The Theta series of Attension tensiometers measure the contact angle of drops with optical/video technology.

Theta optical tensiometer

These instruments have a monochromatic, cold light LED source and a smooth lighting integration sphere – to reduce sample evaporation.

Images are captured by high resolution digital cameras and fast data transfer on fire-wire to the computer.

Software is easy to use and offers superior analysis of drop shape, includes a database of liquid profiles.

The Young-Laplace equation first used by Attension allows the entire drop to be profiled.

Automatic base-line detection and fully automatic contact angle measurements are standard features.

Attension offer two optical tensiometers.


Theta is the versatile, high end instrument while Theta Lite offers affordability and ease of use.

For more information  look at underlying principles or go to the Biolin website

Applications of optical tensiometers:
  • wettability
  • surface tension
  • interfacial tension
  • contact angles
  • absorption
  • surface free energy
  • adsorption
  • spreading
  • cleanliness
  • surface heterogeneity
  • interfacial rheology