- Autocollimator (AC) borrowed from Mike Smith (Nippon Kogaku model 305, phi=2.76", 67.8mm)
- Retroreflector (corner cube)
- Two V grooves borrowed from the 40m
- Autocollimator calibration
o Install the AC on a optical table
o Locate the corner cube in front of the AC.
o Adjust the focus of the AC so that the reflected reticle pattern can be seen.
o If the retroreflection and the AC are perfect, the reference reticle pattern will match with the reflected reticle pattern.
o Measure the deviation of the reflected reticle from the center.
o Rotate the retroreflector by 90 deg. Measure the deviation again.
o Repeat the process until total four coordinates are obtained.
o Analysis of the data separates two types of the error:
The average of these four coordinates gives the systematic error of the AC itself.
The vector from the center of the circle corresponds to the error of the retroreflector.
- Wedge angle measurement
To be continued