What is the primary function of a welding gun in GMAW?

The primary function of a welding gun in Gas Metal Arc Welding (GMAW) is to guide the electrode wire and conduct electricity to create an electric arc between the welding wire and the workpiece. The welding gun is designed to feed the consumable electrode wire into the weld pool while simultaneously delivering a shielding gas to protect the molten weld from atmospheric contamination. This process is crucial for achieving a stable arc and producing quality welds.

By ensuring proper electrode guidance and electrical conductivity, the welding gun plays a vital role in controlling the weld pool's temperature and shape, ultimately influencing the overall quality and characteristics of the weld bead. The effective delivery of shielding gas also helps in preventing defects such as porosity, which can occur if the weld pool is exposed to oxygen or moisture.

Other options focus on additional aspects of the welding operation that do not pertain to the primary role of the welding gun. While fume capture devices, measuring tools, and cooling mechanisms may be relevant to the broader welding environment, they do not define the core function of the welding gun itself in the GMAW process.