MILLER Welds has released a guide to selecting the right welding helmet.
While welding helmets are designed to protect welders from the ultraviolet and infrared rays emitted during the welding process, not all helmets are created equal.
Helmets can have various features: passive or auto-darkening lens, fixed or variable shade, two, three or four sensors, and viewing size.
Helmets should meet ANSI Z87.1 - 2003 standards, which ensure that helmets and lenses have passed independent testing to show they can survive high velocity impact from flying objects, provide 100% ultraviolet and infrared filtering regardless of shade setting and meet advertised switching speeds and darkness shades in a wide range of temperatures.
A passive lens helmet uses UV- and IR-coated dark-tinted glass with a fixed shade value. It is worn in the up position while the electrode, gun or torch is positioned. The operator flips the helmet into position immediately before striking an arc.
According to Miller Welds, novice welders or infrequent welders can find it difficult to simultaneously position the electrode and snap the helmet into place. This can lead to poor weld starts.
Passive helmets are also inefficient for tack welding or jobs requiring numerous short welds. Additionally, poor timing can leave to inadvertent arc flashes, and the act of snapping the helmet in place can cause repetitive stress injuries.
Auto-darkening lens helmets address the issues by sensing when an arc starts to darken the lens. Many manufacturers do not allow passive helmets into their plants.
Auto-darkening helmets come with fixed or variable shade. A fixed-shade helmet will darken the lens to a pre-determined shade, usually $10. However, if the welder is using different processes or varying welding amperage, the brightness of the arc changes, and variable shade lenses are a better option.
Lens reaction time indicates how quickly the lens will switch from its natural light state (usually shade #3 or #4) to the darkened shade when welding begins. Faster switching speeds will reduce the amount of light the welder’s eyes are exposed to throughout the day.
Other factors include viewing size, the number of sensors, adjustable sensitivity control, and adjustable delay controls. Viewing size is based on personal preference as well as how much out-of-position welding is being undertaken.
More sensors mean better coverage, especially for out-of-position welding. Less sensors are needed if there is a clear line of sight to the work.
Sensitivity control is useful at low amperage welding, when the arc is less bright. It will allow the user to adjust how much brightness will trigger the lens to darken.
Adjustable delay controls allows welders to set the period the lens stays dark after the welding arc stops. Short delays help speed up jobs requiring short welds, while longer delay times are ideal for higher amperages to protect the welder from the rays emitted from molten metal.
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