DIN 55660-3:2011-12

This standard specifies a test procedure with an optical method for the measurement of the surface tension of fluids. The procedure can be used for characterization of fluid coating materials. There are limitations with regard to applicability in the case of fluids with non-Newtonian flow behaviour. See DIN EN 13470 and DIN ISO 1409, amongst others, for procedures with other methods. Principle: A drop from each fluid to be examined is depicted hanging on a cannula; the drop shall significantly deviate from the spherical shape. The surface tension is calculated from the shape of the pendant drop according to the Young-Laplace equation. The determination of the polar and dispersive fractions of the surface tension can be carried out using at least two of the methods described in DIN 55660-4 and -5. The committee responsible for this standard is NA 002-00-07-15 AK "Kontaktwinkel/Benetzbarkeit" ("Contact angle/Wettability") at DIN.