Calibrating the corrector length on a Microscribe arm

PWI000036

Context

this document applies to :

  1. PowerINSPECT 1200
  2. PowerINSPECT 1300
  3. PowerINSPECT 1350
  4. PowerINSPECT 1355
  5. PowerINSPECT 2001
  6. PowerINSPECT 2200

 

Summary

When using a different probe on a Microscribe arm it is necessary
to give a probe diameter and a corrector length. 
The corrector length is the difference in length between the
supplied point probe and the new probe. 
It is calculated by comparing reported measurements immediately
before and after changing the probe.

Description

In PowerINSPECT select CMM- Parameters.
Change from point probe to custom probe.
Enter 0 for both diameter and length.
Go to Geometrics and choose a sphere to measure.  (You can use a hole if no sphere is available)

Take measurements around the sphere, or around a very small hole if no sphere is available.

This will produce an answer. Do not worry if the answer is incorrect- this is the reason for getting the corrector length!

Subtract the measured answer from the known sphere diameter plus the probe diameter.
e.g. probe diameter is 2mm, sphere is 50mm, the measurement is 68.6mm, giving
50 + 2 - 68.6  = -16.6mm. 

If using a little hole (diameter approximately equals 0) instead of a sphere with the same probe, the measurement might be
probe diameter is 2mm, sphere is 0mm, measurement is 18.6mm, giving
0 + 2 - 18.6 = -16.6mm)

Divide this measurement by two (-8.3mm in both of these cases) and enter this figure as the "Corrector"  Enter the probe diameter as the "Diameter." 

Measure the sphere again with these settings and the answer should be correct.  The probe is now corrected for diameter and length.