Direct observation of plateau progression in fixed-point blackbodies via X-ray imaging

In this study, we address the challenge of calibrating radiation thermometers using blackbody furnaces that employ a metal melting/freezing plateau. Here, we first present the observation results utilizing X-rays, enabling us to monitor the entire temperature cycle, from heating to cooling, during the calibration process. Through this approach, we directly observe the emergence of voids within deteriorating metal cells, which may give insights into the underlying mechanisms occurring within enclosed graphite cells.