The post-arc characteristic such as the post-arc current, conductance and charge is obtained by measuring and process the post-arc current. The post-arc charge is more stable and smooth, so it is more optimal to describe the post-arc characteristic.

The post-arc charge can be used to describe the residual plasma at current zero and it is the effect of the arc memory. The post-arc charge increases as the arcing time increases and the influence of the current magnitude is weak when the current is from 5 kA to 15 kA.

The relationship between the final position of the last cathode spot and the post-arc characteristic is gained and analyzed.