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 6220-01-587-6452
NSN 6685-00-677-6929
NSN 6685-01-020-8508
NSN 5855-01-212-6612
NSN 5985-01-192-3916
NSN 5835-01-610-5744
NSN 5895-01-075-9645
NSN 5990-01-249-8212
NSN 6610-01-065-6057
NSN 5915-00-970-6590
NSN 6610-01-211-4210
NSN 5855-01-103-8650