1. Acceptance Test for Thin Al Windows Presented by: Michael Wojcik Feb 22nd 2007

2. Purpose Creation of an acceptance test that is: Non-destructive Simple Repeatable The measurable wanted is the thickness of window These Al windows will be used in the LH2 Absorber apparatus.

3. Design of Al Window R1=140.0mm R2=142.2mm R3=95.36mm R4=102.1mm Win Dia.=210mm

4. Probe Setup

5. CMM Touch Probe Specs: Trigger Force < 10 mg ~ 0.1 mN Measuring Error ~ 1 µm Mounted on an table with a robotic arm.

6. Measurement in a 1.Create a coordinate system using spheres attached to the window 2.Measure points on the concave side and convex side 3.Take the difference in the measurements to find the thickness Ewa Skup and Mike Roman at Fermilab are conducting the measurements So we can expect to get something like…

7. Measurement Should Resemble Touch Probe Al Window Tangential axis The probe touches one side then the other side on the axis tangential to the window

8. First Set of Data

9. The Second Set of Measurements

10. A Zero Problem There is a average of 10 micron difference of thickness at center of window. Why?

11. The Problem Diameter of Sphere

12. Third Set of Data

14. Window from RAL

15. Sources of Error ~1 µm from probe Touch probe difficulties Expected Touch Actual Touch Wrong touch location Wrong touch Axis Expected Touch Actual Touch

16. In the Future Take another run on the RAL Window and compare to the measurements Why is measured thickness > design? And why is meas. Sphere diameter > design? Implement more statistical analysis More analysis on Window 2 Finalize the measuring procedure with the actual MICE windows