- Automatic droplet creation, pulsation and shape analysis
Less user-dependency, more accuracy - Autonomous measurements
Set up the desired measurement parameters and the entire measurement will run automatically - Versatile pulsation features
Sinusoidal, triangle, and square waveforms. Adjustable frequency, amplitude, recording time, and settle time - Results always available
Reanalyze the results as many times as you wish. Plotting, exporting, comparing, and reporting all included - User-friendly interface
To get you going in no time - Comes with full capabilities
Every measurement mode included from interfacial rheology to interfacial tension and contact angle
- Products
- Attension
- Optical Tensiometers
- Theta Pulsating Drop
Optical Tensiometer
Theta Pulsating Drop

measurements
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Pulsating drop For dilational interfacial rheology measurement
-
Pendant drop For surface and interfacial tension
-
Reverse pendant drop For surface and interfacial tension

Pulsating drop
Key features
-
Evaporation compensation tool
Keeps the drop volume stable even during long measurements -
Modularity
Same instrument for interfacial rheology, surface tension, interfacial tension, and contact angle measurements -
Measurements with captive bubble
Enables measurements at liquid-liquid interface -
Versatility
One instrument for contact angle, surface and interfacial tension and interfacial rheology -
Temperature control
Temperature control up to 250 C to measure at temperatures meaningful for you -
Modularity
Upgrade with additional modules as your research evolves
Software that is all-inclusive, with unlimited licenses and free updates!
Every Attension Optical Tensiometer is complemented by seamlessly integrated sophisticated OneAttension software. Our software updates are effortlessly automatic and, best of all, completely complimentary.
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Applications
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Food & beverages
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Chemicals
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Pharmaceutical
A closer look
Theta Pulsating Drop is based on the extremely versatile Theta Flex optical tensiometer which is characterized by its versatility, reliability and automation. Check out the system specifications below.
Theta Flex |
|
Available Measurements |
|
Static contact angle |
√ |
Dynamic contact angle |
Automatic |
Surface/Interfacial tension |
√ |
3D surface roughness |
√ |
Interfacial rheology |
√ |
Surface free energy |
Zisman Plot, |
Available Measurement Methods |
|
Sessile drop |
√ |
Batch sessile drop |
√ |
Captive bubble |
√ |
Pendant drop |
√ |
Reverse pendant drop |
√ |
Meniscus |
√ |
Dynamic contact angle |
Automatic |
Pulsating drop |
√ |
3D Topography |
√ |
Hardware |
|
Measuring range (°, mN/m) |
0…180, 0.01…2000 |
Accuracy (°, mN/m) |
±0.1, ±0.01 |
Maximum sample size (mm) |
Unlimited×100×360 (with stage) |
Integrated sample holders |
Yes |
Frame interval |
0.33 ms ... 1000 s |
Maximum resolution (px) |
1936×1216 |
Maximum measuring speed (fps) |
2347 |
Camera |
USB 3.0 digital camera with zoom |
Camera protection |
Inside instrument covers |
Camera view angle (°) |
-4.5 ... 2.5 |
Light source and size |
|
Field of view (Ø, mm) |
0.95…26 |
Measurement indicator LED |
Yes |
Disposable tip dispensing |
√ |
Dimensions — Basic frame (L×W×H, mm) |
765 x 230 x 435 |
Weight — Basic frame (kg) |
26 |
Power supply (VAC) |
100-240 |
Frequency (Hz) |
50...60 |
Pulsating Drop Specifications |
|
Perturbation principle |
Piezo-electric membrane enclosed in a chamber |
Frequency range |
0-30 Hz(most practical range 0.01-10 Hz) |
Frequency resolution |
0.001 Hz |
Maximum peak-to-peak volume |
~ 0.8 μl |
Sample liquid volume needed |
5 μl |
Material |
PEEK, PTFE, FPM, Titanium |
Dispenser |
Droplet placement |
Sample stage |
Camera |
Possible upgrades |
|
Theta Flex Auto 5 |
Auto, 4 liquids | Auto | Auto XYZ | 1984 × 1264 px, max 3009 FPS | Full |
Theta Flex Auto 4 |
Auto, 2 liquids | Auto | Auto XYZ | 1984 × 1264 px, max 3009 FPS | Full |
Theta Flex Auto 3 |
Auto, 1 liquid | Auto | Auto XYZ | 1984 × 1264 px, max 3009 FPS | Full |
Theta Flex Auto 2 |
Auto, 2 liquids | Auto | Auto X, Manual YZ | 1984 × 1264 px, max 3009 FPS | Full |
Theta Flex Auto 1 |
Auto, 1 liquid | Auto | Manual XYZ | 1984 × 1264 px, max 3009 FPS | Full |
Theta Flex Plus |
Auto, 1 liquid | Manual | Manual XYZ | 1984 × 1264 px, max 3009 FPS | Full |
Theta Flex Basic |
Manual | Manual | Manual XYZ | 1984 × 1264 px, max 3009 FPS | Full |
OneAttension Software
OneAttension software is a fine combination of a very intuitive interface and high functionality. Follow your experiment live and get the results within seconds. Let's have a look at the features!
OneAttension Features
Add more possibilities
Have a look at a few of the additional modules to the New Dispensers from Attension Theta that can be used for added capabilities. You can find the full range of accessories below.

