Dropometer
US$4,990 base kit, checked 23 October 2026
Contact angle goniometer comparison
Dropometer vs Ossila Contact Angle Goniometer
The Ossila Contact Angle Goniometer is a US$3,000 benchtop instrument that measures static contact angle and pendant drop surface tension with PC software. The Dropometer costs US$4,990 and adds dynamic angles, surface free energy and battery operation. This page compares the two on price, accuracy, range, software and what each can measure.
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Ossila Contact Angle Goniometer
US$3,000 excl. VAT; PC not included. Checked 23 October 2026
Written by
Abhimanyu Bhandankar
Holds an MBA from Schulich School of Business and a BE in IT. He joined Droplet Lab in July 2019 and now leads sales and marketing.
CEO at Droplet Lab
Read More
Technical Review by
Gurdeep Singh Saini
Holds a BASc in Mechanical Engineering from Ryerson University (now Toronto Metropolitan University) and an MASc from York University. He develops the automatic edge and baseline detection behind the Dropometer's analysis.
COO at Droplet Lab
Read More
The short answer
Buy the Ossila goniometer (US$3,000) if you only need static contact angle and pendant drop surface tension on flat samples, and ±1° is enough. Buy the Dropometer (US$4,990) if you also need advancing and receding angles or surface free energy, a 0.35° accuracy validated against a KRÜSS DSA100E, or battery operation.
When the Ossila goniometer is the better choice
- Lower price. US$3,000 excluding VAT, about US$2,000 less than the Dropometer.
- Wider angle range. 5° to 180°, useful for very hydrophilic and superhydrophobic surfaces.
- Simple bench workflow. Capture, edge detection and fit in one PC software package.
- Calibration included. A 10 mm calibration sphere and 25 µL syringe come in the box.
- Faster video. Up to 30 frames per second from a 1920 × 1080 camera.
When the Dropometer is the better choice
- Dynamic angles. Advancing and receding contact angles in the app; Ossila does not list them.
- Surface free energy. Equation of State, Fowkes and van Oss, Chaudhury and Good in the app; Ossila does not calculate surface energy.
- Validated accuracy. 0.35° measured against a KRÜSS DSA100E in peer reviewed papers, against Ossila's stated ±1°.
- No PC, no mains. Battery power for up to 8 hours and analysis on the included phone.
- Room to grow. Optional tilt stage (US$700) for sliding angle and auto dropper (US$2,000); 5 year warranty.
When not to buy a Dropometer
- Static contact angle on flat, clean substrates is all you measure and ±1° is enough: Ossila does that for about US$2,000 less.
- You need very low or very high angles: Ossila covers 5° to 180°, the Dropometer 10° to 175°.
- You want to record video at a higher frame rate: Ossila's camera captures up to 30 frames per second, the Dropometer's 10.
- You need audit trails or electronic signatures, which the Dropometer does not support and Ossila does not list.
Executive summary
Both are lower cost optical instruments that measure contact angles from a side view image of a droplet and surface tension from a pendant drop. Ossila's goniometer is a bench unit with a 1920 × 1080 camera, Canny edge detection and polynomial fitting, run from PC software on a Windows computer you supply. The Dropometer is a portable kit with automatic edge and baseline detection on an included phone, and it adds advancing and receding angles and surface free energy.
Where they overlap
Static contact angle of a sessile drop from a side view image.
Pendant drop surface tension of liquids.
Automatic fitting in software, so neither relies on a manual protractor reading.
Where they differ and why it matters
Price
US$3,000 excluding VAT for Ossila, plus a Windows PC if you do not have one. US$4,990 for the Dropometer with phone and lifetime licence.
What each measures
Ossila: static contact angle and pendant drop surface tension. Dropometer: those two plus advancing and receding angles, surface free energy and, with the tilt stage, sliding angle.
Accuracy and range
Ossila states ±1° over 5° to 180°. The Dropometer states 0.35° over 10° to 175°, measured against a KRÜSS DSA100E.
