• Ring measurement

    Ring measurement

Rings are for fingers – plates are for surface tension

Force tensiometry with ring and plate

The classic question from tensiometer users, the one surely heard thousands of times at KRÜSS, is, “Should I use the ring or the plate?” We refer, of course, to the Du Noüy ring method for surface or interfacial tension measurement versus the Wilhelmy plate method. Historically, the ring method has been more widely used for both types of measurements (measurements of air/liquid interfaces, commonly referred to as surfaces, and measurements of liquid/liquid interfaces, commonly referred to as interfaces). There are also several standards, perhaps most notably ASTM standards, which call for the ring method. These standards also exist for historical reasons. More old style manual ring surface tension instruments still exist in the world than any other type of tensiometer which has been developed since.

However, if you want to make the most use of your ring, you will put it in a jewelry box while you are measuring surface tension and only remove it for measurements of interfacial tension.

Download the full technical note (TN308) on this subject.

Download | Application Report


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