ISO 696:1975

Surface active agents — Measurement of foaming power — Modified Ross-Miles method

After 500 ml of a solution of the substance to be tested have flowed down from a height of 450 mm onto the surface of the same solution, the volume of foam formed is measured, This method is applicable to all surface active agents, but solutions of easy-hydrolizable substances do not give reliable results because the hydrolysis products accumulate in the liquid films and affect the steadiness of the foam.