Contact failure can occur when excessive heat or a high current or voltage pulse causes the contacts to weld together, resulting in short circuits.
当过热或者高电流或电压脉冲导致触点焊接在一起时，就会发生接触故障，形成短路。
2
Contact mark. Intermittent marks adjacent to the weld line resulting from the electrical contact between the electrodes supplying the welding current and the pipe surface.
触点痕。由于供焊接电流的电极与管子表面间的电接触，致使在焊缝线附近产生不连续痕迹。
3
The automatic internal girth weld tracker using contact type guide wheel as sensor is introduced in this paper.