Rise Time and Peak Current Measurement of ESD Current from Air Discharges with Uncertainty Calculation

The greater number of electrostatic discharges (ESDs) that occur in nature is by air rather than by contact. However, due to low reproducibility in the current of air discharges, the IEC 61000-4-2 defines that the current's calibration of an ESD gun must be made only for contact discharges. In the work presented here, there is an attempt to improve the poor reproducibility of air discharges by a significant observation derived from ESD measurements and, more specifically, the relationship between the rise time and the peak current for every ESD gun. This fact validated in this paper from current measurements of two different ESD guns will help all who are involved in ESD measurements in EMC laboratories by reducing the existing uncertainty in measurements of air discharges.