Drop Shape Analyzer – DSA25

The precision basic instrument for wetting investigations

Our Drop Shape Analyzer – DSA25 is an easy-to-use, reliable instrument for measuring contact angle. From a simple wetting test to the accurate measurement of surface free energy (SFE), the robust instrument provides flexible options for analyzing wetting and adhesion on solid surfaces. Its rapid, manual operation makes our DSA25 outstandingly suitable for occasional wetting measurements with changing tasks and sample types.

Well-conceived details for reliable measurement

The uniform lighting and high-quality optical components ensure that the dispensed drop is portrayed with the correct shape, and that the contact angle is measured reliably. The sample is quickly moved to the required measuring height using our finely adjustable lift table. The table can be easily moved and the required dosing position quickly set thanks to the magnetic fixing.

With dosing units for one or two liquids, the instrument is suitably equipped for simple wetting tests or for measuring surface free energy. With the software-controlled variant, the dosing dynamics can be accurately adjusted in order to make exact measurements of advancing and receding angles. As an alternative, our pressurized double-dosing unit allows measuring the SFE extremely fast and reliable, using our novel, scientifically validated dosing technique, the Liquid Needle.

Flexible accessories and extended measuring options

Process conditions can be ideally simulated using our precision temperature-control methods and other accessories. This enables wetting processes to be optimized in relation to the process. For example, contact angle measurements can be carried out at accurately controlled temperatures between -30 and 400°C or at exactly set humidities.

As well as measuring the contact angle, the DSA25 can also measure the surface tension of liquids using the Pendant Drop method. The results illustrate the relationship between the wetting of the solid and the properties of the liquid, and therefore enable the two components concerned to be optimized.

Tasks and applications

• Characterization of surface pre-treatment processes
• Checking the wettability of plastic, glass, ceramic, wood or metal
• Checking surface cleanliness

Measuring methods and options

• Contact angle between a liquid and a solid
• Surface free energy from contact angles of several test liquids using all common models
• Static contact angle, advancing angle and receding angle
• Measurement of surface tension and liquid-liquid interfacial tension using the Pendant Drop method
• Temperature-controlled measurements from -30 to 400°C
• Measurements at controlled humidity

Accessories (selection)

This list includes a selection of components which are not included in one of the DSA25 versions listed on the right.

• Tempering chamber for large samples from -10 to 120°C
• Tempering chamber for rapid temperature changes from -30 to 160°C
• Tempering chamber for high temperatures up to 400°C
• Module for controlling humidity
• External tilting table
• Special sample holders, for example for cylindrical samples, films, contact lenses or powders
• Dosing accessory for Captive Bubble measurements or measurement of the liquid-liquid interfacial tension