Bilateral Comparison Between CMI and CEM in Radiance Temperature Scale Realization from $232\,^{\circ }\mathrm{C}$ to $1085\,^{\circ }\mathrm{C}$

Abstract

A bilateral comparison between the Centro Español de Metrología (CEM) and the Český Metrologický Institut (CMI) of radiance temperature scale realizations in the range from $232\,^{\circ }\mathrm{C}$ to $1085\, ^{\circ }\mathrm{C}$ was carried out during 2012 to support the calibration measurements capabilities of CMI in radiation thermometry. The CEM capabilities were demonstrated previously in a recent comparison of European laboratories over the range from $156\,^{\circ }\mathrm{C}$ to $1000\,^{\circ }\mathrm{C}$. A CMI KE-LP5 radiation thermometer, working at 1568 nm, was used as a traveling standard. CEM measurements were done at the fixed-points (FPs) of Zn, Ag, and Cu and, for the rest of the temperatures, variable temperature blackbodies (VTBBs) were used. CMI measurements were done at the FPs of Sn, Al, and Cu, and the rest of the temperatures were measured with VTBBs. The size-of-source effect was measured at CEM to decide whether or not the measurements from both laboratories should be corrected by this effect (when the diameter of the sources was different at each laboratory). CMI performed the measurement of the Al FP before and after CEM to evaluate the stability of the radiation thermometer. The results for both laboratories are summarized, and they agree within their expanded uncertainties.