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:
Jan. 13, 2009
Filed:
Sep. 24, 2004
Michael E. Drummond, Malvern, PA (US);
Albert J. Moses, West Chester, PA (US);
Michael E. Drummond, Malvern, PA (US);
Albert J. Moses, West Chester, PA (US);
Drummond Scientific Company, Broomall, PA (US);
Abstract
An apparatus that indicates whether an object has been exposed to a predetermined critical temperature T. The apparatus housing has a reservoir portion and a capillary tube portion in fluid connection with the reservoir portion. A first fluid is contained within the reservoir portion. A second fluid is contained within the capillary portion. A barrier is located intermediate the first fluid and second fluid. The barrier prevents the first and second fluids from intermixing until the apparatus is exposed to the critical temperature, and then allows at least a portion of the second fluid to mix with the first fluid when the apparatus is exposed to the critical temperature. An observable characteristic of one of the fluids irreversibly changes when the apparatus is exposed to the critical temperature. The housing completely encapsulates the fluids and barrier within the housing and prevents evaporation of the fluids and barrier from the housing.