Central Scientific Company Tensiometer

An instrument for measuring surface tension of a liquid using the du Noüy ring method. A container full of the liquid to be measured is placed on the metal disk, then raised up until the hanging wire ring is submerged in the liquid. Then, a knob on the back is twisted, exerting torsion on the straight wire, which raises the lever arm and exerts an upwards force on the wire ring. As this upwards force attempts to pull the ring up and out of the liquid, an opposing downwards force from surface tension attempts to pull it back in. By twisting the knob further and further, the upwards force on the ring increases until eventually surface tension cannot keep up and the ring pops out of the liquid. The force required to achieve this is then recorded, and surface tension is calculated from it.



This Tensiometer was manufactured by the Central Scientific Company, sometimes known as CENCO.