About Theta Flow Optical Tensiometer

The Theta Flow is the premium contact angle meter suitable for demanding surface research and quality control.  This user-friendly instrument is part of the Theta range of optical tensiometers and brings automation to a new high and offers improved accuracy with its high-end camera, image enhancement and sensors.

On top of the features available with the Theta Flex, additional main features of the Theta Flow include:

  • Heightened level of automation – Camera autofocus, automatic surface mapping, and automatically generated results, bringing  for optical tensiometers, simplifying the measurements and increasing accuracy.
  • Highly accurate results – with a camera resolution at 5 MP, image enhancements with DropletPlus technology and sensors keeping track of the surrounding environment for good traceability, Theta Flow will provide . The reliable data, in turn, is a key component for user-independent measurements.
  • Greater user experience – the touch display makes measurement preparation super smooth to handle. Everything from filling the liquids to changing your sample can be done easily at the instrument in seconds.

With optional motorised sample stage, motorised vertical movement and a choice of dispensing systems, Theta Flow can function in a fully automated mode, placing drops in predetermined locations on the substrate and measuring the contact angles.

For a breakdown on the technical specifications of the complete Theta Flow range, please see the Downloads section below.

Features & Benefits

  • Fully automatic measurements avoids user variation and saves time.
  • Select ready-made experiment recipes or create custom programs for quick and repeatable operations.
  • Automatic base line detection and drop shape fitting.
  • Contact angle on curved surfaces (circular or near-circular).
  • Flexible and programmable frame per second rate recorded by the camera.


ThetaFlow is an advanced optical tensiometer for high accuracy and easy measurement of:

  • Static contact angle
    Sessile drop, captive bubble and meniscus methods
  • Dynamic contact angle
    Dynamic contact angle, advancing and receding contact angle, contact angle hysteresis and roll-off angle
  • Surface free energy
    Sessile drop, captive bubble and meniscus methods
  • Surface- and interfacial tension
    Pendant drop and reverse pendant drop methods
  • Roughness-corrected contact angle and 3D surface roughness
    Fringe projection phase shifting method
  • Interfacial dilatational rheology
    Pulsating drop method


Measuring range 0 to 180°, 0.01 to 2000 mN/m
Accuracy ± 0.1°, 0.01 mN/m
Maximum sample size W unlimited x 100 mm x 320mm (with stage)
Integrated sample holders Yes
Maximum resolution (px) 2592 x 2048 (5 MP)
Max. measuring speed (fps) 3422
Camera CMOS 1″ USB 3.0 digital camera with zoom
Image focusing Software-controlled autofocus, manual fine focus in optics
Image quality Enhanced with DropletPlus technology, Native
Camera protection Inside instrument covers
Camera view angle -4.5 to 2.5° with digital scale
Light source and size High power monochromatic LED, 62 x 62mm
Field of view (Ø, mm) 1.44 to 45.3
Measurement indicator LED Yes
Integrated touch display Yes
Environment monitoring Yes
Disposable tip dispensing Yes
Software OneAttension, includes all measurement modes
Dimensions H 435 mm, W 230 mm, L 765 mm
Weight (basic frame) 29 Kg
Power supply 100 to 240 VAC
Frequency 50-60 Hz
Recommended System Requirements:
2 GHz processor, 2 GB RAM, 120 GB hard disk drive1, 1920 x 1080 resolution, 1 USB 3.0 port.
1 SDD hard disk (min. 500 MB/s) needed for high speed recording with high resolution

Operating System Requirements:
Windows 10 (32 or 64 bit).

Other Information

Complement your system with the additional modules that will enable further capabilities:

  • 3D Topography Module: Roughness-corrected contact angle measurements automatically with a single click.  For studying the effect of surface roughness to contact angle results.
  • High Pressure Chamber: Enables measurements at pressures up to 400 bars and temperatures up to 200°C.  Designed for enhanced oil recovery and super-critical fluid applications.
  • Pulsating Drop Module – PD 200: Oscillates drop volume for interfacial rheology studies.
  • Tilting Cradle: For fully automatic dynamic contact angle and roll-off angle measurements by the tilted drop method.
  • Environmental Chambers: To control the measurement environment including the temperature.

Please contact our sales team to discuss your individual requirements.

All Downloads

Filename Size Download
Attension-Theta-Range-Optical-Tensiometers-Brochure 1.22MB Download
Attension-Theta-Flex-and-Flow-Modules-and-Accessories-Brochure 0.88MB Download

Ordering Information

Dispenser Droplet placement Sample stage
Theta Flow Auto 5 Auto, 4 liquids Auto Auto XYZ
Theta Flow Auto 4 Auto, 2 liquids Auto Auto XYZ
Theta Flow Auto 3 Auto, 2 liquids Auto Auto X, Manual YZ
Theta Flow Auto 2 Auto, 1 liquid Auto Auto X, Manual YZ
Theta Flow Auto 1 Auto, 1 liquid Auto Manual XYZ

  • Last updated: May 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.