Non-intrusive pressure and level sensor for sealed containers
US6339960B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 30, 2000 |
| Grant date | Jan 22, 2002 |
| Priority date | — |
| Expiry date | Oct 30, 2020 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2291/2695
- WIPO fieldMeasurement
- WIPO sectorInstruments
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, f1, and a second frequency, preferably the second axisymmetric mode, f2; detecting the vibration resulting from said exciting to determine f1, and f2; using f2, 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 f1, 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…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.