Optical Optical Polygons Webber Optical Polygons provide an easy, accurate method of checking and calibrating angles. They are designed for use with autocollimators in measuring angle spacing. The exclusive one-piece design provides compact, fixed master for precise angle spacing. Target faces are highly reflective and optically flat. Chrome carbide polygons provide a hardness of Rockwell 71-73 C and a corrosion resistance 10-20 times that of 18-8 stainless steel, resulting in lifetime accuracy. Maintenance problems are virtually eliminated due to their ruggedness and extreme stability. A 1" mounting hole, flanged bushing, lapped washer and hold-down bolt, furnished with each unit, permit mounting the polygon in any desired attitude. Available in two accuracy grades. Furnished in case. Certificate of Calibration included. Fused Quartz Optical Fla ts For visually checking the flatness of seals, gages and mating surfaces. Through means of interpreting light interference patterns or bands, the optical flat provides a simple, accurate precision method for measuring surface flatness. Flats are crafted from high quality fused quartz and provide the maximum resistance to wear, damage and temperature variations. Starrett-Webber optical flats are available in single or double surfaces and three accuracy grades. The double flat has both surfaces finished to tolerance but not necessarily parallel. Double flats provide longer service because wear is distributed over two surfaces.All are furnished with case. Coating is available and it aids readability when applied to one surface. Coating is of value on single-sided flats only.Coating on a double surface will reduce the readability of the other surface. When ordering, specify size, accuracy grade, single or double side, and coated or not. To order polygons, specify number in the following key/sequence: Optical Polygon OP No./Faces Decimal Accuracy Grade Example: OP 3.0 = A 3-sided optical polygon with a 0 Reference Accuracy Optical Polygon Specifications No. of Sides Angle Spacing Degrees Diameter Across Corners Height Target Size Area Area in (mm) in (mm) in (mm) Sq. In. Sq. Cm. 3 120 2.90" (73.6mm) .880" (22.3mm) .75" x .75" (19 x 19mm) .56 3.60 4 90 5 72 6 60 8 45 9 40 10 36 12 30 Optical Polygon Specifications Accuracy Grade Target Area Flatness* Accuracy of Calibration (Uncertainty) Maximum Deviation of Faces from Nominal 3-12 Reference: 0 4 µin. (.10 µm) ±1.0 sec. ±1.0 sec. Calibration: 1 ±2.0 sec. * Excludes .020" (0.5mm) from edges. All sizes: Flatness and parallelism – top and bottom – .00005"; maximum pyramidal error ±15 seconds. Fused Quartz Optical Flats, Accuracy Grades Reference Grade 1 µin. (.03 µm) Master Grade 2 µin. (.05 µm) Working Grade 4 µin. (.10 µm) Fused Quartz Optical Flats, Standard Sizes* 1 x 1/2" (25 x 12.7mm) 3 x 11/16" (75 x 17.5mm) 5 x 7/8" (125 x 22mm) 2 x 5/8" (50 x 16mm) 4 x 3/4" (100 x 19mm) 6 x 1" (150 x 25mm) * Dimensions shown in millimeters are approximate. Larger sizes available on special order. Optical flats are made to U.S. Federal Specifications GG-O-635. Certificate of Calibration available at extra cost. Accuracy of Calibration (uncertainty) 3µin. (0.08µm). Optical Polygon Fused Quartz Opticla Flat 404 S t arrett -W ebber G age B locks