Optical sieve comparator development project

The development of an optical sieve comparator for the measurement and certification of sieve conformance to specifications is described. The comparator features: (1) measurement of a wide range of mesh sizes (3/8 in. to no. 400); (2) GO/NO GO sampling for spotcheck statistical certification; (3) absolute measurement; (4) simple calibration procedures; (5) variable optical path distance for wide range magnification; (6) folded optical path; (7) visual resolution and repeatability to 1.5 microns; (8) individual precision viewing reticles for each sieve mesh size; (9) rapid and convenient operation.