METHOD FOR QUANTIFYING THE EFFECTIVE EMISSIVITY CHANGES IN A BLACK BODY CAVITY ALONG THE USEFUL LIFE OF THE SAME.

摘要

Method for quantifying the emissivity changes in a black body cavity along the useful life thereof, which is characterized in that it has a detachable fitting inserted in the block housing said cavity. The change in the effective emissivity of the black body cavity is obtained upon numerically calculating the effective emissivity using the result of the emissivity measurements of the test surface of the detachable fitting as the emissivity value of the cavity walls, and then comparing the new value of effective emissivity with the previous value of effective emissivity of the black body cavity. The detachable fitting has at least a test surface that is used as a sample for measuring the emissivity, having the same characteristics than the inner surface of the cavity (for instance, it is made of the same material and has the same treatment: paint, oxidation degree, etc.), or forming part of the black body cavity, thus being used as a representative sample with the same emissivity than the walls of the black body cavity. As the detachable fitting forms part of the block of the black body cavity, it may suffer the same temperature changes as those changes supported by the cavity along the useful life thereof in measurements and calibrations in radiation thermometry.