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 5975-01-192-5204
NSN 6320-01-072-2073
NSN 6685-01-227-5134
NSN 6150-00-864-5480
NSN 6130-01-625-6382
NSN 6220-00-425-3346
NSN 5950-00-983-5999
NSN 6650-00-241-0970
NSN 6110-01-285-4516
NSN 5999-00-973-3468
NSN 4140-01-424-3271
NSN 5975-01-025-9990