Phase Measurements - GE Everest XLG3 VideoProbe Operating Manual

User Manual
3D Phase Measurements
3D Phase Measurement optical tips and probe capture a three-dimensional surface scan
of the object. Measurements are then made directly on the surface and displayed on the
image. Preliminary steps of matching cursors or marking shadow lines are not necessary.
Taking 3D Phase Measurements
As with other measurement types, PhaseProbe accuracy improves as tip-to-target
distance is reduced. The range finder bar icon can be used to gauge the suitability of the
current tip-to-target distance for a given measurement. When the surface is too far for
measurement, a single red bar is shown, and measurement should not be attempted. As
the tip is moved closer to the surface, more bars are illuminated, and the color gradually
transitions to green. Large length measurements may be performed with few bars
illuminated, while still achieving good accuracy. In general, best accuracy is achieved by
getting as close to the surface as possible.
Accuracy is generally best when viewing a surface from approximately a 45° angle,
especially on surfaces that are shiny or have a speckled appearance.
When measuring surfaces with steps or long, deep features, a side view tip will give better
results if the feature or step is horizontal. A front view tip will give better results if the
feature or step is vertical. This is due to the LED orientations in the tips.
To Take a 3D Phase Measurement
1. Attach either a forward view or side view 3D Phase Measurement optical tip to the
probe. Each measurement tip must be factory calibrated to a particular probe, and
may be calibrated to more than one probe.
2. Verify that the XLG3 system has automatically identified the 3D Phase Measurement
optical tip.
3. Initiate the Image Capture sequence in the following section.
Chapter 7 Measuring Features and Defects 91