UV Spectroscopy - Absorbance vs transmission

[Moogie]

Hi

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

thanks

 

[Rajini]

Hello,
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.

 

[Andy Resnick]

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

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).