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Drop Shape Analysis (DSA)

The Drop Shape Analysis is a technique which allows automated wetting property measurements of sessile drops at high temperatures using the Windows-based software SW21 (DSA1 v.1.80) developed by the Germany-based KRÜSS company. This program fits the measured drop profile with the Young-Laplace differential equation to determine the static and dynamic contact angles according to the sessile drop method.


Model:

DSA10 HT

Manufacturer:

KRÜSS GmbH

Year of manufacture:

2003

heating rate:

Up to 30 °C/min

max. operating temperature:

1750 °C



Tropfenkonturanalyse 1

Tropfenkonturanalyse 2

The DSA setup at the Chair of Ferrous Metallurgy consists of a high temperature tube furnace (interior diameter: 32 mm, length: 600 mm), and a drop shape analysis system DSA1 v. 1.80 for the automatic determination of wetting angles by means of the sessile drop method.

The DSA1 programme has the following technical specifications:

  • Wetting angle measuring range: 0 - 180°
  • Accuracy: ±0.5°
  • Calculation method: curve fitting based on one of the following mathematical models: Young-Laplace, polynomial, tangential, height and width, and spherical fitting.
  • Heating element: Mo

Wetting experiments consist of continuously monitoring the time-dependent variation in contact angle, drop base radius and height during temperature rise and isothermal holding time are continuously monitored. The magnified images and videos of the drop are digitized using a FALCON frame grabber and the DSA1 software before being stored on a personal computer for subsequent analysis.

Next to the determination of wetting properties, the sessile drop method is one of the most suitable methods for investigating interfacial reactions in the solid-liquid-gas system.

Thus, the DSA is a good and accurate technique for gaining insight into several phenomena occurring during the manufacturing and processing of various technical materials where interfacial properties play a key role.