This paper purpose is to re calculate thermodynamic or chemical-physical properties according to thermodynamic temperature T where measured temperature values were obtained according to the ITS-90 T-90 (or the reverse) The main aims of the calculations are to remove the discontinuity of the first derivative at 273 16K that is intrinsic in the ITS-90 definition to use a single cubic spline to model the data base of the available experimental data over the whole temperature range (2 37 to 1235) K while maximising the medium-range smoothness of the correction function to compute corrections using only local polynomial coefficients (C) 2010 Elsevier Ltd All rights reserved