Patent ID: 7569395

Claim:
A method of measuring oxygen concentration in a container comprising: providing a container having a luminescent compound disposed in an interior space of the container, the luminescent compound having a luminescent emission that is sensitive to quenching by oxygen; irradiating the luminescent compound with light having a wavelength that is absorbed by the luminescent compound so that the luminescent compound is promoted into an excited state; terminating the irradiation 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 exponential coefficient of the curve to determine tau; measuring a temperature that is indicative of the temperature of the luminescent compound during the time that the luminescent intensity is measured; and calculating the oxygen concentration within the container using the following equation: [O 2 ]=( A Ta ( T ) 2 +B Ta ( T )+ C Ta )(tau) 2 +( A Tb ( T ) 2 +B Tb ( T )+ C Tb )(tau)+( A Tc ( T ) 2 +B Tc ( T )+ C Tc ) wherein: T is the measured temperature; tau is the exponential coefficient of the decay curve; and A Ta , B Ta , C Ta , A Tb , B Tb , C Tb , A Tc , B Tc , and C Tc are previously determined coefficients for the luminescent compound that describe the luminescent intensity of the luminescent compound as a function of oxygen concentration and temperature.