Dropometer
US$4,990 base kit, checked 25 October 2026, Droplet Lab
Surface energy analyzer comparison
Dropometer vs KRÜSS Mobile Surface Analyzer (MSA)
The KRÜSS MSA One-Click SFE is a mobile surface analyzer: you hold it on the part, it doses two liquids at once and reports surface free energy within a second. The Dropometer is a 1 kg tabletop kit that measures contact angle, surface free energy and surface tension at the bench. This page compares the two on speed, where they measure, accuracy, models, liquids, power and cost.
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KRÜSS MSA One-Click SFE
Quote only new; refurbished €15,307 excl. VAT in the KRÜSS shop, sold out, checked 25 October 2026, KRÜSS
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
If you need surface free energy on the part where it sits, such as car bodies, large panels or overhead surfaces, in about a second, buy the KRÜSS MSA. For bench checks with a tighter stated accuracy, any probe liquid, acid base surface energy and a published price, the Dropometer (US$4,990) is the better buy.
When the KRÜSS MSA is the better choice
- The part cannot come to the lab. KRÜSS says the MSA measures vertically, overhead and on slightly convex parts, from samples as thin as a chopstick to a car body. The Dropometer is not handheld.
- You need a result in seconds. KRÜSS says dosing two drops, measuring and calculating all happen within a second.
- Your surfaces are close to fully wetting. The MSA reads contact angles from 0°; the Dropometer's stated range starts at 10°.
- You want a fixed procedure on the line. Two liquids dosed together by Liquid Needle, with ADVANCE software and an optional API for automation.
When the Dropometer is the better choice
- You need a tighter stated accuracy. 0.35° against a KRÜSS DSA100E in two peer reviewed papers; KRÜSS states 0.8° for the MSA.
- You need acid base surface energy. The Dropometer app calculates van Oss-Chaudhury-Good as well as Equation of State and Fowkes. The MSA lists no acid base model.
- You choose the probe liquids. Any lab liquid, and you can check its surface tension by pendant drop on the same kit. The One-Click SFE doses its own pair of liquids; KRÜSS sells the MSA Flexible Liquid for other liquids.
- You work without a laptop. The Dropometer runs on battery for up to 8 hours and analyses on the included phone. The MSA takes 5 V from a computer over USB.
- You want a published price. US$4,990 base kit with a 5 year warranty; US$9,000 with two automatic droppers that dose two liquids in sync. KRÜSS sells the MSA new by quote. See the Dropometer contact angle and surface energy kit.
When not to buy a Dropometer
- You need readings on large, curved or installed parts where they sit. The Dropometer is a tabletop kit, so samples come to its stage.
- You inspect parts on the line and need a result within seconds of the treatment.
- Your treated surfaces read below 10°, the bottom of the Dropometer's stated range.
- You need humidity or temperature control at the measurement. Our temperature control is a built to order upgrade, so ask for range and lead time first.
Executive summary
Both instruments measure contact angles of probe liquids on a solid and calculate surface free energy from them. The MSA is a mobile analyzer built for treated surfaces in production: it sits on the part and doses two liquids at once. The Dropometer is a bench kit: it measures sessile drop contact angles on samples you bring to its stage, and adds pendant drop surface tension and interfacial tension. New to the topic? Our surface energy measurement guide explains the models, and Beyond 38 dynes explains what surface energy says about adhesion.
Where they overlap
Both measure static contact angles and report surface free energy with polar and dispersive parts.
Both offer Equation of State and Fowkes; OWRK runs on the MSA and in our free calculator for the Dropometer.
Both save results with the drop image, so a reading can be checked later.
Where they differ and why it matters
Where you measure
The MSA goes to the part: 0.85 kg, held on the surface, any sample size. The Dropometer is a 1 kg tabletop kit, so the sample sits on its stage.
Speed
KRÜSS says the MSA doses, measures and calculates within a second. The Dropometer places one drop per liquid, or two together with the optional two dropper setup; we do not publish a time per reading.
Accuracy and range
KRÜSS states 0.8° accuracy and 0° to 180° for the MSA. The Dropometer states 0.35°, checked against a KRÜSS DSA100E in peer review, over 10° to 175°.
Models and liquids
MSA: OWRK, Fowkes, Wu, Zisman and Equation of State from its two liquids. Dropometer app: Equation of State, Fowkes and van Oss-Chaudhury-Good from any liquids; OWRK, Fowkes and Zisman in our free calculator.
