My auto-dark welding helmet claims 100% reduction of UV and IR by the lens alone i.e. in it's undarkened state which is apparenlty about #5.
So then, if my batteries happen to be dead (lens does not darken), can I weld wih any degree of safety?? I've tried it a bit and found I can actually see better under this condition (at about 100A) than when it darkens. The initial flash is a bit bright but afterwards visibility seems pretty good.
Any opinions appreciated............
Laurie Forbes