No other part numbers with same form, fit, and function found.
A flat, transparent piece of glass, generally of fused quartz, with one or both principal surfaces polished to within a few millionths of an inch of a true plane. It is used in conjunction with a monochromatic light source to measure the flatness of precision finished surfaces, and to determine the distance and parallelism between precision finished surfaces by comparison with known standards. In operation the flat is superimposed, reference surface downward, on the parts under test and when illuminated by monochromatic light the rays reflected from the reference surface are either reinforced or neutralized by the rays reflected from the surface under test producing interference bands which reveal any variations in the thickness of the film of air between surface under test and the flat. Excludes optical parallels.
NSN 6320-01-236-9562
NSN 5990-01-433-3786
NSN 5920-01-539-8884
NSN 6220-01-505-8198
NSN 5910-00-952-7251
NSN 6220-01-162-7954
NSN 5975-00-652-8900
NSN 6240-00-267-1167
NSN 2925-01-026-1000
NSN 6130-00-825-7552
NSN 6130-00-938-3740
NSN 5998-01-518-6759