Dropometer
US$4,990 base kit, checked 23 October 2026
Contact angle goniometer comparison
Dropometer vs DataPhysics OCA series
The DataPhysics Instruments OCA series are optical contact angle measuring and contour analysis systems, from the manual OCA 15EC to the motorised OCA 200 with picolitre dosing. They measure contact angles, surface energy and surface and interfacial tension, with chambers from −30 to 700 °C. This page compares the OCA range with the Dropometer on price, accuracy, sample positioning, dosing and portability.
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DataPhysics OCA 15EC to OCA 200
Quote only; DataPhysics does not publish prices. 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
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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 a DataPhysics OCA if you need motorised sample positioning, picolitre dosing, temperature or humidity chambers, high speed video or surface tension above 75 mN/m. Buy the Dropometer (US$4,990) for contact angle, pendant drop surface tension and surface energy at room temperature, with accuracy validated against a KRÜSS DSA100E.
When a DataPhysics OCA is the better choice
- Chambers. Temperature from −30 to 700 °C and humidity from 5 to 90% RH, plus special models to 1,800 °C (OCA 25-HTV 1800) and 750 bar (OCA 25-PMC 750).
- Tiny drops. FlexDrop dosing down to 2 nL or 25 pL on the OCA 200 for fibres and micro structures.
- Motorised sample positioning. The OCA 50 and OCA 200 move the sample electrically for unattended series.
- Wider ranges. 0° to 180° at ±0.1°, and surface and interfacial tension from 0.01 to 2,000 mN/m.
- Fast cameras. 170 to 227 fps as standard and up to 4,276 fps at reduced resolution.
When the Dropometer is the better choice
- Price. US$4,990 with a published price; every OCA is quote only.
- Validated accuracy. 0.35° contact angle accuracy measured against a KRÜSS DSA100E in peer reviewed papers.
- Portable. Battery power for up to 8 hours and offline analysis; the lightest OCA, the 15EC, is 14 kg on mains power with a PC.
- Simple setup. About 2 minutes from box to first measurement.
- Support. 5 year warranty and 5 years of software updates.
When not to buy a Dropometer
- You need chambers from −30 to 700 °C, humidity control from 5 to 90% RH, or high temperature and pressure models such as the OCA 25-HTV 1800 or OCA 25-PMC 750.
- You measure tiny structures and need nanolitre or picolitre drops: the OCA 200 doses down to 25 pL.
- You need motorised sample positioning for long unattended series (OCA 50 and OCA 200).
- You need 0.1° stated accuracy, contact angles below 10° or above 175°, or surface tension above 75 mN/m.
- You need audit trails or electronic signatures, which the Dropometer does not support.
Executive summary
Both are optical contact angle measuring devices that analyse the drop contour. The OCA series is a family of high precision benchtop systems run from dpiMAX software on a PC, from 14 kg (OCA 15EC) to 28 kg (OCA 200), with a long list of dosing, camera and chamber options. The Dropometer is one portable kit for contact angle, pendant drop surface tension and surface free energy at room temperature, for US$4,990.
Where they overlap
Static and dynamic optical contact angle measurement from the drop contour.
Surface energy of solids from the contact angles of several liquids.
Surface and interfacial tension by the pendant drop method with a Young–Laplace fit.
Where they differ and why it matters
Price
DataPhysics sells the OCA series by quote only. The Dropometer is US$4,990, with optional tilt stage (US$700) and auto dropper (US$2,000).
Sample positioning and dosing
The OCA 15EC positions the sample by hand on a sliding magnetic base and doses with one or two electronic syringe modules; the OCA 50 and 200 are motorised and dose with up to four. The Dropometer positions by hand and doses manually or with its auto dropper.
Environment
OCA chambers cover −30 to 700 °C and 5 to 90% RH. On the Dropometer a temperature and humidity chamber is a built to order upgrade.
Where you can measure
OCA systems weigh 14 to 28 kg and run on mains with a PC. The Dropometer runs on battery and goes to the sample.
A deeper look at the criteria that decide it
Which OCA models we compared
- OCA 15EC: the entry model, 14 kg, manual sample positioning and direct dosing with one or two electronic syringe modules.
- OCA 25: manual precision axes, manual or electronic dosing with up to four syringes; special versions OCA 25-HTV 1800 (to 1,800 °C) and OCA 25-PMC 750 (to 750 bar and 200 °C).
