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National Stock Number:
5210-00-882-6636
Federal Supply Class:
5210
National Item Identification Number:
008826636
Description:
OPTICAL FLAT
Detail:
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.
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Manufacturer Information:
| A-A-58051 | 58536 | FEDERAL COMMERCIAL ITEM DESCRIPTION PROMULGATED BY GENERAL SERVICES ADMINISTRATION WASHINGTON DC | | A-A-58051 TY2CL2 | 58536 | FEDERAL COMMERCIAL ITEM DESCRIPTION PROMULGATED BY GENERAL SERVICES ADMINISTRATION WASHINGTON DC | | A-A-58051 TY2CL2 | 80244 | GENERAL SERVICES ADMINISTRATION FEDERAL SUPPLY SERVICE | | GG-O-635 | 81348 | FEDERAL SPECIFICATIONS PROMULGATED BY GENERAL SERVICES ADMINISTRATION WASHINGTON DC | | GG0635 | 81348 | FEDERAL SPECIFICATIONS PROMULGATED BY GENERAL SERVICES ADMINISTRATION WASHINGTON DC |
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Techincal Specification:
| WORKING SURFACE FLATNESS ACCURACY | 0.00000200 INCHES NOMINAL | | CASE | PROVIDED | | DESIGN TYPE | MASTER DOUBLE | | NONDEFINITIVE SPEC/STD DATA | 2 TYPE AND 2 CLASS | | THICKNESS | 0.875 INCHES NOMINAL | | DIAMETER | 5.000 INCHES NOMINAL | | MATERIAL | GLASS BOROSILICATE |
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