ASTM D7490-13

Standard test method for measurement of the surface tension of solid coatings, substrates and pigments using contact angle measurements

The method described in this standard is based on the concept that the total free energy at a surface is the sum of contributions from different intermolecular forces, such as dispersion, polar, and hydrogen bonding. This test method describes a procedure for the measurement of contact angles of two liquids, one polar and the other nonpolar, of known surface tension on a substrate, pigment (in the form of a disk), or cured or air dried coating in order to calculate the surface properties (surface free energy and its disperse and polar components) of the solid.