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Spinning drop tensiometer – SVT 25 DataPhysics Instruments Logo

Spinning drop tensiometer – SVT 25

The spinning drop video tensiometers of the SVT series are special-purpose optical instruments for measuring extremely low interfacial tensions and rheological properties. This measuring technique offers unrivalled possibilities for the analysis of surfactant effectiveness in the development of emulsions or in the enhanced oil recovery.

The Spinning drop video tensiometer SVT 25 is a compact optical measuring instrument for the determination of low to ultra-low interfacial tensions and rheological interface properties. Highest precision and reproducibility of the measuring results is guaranteed by a well-established measuring technique and first grade mechanical and optical components. Due to state of the art electronic components the SVT 25 can be operated intuitively via the TP 50 control panel.

For an efficient measuring procedure the measuring cell, with the rotating capillary, is mounted on a tilting table, which allows the operator to easily move the drop of interest into the camera view. The fast 6.5-fold zoom lens with fine focus enables an analysis of small and large drops alike.

Due to the high-performance camera with USB 3 interface the spinning drop can be analyzed with exceptional resolution. Fast processes e.g. during oscillation experiments can be captured with up to 3250 frames/s. Once detected the drop is automatically tracked by the movable camera.

A highly dynamic measurement drive creates a uniform rotation even at highest rotational velocities of up to 20 000 rev/min. In addition it allows for sinusoidal changes in revolution speed for oscillation measurements and for rapid rotational velocity steps with a max. acceleration of up to 500 rev/s2.

Samples can be easily placed inside the SVT 25, within seconds, due to fast-exchange capillaries with perfect fitting accuracy. Hence the highest throughput rates can be assured. In order to avoid extensive cleaning procedures disposable glass tubes with corresponding holders can also be used for the measurement. The observation windows of the measuring cells for the SVT 25 can be easily removed by opening just two knurled screws and are easy to clean in case they came into contact with sample material.

Temperatures within the range of -30 °C to 180 °C can be reached inside the temperature controlled measuring cells. This facilitates the recreation of many different environmental conditions. Due to a specially designed capillary and a resulting higher pressure tolerance the SVT 25 can even be used with water-based solutions at up to 130 °C.

SVT 25 with temperature controlled measuring cell MC-TPC 25 and TP 50 control panel

Main features

  • Measurement of low to ultra-low interfacial tensions based on the contour of spinning drops according to models by Vonnegut, Cayias-Schechter-Wade or Young-Laplace
  • highly dynamic measurement drive with 0 … 20000 rev/min
  • oscillation measurements with oscillation periods of 0.5 s …∞ and max. acceleration of 500 rev/s2
  • motorized tilting table
  • fast 6.5-fold zoom lens with integrated continuous fine focus
  • motorized movable optics for automatically following moving drops
  • high-performance camera with USB 3 interface, 2/3″ sensor, max. 2048 x 1088 pixel, max. 3250 frames/s
  • precise, fast and easy to use capillary exchange system
  • LED-lighting with strobe function and adjustable slit diaphragm
  • temperature controlled measuring cells for temperatures ranging from -30 °C to 180 °C
  • special capillary for measuring water-based solutions at up to 130 °C
  • automatic calibration function for correcting optical distortions caused by the capillaries (cylindrical lens effects)
  • TP 50 control panel with touch screen and precision control wheel

Application video: Spinning Drop Tensiometer


The SVTSoftware is available in various independently usable modules. The available software modules for the SVT 25 are:

Learn more about the SVTS modules.


Due to the modular product design the SVT 25 can be combined with a multitude of options of the versatile SVT accessories range. Learn more about the available accessories.

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