TB 9-5220-212-40
(24) Compare midpoints of centerlines and diagonal lines. Midpoints will not be off 0
by more than 20 percent of the difference between highest and lowest points on plate or
0.000030 inch, whichever is greater.
(25) An estimate of uncertainty in the calibration is 3.0 micro inches/inch X length of
carriage used plus 1/2 the absolute sum (added without regard to sign) of the midpoints of
the 2 centerlines.
NOTE
A copy of surface-plate deviations is to accompany the surface
plate.
Figure 2. Sample Plot of Surface Plate Deviations.
b. Adjustments. No adjustments can be made.
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