Spinning Drop Tensiometer


Measurement of interfacial tension in a wide range for optimizing emulsions


The SDT Spinning Drop Tensiometer measures interfacial tension with a high degree of accuracy and a particularly wide range down to very low values. The SDT is the ideal solution for the quality control and development of emulsions and surfactants thanks to its enormous bandwidth, small sample volumes, and simple handling during preparation. The instrument is particularly well-suited for analyzing the interfacial behavior of mini- and microemulsions, e.g. for enhanced oil recovery (EOR) or the pharmaceutical and cosmetics branches.


  • Development of emulsions and microemulsions

  • Surfactant flooding in enhanced oil recovery (EOR)

  • Formulations in pharmaceuticals and cosmetics

  • Bioavailability of drugs

  • Food emulsions

  • Surfactant research

Measuring methods

  • Interfacial tension using the diameter or curvature of a drop of a light phase inside a heavy phase in a rotating capillary

  • Carrying out a measurement up to 20 consecutive times and displaying the results together

Measuring results

  • Interfacial tension between two liquids

  • Drop image evaluation according to Vonnegut or Young-Laplace

  • Time- and temperature-dependent results

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Ultralow surface tension – ultrahigh efficiency

A model of usability for scientific analysis: watch the performance of the SDT and learn about its potential for emulsion analysis.

Exact rotation, image evaluation, and drop positioning

The accuracy of the video analysis and the rotational speed is the reason the SDT is so precise. A high-resolution camera and a motor with excellent speed constancy are among the most important components of the instrument, combined with the intelligent image evaluation algorithm of the software ADVANCE. The previously necessary observation of a running measurement is now obsolete, as the drop can be automatically held in the middle of the video image.


In addition to the standard Vonnegut method, the software also evaluates the drop shape with the more robust Young-Laplace approach. Adding to this advantage, this method also extends the measuring range to higher interfacial tensions.

Innovations for quick sample preparation

Putting a drop inside the filled capillary used to be a tedious job. We have rendered this step especially quick and easy with a unique, patented procedure, which vastly increases the sample throughput.

Efficient and versatile temperature control

The quick capillary changeover is also achieved by using an integrated electric heater instead of a thermostat with a surrounding liquid medium. The heater reaches the target temperature quickly and accurately and keeps it exactly constant, while an accurate infrared sensor records the temperature condition in close vicinity to the drop.

Ergonomic and safe design

In the award-winning design of the SDT, all components, including the rotating capillary, are enclosed in a sturdy housing, which is completely novel in respect to the spinning drop technique. The camera is protected by a special recess that accommodates it in its park position, while the clearly highlighted control elements make working with the instrument very easy. The tilting and the camera position are motor-driven and controlled via the instrument or ADVANCE software.

Satisfied voices

The team at VeriFrac is very excited to have our new Spinning Drop Tensiometer, and is thankful for the exceptional installation and training. Great customer service to say the least! The SDT has very elegant design and operation, with a neat technical history. Excited to use it to its full capability – developing cost effective surfactant products for our customers!

Tom McLoughlin

General Manager, Veri Frac


  • Intuitive software with a workflow-oriented user interface

  • Swift and repeatable analyses thanks to measurement templates and powerful automation functions

  • Result management made easy with clear and comprehensive charts and tables

  • A wide range of evaluation methods makes ADVANCE a reliable scientific tool