What is the primary purpose of a welding helmet shade, and what factors determine the correct shade number?

• A. Filters ultraviolet and infrared radiation; shade number is determined by welding process and amperage.
• B. Filters visible light to reduce glare; shade number is chosen by comfort.
• C. Protects eyes from sparks only; shade number is arbitrary.
• D. Reduces ambient heat and reflections; shade number is based on room temperature.

Answer: (A)

The main idea is that a welding helmet shade protects your eyes from the arc’s radiation. The welding arc emits ultraviolet and infrared light that can cause eye injuries and long-term damage, so the filter in the helmet is chosen to block those hazards while letting you see the weld area well enough to work. The shade number represents how dark the filter is, and it’s selected based on how bright the arc will be.

The correct shade is determined by the welding process and the amperage. Different processes produce different amounts of arc brightness and UV/IR output, and higher current generally means a brighter arc, which requires a darker shade to protect your eyes. Conversely, lower-current or less intense processes can use lighter shades while still staying safe. If the shade is too dark, you won’t be able to see the weld puddle clearly; if it’s too light, your eyes aren’t adequately protected.