Comparison of current signatures for brush discharges using different resistance values in the discharge probes

Incendiary brush discharges can occur when a large or grounded conductor approaches a charged insulator in the presence of flammable atmosphere. The probability of ignition of these discharges is essential to risk assessment in process industry. It is known that even if the total energy released in the discharge exceeds the minimum ignition energy (MIE), there may not be an ignition [1]. In a companion paper in this conference, we have reported simultaneous measurements of ignition and discharge current waveforms for brush discharges in an ethylene-air mixture in ignition tests based on an IEC standard test method [2]. In this paper we show that the resistance of the electrostatic discharge measurement system can have an effect on the peak discharge current signatures and charge transferred in the brush discharge from an insulating surface. The resistance of the discharge probe seems to affect the peak current value, but also to lesser extent the amount of charge transferred in the discharge.