Question

what uses a high voltage/low current/high hertz arc to start and stabilize the welding arc?

low frequency
lift arc
scratch start
high frequency

Explanation:

Identify the core question

The question asks what uses a high voltage, low current, and high hertz (frequency) arc to start and stabilize a welding arc.

Analyze the options

Using the HF Arc Start and Plasma Arc Starting Methods knowledge points:

• Low frequency: This does not provide the high hertz (high frequency) required to ionize the air gap.
• Lift arc: This is a contact starting method where the tungsten electrode touches the work, a low current is established, and then the electrode is lifted to form the arc. It does not use high frequency.
• Scratch start: This is a basic contact starting method where the electrode is scratched against the metal, similar to striking a match. It does not use high frequency.
• High frequency: High-frequency (HF) starting uses high voltage, low current, and high frequency (high hertz) electricity to ionize the air gap between the electrode and the workpiece, allowing the welding arc to establish without touching the metal. It is also used to stabilize the arc in AC TIG welding.

Select the correct option

The description perfectly matches "High frequency" (HF).

Answer:

• Low frequency
• Lift arc
• Scratch start
• High frequency (Correct answer)