A Wilhelmy plate (26), supported from a strain gauge (27), is brought into contact with the surface of the liquid in a trough (20). A partially submerged glass ring (21) is then suspended around the Wilhelmy plate. The ring is counterbalanced by a partially submerged object (22) which compensates for the change in volume and keeps the overall liquid level constant as the ring is moved up and down sinusoidally by a drive mechanism (23). The position of the ring and the strain gauge output are monitored (25,25;28). The modulus is calculated (29,30) by multiplying the change in surface tension by the change in area. @(10pp Dwg.No.6/6).
|Publication status||Published - 20 Nov 1989|