Behavior of water droplet on polymer material and the influence on discharge characteristics

To clarify the influence of a water droplet on discharge characteristics, water droplet was put on the polymer and the current and voltage characteristics of corona discharge was investigated under the application of AC voltage, using two different types of electrode systems (plane with needle to plane, needle to plane). The behavior of the water droplet was also investigated by using a high speed camera. In the case when AC high voltage was applied to the needle electrode, corona of the same polarity with the voltage applied to the needle was observed. When the water droplet tilted towards the positive electrode every half cycle, it was considered to possess a negative charge at the tilted tip of the water droplet.