Setup and power
Ossila runs from mains through a 24 V adapter and a lab PC. The Dropometer runs on battery and analyses on its own phone.
A deeper look at the criteria that decide it
What we compared
Ossila sells one model, the Contact Angle Goniometer (L2004A1), at US$3,000 excluding VAT. It ships with a 1920 × 1080 camera, sample stage, 25 µL syringe, 10 mm calibration sphere and Ossila Contact Angle software. Ossila also supplies materials and equipment for thin film and solar cell research. Ossila product page.
How each finds the droplet edge
Ossila's software uses Canny edge detection on the droplet image, then fits a polynomial to the droplet edge above 10° and a circle below it. The Dropometer detects the edge and baseline automatically and fits Young–Laplace or polynomial models.
Static angle is not the whole story
A single static reading sits somewhere between the advancing and receding angles. On rough, coated or contaminated substrates that gap, the hysteresis, is the useful number. The Dropometer measures advancing and receding angles in the app; Ossila's documentation does not list them. See our contact angle measurement guide.
Surface energy for coatings and adhesion
If you need surface free energy for coating or adhesion work, the Dropometer calculates it from several liquids in the app. With Ossila you would export the angles and calculate it yourself, for example in our free contact angle to surface energy calculator. Read more in the surface energy measurement guide.
Specification and capability matrix
| Criterion | Dropometer | Ossila Contact Angle Goniometer |
|---|---|---|
| Price (checked 23 October 2026) | US$4,990 base kit (phone and lifetime licence included) | US$3,000 excl. VAT; PC not included |
| Contact angle | 10° to 175°; 0.35° accuracy vs a KRÜSS DSA100E (peer reviewed); 0.01° resolution | 5° to 180°; ±1° |
| Edge detection and fit | Automatic edge and baseline detection; Young–Laplace and polynomial | Canny edge detection; polynomial above 10°, circle below |
| Advancing and receding angles | Advancing and receding in the app | Not listed |
| Sliding angle | Optional tilt stage, US$700 (0° to 60°); auto tilt US$1,500 | Not offered (stage tilt is for alignment) |
| Surface tension | Pendant drop, up to 75 mN/m; 0.01 mN/m resolution | Pendant drop |
| Surface free energy | Equation of State, Fowkes, van Oss Chaudhury Good in the app; OWRK in our free calculator | Not calculated in the software |
| Dosing | Manual Hamilton syringe; optional auto dropper, US$2,000 (from 0.05 µL) | Manual 25 µL syringe |
| Camera | Pixel 7a phone camera, 10 fps, 4x zoom, manual focus; high power LED backlight | 1920 × 1080, up to 30 fps |
| Calibration | Software calibration; built in bubble level | 10 mm calibration sphere included |
| Power and setup | 5 V, battery up to 8 h; 1 kg; sets up in about 2 minutes | Mains through 24 V, 2 A adapter |
| Software and platform | Android app on the included phone, or your own iPhone (iOS 15 or later); analysis offline; lifetime licence | Ossila PC software on Windows (product page: Windows 11 64 bit) |
| Warranty | 5 years (phone and syringe excluded as consumables), plus 5 years of software updates | 2 years |
Checked 23 October 2026. Ossila figures come from the Ossila product page and user manual (v1.3.0). The product page asks for a Windows 11 64 bit PC; the manual lists Windows 10 or 11. Dropometer figures come from the Dropometer specification.
How we built this comparison
We compared Ossila's product page and user manual with the Dropometer's specification and its peer reviewed validation against a KRÜSS DSA100E. We have not tested the two side by side. Where Ossila is stronger, on price, angle range and camera frame rate, the page says so.
Disclosure: Droplet Lab makes the Dropometer, so read this page knowing that. Every competitor figure links to the maker's own page or datasheet, and where a figure is not published we say so. If your work is static contact angle only and ±1° is enough, the Ossila goniometer is the better buy and the verdict flips.