- OCA 50 and OCA 50EC: motorised sample positioning for automated series, 26 kg.
- OCA 200: the top model, motorised, with FlexDrop nanolitre and picolitre dosing for micro structures, 28 kg.
- All share 0° to 180° at ±0.1°, 0.01 to 2,000 mN/m, and dpiMAX software. Data sheet.
The picolitre dosing system and micro samples
To measure a contact angle on a single fibre, a stent strut or a micro pattern, the drop has to be smaller than the feature. The OCA 200 deposits drops down to 25 pL with its FlexDrop dosing system. The Dropometer's smallest automatic drop is 0.05 µL, which suits flat samples, films and parts, not micro structures.
Surface energy models
DataPhysics lists Owens, Wendt, Rabel and Kaelble (OWRK) and Wu among the surface energy analysis models in dpiMAX. The Dropometer app calculates Equation of State, Fowkes and van Oss, Chaudhury and Good; for OWRK, enter your angles in our free contact angle to surface energy calculator. Read more in our surface energy measurement guide.
Portability is not unique to the Dropometer
DataPhysics launched a portable, battery powered contact angle meter, the PCA 200, in 2024. So the question is which measurements you need away from the bench. The Dropometer carries static and dynamic contact angle, pendant drop surface tension and surface energy in one kit. See our field and on site buying guide for portable options.
Specification and capability matrix
| Criterion | Dropometer | OCA 15EC | OCA 25 | OCA 50 and OCA 200 |
|---|---|---|---|---|
| Price (checked 23 October 2026) | US$4,990 base kit (phone and lifetime licence included) | Quote only | Quote only | Quote only |
| Contact angle | 10° to 175°; 0.35° accuracy vs a KRÜSS DSA100E (peer reviewed); 0.01° resolution | 0° to 180°, ±0.1° | 0° to 180°, ±0.1° | 0° to 180°, ±0.1° |
| Advancing and receding angles | Advancing and receding in the app | Yes | Yes | Yes |
| Sliding or roll off angle | Optional tilt stage, US$700 (0° to 60°); auto tilt US$1,500 | Tilting base unit (−5° to 95°) | Tilting base unit (−5° to 95°) | Tilting base unit (−5° to 95°) |
| Surface and interfacial tension | Pendant drop, up to 75 mN/m; 0.01 mN/m resolution | 0.01 to 2,000 mN/m | 0.01 to 2,000 mN/m | 0.01 to 2,000 mN/m |
| Surface energy | Equation of State, Fowkes, van Oss Chaudhury Good in the app; OWRK in our free calculator | Option; OWRK, Wu and others | Option; OWRK, Wu and others | Option; OWRK, Wu and others |
| Sample positioning | Manual | Manual, sliding magnetic base | Manual precision axes | Motorised |
| Dosing | Manual Hamilton syringe; optional auto dropper, US$2,000 (from 0.05 µL) | One or two electronic syringe modules | Manual or up to 4 electronic syringes | Up to 4 electronic syringes; OCA 200 FlexDrop to 2 nL and 25 pL |
| Camera | Pixel 7a phone camera, 10 fps, 4x zoom, manual focus; high power LED backlight | 227 fps standard; up to 3,246 fps (4,276 fps with the optional 2/3 inch camera) | Up to 4,276 fps at reduced resolution | Up to 4,276 fps at reduced resolution |
| Temperature and humidity | Operates 10 to 45 °C as standard; temperature and humidity chamber available as a built to order upgrade (ask for range and lead time) | Chambers −30 to 700 °C; humidity 5 to 90% RH | Chambers −30 to 700 °C; humidity 5 to 90% RH | Chambers −30 to 700 °C; humidity 5 to 90% RH |
| Weight and power | 5 V, battery up to 8 h; 1 kg; sets up in about 2 minutes | 14 kg; mains | 16 kg; mains | 26 kg (OCA 50), 28 kg (OCA 200); mains |
| Software | Android app on the included phone, or your own iPhone (iOS 15 or later); analysis offline; lifetime licence | dpiMAX on a PC | dpiMAX on a PC | dpiMAX on a PC |
| Warranty | 5 years (phone and syringe excluded as consumables), plus 5 years of software updates | Not published | Not published | Not published |
Checked 23 October 2026. OCA figures come from the DataPhysics OCA data sheet (DS/OCA 26-07 2.1) and the OCA product page. DataPhysics does not publish prices or a warranty term. Dropometer figures come from the Dropometer specification.
