What waveform eliminates the need for continuous HF in GTAW?

• A. Square Wave
• B. Sine Wave
• C. Triangular Wave
• D. No Wave

Answer: (B)

A square waveform in GTAW provides very abrupt current changes and a strong, rapid ionization path in the arc column. Those sharp transitions help the arc ignite and stay conductive across each half-cycle, so you don’t rely on continuous high-frequency to keep the arc alive. In practice, this means you can maintain the weld with less or no continuous HF, especially at lower amperages or with thinner materials. Sine or triangular waveforms change more gradually and don’t promote ionization as aggressively, so they typically still depend on continuous HF to sustain the arc. No Wave would not provide a usable alternating current waveform, so it wouldn’t eliminate the need for HF.