Force Tensiometer


Fully automated measurements of surface and interfacial tension for quality control


The K100C Force Tensiometer is a fully automated instrument for routine tasks, but also demanding measurements in quality control. The instrument's precision force sensor and the accurately shaped measuring probes ensure reliable results of the surface tension and interfacial tension.

Uniform procedures based on measurement templates of the ADVANCE software provide for user-independent results. Measurement preparation is quick and easy thanks to the user-friendly design and the intuitive control of the instrument’s components.


  • Surface tension validation for cleaning or wetting agents as well as other surfactants

  • Determination of the effectiveness and efficiency of surfactants by CMC measurement

  • Checking the aging status of transformer and other oils according to ASTM D 971 and IEC 62961

  • Checking for cleaning agent residues in the food industry and other areas

  • Quality assurance of emulsifiers

Measuring methods

  • Surface tension using the tensile force of a lamella underneath a ring

  • Interfacial tension using the tensile force of a lamella underneath a ring

  • Surface tension using the tensile force of a lamella which is stretched until it disrupts

  • Interfacial tension using the tensile force of a lamella which is stretched until it disrupts

  • Automated determination of the critical micelle concentration by measuring the SFT at different concentrations

  • Surface tension using the wetting force of a liquid at a platinum plate or rod

  • Interfacial tension using the wetting force of a liquid at a platinum plate or rod

  • Density determination of a liquid using the buoyancy of a probe immersed in the sample

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

Measuring results

  • Surface tension of a liquid

  • Interfacial tension between two liquids

  • Critical micelle concentration (CMC) of a surfactant and calculation of excess concentration and surface area per molecule

  • Density of a liquid

  • Sample temperature

Standardized QC measurements with precision

The combination of automation, precise force measurement and the absolute standardization of the measuring procedures is what makes the K100C ideal for quality control. The measuring methods run with prepared templates of the ADVANCE software in order to repeat the instrument’s behavior down to the smallest detail, reducing user intervention to a minimum.


The highly accurate contours of our ring and plate measuring probes also contribute to the reliability of the K100C. To ensure the accuracy of raw data for the detected force in different environments, the force sensor can be adjusted using an external precision weight.



Easy handling and preparation

Thanks to the large sample chamber, the sample is loaded quickly and conveniently into the instrument. Magnetically locking glass swing doors shield the force measurement from troublesome air currents. The closing of these doors is electronically recognized and can trigger the next automation step in order to speed up the measuring procedure.

As a supplement to the software control, the instrument's intuitive keyboard ensures easy operation of the sample stage and other components, such as the lighting.



Adaptable for different measuring conditions

Optional thermostat jackets provide for measurements under consistent conditions. They can also be used for high or low temperatures to give a realistic picture of the sample’s behavior in the actual process. When testing dispersions, an integral magnetic stirrer, which can also be used in an automation, ensures that the sample is homogenous before the measurement is carried out.


Micro DispenserS

Fully automated CMC measurement

Our specially developed Micro Dispensers equip the K100 for measuring the critical micelle concentration (CMC) with the utmost precision. The surfactant concentration range is set up and then measured fully automatically.



Analyze samples at up to 300 °C

With the high temperature solution TJ60, precise surface tension and contact angle data of hot liquids such as polymer melts or bitumen are easily accessible. The unit quickly heats up the sample to reach and keep a stable target temperature

Satisfied voices

The surface tension measurements from the K100 helped us characterize and optimize a novel surface treatment on a nitinol wire.  The K100 offered us a unique capability over conventional goniometry due to the ability to analyze very small samples. 

Tom G.

Principal Scientist, Medtronic

We have extensively used the KRÜSS K100 Force Tensiometer and Mobile Surface Analyzer in a variety of projects and have found them to be invaluable instruments. The much-needed repeatability and precision of the instruments gives us high confidence in the data we produce.

Geoff Allen

Member of Research Staff, Xerox Research Centre of Canada


  • 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