Expert perspective
Ossila's software measures a static angle: place a droplet, capture it, fit it. Dr. Alidad Amirfazli explains what advancing and receding angles add to a static reading.
Why advancing and receding angles matter
"Repeatable numbers don't come from dropping a droplet and reading it. They come from advancing and receding slowly enough that you are measuring thermodynamics, not fluid dynamics."
What this means here: if your samples are real world surfaces, plan to measure advancing and receding angles, not only a static one.
Recommendations by scenario
Static angle and surface tension only, tight budget
Pick: Ossila Contact Angle Goniometer, US$3,000. See the under US$5,000 guide.
You need hysteresis, sliding angle or surface energy
Pick: Dropometer. See the under US$5,000 guide.
Teaching labs with several groups
Pick: the US$999 Droplet Lab education unit per group, or Ossila for a single shared bench. See the teaching lab guide.
Measuring on the line, on site or without a PC
Pick: Dropometer. See the field and on site guide.
Bottom line
The Ossila Contact Angle Goniometer is a good buy for a lab that needs static contact angle and surface tension on a fixed bench for US$3,000. The Dropometer is the better buy when you need advancing and receding angles, surface free energy, a validated accuracy figure or measurement away from the bench, for US$4,990. Book a 15 minute demo if you are weighing the two.
Frequently asked questions
How much does the Ossila Contact Angle Goniometer cost?
US$3,000 excluding VAT on Ossila's product page on 23 October 2026. You also need a Windows PC to run the software.
How accurate is the Ossila goniometer?
Ossila states ±1° over a 5° to 180° range. The Dropometer states 0.35° over 10° to 175°, measured against a KRÜSS DSA100E in peer reviewed studies.
Can the Ossila goniometer measure surface energy?
Ossila's software measures contact angle and surface tension; it does not calculate surface free energy. You can calculate it from the angles of several liquids with Droplet Lab's free calculator.
Does the Ossila goniometer measure advancing and receding angles?
Ossila's product page and manual do not list dynamic angle measurement. The Dropometer measures advancing and receding angles in its app.
Which is better for a teaching lab?
For one shared bench, Ossila is the lower cost instrument. For several groups, Droplet Lab's US$999 education unit gives each group its own instrument.
Other instrument comparisons
How the Dropometer compares with other contact angle goniometers and surface screening tools.
DIY ImageJ vs Dropometer
Free software plus a rig you build
Dropometer vs KRÜSS DSA100 and DSA25
Premium benchtop, quote only
Dropometer vs DataPhysics OCA series
Premium benchtop, quote only
Dropometer vs Biolin Scientific Attension Theta
Premium optical tensiometer, quote only
Dropometer vs ramé-hart goniometers
Benchtop range with published prices
Dropometer vs Brighton Science Surface Analyst
Handheld water contact angle for production
Dropometer vs dyne pens and test inks
Pass or fail surface energy screening
All contact angle goniometer buying guides
Best instrument by budget and use case
Validated measurement approach
Where the Dropometer's accuracy figure comes from.
Benchmarked against a KRÜSS DSA100E
Dropometer contact angle and pendant drop surface tension were compared with a KRÜSS DSA100E in two peer reviewed papers: Review of Scientific Instruments (2018) and Colloids and Surfaces A (2017).
Used in 52 customer publications
Customers have cited the Dropometer in 52 peer reviewed papers, theses and conference papers, listed with links.
References
1.
Ossila: Contact Angle Goniometer product page
Price, range, accuracy, camera, power and warranty, checked 23 October 2026.
2.
Ossila: Contact Angle Goniometer user manual (v1.3.0)
Edge detection, fitting and PC requirements.
3.
Chen, Muros-Cobos and Amirfazli (2018). Contact angle measurement with a smartphone. Review of Scientific Instruments 89, 035117
Peer reviewed validation of the Dropometer's contact angle method against a KRÜSS DSA100E.
4.
Droplet Lab: Dropometer technical specification
Dropometer price, ranges, accuracy, add-ons and export formats, checked 23 October 2026.