In combination with the DSA100 (Fig. 1) you now have the possibility of inclining the sample and the liquid drop positioned on it (sessile drop) at an angle of up to 90°. Not only the sample is tilted, but the whole measuring instrument. This means that the drop always remains in the optical axis; readjustment of the drop and sample at large angles of inclination is no longer necessary. Once the drop has been located in the center of the field of view then this arrangement ensures maximum utilization of this field of view even as the angle of inclination increases. This is because the video camera and sample are always in the same plane.
Starting from a horizontal sessile drop (Fig. 2) with symmetrical contours the drop contour becomes displaced as the angle of inclination increases.

Fig. 1: DSA 100 with Tilting table

Fig. 2: Horizontal sessile drop with symmetrical contours.

Fig. 3: Sessile drop on inclined sample with obvious asymmetric contours.

Fig. 4: Sample has tilted so much that the sessile drop is running off the sample.

n combination with the high-speed camera J1H you can record alterations to the drop contour at up to 360 frames per second. At a large angle of inclination the probability that the sessile drop will run off is very large. It is just at this stage of the measurement that the high-speed camera with its high temporal resolution offers the optimum solution for carrying out dynamic contact angle measurements.

The tilting table's features:

• Motor-driven
• Highly reproducible angles
• Comfortable creation of repeat measurements
• Determination of the maximum angle of inclination