After having selected the wire and gas for a weld, operating conditions must be chosen. The four importantparameters are the welding current, wire electrode extension, welding voltage and arc travel speed. Theseparameters will affect the weld characteristics to a great extent. Because these factors can be varied over alarge range, they are considered the primary adjustments in any welding operation. Their values should berecorded for every different type of weld to permit reproducibility.