Measuring of electrostatically induced voltage and its polarity in partially opened metal box by means of neon lamp and photomultiplier tube

Electronic apparatus in partially opened metal boxes often malfunctions due to electrostatically induced voltage. The induced voltage (induced potential difference, IPD) produces when charged bodies exist and move close. Objectives of this study are (1) to improve the voltage level capable of measuring an induced voltage, (2) to discriminate its polarity. In this study, the IPD and its polarity are demonstrated by means of a neon lamp and a photomultiplier tube. The results will be useful to estimate the value and polarity of the IPD as well as to help with the basic design of printed circuit boards.