How we built this comparison
We read DataPhysics' current OCA data sheet and product page and compared them with the Dropometer's specification and its peer reviewed validation against a KRÜSS DSA100E. We have not measured an OCA ourselves. DataPhysics also makes a portable instrument, the PCA 200; we could not open its specification page, so it is not in the table.
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. The verdict flips to an OCA once chambers, picolitre dosing, motorised positioning or tension above 75 mN/m is on your requirement list.
Expert perspective
An OCA can add a tilting base and run both sessile and tilted measurements, and so can the Dropometer with its optional tilt stage. Dr. Alidad Amirfazli's point is that the method has to match the question.
Match the method to the application
"Not all contact-angle measurements are created equal: the right method depends on the application. A sessile drop and a tilted plate can give very different, and equally correct, numbers."
What this means here: decide whether you need sessile drop, tilted plate or pendant drop results before you compare instruments, then check which of those each one runs.
Recommendations by scenario
Chambers, high temperature or high pressure work
Pick: OCA 25 (or its HTV 1800 and PMC 750 versions). See the advanced research guide.
Fibres, stents and micro structures
Pick: OCA 200 with picolitre dosing. See the advanced research guide.
Automated series in a central lab
Pick: OCA 50. See the regulated high throughput QC guide.
Contact angle, surface tension and surface energy at room temperature
Pick: Dropometer, US$4,990. See the under US$5,000 guide.
Measuring on the line or at a supplier
Pick: Dropometer. See the industrial QA guide.
Bottom line
A DataPhysics OCA is the right buy for a lab that will use its options: motorised positioning, picolitre dosing, chambers to 700 °C, high speed cameras or the special high temperature and pressure models. The Dropometer is the right buy for contact angle, surface tension and surface energy at room temperature, at US$4,990, in the lab or on site. Book a 15 minute demo with a sample you would otherwise send to an OCA.
Frequently asked questions
Which DataPhysics OCA models are current?
The OCA 15EC, OCA 25, OCA 25-HTV 1800, OCA 25-PMC 750, OCA 50, OCA 50EC and OCA 200 are listed on DataPhysics' product page and data sheet as of 23 October 2026.
How much does a DataPhysics OCA 200 cost?
DataPhysics does not publish prices for any OCA model; prices are by quote and depend on the dosing, camera and chamber options.
Is a DataPhysics OCA more accurate than the Dropometer?
DataPhysics states ±0.1° over 0° to 180°. The Dropometer's accuracy is 0.35° over 10° to 175°, measured against a KRÜSS DSA100E in peer reviewed studies.
Can the Dropometer measure surface energy like an OCA?
Yes, from the contact angles of several liquids, using Equation of State, Fowkes or van Oss, Chaudhury and Good in the app. OWRK is available in Droplet Lab's free online calculator.
Can the Dropometer replace an OCA?
For contact angle, pendant drop surface tension up to 75 mN/m and surface energy at room temperature, yes. For chambers, picolitre dosing, motorised positioning or tension above 75 mN/m, no.
Other instrument comparisons
How the Dropometer compares with other contact angle goniometers and surface screening tools.
Dropometer vs Ossila Contact Angle Goniometer
Entry benchtop, about US$3,000
DIY ImageJ vs Dropometer
Free software plus a rig you build
Dropometer vs KRÜSS DSA100 and DSA25
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.
DataPhysics Instruments: OCA data sheet (DS/OCA 26-07 2.1)
Ranges, cameras, dosing, positioning, weights and chambers for every OCA model, checked 23 October 2026.
2.
DataPhysics Instruments: OCA product page
Current OCA models.
3.
DataPhysics Instruments: Surface energy of solids
Surface energy models in dpiMAX.
4.
PFFC: DataPhysics Instruments launches portable contact angle goniometer PCA 200 (August 2024)
Launch news for DataPhysics' portable instrument.
5.
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.
6.
Droplet Lab: Dropometer technical specification
Dropometer price, ranges, accuracy, add-ons and export formats, checked 23 October 2026.