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:
Jul. 21, 1981
Filed:
Jun. 03, 1980
James D Barden, Chester, MD (US);
Versar, Inc., Springfield, VA (US);
Abstract
A method and apparatus for determining the level of sufuric acid in atmospheric air which also contains other interferrants, including a sampling cycle to collect sulfuric acid on the walls of a collection chamber tube which is cooled, while at the same time eliminating interfering sulfur dioxide and ammonia by treating them with a dilute flow of hydrochloric acid through the collection chamber, and further including an analysis cycle during which the walls of the collection chamber tube are heated so as to revolatilize the sulfuric acid and entrain it in a clean air stream which then passes to the burner block of a flame photometric detector, the clean air stream being saturated with water vapor to make the revaporization of sulfuric acid more rapid and complete. The apparatus includes a timing clock which operates valves to select the cooling and heating of the collection tube, and to initiate the timely introduction of sample ambient air streams, air carrying the hydrochloric acid, and the saturated air stream, as appropriate for the various different cycles of the system. The apparatus further includes a source of sulfuric acid entrained in a clean air stream which is used to check proper operation of the system in a mode of operation which is in the nature of a calibrating mode.