The heart of the instrument is a torsion wire which is connected to a measuring ring. To make the measurement, the ring is immersed in the sample and slowly withdrawn by lowering the liquid. As the ring is withdrawn, the surface tension causes the wire to twist and its defection is indicated on a scale which is calibrated for the surface tension. The result of the measurement is indicated accurately to 0.5 mN/m.
The horizontal alignment of the instrument, which is necessary to achieve precision measurements, is provided by a special platform with leveling facility. Our K6 has a large measuring range of 1 to 90 mN/m. It therefore measures high surface tensions, such as that of water, and low surface tensions, such as that of hexane and other solvents, equally reliably.
As well as simple investigations of liquid and liquid-liquid interfaces, our K6 is also suitable for training purposes in schools and universities for demonstrating the action of the surface tension force in a comprehensible manner.