Measurements of the Size of Source for Pyrometers Directly Indicating in Temperature

− The calibration of radiation thermometers requires knowledge of the target size effect on the thermometer output, namely the size of source effect (SSE). The measurement of an instrument SSE allows to calculate a correction, or an estimation for this source of uncertainty. For a correct determination of SSE it is necessary to use large aperture radiation sources of uniform spectral radiance. We show here an experimental system to measure SSE at high temperature (up to 600 °C) with an enough large aperture of broad band radiation thermometer with output in terms of temperature.