The critical factor in the auto darkening lens systems is that they
are supposed to filter out all the UV - all the time -
It is only the visible spectrum that gets switched between two degrees
of filtering. That being the case, if the Chinese systems filter out
all the UV, then they are probably OK (and your eyes will tell you
otherwise before damage occurs). I don't know how you can tell the
degree of UV filtering without measuring it, or trusting the
manufacturer.
The other dynamic between low and high cost models is the size of the
plate you can see through. If you are always welding in position then
it doesn't matter too much, but if you are trying to weld on cars,
trying to get the torch to reach some occluded spot inside the engine
compartment or some such, then the size of the field of view is very
important.
-Roland
with an old and pretty small field of view auto helmet
On Tue, 13 Jun 2000 22:55:15 -0400, you wrote:
::
:: After burning a couple of pounds of wire putting a new floor in my
:: Spitfire, I came to the conclusion that a new helmet was called for.
:: Northern has an autodarkening one for under $80!. I realize this will be
:: a cheap plastic
:: helmet, but the lens is my main concern. A net search didn't reveal
:: much on the technology & safety of the powered lenses.
::
:: Are these proven safe? Does is make any difference if these low-end
:: versions are all coming out of China? I don't know if the US made ones
:: are subject to any better inspection / standard compliance or not.
::
:: Thanks,
:: MRB
:: ________________________________________________________________
:: http://dl.www.juno.com/get/tagj.
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