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 6150-00-891-1659
NSN 6620-01-141-5747
NSN 5835-00-617-3578
NSN 5960-00-728-3459
NSN 6150-01-103-0371
NSN 5855-01-262-1766
NSN 6610-01-053-6781
NSN 6130-00-762-2239
NSN 6240-00-423-9575
NSN 5960-00-064-6530
NSN 5925-01-470-9525
NSN 2925-00-795-4064