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:
Sep. 24, 1985
Filed:
Dec. 09, 1982
Bernhard Westrup, Lubeck, DE;
Abstract
An indicator for determining sulfur dioxide is required for monitoring, e.g. the content of the noxious substance in the air, due to emissions or in particularly jeopardized working places. With a high sensitivity and spacificity, it must allow simple handling and be ready to use immediately even after prolonged storage. Suitable for this purpose is the color reaction of nitroprussiate, which only takes place in the moist state. In order to attain a sufficient sensitivity an additive is principally required. Usual additives, however, lead on storage in the moist state to rapid decomposition so that immediate use is not possible after prolonged storage. This can be remedied by the use of a tetra-substituted ammonium salt as an additive, which yields at the same time a good sensitivity and storability in the moist state for months. It is preferably used in the form of the known test papers of test tapes.