Agilent Technologies 5530 Reference Manual page 165

1
Alignment ring
2
Interferometer
3
Retroreflector
1
Two dots
Chapter 5 Straightness Measurements
Making Vertical Axis Straightness Measurements
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2
3
Figure 5-15. Alignment ring on the retroreflector
1
Figure 5-16. Initial position of the dots on the reflector
Measurements Reference Guide 5-21