Change in electrostatically induced voltages of an ungrounded metal box without openings generated by a moving charged object

A change in the induced voltage of an ungrounded metal box is measured when the charged object passes near the box. The change is just like as a Gaussian line shape by moving the charged object. The induced voltage decreases as a distance between the box and the charged object increases. The induced voltage (induced ratio × given voltage of charged object) can be estimated by using the induced ratio obtained at given distance. The results obtained will help the basic design of tablet devices etc. to prevent an error of electronic device.