Wednesday, January 4, 2012

INCREASING ADF LENS VIEWING AREA REQUIRES TOP OPTICAL QUALITY

Happy New Year!

Since their inception, auto darkening filter lenses (ADF) for welding have gone through a number of phases as producers sought a differential competitive advantage. First, it was "switching speed", how fast the lenses switched from their light to dark state. But when it was determined that all major brands switched many times faster than the human eye can see and switching occurs at the instant welding commences and plays no further role in the welding process, switching speed became an expected feature rather than a differentiator.

Once the switching speed phase passed, new suppliers, looking to break into the market and establish a position, started marketing elaborate shell graphics. Graphics caught on in certain segments of the market (casual welders, home hobbyists) but it was soon learned that often the most attractive graphics masked a flimsy, inferior helmet and a low quality, poor functioning ADF. In addition, in any kind of real, industrial welding environment, the graphics quickly turned brown or gray. So serious production welders learned to look beyond graphics and look for quality, durable helmets with high performance ADF's to help them do their jobs better.

The "gimmick" phase followed the "graphics" phase. Unable to enhance the basic ADF technology, some manufacturers resorted to gimmicks to try to set their products apart from the field. "3 in 1", shade 5 side panels, exhalation valves, flashing display lights and a host of other gimmicks flooded the market. But none of them helped a welder be more productive by making more and better welds with fewer accidents.

It is important to note that none of the ADF phases improved the basic function of the lens or the most important ADF attribute - the optical quality of the lens. Once the arc is struck, the ability of a welder to see his work clearly with no distortion determines his ability to produce,safely. From the beginning, a number of the major ADF lenses had numerous optical quality flaws. Poor lens clarity resulted in shadowing, fluttering, halo-effects around the edges of the lens, and "image persistence."  Image persistence, for example, occurs during stick welding when the shower of sparks persists as images in the lens (like tracers). Those distractions expose a welder to a higher level of risk than is necessary.

So all of the phases ADF's have passed through have essentially missed the mark. Welders want a top quality lens with as large of a viewing area as possible. To date, no supplier has been able to put those attributes together. The ADF's initially plagued with optical flaws, still have the flaws. And attempts to increase viewing area has been mostly done with smoke and mirrors. At first, the overall size of the lens was increased but not all of it was "active". Only a small portion of it actually turned dark while the surrounding area remained at a fixed shade. More recent attempts to increase viewing areas have resulted in even worse optical flaws. ADF's with angle dependency have even worse angle dependency in larger size lenses.

But there is some good news. Fibre-Metal by Honeywell, a top quality ADF supplier, now provides the only ADF in the world with a perfect optical quality EN standard rating of 1/1/1/1. That means the lens performs at the highest level in every measurable optical quality characteristic including, and especially angle dependency. That is the only real, practical, improvement in ADF technology since its inception. The Fibre-Metal by Honeywell ADF lens allows a welder to see more clearly, with no distracting flaws, and in more natural colors. Most importantly, he can use the entire viewing area because the lens is angle dependency free.

The trend toward larger ADF lens viewing areas will no doubt continue. But enhanced lens size without the requisite optical quality is useless. Learn to distinguish between the physical size of the lens (usually measured in square inches) vs the functional viewing area measured by how much of the lens is actually usable.

January is a good month to review the ADF's you are using. Are they the best that they could be? Do they actually help your welders be more productive with less downtime and fewer injuries? Talk to your and other suppliers. What improvements have they made in their ADF's? What are they working on? Compare what is available. If you are not using the highest optical quality ADF, with the largest functional viewing area, you are not getting all of the value you should be getting. The start of a new year is a good time to change that.

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