The du Noüy ring method is one technique by which the surface tension of a liquid can be measured. The method involves slowly lifting a ring, often made of platinum, from the surface of a liquid. The force required to raise the ring from the liquid's surface is measured and related to the liquid's surface tension.
This technique was proposed by the French physicist Pierre Lecomte du Noüy (1883–1947) in a paper published in 1925.[1]
