Dear Mr Yvl, where did you find this equation? e is the Neper number. Its value is 2.7182818. Hence, log e is equal 0.4342945. I think that KI are two constants, therefore A = 0.4343KI. But I never saw this equation. In atomic absorption spectrometry, the system follow Beer law. What is meaning of k and I? Please, tell us in which reference is cited this equation.

thank you

This is a reference. Equation exist in the page 17

http://sci-lib.org/books_1/E/ebdon.pdf

Thank you Mr Yvl. I read the pdf that sent for us.The equation is the Beer law explained to atomic absorbtion. As the intensity of transmitted light (I) is a exponential relationship we can write:

Please, see the file in attachment. This editor does not allow to write a mathematical equation.

I hope to have helped.

Thank you very much

How did you get the number 2.7182818?

The e number is similar to pi number. Neper number or Euler's number is a limit (1+1/n) elevated to n when n approaches to infinity. See the link: http://en.wikipedia.org/wiki/Euler%27s_number. I think that it explain better than me.

Thank you

I agree with Julio Cesar Bastos Fernandes.