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 6650-01-040-9637
NSN 6320-01-301-4699
NSN 5935-01-421-0990
NSN 6135-01-291-6712
NSN 2925-01-560-4123
NSN 6130-00-291-4877
NSN 5895-01-044-5425
NSN 6620-01-088-1272
NSN 6620-01-083-4672
NSN 5930-00-067-7347
NSN 6110-01-431-4223
NSN 5835-00-215-3769