Welding helmets come in all shapes and sizes. There are some that are used specifically for welding while others are used by welder’s goggles. And then, on the extreme end of the spectrum, there is auto-darkening welding helmets. These auto darkening welders have a sensor that automatically adjusts to project only light when it’s time for your eyes to be shielded from any possible glares or UV rays so you can keep working without having to take a break.
The Auto Darkening Welding Lens
The auto-darkening welding helmet is made up of a special lens that has three layers. The outermost layer is made up of a special liquid crystal fluid that provides the dark tint and that also reacts with the UV light. This outer layer, in turn, is covered by the next layer, which consists of a thin sheet of metal. This sheet of metal actually protects the final layer from getting damaged or worn down because it’s vulnerable to chipping and cracking due to its flimsiness. The final layer is the clear glass.
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How does the auto darkening helmet work?
Auto-darkening helmets are primarily activated by the arc light. Once it senses light, an electronic liquid crystal filter is activated to darken to a pre-selected shade and protects the welder’s face and eyes from UV and IR radiation.
In generally, when a person is using the auto-darkening welding helmet, the outermost layer changes depending on the UV rays and it gets darker or lighter. The darker layer actually causes objects to appear clearer. This is because when a person looks through something that is tinted darker they automatically adjust their focus to see better, so everything appears sharper.
Light cutting is also made possible on the lenses because the outermost layer can be changed as needed to adapt for different environments.
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Components of an auto-darkening welding helmet
The auto-darkening helmets are made from a thermoplastic crystal that is similar to the liquid crystal televisions. This is the material used as the outermost layer of the lens. The metal layer on top of it protects it from getting damaged or worn down due to its flimsiness.
The innermost layer is completely clear and serves as a shield against UV light and also filters out most of the visible light to make it easier for people who work outdoors.
When light hits the lens, it is carried on to the crystal and then through the metal layer. The metal layer is polarized so that the light waves are bent or refracted to create a protective veil against harmful UV rays. In this way, there is no need for an additional additional lens such as a pair of welding goggles with lenses built in.
Polarized sunglasses are used to protect people’s eyes from UV rays and contain a polarizing filter over their lenses.
UV/IR Interference Filter
Ultraviolet and infrared rays can create problems for welder’s eyes. When the light waves hit the photo-sensitive membrane of the lens, it reacts with the metal layer to produce varying shades of gray, which is how the lens adapts to suit different environments.
The liquid crystal cells layer is the very important technology used in auto-darkening welding helmets. The outer layer of the lens contains a special liquid crystal fluid to change color when it senses UV light. The liquid crystal changes from black to clear according to the intensity of UV light, which is why this layer serves as a shield from harmful UV rays.
The liquid crystal layer has a very high sensitivity to UV and IR light waves. When it senses the incoming light, it starts to change color so that everything appears clearer. This makes it possible for the auto-darkening welding helmet to be used under a variety of conditions.
This layer is also responsible for the auto-darkening welding lenses’ ability to adapt to different environments.
Initial darkening and light sensitivity
A common complaint among people who wear these helmets is that they have trouble seeing at first when they are wearing them, because they are so dark.
This is due to the fact that the outermost layer of the lens isn’t visible at first. When you first put on a welding helmet it will very dark because everything will become clear and then as you get used to it you’ll be able to see better through it.
The lens darkens as the temperature drops, which causes visibility problems because there is no marked contrast at first.
How Does The Lens Work?
Welding Helmets and Lens Screens
Auto darkening welding helmets look like regular welding goggles, but they are completely different from any welding goggles that you have seen before. The main difference is that the auto darkening helmet has an outermost layer of liquid crystal instead of a lens. This layer is sensitive to light and is made up of a special liquid crystal fluid which responds to incoming light waves.
This layer also reacts with the light waves and changes color as it changes temperature. This gives it the ability to adjust to different levels of light, so it can be used under a variety of conditions. This is yet another advantage over regular welding helmets and allows you to use the auto darkening helmet during outdoor work as well.
Intensity of Light
The intensity of the light is measured in amps or milliamps. The more amps or milliamps a helmet is rated for, the more intense the light it can deal with. Auto darkening helmets have various ratings from 100 amps up to 400 amps. The amount of amps necessary for your helmet depends on how much welding you do.
Those who like to do a lot of welding should opt for helmets with high amp ratings. Helmets with lower amp ratings can be used for light welding, but it may not be able to deal with the heat from arc welding.
If you are looking for an auto darkening helmet to use when you are welding outdoors, then it would probably be best if you get one that has the highest amp rating possible. You never know what the conditions might be when you are welding outdoors, so it is best if you’re prepared for anything.
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All in all, auto darkening welding helmets are a great invention. They’re able to adapt to various light conditions and tones, so they can be used anywhere you go.
They’re very convenient because you don’t have to waste time always having to look down into a welding mask or the dark goggles that come with most welding helmets. You won’t have any of these problems with an auto darkening helmet and you’ll be able to focus on your work without having any pesky distractions or obstacles in your way.
Good luck and enjoy reading.
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Walton M. Edwards was born in 1994 in a coal mining town, he has worked as a welder, a hardware salesman, and as a pipe fitter and has been employed as a laborer for about fifty years. Walton is a native of Wabash County in Indiana, but he now resides in Bloomington, Indiana.