About Sigma 700 / 701 Force Tensiometer

UK based Dyne Testing offer Sigma 700 and 701 force tensiometers which are powerful and accurate instruments for measuring 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.

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).

Software and Accessory Modules

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.

Features & Benefits

Sigma 700 and the Sigma 701 force tensiometers come with the OneAttension software for unparalleled performance and usability:

  • Fully automatic measurements avoids user dependent 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


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


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 to 2000 1 to 1000
Displayed resolution (mN/m) 0.001 0.001
Density range (g/cm³) 0 to 2.2 0 to 2.2
Maximum load (g) 210 5
Weighing resolution (mg) 0.01 0.005
Contact angle range 0 to 180° 0 to 180°
Contact angle resolution 0.01° 0.01°
Calibration & locking Automatic Manual
Sample state Motorised Motorised
Temperature range (°C) -20 to +200 -20 to +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)


All Downloads

Filename Size Download
Sigma Force Tensiometers Brochure 1.04MB Download
Sigma Force Tensiometers Technical Specifications 0.37MB Download
Sigma 700-701 Force Tensiometer Accessory List 0.87MB Download

Ordering Information

Part Number 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 further information about Accessories, see the Sigma 700 & 701 Force Tensiometers Accessories Brochure.

Part Number 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
  • Last updated: June 2024
  • Version: 1.0

Statements, technical information and recommendations contained herein are based on tests we believe to be reliable but they are not to be construed in any manner as warrantees expressed or implied. The user shall determine the suitability of the product for his intended use and the user assumes all risk and liability whatsoever in connection therewith.