Classifies filters into shades according to visual density, recommends shades for various industrial uses. Visual density, protection against ultra-violet radiation, total-heat protection, antiglare protection, refractive properties, freedom from optical imperfections, uniformity of density, permanence, quality of cover glasses, colour grading, and (for plastics filters) flammability tests.
BS 679:1959
Original price was: $264.16.$132.00Current price is: $132.00.
Specification for filters for use during welding and similar industrial operations
BSI Group , 02/28/1977
