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{ RCSid $Id$ } |
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{ |
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These formulas compute the index of refraction and |
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normal transmission for a pane of glass given the |
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measured normal transmittance and reflectance values, |
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Tn and Rn, respectively. |
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|
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These formulas are approximate -- the exact solution |
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involves a quartic equation and seemed more trouble |
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than it was worth. If you know the index of refraction, |
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you are better off with the formula in trans.cal. |
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|
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Oct. 2002 Greg Ward |
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} |
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{ formula for normal transmission } |
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tn = Tn / (1 - Rn); |
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F = Rn / (1 + tn*tn); |
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n = (1 + sqrt(F)) / (1 - sqrt(F)); |