Measuring Chamber, electrically heated, 250° C
Thermostatted electrically heated measuring chamber for temperature control up to 250 C.

Topography 3D module
The unique 3D Topography module takes the wettability and adhesion analysis into a completely new level by measuring both contact angle and surface roughness of the sample in a single measurement. Distinguish the effect of roughness on contact angle and surface free energy.

High Pressure Chamber
The High Pressure Chamber is designed for wettability research within enhanced oil recovery and enables measurements at pressures up to 400 bars and temperatures up to 200°C. Integrated chamber piston and sample port are optimized for the best usability and versatility.

Tilting Cradle
A software controlled tilting cradle. Used for studying dynamic contact angles. Tilting range from 0 to 90° and tilting resolution 0.1°.

Picoliter Dispenser
Automated picoliter-scale drop formation. Especially for inkjet applications and for measuring contact angle on very small sample areas.
What others say
Our instruments are present at many prestigious universities and research facilities world wide. Take a minute to find out what others say about Theta Flex.
Precision Contact Angle Meters and Tensiometers
"The ability to accurately measure contact angle as a measure of surface wettability is of utmost importance as we develop new technologies to prevent medical device-associated issues of infection and tissue trauma. The ease-of-use of the instrument and associated software is a major advantage and the support offered by the team, particularly with new applications, is exceptional.”

Queen’s University Belfast
This prestigious university in Northern Ireland is ranked amongst the top 200 in the world. Dr. Nicola J. Irwin, Lecturer in Pharmaceutical Materials Science School of Pharmacy, has been using our instrument in her work.
Ville Jokinen. Aalto University
"The ability to measure the advancing and receding contact angles with a single click and having the data into a convenient format saves time and reduces the human error."
Watch the full story

Aalto University, Finland
Aalto University is a top Finnish university combining science, technology and arts into a collaborative environment for both scientific communities and companies. Our contact angle meters and tensiometers have been used there in research for decades.
Researcher at MIT
“The reproducibility of the measurements acquired is excellent even with the lowest surface energy values and the tensiometers are quite flexible with regards to sample size. The software is also very useful and the customer support for the products is excellent.”

MIT, USA
MIT, Massachusetts Institute of Technology, is a world-leading research university with a mission to advance knowledge and educate students in science and technology. MIT use our tensiometers to study contact angles and interfacial energy.
Learn more
We have gathered all our in-depth knowledge associated with Theta Pulsating Drop. Browse around amongst webinars, case studies and white papers to find a topic of interest.
- KSV NIMA

Interfacial Rheology: From Fundamentals to Application
- Attension

How to Measure Quality of Transformer Oils
- Attension

Surface and Interfacial Tension
- Attension

Surface Tension and Surfactants in Industrial Processes
- Attension

Interfacial Rheology as Emulsion and Foam Stability Indicator
- Attension

Surface and Interfacial Tension
- Attension

Comparison of ASTM D971 and IEC 62961 Standards
- Attension

Critical Micelle Concentration - What is it and how to measure it?
- Attension

Why Interfacial Rheology is Important
- Attension

Effect of Temperature and Pressure on Wettability of Solids
- Attension
