Patent ID: 7749768
Filing Date: 2010-07-06
Classification: G01M,G01N,Y10T

Abstract:
1. A method of verifying the oxygen concentration of a sealed package comprising: providing a sealed package defining an interior and having a luminescent compound provided in the interior of the sealed package the luminescent compound having a luminescent emission that is sensitive to quenching by oxygen; exposing the luminescent compound to light having a wavelength that is absorbed by the luminescent compound so that the luminescent compound is promoted into an excited state; terminating the exposure of the luminescent compound when the luminescent compound achieves a steady state between excitation and luminescence; measuring luminescent intensity over a period of time to produce an exponential decay curve; calculating the coefficient of the decay curve to determine tau; measuring a temperature that is indicative of the temperature of the luminescent compound; determining the oxygen concentration within the sealed package using the equation: wherein: T is the measured temperature; tau is the coefficient of the exponential decay curve; and A comparing the measured oxygen concentration to a predetermined minimum or maximum to verify that the measured oxygen concentration is within acceptable limits.