What is the primary purpose of a lighter in welding?

The primary purpose of a lighter in welding is to ignite the gas used for welding. In many welding processes, especially those that involve gas such as oxy-acetylene welding, a lighter is essential for initiating the flame. The lighter provides the necessary spark or flame to ignite the fuel gas and oxygen mixture, enabling the welder to create a focused flame that can melt the base material and the filler rod. This ignition is crucial as it sets the stage for the welding operation to commence effectively.

Other functions indicated in the choices do not align with the roles typical of a lighter in welding. For instance, cooling the welded area, holding the welding rod in place, or measuring the temperature of the weld are tasks typically carried out by different tools or techniques specifically designed for those purposes. Understanding the function of a lighter helps clarify its importance in the welding process, facilitating successful welds.