Voltage-sensing wire feeders set their speed according to:

Voltage-sensing wire feeders adjust their wire feed speed based on arc voltage. This is because the arc voltage directly reflects the actual distance between the welding tip and the workpiece, which influences the welding arc characteristics. When the arc voltage changes, the wire feeder compensates by altering its speed to maintain a consistent arc length. This ensures stable and efficient welding conditions, preventing issues like excessive spatter or incomplete fusion.

Choosing arc voltage as the basis for speed adjustment allows for dynamic responses to variations in the welding process. Such variations can occur due to changes in workpiece surface conditions, joint configurations, or other aspects of the welding environment. The ability to maintain the proper arc length through voltage sensing enhances the quality and consistency of the welds produced.

Other options, such as current voltage, weld pool temperature, and feed roller tension, do not provide direct feedback about the arc length or maintain the consistency needed in the welding process, which is why they do not serve as suitable indicators for adjusting wire feed speed in this context.