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 6620-01-633-8443
NSN 6220-01-027-1294
NSN 2925-00-969-8340
NSN 5985-00-146-2450
NSN 5835-01-039-9973
NSN 5990-01-304-7597
NSN 5915-01-433-9463
NSN 5999-01-356-0980
NSN 5990-01-649-4647
NSN 5905-00-085-8442
NSN 5915-00-946-6906
NSN 6105-01-129-7091