Light sources and shade number of welding filters.
D005374:Filtration / Q000295:instrumentation*; D006801:Humans; D007259:Infrared Rays; D008027:Light; D009787:Occupational Medicine; D011044:Poland; D011482:Protective Devices / Q000592:standards*; D011835:Radiation Protection / Q000295:instrumentation*; D014466:Ultraviolet Rays