Not all auto-darkening helmets are created equal. They range in quality, from those that are made for the casual hobby welder, to the true professional who's welding all day, every day. So, depending on the type of welder you are, and the amount and types of welding you do, there's a number of features you need to consider when choosing an auto-darkening welding helmet that will suit your needs.
Type of shade
Fixed or variable? What does that even mean?
Well a fixed shade auto-darkening helmet will sense an arc, and then darken to a fixed #10 shade. So basically it provides the wearer with a 2-in-1 lens situation, where you're either looking through a clear or shade #10 lens. The benefit here is that you don't need to change the lens, or flip it up and down.
A fixed shade auto-darkening helmet is used when most of your welding uses the same process, material and material thickness (or similar). This ensures you have the right protection for the job.
A variable shade auto-darkening helmet provides the wearer with a range of shades, often between shades #9 to #13. The helmet will automatically adjust the shade depending on the brightness of the arc, allowing the wearer to protect their eyes while still maintaining the best possible vision.
Variable shade auto-darkening helmets are for anyone who uses different welding processes, varying amps, and differing materials and material thicknesses.
Below is a chart indicating the shade required for varying amps and welding processes:
Lens reaction time
How quickly will the lens change from its natural light state, to the darkened shade you need when welding begins? This is important as the quicker your eyes are protected, the better. As a guide, an entry level lens (for the hobbyist) are commonly rated at 1/3,600 of a second, where professional level lens are commonly rated as high as 1/20,000 of a second. Someone welding all day with a lens rated at 1/3,600 is likely to experience eye fatigue by the end of the day due to the cumulative effect of increased arc light exposure. The more you weld, the more you will appreciate faster lens reaction times!
Auto-darkening lens quality
To cut to the chase, if you want the best quality lens, you're looking for a lens with a 1/1/1/1 optical rating. This is the best you can get.
What does it mean? Well optical ratings are based on 4 criteria as described below. Each criteria is given a rating of 1-3, with 1 being the best and 3 the worst:
1/X/X/X = Accuracy of vision — this rates how distorted the image is when you look at it through a welding helmet lens. A rating of 3 would be like looking through rippled water, and 1 would be clear and crisp.
X/1/X/X = Diffusion of light — rates the lens for any manufacturing impurities in the cartridge’s glass. A rating of 1 is clear, defect free and uniform.
X/X/1/X = Variations in luminous transmittance — this rates the lens ability to adjust to different shades, and the consistency of the shade across different points of the lens surface. A rating of 1 indicates the lens provides a consistent shade across the entire surface.
X/X/X/1 = Luminous transmittance — this rates the clarity of the lens when viewed at an angle. It tests for a clear view without stretching, dark areas, or blurriness as the result of inconsistent shade.
The bigger the better right? Not always. It really comes down to personal preference when it comes to the size of your lens. Of course if you're doing a lot of out-of-position welding, a larger screen will assist with a better view. Many of the largest view sizes available in auto-darkening helmets are 97x 62 mm (3.82 x 2.44 inches) or larger. This helps in delivering a clear natural view when combined with the helmet’s LCD technology.
The TECMEN TM1000 flip front helmet has additional side view lens, giving the wearer 150º viewing. Test drive one in your workshop here
Arc sensors are used to sense the arc light and adjust the lens accordingly. An entry level helmet will typically have 2 sensors, where a higher performance helmets can have up to 4. However more recent professional helmets include ‘Intelligent Sensing Technology'. These sensors have an enhanced ability to distinguish between the welding arc and other light sources, and indirect welds. In this case the helmet only requires 2 sensors for top performance.
The ability to adjust how much brightness will trigger the lens to darken is particularly important at a professional level, and/or when working in close proximity to other welders. Sensitivity controls help to make sure the helmet will darken as/when you want it to. For example, when other welders are operating very close by, the helmet’s arc sensor sensitivity can be reduced to help prevent triggering or darkening when fellow welders strike their own arc. It is also useful when welding at low amperages, especially TIG, when the arc isn't as bright as other welding processes.
Delay controls allow you to adjust how long the lens remains dark after the welding arc stops. Generally it can be adjusted to a delay of 0.5 seconds up to 2 seconds. This is useful when tack welding a large project when you need a short delay to reposition for the next weld. On the other hand a longer delay is useful when welding at high amperages when the metal can still emit harmful rays until it cools.
So if you're deciding on an auto-darkening helmet, and not sure which one to go for, consider the points above. If you're after something that has it all, we'd recommend the TECMEN range. For more info and to arrange a free workshop trial click here