Thread: Window glass
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Old 05-01-2019, 08:56 AM   #7
jhowes
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Join Date: Jul 2010
Location: upstate NY near Mass border
Posts: 789
Default Re: Window glass

The use of the polarized films, or sometimes glass rings, is used in industry to look for stress in the glass being examined. The stress will disorenate the lines of polarized light coming through the glass being examined so that the 90 degree polarized lens on the opposite side of the glass cannot shut it out. Hence some amount of light will come through the second lenze.
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