Patent ID: 8093055

Claim:
A calibration tool for use in combination with a photoluminescent oxygen-sensitive working probe and an analytical instrument capable of reading the working probe from which the concentration of oxygen in a sample communicating with the working probe can be determined, wherein the working probe comprises an oxygen-sensitive photoluminescent dye embedded within an oxygen-permeable carrier matrix, the calibration tool effective for achieving two-point calibration of the analytical instrument and comprising: (a) a first mass of a first solid state composition comprising an oxygen-sensitive photoluminescent dye that is the same as the probe dye, embedded within an oxygen-permeable carrier matrix that is the same as the probe carrier matrix, wherein the first composition has a first sensitivity to oxygen, and (b) a second mass of a second solid state composition comprising an oxygen-sensitive photoluminescent dye that is the same as the dye in the first mass, embedded within a carrier matrix that is different from the carrier matrix in the first mass, wherein the second composition has a known second sensitivity to oxygen that is less than the first sensitivity to oxygen.