Tensiometry is the measurement of the surface tension of liquids and this can be done in different ways, each conferring some benefit and favouring certain applications.

  1. Optical tensiometers measure droplet shape as measured by the Theta series tensiometers.
  2. Force tensiometers using plates use mass balances with ring or plate geometries contacting the liquid –the Sigma series.
  3. Bubble tensiometers measure the pressure needed to extrude an air bubble into your liquid
  4. Volumetric tensiometers measure the sizes of drops.

Surface tension is a property of the surface of a liquid that allows it to resist an external force.

:Water drop animation This is something we see in everyday things from wetting surfaces to things floating or phases not mixing; but it has complexities and there is quite fundamental science underpinning it.

Surface tension is explained in great detail in the Wikipeadia site from which this dripping tap graphic originated.

Measurement of surface tension is a useful tool for understanding material behavior and to study surfaces of materials and liquids by measuring contact angle, surface tension and surface free energy.
The Critical Micellar Concentration test is so useful that we have a specific Biolin backgrounder on this.