A method of obtaining inception voltage in spark discharge utilizing a current probe

There is usually a significant voltage drop on the electrode during the brief delay before spark discharge occurs when the storage capacitance is small (around or below 100 pF). This leads to a decrease in capacitor energy, which may result in an overestimation of the minimum ignition energy (MIE) of dust cloud. A method that utilizes a current probe to obtain the inception discharge voltage was therefore developed. Firstly, the voltage attenuation on the electrode without spark discharge is measured, enabling an accurate calculation of parasitic capacitance. Subsequently, the inception discharge voltage in a spark discharge is calculated based on the measured spark current, thereby enabling the determination of capacitor energy before spark discharge. The results show that the fitted current curves based on the calculated inception discharge voltage exhibited consistency with the actual spark current curves, indicating that the calculated value of inception discharge voltage was consistent with the actual situation. The method effectively addresses challenges associated with measuring the inception discharge voltage in cases of small storage capacitance, which helps to calculate the capacitor energy before spark discharge for MIE testing of dust clouds that are highly sensitive to electrostatic discharge.