HP 5528A

Model SS28A
Squareness Mea s urement s (In A Horizontal Plane)
12 -8
Figure 12-4. M ounting of Oplical Square
5. Po s ition the Straightness Int erferometer relative to the Optical Square.
• Bring the Interferometer close enough to the Opti ca l Square to line up the
I nterferometer with the ce nter of the Optical Square's slot. Be sure it is centered in
both axes i up-and-down , and side-to-side).
• This is a very important step. If the Op ti cs are not physically lined up at this point,
aligning
along the travel axis will be impossible.
•
Be sure this establishes the " near end of travel", I.e., that any later movement of the
machine can only incr ease the distan ce between the Opti cs.