Angles of entry of ultraviolet radiation into welding helmets

To investigate the angles of entry of ultraviolet (UV) radiation into welding helmets, a UV detector was placed in the eye socket of a head form that was then fitted with a range of welding helmets. The head form was exposed to a collimated beam of UV radiation from various orientations, and the amount of infiltration was measured. Radiation was found to be reflected from the filter plate and into the detector (eye) after entering through (1) an opening between the edge of the shield and the side of the face, and (2) an opening between the top edge of the shield and the top of the head. These results have significance for UV exposure when welding is performed in highly reflective and enclosed situations, and for the design of welding helmets.