HP 5501A Operating And Service Manual page 39

The laser head may be used upside down or o n its side but must be fastened using the
3
feet.
3r, if the feet are removed, use only the 8-32 UNC tapped holes under the bases (Figure 2-8).
a. Allow 50 m m (2 inches) clearance around the laser head for easy service.
b. To maintain good pointing stability it i s good practice to use kinematic mounting
principles. For example, a 10 arcsecond drift error i n the pointing stability of the laser
head causes a beam displacement of over 0.01 inch at the receiver if the cube-corner
i s at a distance of 100 feet.
135
mm
7 1 1 mm
'
53)
(028)
I
25
4
( 1 0)
-T
i
111.8 rnm
4, 132.1 rnm
"
6
(5.2)
58.4 mm
(2.3)
16.5 mm
-
105.2 rnm
NOTE: LEAVE ONE INCH CLEARANCE ON
-
SIDES AND TOP OF UNIT.
THREE INCHES ON FRONT AND
BACK FOR SERVICE.
Figure 2-8. 550lA Laser Transducer Dimensions