Combined standard uncertainty in direct emissivity measurements

In order to design a device to carry out direct emissivity measurements, a key point is the analysis of all the uncertainty components that give rise to the combined standard uncertainty. This will permit to choose the most appropriate measurement method to minimize the uncertainty, and also to identify the sources of the largest errors. If the experimental device is already in use, the complete uncertainty characterization, in addition to the emissivity uncertainty calculation, will permit the improvement of the device capabilities. Thus, a guideline to the experimentalists working in this subject is provided. In this work, a complete study of the uncertainty components in direct emissivity determination is carried out. First of all, the emissivity measurement method and the uncertainty estimation methodology are introduced. After that, the influence of the uncertainties of each of the magnitudes used to obtain the emissivity is analyzed theoretically. The most important error sources depending on the me...