Surface tension measurements – A comparative study

The lack of intercomparisons in surface tension measurements, and the need to establish the degree of equivalence of such measurements, lead to a comparative study on this subject carried out by 3 National Metrology Institutes (from Poland, Portugal, and Turkey), within the scope of the Project 17RPT02-rhoLiq. For this purpose, the surface tension of 6 liquids, was determined at 20 °C, using force tensiometers, with 2 different measuring probes (Du Noüy ring and Wilhelmy plate), and by applying different correction factors. The results of this work allowed to conclude on the degree of equivalence of surface tension measurement results, obtained by each NMI, by using different probes and measurement models.