Concerning the consistency of fixed points of the temperature scale

An analysis of calibration data suggests that Wref(In) and Wref(Ga), the resistance ratios at the freezing point of indium and the melting point of gallium, may have been assigned temperatures a fraction of one millikelvin higher and lower, respectively, on the ITS-90, than the values indicated by some high-purity samples. Illustrations are given of how the quality of calibration services can be assessed using issued calibration data.