This example is taken from an investigation
concerning surface charge accumulation at the gas–dielectric interface under
a d.c. voltage application. The experimental investigations showed a high
accumulation of positive or negative surface charges after applying high d.c.
voltages to the electrode for a long time, i.e. up to hours, but the polarity and
magnitude of these charges are directly related to this original electrostatic
field, i.e. the field before charge is deposited and fixed to the interface.