Application of capacitive tensiography to investigation of pendant drop growth

The new technique of capacitive tensiography is applied to monitor the formation of liquid drops under conditions of extremely slow growth. When drop growth is sufficiently slow, the effect of forces arising from surface tension due to the changing dimensions of the drop becomes evident. We present here the results showing qualitative variations in the signal representing drop growth over a range of flow rates, whose form is explicable by simple physical arguments based on the imbalance between the motive pressure, the weight of the drop and the opposing Laplace-Young pressure. It is proposed that this technique may be used to monitor capillary flow in more complex systems, and assist studies of drop growth.