ISO 6889:1986 Preview
Surface active agents -- Determination of interfacial tension by drawing up liquid films
This standard was last reviewed and confirmed in 2013. Therefore this version remains current.
The determination is carried out in the following way: Measurement of the maximum force which can be exerted before the film breaks, the force being exerted vertically on a stirrup or ring, in contact with he interfacial liquid film between two immiscible liquid phases placed in a measuring cup, in order to draw up the interfacial film. The force must pass through a maximum, otherwise the measurement is not valid.