layer. When the tube is viewed from the end which is to be opened, the indicator layer that is adjacent the opening end is inert to the gas that is to be detected. The indicator layer is followed by a porous reagent layer for converting this gas into the substances that change the color of the indicator layer.