Written verification that a welder has produced welds meeting a prescribed standard of welder performance.

A controlled electrical discharge between the electrode and the workpiece that is formed and sustained by the establishment of a gaseous conductive medium, called an arc plasma.

The metal or alloy to be added in making a weld joint that alloys with the base metal to form weld metal in a fusion welded joint.

The work piece lead and electrode lead of an arc welding circuit.

One who operates adaptive control, automatic, mechanized, or robotic welding equipment.