Investigation on Factors Influencing Discharge Characteristics of Electrostatic Sensor

The measurement of electrostatic sensitivity of flammable and explosive materials using an electrostatic sensor is an irreplaceable procedure for electrostatic safety and management technology. But in many cases, the discharge circuit usually develops oscillations, which change the electrostatic discharge characteristics significantly, affecting the discharge energy feed and hence the measurement accuracy. This paper develops the charge-discharge circuit of electrostatic sensor in contact discharge form by modelling. The effect of voltage, stray inductance in discharge circuit, and stray capacitance of relay switch on electrostatic discharge characteristics is investigated. It is shown that, the effect of stray inductance on discharge current is relatively week, but it will introduce oscillations to the current and also decrease the discharge energy feed when its value is high up to such as 100 μH; the stray capacitance of relay switch introduces significant oscillations to discharge current.