Surface Plate Information


We Have Resurfaced Granite Surface Plates from California to North Carolina to Mexico

The  Dark areas are as  result of normal use. Note the wear areas are on both sides of the plate.  This  is  good  and  indicates that  the Inspector is using different areas to prevent major wear in one area.  These wear areas are only a few tenth's, ( .0001's ),  however if all of this wear was to occur in one  place,  it would  be  thousandths,  ( .001's)  of  an inch.


After lapping, all of the plates are inspected using a repeat-o-meter. This  simulates an indicator  on a height stand  but uses a  .000010 resolution indicator  to  determine the ability  to  duplicate a  reading anywhere on this surface.   This is only  one  half  of  the  calibration procedure  due  to the  fact  that a repeat-o-meter can not determine flatness, only repeatability.


Close the deal

An Autocollimator is used to measure the flatness of the surface plate. This instrument uses collimated  light that is bounced off of a mirror mounted on a  sled  selected  for  its  pad spacing. Sleds work like sine bars and convert 

arc. seconds into millionths of an inch, rise or fall when moved in increments  equal to the pad spacing. This data is assembled into an actual contour plot of the surface plate and calculates the  overall  flatness.

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