A deeper look at the criteria that decide it
How the MSA measures
The Liquid Needle doses two drops side by side in milliseconds, at 0.1 µL resolution, with low kinetic energy so the drops do not prewet the surface. A 25 fps camera records them, and ADVANCE software calculates contact angles, surface free energy, work of adhesion and spreading coefficient. A full charge doses 1,000 drops of each liquid. KRÜSS's page says cartridges can be refilled outside the instrument; its data sheet lists a disposable 1 mL cartridge. See the MSA data sheet.
How the Dropometer measures
A drop sits on the sample in front of an LED backlight. The phone camera records the profile, and the app detects the edge and baseline automatically and fits Young–Laplace or polynomial models. Enter angles from two or more liquids for surface free energy, or use our free surface energy calculator. Our reproducible surface energy guide covers liquid choice and technique.
Which model to report
Models give different numbers on the same surface, so report the model with each value. Zisman gives a critical surface tension, explained in our Zisman glossary entry and multi liquid experiment. Compare your results with our surface free energy of common polymers. ISO 19403-2 describes surface free energy from contact angles; see our ISO 19403-2 summary.
Which MSA models we compared
KRÜSS sells the MSA One-Click SFE for its fixed pair of liquids and the MSA Flexible Liquid for other liquids. Both are quote only new. The KRÜSS shop lists a refurbished MSA One-Click SFE at €15,307 excluding 19% VAT (discounted to €13,010.95, sold out) and a refurbished MSA Flexible Liquid at €6,694.50, both for listed European countries only.
Specification and capability matrix
Figures from each maker's own pages and data sheets, checked 25 October 2026.
| Criterion | KRÜSS MSA One-Click SFE | Dropometer |
|---|---|---|
| What it is | Mobile surface analyzer, held on the part | Tabletop contact angle and surface tension kit |
| Price (checked 25 October 2026) | Quote only new; refurbished €15,307 excl. VAT (KRÜSS shop, sold out) | US$4,990 base kit; US$9,000 with two automatic droppers in sync |
| Where it measures | On the part: vertical, overhead, slightly convex; any sample size | Samples on the stage |
| Liquids per measurement | Two, dosed together by Liquid Needle | One by hand in the base kit; two together with two automatic droppers |
| Probe liquids | Its own pair; MSA Flexible Liquid for other liquids | Any lab liquid |
| Time per result | Within a second (KRÜSS) | Not published |
| Contact angle range | 0° to 180° | 10° to 175° |
| Stated accuracy | 0.8° (KRÜSS) | 0.35° vs KRÜSS DSA100E (peer reviewed) |
| Surface energy models | OWRK, Fowkes, Wu, Zisman, Equation of State | Equation of State, Fowkes, van Oss-Chaudhury-Good in the app; OWRK, Fowkes, Zisman in the free calculator |
| Surface tension of liquids | Constrained sessile drop on a pedestal | Pendant drop up to 75 mN/m; interfacial tension too |
| Camera | 25 fps, 1000 × 700 px | Phone camera; 50 MP stills |
| Power | 5 V over USB from a computer, 4.5 W | 5 V battery, up to 8 h |
| Size and weight | 84 × 32 × 112 mm, 0.85 kg | 1 kg |
| Software and data | ADVANCE on a computer; optional remote control API | App on the included phone; CSV and TIFF export |
| Operating temperature | 10 to 40 °C | 10 to 45 °C (automatic version); −5 to 45 °C (manual) |
| Warranty | Not stated for new units; 12 months on refurbished | 5 years |
Sources: KRÜSS MSA One-Click SFE page, MSA data sheet, KRÜSS shop, Dropometer specification. All checked 25 October 2026. KRÜSS publishes no new price or measurement time beyond "within a second", and its page and data sheet differ on whether cartridges are refillable.
How we built this comparison
We read the KRÜSS MSA One-Click SFE page, data sheet and shop listings and the Dropometer specification on 25 October 2026. We did not run the two side by side, so this page gives no repeatability figures, and it quotes KRÜSS's own measurement time.
