If you have done some welding projects or seen welders working, you can see that a welding helmet is always needed to protect the welder from the dazzling sparks. However, most modern welders do not use traditional helmets anymore but replace them with convenient auto-darkening welding helmet instead.
So how does auto-darkening welding helmet work? Why are they so effective in welding and some other jobs?
Let’s find out the secret in this article!
Table of Contents
Parts of an Auto-Darkening Welding Helmet
Like classical helmets, this modern pattern also uses a filter lens to protect the wearer’s eyes. Yet, the difference is that it is an auto-darkening lens.
What’s more, the welding helmet also provides an LCD screen just like in electronic clocks to support you utilize it. You can see the parameters and adjust them there at ease.
As an electronic device, each auto-darkening helmet has filter cartridges that need a power source to operate. To take advantage of the light coming from the sparks and other sources, the producers often integrate solar power into the batteries.
On top of that, a wide range of photosensors around the lens would continuously detect the welding arc to darken the screen automatically, too.
Even when deactivated, the helmet still provides a bit shade. As a result, you can see the details of your workpiece and anything else clearly without having to remove the helmet.
That’s the basic operation principle of an auto-darkening welding helmet. Here we go deeper into the three main parts of its lens.
1. The UV/IR (Ultraviolet/Infrared) Interference Filter:
Including a number of metallic layers as well as a slim glass panel, this filter can dramatically reduce the radiation from UV/IR rays in addition to the ADL (auto-darkening lens).
Within the ADL shade range, the metallic layers of the filter manage to absorb nearly 100% of the infrared and ultraviolet rays. In this way, they can protect both the user’s eyes from dangerous radiation and the screen from the heat of the arc.
Meanwhile, the glass substrate will alleviate the harmful UVB ray, and the polarising filters combined with the UV/IR filter will block UVA radiation.
2. Polarising filters:
Thanks to this equipment, the brightness of visible light will decrease remarkably. In general, moving these polarizers to different positions will have different impacts on the light level.
For instance, you can achieve the darkest vision by placing two polarizers perpendicularly. On the contrary, the 180-degree angle will give you less shade.
3. Liquid Crystal Cells (LCC):
The LCC works like a mirror to twist the light. A flat LCC can bend the light ray by the square angle. Nonetheless, you can customize it by the amperage volume when the helmet is active.
How Does Auto-Darkening Welding Helmet Work?
After you have learned how each part works, we will explain the way they work together.
Once the lens is off, the LCCs between the polarizers will bend the light by a ninety-degree angle to darken your sight. Therefore, regardless of the state of the lens, your eyes are always safe no matter how bright the light is.
Vice versa, if turned on, the LCC between the two polarization filters will not twist the light. Unless the helmet works, you had better stop welding.
Right after the moment that you strike the welding arc, the light sensors will enable the LC panel to darken the lens as you set beforehand. Later, when you have finished your project, the lens will become clear so that you can observe everything easily.
We can even go further into more details of an auto-darkening welding helmet. Nonetheless, basic information about the major parts and how they work individually and together are enough for you to understand the device’s operation.
Surely now you have a sufficient answer for the question “How does auto-darkening welding helmet work?”.
Thanks for reading!