REALIZATION OF THE SILVER POINT USING A CALORIMETRIC METHOD

Most of the ITS-90 temperature fixed points are established by the mel ting or freezing of a specified substance. The question which may be a sked is how closely this definition leads to a temperature value corre sponding to the ideal thermodynamic state of the phase change temperat ure of a substance containing a small amount of impurities. In the lig ht of experiments performed in the low temperature range it seems poss ible to use a calorimetric method to realize the temperature fixed poi nts closer to the thermodynamic definition than by using the actual IT S-90 definition. This technique could lead to a more reliable (or more reproducible) temperature and could be a worthwhile improvement of th e ITS-90.