Precision Contact Angle Tensiometers

Smart Interfacial Measurement Solutions for Wettability and Adhesion


Attension Theta Flow

Product image of the Theta Flow tensiometer

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The Theta Flow is a premium instrument for measuring contact angle, surface tension, surface free energy, dynamic contact angle, and more. With a focus on practical, everyday usage, Theta Flow adds a collection of features that automate or sense key instrument settings, thereby improving data quality and repeatability with minimal user effort.

A full list of possible measurements supported by Theta Flow are:

  • Static contact angle
  • Dynamic contact angles
  • Surface free energy
  • Surface tension
  • Interfacial tension
  • Batch contact angle
  • Roughness corrected contact angle
  • Interfacial rheology (viscoelasticity)
  • High pressure and high temperature measurements

Compare Optical Tensiometers


The Theta Flow was designed with meticulous attention to detail and delivers a user-friendly experience while maintaining accuracy across experiments. Theta Flow’s design includes integrated sensors for commonly overlooked factors such as camera tilt angle, system levelness, temperature, and relative humidity which can all affect experimental reproducibility.

Theta Flow’s many high-end features work synergistically to ensure a faster workflow and consistently reproducible results—independent of day-to-day or operator-to-operator variation:

  • Touchscreen to control automated components using context-sensitive sliders, streamlining and ensuring consistency in experimental setup
  • Large 12 cm x 12 cm sample stage accommodates larger samples and allows for more measurements per sample
  • Powerful 5-Megapixel camera with software controlled autofocus delivers superior image definition and sharp contrast for accurate, user-independent contact angle measurements

GIF of the Theta Flow tensiometer


Automated experiments are simple thanks to the Theta Flow’s motorized hardware, intelligent sensors, and pre-programmable software. From standard sessile drop contact angle measurements to comprehensive dynamic contact angle protocols like those that utilize the tilting cradle, the Theta Flow makes it easy to gather accurate and reproducible data from every experiment.

In this video, the Theta Flow carries out a pre-programmed recipe, collecting a batch of consecutive sessile drop contact angle measurements on the same sample.

In this experiment, the Theta Flow was mounted in the tilting cradle apparatus and pre-programmed to collect contact angle data as the cradle tilts from 0 to 90° and back. As the system automatically tilts, the camera’s built-in autofocus keeps the image steady, and the DropletPlus image enhancement software maintains the crisp contrast between baseline and droplet throughout the duration of the experiment.


The OneAttension software suite supports Theta Flow’s carefully designed hardware with all-inclusive data acquisition and data analysis, enabling immediate access to all measurement capabilities—no need to purchase and install separate software modules. OneAttension’s user interface is designed to intelligently display all relevant environmental measurements and experiment settings.

With a focus on automation for a streamlined workflow and accurate results, Theta Flow allows you to:

  • Easily configure user groups and accounts for optimal data traceability
  • Choose a testing mode from OneAttension’s extensive menu of available measurements
  • Adjust settings for automated hardware components and quickly set up experiments directly from the instrument’s touchscreen
  • Sit back and watch Theta Flow automatically enhance the drop image with its exclusive new DropletPlus technology, and collect and analyze your data in real-time on the live results plot and/or live results table

DropletPlus, available exclusively on Theta Flow, automatically optimizes camera focus and contrast settings to deliver consistently exceptional definition and contrast between the substrate, drop, and background:


The Theta Flow supports several plug-and-play modules for highly specialized applications, including:

Product Image of the Attension Theta Topography

Attension Theta Topography

This module takes the wettability and adhesion analysis to a completely new level. It is the first system that can measure both contact angle and surface roughness of the sample in a single measurement while calculating the contact angle without the effect of roughness.

  • Integrated method to define contact angle and surface roughness
  • 2D and 3D surface roughness characterization
  • Automatic disposable tip dispenser
Product Image of the Attension Theta High Pressure

Attension Theta High Pressure Chamber

This module enables measurements at pressures up to 400 bars and temperatures up to 200 °C. Designed for enhanced oil recovery and supercritical fluid applications.

  • Smart sample port for direct introduction of sample with syringe bypassing the pump
  • High resistant chamber minimizes corrosion risk
  • Automated pressure control


Watch a short demo video about the Attension Theta Flow: