“…However, the issues concerning the physical basis of temperature measurements, the formation of differential radiative heat transfer fluxes and the corresponding digital signals, the methods of temperature calculation with the uncertainty of the thermal emission coefficient, as well as the sources of uncertainty in temperature measurements are considered official information that is not widely disseminated. For users of thermographic equipment, such absence causes difficulties in the interpretation of measurement results in complex cases [3], e.g., with non-uniform heating, dynamic change processes in a thin surface layer of about 4 nm thick. Therefore, when the metal is heated to high temperatures, its surface roughness degree, its oxidation by atmospheric oxygen, presence of impurities, etc.…”