As we all know, auto-darkening helmets are used to save your eyes and face from harmful radiations of welding and spatter. It’s a very hot topic among the people that how auto-darkening welding helmets work? Do you need any technical background to know it’s working?
The answers are quite simple. The working is straightforward, you just need to understand some basic principles, and you will be able to learn about the working.
Auto Darkening Welding Helmet Working
However, welding helmets are made up of many small or big elements. Each element has its own work and task. The manufacturers just combine all the components, and overall the result comes as an auto-darkening helmet.
Here, we will explain every component of a welding helmet, its working. After all, we will describe how all the parts are combined? And how they work together?
Components of an auto-darkening welding helmet:
A welding helmet is a combination of certain small parts that perform different functions. The major parts of a welding helmet are listed below:
IR/UV Filter Section:
It is the purple color section in the welding helmet. As the name suggests, it blocks the Infrared (IR) and UV (Ultraviolet) radiations irrespective of the turning ON/OFF of the auto-darkening helmet. The filter is made up of a thin glass substrate combined with several metal layers.
These metal layers consist of six aluminum oxide layers and five silver layers. Both ingredients help to cover different things. The metal layer assists in absorbing and reflect approximately 99.99% of Infrared (IR) radiations. Furthermore, they also save the LCD (Liquid crystal) panels.
Further explanation of the liquid crystal panel is in the following. It can absorb radiations up to 99.9997% of UV radiations using the range of auto-darkening liquid crystals. The plus is, due to various layers, the thickness is only 0.7 microns even after eleven layers.
Glass is used because it has intrinsic property as ultraviolet blocking. The layers used in an auto-darkening layer can absorb maximum harmful radiation of a longer wavelength. Furthermore, ultraviolet radiations with high penetrating power can pass through the glass easily, and they are hard to detect. To sought out this problem, an IR filter is also used along with a UV filter that is known as UV/IR filter.
This combination of UV and IR filters gives the screen purple color that is a reflective surface. It allows the light to pass through a green tint that absorbs the light at the end of the spectrum.
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LC-cell
LC cell or liquid crystal cells (LCC) can change the direction of light. They can change the direction of light in different angles depending upon their placement. If you place a liquid crystal on a flat surface, it will tilt the light by 90 degrees of angle. However, these cells are operated with the help of electricity to make them work how far or near you want to bend the light.
We can bend light on those points where the light cannot be reflected. To cut a long story short, there are two polarization filters are nearer to the eye surface. They are arranged in symmetry. When we turn OFF, the LC cells between the polarization filters bend the light by 90 degrees.
Here comes the concept that when the auto-darkening layer is OFF, the lens will become dark (shade level 5-6). It is for safety in actuality that protects your eyes from bright light even if the auto-darkening filter stops working.
When the ADL in ON, the liquid cells did not twist the waves of polarizing light. The shade is set on level 3 before the starting of the welding arc. If this feature is not included, you cannot continue welding. We hope you have clearly understood the procedure.
Summary:
We have listed the key elements of an auto-darkening helmet. An auto-darkening welding helmet consists of seven layers, including UV/IR filter, polarization filter, and LC cells. LC cells and polarization filters work back and forth.
The combination is made to protect your eyes even if the helmet working gets a failure. In short, all the small components work together to behave like a shield against harmful welding radiation.