HP 5528A User Manual page 219

Model 5526A
Squ3reness Measurements (I n A Hori zo ntal Plane)
12-12
y
l(z
X
STRAI GHTNESS REFLE CTOR
STRAI GHTNESS
INT ERFEROM ETER
STRAI GHTNESS
RETAOREFLE CTOR
.,.--OPTICAL
SQUAR E
~
Figure 12-7. Squarelless Measuremeflf
on
a Horizon/al Z-axis
7. Make sure the Opti ca l Square is fairly square relative to the ma chine and to the Interfe r-
omete r, and then secure it to the ma chine.
8.
Switch to the large aperture on the la ser Head's ex it port, and set the turret ring to " OTH ER ".
(Whc r, aligning your set up it is good pra cti ce to work with the strongest possib le beam,
which this setting provides.)
9. VisuaJJy align the laser Head as well as you can parallel to the ma chine's table, and position it
to have th e beam go over the Optical Square and through the Relroreflcctor's Alignment
ring . (See Figure 12-8.)
NOTE
Once you become familiar with alignment principles, you may
want to do this using " A UTOREFlECTION " techniqu es .
10. Orient th e In terfero meter bezel's scribed line 90 de8rees to the Optica l Square's slotted
opening. Two dots should appear on the Optical Square's front surfa ce unless the Optics are
quite close together.
If
so. ioser! a piece of paper across the front of th e Optical Square to see
the d o ts.
11. Further adjust the Optical Sq uare's position , if necessa ry, until the two dots are directly in line
with the scribed line at the cen ter of the Optical Square's slot and are also symmetrical within
its opening. (See Figure 12-5.)