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Resolution
The least significant digit to which a physical quantity can be read. High
resolution does not imply high accuracy.
Skew
Misalignment of the part with respect to the X and Y axes. This will create
measurement errors unless the part is repositioned or the deskew feature of
the metrology software redefines the measurement axes.
Squareness
The alignment of the camera relative to the motion of the metrology stage.
If the camera is misaligned (out of square), the image will drift diagonally
as the stage position is moved along one axis.
Substage Lighting
Illumination from below the stage glass. Used for profile or silhouette video
edge measurements.
Telecentric
A lens property where the light from the object stays parallel to the optical
axis across the entire field of view, thereby eliminating optical distortion.
This can only happen if the entrance aperture of the lens is larger than the
field of view, requiring a large and expensive lens.
Object Telecentric lens CCD detector
TFE
Tetrafluoroethylene, a self-lubricating polymer coating used on precision
lead screws.
VED
Video Edge Detection, a system where a video camera and digital image
processing are used to detect edges and other features.
Zoom Optics
Optics which can change magnification based on a user selection. Zoom
control can be manual or motorized, depending on the metrology system.