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. 22, 2002
Filed:
Oct. 30, 2000
R. Daniel Costley, Oxford, MS (US);
Mark Henderson, Long Beach, MS (US);
Mississippi State University, Mississppi, MS (US);
Abstract
A method and apparatus for determining the internal pressure of a sealed container are disclosed. The method involves: exciting a lid of the container so as to create at least two modes of vibration having separate frequencies, wherein said frequencies are fundamental, f , and a second frequency, preferably the second axisymmetric mode, f ; detecting the vibration resulting from said exciting to determine f , and f ; using f , which is indicative of internal pressure, to calculate a first value for internal pressure using a first mathematical model that is calibrated to the lid on the sealed container; using f , which is indicative of volume of contents, to calculate the volume of contents in the sealed container using a second mathematical model that is calibrated to the lid on the sealed container, wherein a natural frequency of said lid is a function of said internal pressure and said volume of contents; and compensating for said volume of contents to determine a second value for internal pressure, wherein said second value for internal pressure is more reliable than said first value for internal pressure. The apparatus for determining the internal pressure of a sealed container of the invention includes: means for exciting a lid of the container so as to create at least two modes of vibration having separate frequencies, wherein said frequencies are fundamental, f , and a second frequency, preferably the second axisymmetric mode, f ; detecting means for detecting vibration resulting from the exciting of said container to determine f , and f ; calculating means for calculating a first value for internal pressure of said container using f ; calculating means for calculating the volume of contents of said container using f ; wherein a natural frequency of said lid is a function of said internal pressure and said volume of contents; and calculating means for compensating for said volume of contents to determine a second value for internal pressure, wherein said second value for internal pressure is more reliable than said first value for internal pressure.