A new measurement method of profile tolerance for the LAMOST focal plane

Zengxiang Zhou; Yi Jin; Chao Zhai; Xiaozheng Xing

doi:10.1117/12.787054

11 July 2008 A new measurement method of profile tolerance for the LAMOST focal plane

Zengxiang Zhou, Yi Jin, Chao Zhai, Xiaozheng Xing

Proceedings Volume 7014, Ground-based and Airborne Instrumentation for Astronomy II; 701440 (2008) https://doi.org/10.1117/12.787054
Event: SPIE Astronomical Telescopes + Instrumentation, 2008, Marseille, France

Abstract

There were a few methods taken in the profile tolerance measurement of the LAMOST Focal Plane Plate. One of the methods was to use CMM (Coordinate Measurement Machine) to measure the points on the small Focal Plane Plate and calculate the points whether or not in the tolerance zone. In this process there are some small shortcomings. The measuring point positions on the Focal Plane Plate are not the actual installation location of the optical fiber positioning system. In order to eliminate these principle errors, a measuring mandrel is inserted into the unit-holes, and the precision for the mandrel with the hole is controlled in the high level. Then measure the center of the precise target ball which is placed on the measuring mandrel by CMM. At last, fit a sphere surface with the measuring center points of the target ball and analyze the profile tolerance of the Focal Plane Plate. This process will be more in line with the actual installation location of the optical fiber positioning system. When use this method to judge the profile tolerance can provide the reference date for maintaining the ultra error unit-holes on the Focal Plane Plate. But when insert the measuring mandrel into the unit hole, there are manufacturing errors in the measuring mandrel, target ball and assembly errors. All these errors will bring the influence in the measurement. In the paper, an impact evaluation assesses the intermediate process with all these errors through experiments. And the experiment results show that there are little influence when use the target ball and the measuring mandrel in the measurement of the profile tolerance. Instead, there are more advantages than many past use of measuring methods.

Citation Download Citation

Zengxiang Zhou, Yi Jin, Chao Zhai, and Xiaozheng Xing "A new measurement method of profile tolerance for the LAMOST focal plane", Proc. SPIE 7014, Ground-based and Airborne Instrumentation for Astronomy II, 701440 (11 July 2008); https://doi.org/10.1117/12.787054

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available