GE Everest XLG3 VideoProbe, Руководство по эксплуатации

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User Manual Chapter 7 Measuring Features and Defects 113
Troubleshooting Measurements
Help: I’m Getting Inaccurate 3D Phase or Stereo or Shadow Measurements
Move the probe tip as close as possible to the target, maximizing magnification.
After capturing an image, verify that the tip attached to the probe matches the tip that is
selected in the software. Press
. Select Measure > Tip (For 3D phase measurements,
the tip serial number is shown in the corner of the measurement screen).
Verify that you have selected the correct type of measurement. Press . Select
Measure > Phase or Shadow or Stereo > measurement type.
Verify that the optical tip is threaded on to the probe head securely.
Measure the target contained in the verification block to ensure that no tip damage has
occurred. See
“Verifying Measurement Tips” on page 112.
Help: I’m Getting Inaccurate 3D Phase Measurements
Be sure to hold the probe still for approximately one second during the surface scan. Do
not move the probe until after the “processing” message appears on-screen.
Reposition the probe tip until the range finder bar pattern on the Live screen shows the
maximum possible number of green bars. It is acceptable to be slightly out of focus for
very small defects.
Make sure the gratings are clean.
Try a non-perpendicular view, such as 30-45°. This often significantly decreases the noise
level in the data, especially for surfaces that are shiny or have a speckled appearance.
Check with verification block. Check point cloud view for excessive waviness or ripple,
which would indicate dirt or oil contamination or tip damage.