What is the purpose of a gas lens in GTAW?

The purpose of a gas lens in Gas Tungsten Arc Welding (GTAW) is to improve shielding gas coverage. A gas lens is a device that is placed at the end of the welding torch, and it helps to stabilize and direct the flow of shielding gas around the tungsten electrode and the weld pool. This stabilization enhances the coverage of the shielding gas by creating a more uniform gas flow, which in turn protects the weld area from contamination by atmospheric gases that can lead to defects like porosity.

By providing a more consistent and directed shielding gas coverage, the gas lens contributes to better weld quality and integrity. It ensures that the area around the weld is adequately shielded during the welding process, reducing the chances of oxidation or other adverse effects that can compromise the weld.

While increasing the electric current to the torch, controlling the temperature of the weld pool, and decreasing the welder's fatigue are all important factors in the welding process, they are not the primary function of the gas lens. The focus of the gas lens is specifically related to enhancing the effectiveness of the shielding gas, making option B the correct and most pertinent answer.