Force Tensiometer


The premium instrument for analyzing surfactants and solid surfaces


The K100 Force Tensiometer performs highly accurate and automatic measurements of surface tension and interfacial tension, critical micelle concentration (CMC) as well as contact angle measurement on solids, fibers, and powders. With this uniquely wide range of methods and quality components, the K100 is our all-round solution for surfactant analysis and wetting measurement in research and development.


  • Surface tension and interfacial tension measurement for wetting and cleaning agents, emulsifiers, or other surfactants

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

  • Wetting behavior of tablets, pharmaceutical active ingredients, and excipients

  • Wetting of varnishes and paints

  • Wetting and adhesion of coatings

  • Development of cosmetic products

  • Wetting properties of inks

  • Wetting of fiber bundles and textiles, also for fiber-reinforced polymers

  • Sedimentation and ductility of dispersions

  • Analyzing surface modifications

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

  • Contact angle using the wetting force of a liquid at a solid sample

  • Contact angle between a liquid and porous material using the capillary force

  • Surface free energy of a solid using contact angle data

  • Calculating adhesion-related scientific parameters for the interfacial contact

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

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

  • Sedimentation speed of a dispersion

  • Penetration resistance of a sediment against a probe

  • Using a force sensor and a software-controlled sample stage for freely defined procedures

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

  • Calculating the polar and disperse part of the surface tension from contact angle and surface tension data

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

  • Advancing and receding contact angle of a solid body

  • Surface free energy of a solid

  • Work of adhesion, interfacial tension, and spreading coefficient between a solid and a liquid

  • Contact angle of a powder

  • Density of a liquid

  • Density of a solid

  • Sedimentation speed of a dispersion

  • Penetration resistance of a sediment

  • Sample temperature

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Experience the performance of the K100

Get to know our premium tensiometer K100: highly accurate force detection for surface analysis of liquids and solids with an immense portfolio of measuring methods and accessories.

High force and position resolution for maximum precision

The measuring methods of the K100 are mainly based on the wetting force that acts on a measuring probe or a solid sample. To obtain results that are as accurate as possible, the instrument uses a special force sensor with a particularly high resolution. An automated adjustment procedure with an internal precision weight ensures the long-term reliability of raw data for the detected force.


With excellent height resolution of the sample stage position, it is possible to achieve highly accurate surface tension measurements using the ring method or measurements of the Wilhelmy contact angle. This leads to exact measurements even in the lower measuring range, i.e. for samples with a small interfacial tension or contact angle.



Electrostatic discharge for reliable analysis of solids

When analyzing solid samples, electrostatic charges can be annoying and even make it impossible to carry out the measurement, because they produce an additional force. A built-in ionizer disposes of those charges in order to ensure reliable contact angle measurements on solid samples. The ionizer can easily be used within an automation program of the ADVANCE software.



Easy preparation and measurement control

The K100 measuring methods run with prepared templates of the ADVANCE software that standardize the fully automated procedures down to the smallest detail, thus providing maximum repeatability. Moreover, ADVANCE can incorporate the precise force measurement and the ultra-fine step movement of the sample stage for customizable measuring procedures.


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 or a stirrer. 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.





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

  • Does your powder disperse or form lumps in a mixture? Find out with the Washburn method.

  • Analyzing the wetting behavior of solids and their coatings: Wilhelmy contact angle

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