Breakdown process of long air gaps on rod-rod electrodes by lightning voltages

In the past, it was difficult to measure the breakdown phenomenon by lightning voltages because of technical problems. As it was reported in the further works of the authors, it is now possible to use the modern measurement techniques in order to record the pre-discharge properties in nanosecond-range and even more precisely. This paper presents the measurement results of the breakdown of rod-rod electrodes with long air gaps by lightning voltages up to 2.4 MV. The pre-discharge currents have been measured on the both electrodes synchronously, which represented the main challenge for the measurement system. Beside the current measurement, discharge phenomena are photographed.