Graphical representation of differences from the KCRV of K2-xx and Star direct-cell Inter-comparison, uncorrected (gray dots and lines) and corrected (black squares and lines): (T – KCRV_K2ac) = DT_thermal,ac (Tab. 2); (T – KCRV_K2bc) = ΔT_original (Fig. 1). On the left until #28: K2-xx differences for cells #1 to #15 and thermometer sets #1 and #2. ΔT_original,#1 = –147(268) µK, ΔT_original,#2 = –166(309) µK; DT_{thermal,ac,#1} = –167(233) µK, DT_{thermal,ac,#2} = –147(240) µK. On the right from #30 to end: Star differences (56(68) µK; 74(87) µK before isotopic correction), u = 47 µK [12]⋅ The dotted lines indicate the range of the isotopic effect for the studied samples, as obtained from the MeP [31] in Table 3.