How do I convert %R to Extinction in UVvis spectrum?

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Johannes Kiefer

%R + %T + %A = 100% (R= reflection, T= transmission, A= absorption)

extinction = -log(T)

Ranjit De

Thank you both for the nice explanations. Since my work is in reflection mode (%R), the rule %R+%T+%A=100% and Extingtion = -log(T) will be greatly helpful. Thank you again.

Adela E. Croce

If you only measure %R, you cannot determine the extinction: you have to measure %T as well.

Please have a look into Photochemistry, J. G. Calvert and J. N. Pitts, jr., John Wiley & Sons, Inc., New York-London-Sydney 1966.

Thank you Dr. Croce.

T. H. Al-Noor

https://www.agilent.com/.../library/.../G1115-90041_UnderstandingG...