Disclosure: Droplet Lab makes the Dropometer, so read this page knowing that. Every MSA figure links to KRÜSS's own pages. The verdict changes for any team that must measure on the part: the MSA wins there, because the Dropometer is a tabletop kit. Made with Claude Opus 5.5 and reviewed by Droplet Lab.
Expert perspective
A two second reading on the part and a bench reading with several liquids can both be correct. They answer different questions, as the quote below explains.
The method decides the number
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: use the same method, liquids and model for every reading you compare, whether you measure on the part or at the bench.
Recommendations by scenario
Checking treated parts on the line before bonding
Pick: KRÜSS MSA. It measures on the part in seconds. See the production QC guide.
Corona or plasma treated film at the bench
Pick: Dropometer. Full surface energy and a stated accuracy. See our corona treatment monitoring use case and the fused silica and quartz case study.
Acid base or multi liquid research
Pick: Dropometer within budget, or a research goniometer. See the research guide.
Replacing dyne pens
Either can, once you have checked them against your pens on your own parts. See Dropometer vs dyne pens.
Fast pass or fail on water contact angle only
Consider the Brighton Science Surface Analyst. See Dropometer vs Brighton Science Surface Analyst.
Bottom line
Choose the KRÜSS MSA when you have to measure on the part, in seconds, or on surfaces that read close to 0°. Choose the Dropometer for bench checks with a tighter stated accuracy, acid base surface energy, any probe liquid, battery power and a published price. If you are unsure, book a 15 minute consult and bring a treated sample you already check.
Frequently asked questions
Can I hold the Dropometer on the part like the MSA?
No. The Dropometer is a 1 kg tabletop kit that runs on battery, so it moves between benches, but samples come to its stage. The MSA is held on the part.
Which is more accurate?
On stated figures, the Dropometer: 0.35° against a KRÜSS DSA100E in peer review, against 0.8° stated by KRÜSS for the MSA. Speed and where you can measure matter as much for production checks.
Can the Dropometer dose two liquids at once like the MSA?
Yes, with the two automatic dropper setup, US$9,000 as a kit. The base kit doses one liquid at a time by hand. KRÜSS says the MSA completes a two liquid measurement within a second; we do not publish a time per reading.
Which surface energy models does each calculate?
MSA: OWRK, Fowkes, Wu, Zisman and Equation of State. Dropometer app: Equation of State, Fowkes and van Oss-Chaudhury-Good; OWRK, Fowkes and Zisman in our free calculator.
Can either replace dyne pens?
KRÜSS says the MSA replaces test inks and dyne pens. Check any instrument against your pens on your own parts before you switch; see Dropometer vs dyne pens.
Other instrument comparisons
How the Dropometer compares with other surface energy and contact angle instruments.
Dropometer vs Brighton Science Surface Analyst
Bench surface energy against portable water contact angle
Dropometer vs dyne pens
Contact angle and surface energy against test inks
Dropometer vs KRÜSS DSA100 and DSA25
Premium drop shape analyzers, quote only
Dropometer vs Biolin Scientific Attension Theta
Premium optical tensiometer, quote only
Dropometer vs Ossila
Entry benchtop goniometer, US$3,000
DIY ImageJ vs Dropometer
Free software against an integrated kit
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 57 customer publications
Customers have cited the Dropometer in 57 peer reviewed papers, theses and conference papers, listed with links.
References
1.
KRÜSS MSA One-Click SFE
Method, models, dosing, applications; checked 25 October 2026
2.
KRÜSS MSA One-Click SFE technical data
Range, accuracy, camera, size, power; checked 25 October 2026
3.
KRÜSS shop: MSA One-Click SFE, refurbished
€15,307 excl. VAT, sold out; checked 25 October 2026
4.
KRÜSS shop: MSA Flexible Liquid, refurbished
€6,694.50 excl. VAT; checked 25 October 2026
5.
ISO 19403-2, Droplet Lab summary
Surface free energy from contact angles
6.
Hejda F, Solař P, Kousal J. Surface free energy determination by contact angle measurements: a comparison of various approaches. WDS'10 Proceedings Part III (2010)
Different models give different values on the same surface
7.
Dropometer product page and specification, Droplet Lab
Pendant drop range, accuracy, resolution, power and price; checked 25 October 2026
8.
Droplet Lab validation papers
Peer reviewed comparisons with a KRÜSS DSA100E: Review of Scientific Instruments (2018) and Colloids and Surfaces A (2017)