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, 1991
Filed:
Sep. 01, 1988
Rainer Bommer, Lubeck, DE;
Dragerwerk Aktiengsellschaft, Lubeck, DE;
Abstract
The invention relates to a colorimetric detector tube having a porous charge. The charge contains an indicating region provided with an indicator ahead of which a pretreatment region is placed which carries a pretreatment substance. The material to be detected form products with the pretreatment substance which lead to a coloration in the indicating region. The detector tube is improved so that its indication is expanded to indicate higher detection concentrations. The detector tube is further improved so that even when the first pretreatment substance is exhausted, a colorimetric indication is made accessible to further quantities of the material to be detected. For this purpose, the charge contained in the tube includes a sequence of several pretreatment regions and indicating regions which alternate one with the other. In another configuration, the charge includes a mixture of pretreatment material and indicating material.