Welding as an industry has evolved significantly with the evolution of technology and this is no more evident than with the development of Auto-Darkening Helmets.



While traditional fixed-lens helmets are still used, Auto-Darkening units are now widely utilised for most welding applications and processes.



But what are Auto-Darkening Helmets and how do they differ from traditional fixed-shade helmets? Read on.



TRADITIONAL FIXED-SHADE V AUTO-DARKENING HELMETS



Some welders still prefer more traditional helmets with a traditional glass lens and a fixed shade that remains darkened at all times.



While these helmets do provide rugged and inexpensive safety protection, they also have a few disadvantages.



Welding helmets featuring a fixed shade can create difficulties and discomfort on a number of levels, especially over an extended period of time. A welder has to lift the helmet every time he or she wants to examine the weld and joint, set his position and prepare for welding, and then flip the helmet back down again when it’s time to strike the arc. This repetitive movement can lead to neck strain and fatigue after a full day’s work. In addition, in tight or restricted spaces, it can be difficult to move the helmet up or down.



Conversely, Auto-Darkening Helmets have continuously variable controls that adjust the shade from a light state to a dark one and back.



These helmets protect from harmful light emissions at all times and darken to almost any pre-selected shade in milliseconds, thanks to quick-changing LCD (liquid crystal display) technology in the auto-darkening cartridges.



With auto-darkening helmets, welders can see clearly while the helmet is already in the down position, so that setting up to weld a joint can be done with the hood in position.



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THE BENEFITS OF USING AUTO-DARKENING HELMETS



In its inactive state, an auto-darkening lens usually has a #3 or #4 shade, which is relatively easy to see through. When sensors on the helmet sense an arc start, the lens darkens, in a fraction of a second (typically 1/12,000 to 1/20,000 of a second for industrial-grade helmets), to shade #8 to #13.



Because the helmet stays in position before, during, and after the weld, an auto-darkening welding helmet enables you to set up your welding joint with the hood in position. This removes the need for head snaps to lower the helmet and makes it easier to start the weld as the job is clearly visible at all times. With less raising and lowering of the helmet, there is far less strain on the welder’s neck which improves the comfort and overall safety of the user.



These helmets permit more continuous work, reducing the need for frequent stops, readjustments, repositioning and restarts.



Increased productivity, ease-of-use, less fatigue and improved safety are just some of the benefits of using Auto-Darkening Helmets.



CONSIDERATIONS FOR USING AUTO-DARKENING HELMETS



Fixed or Variable Shade - When a fixed-shade auto-darkening helmet senses an arc, it darkens to a fixed #10 shade. If you weld similar material of similar thicknesses using the same welding process with a limited amperage range, then a fixed shade helmet may be the right choice for you.



However, if you use different welding processes (Stick, MIG, TIG), or vary your welding amperage and therefore vary the brightness of the arc, a variable shade lens will allow you to properly protect your eyes while achieving the best view of the weld puddle. Most variable shade lenses adjust from shade #9 through #13.



Lens reaction time – This indicates how quickly the lens will switch from its natural light state (usually shade #3 or #4) to the darkened shade when welding begins. The quicker a welder' s eyes are shaded from the high-intensity light, the better.



Entry-level lenses are often rated at 1/3600 of a second, while industrial or professional grade helmets can be rated as high as 1/20000 of a second. The more arcs you start in a day, the more you'll appreciate the quicker speed. If you spend all day welding with a lens rated at 1/3600, the cumulative effect of the increased exposure to the arc light may lead to eye fatigue at the end of the day. With faster switching speeds, these effects are reduced.



Viewing size – The viewing areas of helmets vary in size depending on the application. Lighter applications typically use helmets with a viewing size of 26cm sq, while industrial work will use helmets with a viewing area of up to 58cm Sq.



The viewing size of a helmet is usually dictated by personal preference but a user must also consider how much ‘out of position’ welding they do as well. Out of Position Welding is essentially any welding which is not in a flat/horizontal fixed-position and typically involved overhead and/or vertical welds.



Number of Sensors – In short, the more sensors, the better coverage a helmet will have. The number of sensors ranges from two for a light industrial level helmet to four for an industrial grade helmet. Industrial Users and those involved in regular ‘Out of Position’ welding should consider helmets with three or four sensors, while helmets with two sensors are usually sufficient for lighter users.



Adjustable Sensitivity Control - Both intermediate and professional level auto-darkening helmets usually provide the ability to adjust how much brightness will trigger the lens to darken. Sensitivity control is useful when welding at low amperages, especially TIG, when the arc isn't as bright as other welding processes. Also, when welding outside in bright sunlight, it can cause the lens to darken at the end of welding.



Adjustable Delay Controls - A delay control is another useful feature. This control enables you to set how long the lens stays dark after the welding arc stops. When tack welding on a large project, a short delay helps get the job done faster as you reposition for the next weld. A longer delay time is helpful when welding at very high amperages, since molten metal may still emit harmful rays until it cools.



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