Measurement Type Selection - GE XL Vu+ VideoProbe Operating Manual

Chapter 6. Measurement

6.4.4 Measurement Type Selection

Table 2 below summarizes the pros and cons for each measurement type.
Measurement
Type
Stereo
Shadow
98
Table 2: Measurement Type Comparisons
Advantages
Over comparison
measurements:
•
More accurate
•
No known reference is
needed
•
Measure depth
•
Surface does not need to be
perpendicular to the probe
view.
Over shadow measurements:
•
The surface does not need
to be perpendicular to the
probe view.
Over comparison
measurements:
•
More accurate
•
No known reference is
needed
•
Measure depth
•
Measure distance along a
skew
Over stereo measurements:
•
Height and depth contours
are more discernible
•
Measure along smooth,
straight lines
Disadvantages
The system may be unable to
position matching cursors
accurately with any of these
conditions in the measurement
area:
•
Insufficient detail
•
Repeating patterns
•
Glare
•
Smooth, straight lines to
measure along
In some cases, the problem can
be eliminated by repositioning
the probe tip and adjusting the
brightness. Otherwise, try
shadow measurement.
•
Measurement surface must
be nearly perpendicular to
the probe view for accurate
measurement.
•
The shadow is sometimes
difficult to see.
•
Cannot always place the
shadow in the desired
location.
XL Vu+™ VideoProbe® Operating Manual