Figure 1
Water drop analysed by Pendent_Drop. The free-pendent part of the drop has to be selected (yellow rectangle). The blue line marks the detected drop boundary, while red marks the theoretical contour corresponding to the parameters in the dialog to the right.
Figure 2
After automatic optimisation of the drop shape parameters, the calculated contour fits the image well. The parameters and drop properties such as its volume are summarised in the Results table visible at the bottom.
Figure 3
Schematics of a simple surface tension measurement set-up. Some experimental details and tips are provided in the PDF article installed along with the software (Plugins->Drop Analysis->About Pendent Drop) [11].
Figure 4
Surface tension of a drop of surfactine solution as a function of the time since drop extrusion. The discontinuities (e.g. around t = 70s or t = 130s) are due to changes in the drop volume caused by the operator. Surfactine is an amphiphile lipopeptide produced by Bacillus subtilis.