NSN 5210-00-685-5545

Part Details | OPTICAL FLAT

5210-00-685-5545 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.

Alternate Parts: MIL026901CLASS1SIZE11, 5210-00-685-5545, 00-685-5545, 5210006855545, 006855545

Supply Group (FSG) NSN Assigned NIIN Item Name Code (INC)
52JAN 01, 196300-685-554518274 ( OPTICAL FLAT )
REFERENCE DRAWINGS & PICTURES
Cross Reference | NSN 5210-00-685-5545
Part Number Cage Code Manufacturer
MIL026901CLASS1SIZE1181349MILITARY SPECIFICATIONSPROMULGATED BY MILITARY
Technical Data | NSN 5210-00-685-5545
Characteristic Specifications
DESIGN TYPE MASTER DOUBLE
WORKING SURFACE FLATNESS ACCURACY0.00000200 INCHES NOMINAL
DIAMETER4.000 INCHES NOMINAL
THICKNESS0.750 INCHES NOMINAL
CASE PROVIDED
NONDEFINITIVE SPEC/STD DATA1 CLASS AND 11 SIZE