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UV Spectroscopy - Absorbance vs transmission

  1. Jun 18, 2010 #1

    In UV spectrscopy, is the definition of absorbance (A = ecl) derived from the definition of transmission (T = It/Io) where It is the transmitted light and Io is the incident light, or is the definition of transmission defined from absorbance.

    Also A = -log(T) and T = 10^-A = 10-ecl.

    It looks to me as though transmission is a physical quantity based on recorded data and then the definition of absorbance is based on this

  2. jcsd
  3. Jun 19, 2010 #2
    In UV both transmission and absorption occurs..
    You transmits the light and the sample absorbs the light..
    May be you are familiar with Lambert-Beer law.
  4. Jun 19, 2010 #3

    Andy Resnick

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    That's essentially correct; there is a slight difference in that absorbance can be expressed in terms that do not depend on the thickness of the sample (e.g. e*c, if I understand what you wrote).
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