Force Tensiometer – Sigma 700 / 701

UK based Dyne Testing offer Sigma 700 and 701 force tensiometers that are a powerful and accurate technique to measure static surface and interfacial tension of liquids.

These direct measurements allow determination of a number of material and surface properties, such as dynamic contact angle, surface free energy, critical micelle concentration (CMC) and wettability.

This information can be used to determine adhesion, absorption, adsorption, cleanliness, surface heterogeneity, density, spreading, porosity, powder or sedimentation wettability, material solubility, biocompatibility and lubricity of solid surfaces, to name but a few.

Sigma force tensiometers are widely used in research, quality control and process control for the determination of:

·          Surface tension
·          Interfacial tension
·          Critical micelle concentration
·          Powder wettability
·          Dynamic contact angle
·          Sedimentation
·          Surface free energy
·          Adhesion force
·          Density

Density force tensiometry has become the method of choice for many industrial standards related to characterization of liquids.  It is also the most widely used technique for measuring critical micelle concentration (CMC) of surfactants. In addition, it is the only method to determine the absorption and contact angle of a packed powder or of fibre beds using the Washburn method. The wetting of textiles and individual fibres can also be studied with Sigma force tensiometers.

Measurement principle
When a liquid touches the surface of a solid, the liquid tends to be drawn up in a meniscus. The force exerted by the meniscus is measured and analyzed to determine surface tension. Using high surface free energy probes such as a platinum Du Noüy ring or Wilhelmy plate allow precise measurement of these forces. All Sigma force tensiometers measure surface and interfacial tension using plates or push and pull modes by ring. Correction calculations for rings are made using models from Huh and Mason (Harkins and Jordan, Zuidema & Waters and others also available).

Sigma 700 and the Sigma 701 force tensiometers come with the OneAttension software for unparalleled performance and usability:
  • Fully automatic measurements avoids user dependant variation and saves time
  • Select readymade experiment recipes or create custom programs for quick and repeatable operations
  • Programmable probe and sample immersion and withdrawal cycle(s)
  • Step by step powder protocol for simple powder wettability measurement
  • Fully automatic CMC measurement

OneAttension is an all-inclusive software enabling immediate access to all measurement capabilities with no need to purchase and install separate software modules. It features an intuitive user interface, live analysis, configurable user groups and accounts and a preset liquid database. Any datapoints or groups of datapoints can be selected, transformed, plotted and analyzed. Data can easily be exported. In-depth analysis is now just a matter of seconds. Accessory modules for dispensers and temperature or pH control can be easily mounted into the measuring unit. In addition, special probes are available for density, wettability and tensiometry measurements as well as holders for fiber and plate studies. Two dispensers can be used simultaneously for critical micelle concentration (CMC) measurements, allowing a full CMC curve to be obtained in one measurement. 


Sigma 700

The Sigma 700 has a wide weight range and microbalance maximum load of 210g, which makes it  well suited for dynamic contact angle measurements of large and heavy solid and powder samples.

Sigma 701

Sigma 701 is also a multipurpose tensiometer but equipped with a different microbalance  – 5g optimized for a different range of applications. Sigma 701 can measure in a much more narrow weight range but with improved sensitivity, optimized for fiber measurements.

Software modules for both models are independent and can be acquired separately, giving you the flexibility to customize the instrument to your needs. Modules are available for the following measurements: surface and interfacial tension, dynamic contact angle, CMC, density, powder wettability and sedimentation.



          Sigma 700           Sigma 701
Available Measurements
Surface tension           Yes           Yes
Interfacial tension           Yes           Yes
Critical micelle concentration           Automatic           Automatic
Dynamic contact angle           Yes           Yes
Surface free energy           Yes           Yes
Powder wettability           Yes           Yes
Density           Yes           Yes
Technical Specifications
Measuring range (mN/m)           1 …2000           1 …1000
Displayed resolution (mN/m)           0.001           0.001
Density range (g/cm³)           0…2.2           0…2.2
Maximum load (g)           210           5
Weighing resolution (mg)           0.01           0.005
Contact angle range           0 …180°           0 …180°
Contact angle resolution           0.01°           0.01°
Calibration & locking           Automatic           Manual
Sample state           Motorised           Motorised
Temperature range (°C)           -20 … +200           -20 … +200

Recommended system requirements

1GHz processor, 1GB MB RAM, 40 GB hard disk drive (20GB free), 1 USB port.

Accessories such as water bath and liquid dispenser may require a free RS-232 port.

Operating system requirements

Windows 7 & 8 (32 or 64 bit), Windows Vista (32 bit), Windows XP SP3 (32 bit).



Order Code Description
40-Sigma 700 Sigma 700 Tensiometer, 240VAC, 50 Hz Including:

  • Motorised sample stage
  • Automatic calibration and locking
40-Sigma 701 Sigma 701 Tensiometer, 240VAC, 50 Hz Including:

  • Motorised sample stage
  • Automatic calibration and locking






For accessory details please refer to the list below or contact our Sales Team for assistance.

Order Code      Description
Environment and Sample Control: Temperature, pH, Stirrer & Cabinet
40-T705      Thermostatic vessel (from -10 to +100ºC)
40-T705A      Thermostatic vessel (from -10 to +200ºC)
40-T115      Gas phase temperature controller
40-T708      Temperature probe
40-T102MC      Bath/circulator, Julabo F12-MA
40-T102ME      Bath/circulator, Julabo F25-MA
40-T102MT      Temperature probe for the Julabo bath circulator F25Me
40-T102ED      Bath/circulator, Julabo F12-ED
40-T140CAB      Cabinet
40-T706      Magnetic stirrer
40-T118      pH meter
Critical Micelle Concentration
40-T101      Liquid dispenser, Schott titronic universal 20ml
40-T101A      Cable to connect two T101 dispensers
Powder Wettability
40-T112      Powder wettability measuring device, glass
40-T112A      Powder wettability measuring device, steel Sigma 700 only
40-T112B      Filter paper for T112A, 100 pcs/bag
40-T113      Density measuring device
40-T119      Sedimentation measuring device
Probes and Calibration
40-T106      Platinum Du Nouy ring
40-T106A      Certificate for Du Nouy ring dimensions
40-T106B      MIKES calibration certificate for Du Nouy ring
40-T107      Wilhelmy Plate, platinum plate with micro roughened surface
40-T107A      Certificate for Wilhelmy plate dimensions
40-T107C      MIKES calibration certificate for Wilhelmy plate
40-T110      Platinum rod
40-T117B      Certified calibration kit
40-T120      Calibration weight
40-T108      Ring re-form tool
Sample Holders
40-T109RF      Sample holder for plates
40-T111      Sample holders for fibres
40-T104      Sample vessel, diameter 70mm, 5 pcs/box
40-T105      Sample vessel, diameter 50mm, 5 pcs/box
40-T130      Computer with pre-installed OneAttension Software
Maintenance & Services
40-STUP-EU      Start up & training
40-1A-UG      OneAttension upgrade
40-SERV1      Service contract level 1
40-SERV2      Service contract level 2
40-SERV3      Extended warranty


For a detailed list of accessories please refer to the attachment

  Sigma 700-701-Accessory List