Comparison Measurement - GE XL VU Operating Manual

Measurement

Comparison Measurement

Comparison measurements are to be taken when an item in the image
has a known dimension and that item's dimension is used as a reference
to measure other items.
Measurement Advantages
Type
Stereo
Over comparison
measurements:
• More accurate
• No known reference
is needed
• Measure depth
• Surface does
not need to be
perpendicular to the
prove view.
• The surface does
not need to be
perpendicular to the
probe view.
Comparison • Use standard optical
tip
• Measure with tip
further away
• Measure large objects
• Check the
approximate size of
many items quickly
100
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
• Less accurate than
shadow or stereo
measurement
• Known references
may not be present
and may be difficult
to deliver to the
measurement site
• Measurement surface
must be nearly
perpendicular to
the probe view for
accurate results
XL Go+™ VideoProbe
®