Figure 6

In-situ electrical measurements.

The insets show the schematic side and plan view of the electrical measurement setup. In the plan view, the vial (marked by solid circle) moves on a circular orbit (dashed circle). The distances A and r mark the distance of the electrode from the centre of the orbit and the instantaneous position of the centre of the vial respectively. The distance of closest approach from the surface of the vial to the electrode is shown by s. Control experiment on the electrical measurement setup is performed by inserting a conducting tube inside the PP vial, which is connected to high voltage source. (A) and (B) show the measured amplitude and phase as a function of the voltage applied on the conducting tube. In this experiment, f = 20 Hz. The inset of (B) shows the variation of i₀ and δ with the closest distance between the measuring electrode and the vial. (C) and (D) show i₀ and δ as a function of f for two values of applied voltage V = 1 kVand −1 kV. The presence of a conducting tube to which a voltage is applied is specific to the control experiment. This is absent in the main experiments (described in Fig. 1). (E) and (F) show the simultaneously measured i₀ and δ during the experiment described in Fig. 1. The dash dot line marks the position of .