Description: Scratch & dig standards are surface quality standards ideal for qualifying the scratch and dig surface defects on optical components. There is a 60 mm scale, 6 grids of various sizes and 6 blocks of lines with varying frequencies on each plate in addition to the scratch dig markings. These grids help to measure the area of irregularly shaped defects. The square root of the total defect area for a region is the grade number for that region. Sets of two plates are offered as standards. Plate I includes grade numbers ranging from 0.004 to 0.040 while plate 2 includes grade numbers from 0.040 to 0.400.The features for the first surface set are marked on the top of the glass substrate and the features for the second surface set are marked on the bottom of the glass substrate. Scratch & dig standards are produced at Edmund Optics Inc. Specifications: 60 mm scale length - 60 mm ±0.002 mm; scale divisions every 0.025 mm; substrate material soda lime float glass; thickness - 1.5 mm nominal; surface quality - 20:10; flatness - 3-4 wavelength/inch; frame material - black anodised aluminium; frame dimensions - 114.3 x 50.8 mm ±0.100 mm; angle of incidence - 45°; and line width and dot dia tolerance - plate 1 ±0.00025 mm, plate 2 ±0.0005 mm.
Other Catalogs (From Edmund Optics Inc.) :
