Machinery's Handbook, 31st Edition
CALIBRATION OF REFERENCE SETTING STANDARDS 787 Calibration of Reference Setting Standards Preliminary Operations 1) Review and become familiar with the entire calibration procedure before beginning the calibration process. Ensure familiarity with setup and operation of all standards involved in the procedure. 2) Always observe safe operating methods for all standards, whether electrical, physical, mechanical, or dimensional; exercise caution in handling of all precision standards. 3) Ensure measuring surfaces are clean and free of nicks and burrs that could affect the accuracy of the measurements. Observe the rod ends for any possible damage and observe the unit for bending or any condition that may affect the parallelism of the measuring surfaces. If any condition of concern is observed, light stoning with a hard Arkansas stone can be used with care to remove any nicks or burrs. 4) Bring the UUT (Unit Under Test) into the controlled environment 12 hours prior to beginning the calibration process. Allow all standards and UUT to stabilize to common temperature. Typical Equipment Requirements Name Minimum Use Specifications Recommended Measurement Standards Alternative
Universal Horizontal Measuring Machine
Range: 0 to 24 inch Accuracy: ± 30 m in Range: 0.050 to 4.000 inch 2.0 to 450 mm
Mahr-Federal 828
Mahr Linear 1200
Starrett Webber SC 81.A1 Starrett Webber S2C 88.MA1 Starrett Webber SS 8.A1X Starrett Webber SS 8. MA1X Starrett DIGI-CHECK II DHG 49
Mitutoyo 516-401-16 Mitutoyo 516-442-10
Gage Block Set
Gage Block Set (Long Block) Height Transfer Gage Electronic Height Indicator
5 to 84 inch 125 to 500 mm
Mitutoyo 516-762-16 Mitutoyo 516-753-10 Mitutoyo Universal Height Master Model 515-513 Mitutoyo Analog MU-Checker 519-420A with 519-327 Lever Head
Range: 1 to 48 inch
Range: ± 0.032 in. (min.) Accuracy: ± 50 m in ± 0.001 mm
Mahr Federal Model 832 w/ LVDT
Precision V-Block Range: Adequate to support UUT in vertical position.
Accuracy: Calibrated to specifications of GGG-V-191D (or equivalent) Surface Plate Mitutoyo 517-808 Reference Setting Standard Calibration Process.— Note: Special care should be taken to clean and apply a protective coating when handling gage blocks or other precision stan dards with bare hands. The use of clean cotton or vinyl gloves is recommended to prevent corrosive oils from damaging precision surfaces. The temperature of the calibration environment must be maintained at approximately 23° C (73.4° F) with a fluctuation of no more than ± 0.5° C ( ± 0.9 °F) per hour. Range: 24 x 36 Accuracy: Grade A Starrett Crystal Pink EDP 80655 1) Calibration of UUT up to 4.000 inch shall be performed on the horizontal measuring machine. All other measurements shall be performed in the vertical position as described in this procedure. 2) Select gage block equal to the size of the UUT. Wringing blocks together to achieve the desired size should be avoided if possible as this method increases possibility of error. 3) Insert the gage block between the anvil and spindle of the universal horizontal measuring machine resting against the anvil. Bring the head (spindle) into contact with
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