When you were a child, how many times did your parents chastise you that you had only one pair of eyes and you’d better take care of them? That lesson couldn’t be more important than when you’re welding. After all, the welding process creates not only intensely bright visible light but also lots of infrared and ultraviolet light that can seriously damage your eyes. Without proper protection, your vision can be seriously impaired or even destroyed.
Though welding shields, goggles and fixed black helmets have been around for decades, the advent of auto-darkening welding helmets sparked a true revolution in welding safety and comfort. Forget about constantly flipping your helmet up to see what you’re working on and then back down to weld: Auto-darkening helmets never hinder your ability to clearly see what you’re working on. In fact, they can make welding a real eye-opening experience.
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Auto-darkening welding helmets provide automatic protection
An auto-darkening welding helmet contains an electronic module that controls the helmet’s darkening (and thus its ability to protect your eyes). When the module senses either fixed/static infrared (IR) or ultraviolet (UV) light waves – the type of light emitted by a welding arc – it sends an electrical charge to the crystals that float between the two sheets of glass that make up the viewing window and causes them to re-orient, almost instantly becoming dark. Once the arc goes out and light returns to normal levels, a timer lightens the screen again (after about 100 milliseconds). Some helmets feature a delay control that allows you to control how long the viewing window remains dark after the spark ends.
Sensitivity controls allow you to adjust how easily the helmet’s viewing window darkens, but it may take a few tries to get everything set just right. If the sensitivity is set too low, the helmet may not darken when an arc is struck, but if it’s set too high, the helmet may darken when exposed to sunlight or even bright indoor lights.
Some auto-darkening welding helmets take customization a step further and enable you to adjust the “shade” (or level of darkness) – in short, allowing you to control just how dark the helmet gets when it activates. This level of versatility may not be necessary if you always use the same process, materials and amperage settings, but it’s vital if you’re often switching between jobs such as low-amperage TIG work and higher-powered MIG welding.
It’s a common misconception to equate the lens shade number with the degree of eye protection. In reality, all helmets that comply with ANSI standards filter out a vast majority of the harmful UV and IR emissions even at the lowest shade setting, so the choice is simply a matter of comfort and ease-of-use.
Auto-darkening welding helmet power sources
When it comes to providing the electrical charge that causes the viewing window to darken, there are two options: solar or battery power. As long as you can always remember to turn on your welding helmet, a battery-operated unit may be fine. But solar-powered helmets do have some advantages: First, because there is no “on/off” switch on a solar-powered helmet, you know that it’s always ready to go whenever you strike a spark. And because solar-powered helmets do not rely on batteries, you won’t have the hassle or expense of replacing them when they wear out. However, if solar-powered helmets are regularly stored in very dark locations, they can lose their ability to hold a charge. So if you opt for solar, don’t store your helmet in a closed cabinet or closet.
Other considerations when selecting an auto-darkening welding helmet
Because prices can vary from $50 to as much as $300 for an auto-darkening helmet, there are obviously benchmarks that separate the budget players from the top-end units:
• Viewing window size: Entry-level helmets will have a much smaller window (sometimes as small as 1-1/2 x 3-1/2 in.). More expensive models have viewing windows as large as 4 x 3 in.
• Sensor bar: Will you be welding near other welders? If so, you’ll want a helmet with a sensor bar that restricts the ability of peripheral light sources to trigger your helmet.
• Headband adjustability: Though all helmets have adjustable headbands, some are easier to adjust than others. Higher-end models will feature extras such as adjustment wheels and full-up detents that keep your helmet in the up position.
• Cheaters: If you need magnification to clearly see what you’re working on, make sure to purchase a helmet that accepts “cheaters,” or magnification inserts that clip inside the viewing window.
Because of the big price range in welding helmets, there’s bound to be one that within your budget. Look for a reputable helmet manufacturer, weigh the options and then make your purchase. Whether you’re a novice welder or a long-time spark-striker, you’ll appreciate the versatility and comfort these devices bring to your welding activities.
Types of emissions radiating from the welding arc: UV and IR light
When selecting an auto-darkening helmet, it’s important to understand arc flash and what types of emissions radiate from the welding arc. Arc flash is simply the unexpected exposure of the eyes to the welding arc. The welding arc emits several forms of light including ultraviolet (UV), infrared (IR) radiation and high-intensity visible light. Both IR and UV radiation can cause permanent damage (such as retinal burns) to the eyes. Although high-intensity visible light may not cause permanent eye damage, it may leave the operator with temporary discomfort similar to being exposed to a camera flash. All helmets that comply with the current ANSI Z87.1 standard (when in the proper down position) always protect operators from the harmful UV and IR damaging elements of the arc.
If you’re afraid that your eyes could be damaged during that split second after the strike of the arc and before the helmet darkens, you can rest easy. All helmets that comply with the current ANSI Z87.1 standard always protect operators from the harmful UV and IR emissions from the arc whether the lens is darkened or not. However, the faster the helmet darkens, the more likely it is to prevent discomfort from the high-intensity visible light. Less than a millisecond in response time is not perceivable by the human eye and will provide the most comfort, so look for a helmet that has a response darkening time of a millisecond or less.