RECOMMENDATIONS 
The acrylic plastic windows supplied by NCEL to EDU should be 
periodically inspected for presence of cracks. Upon visual discovery 
of a crack in the window it should be replaced. If properly installed 
and cleaned only with cleaning solutions approved for acrylic plastic, 
the minimum crack-free life of the windows should be at least 1000 
chamber pressurizations to 450 psi. 
ACKNOWLEDGEMENT 
The setting up of test equipment and supervision of tests was 
performed by Mr. K. O. Gray, General Engineer. His assistance in the 
accomplishment of the tests is appreciated. 
WZ 
