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 5945-00-731-9223
NSN 5855-00-004-0904
NSN 5915-01-040-8164
NSN 5990-01-472-2447
NSN 6685-00-978-7709
NSN 5855-01-319-9757
NSN 4140-01-025-9699
NSN 5915-00-845-1407
NSN 5950-01-310-8481
NSN 5855-00-285-8172
NSN 6610-01-382-4974
NSN 6110-01-430-2408