Q. How does a stalagmometer measure surface tension?

Answer

Droplets of the fluid of interest are dropped into a capillary glass tube, and their weight is measured to determine the surface tension of the fluid. A force tensiometer can be used to measure surface tension. This type of device works by measuring the pressure at the liquid-gas or liquid-liquid interface using a probe. An extremely delicate balance is linked to the probe, and the liquid interface of concern is brought in contact with the probe. Surface tension may be determined by weighing the forces registered by the balance when the probe contacts the liquid's surface. The probe's dimensions and profile may be adjusted with little effort.