Re: Beer-Lambert Law

["Bob Sciamanda" <trebor@velocity.net>]

Herb,
        Beer's law is routinely used in spectrophotometric analysis (to
measure chemical concentrations) in the form:

I(x,c) = Io*exp(-kcx)  where I = beam intensity, x = thickness of sample,
c = concentration of absorbing species whose absorptivity is given by k.

In this context, instruments usually display the value of the  Absorbance
= Ln(Io/I)  = kcx

(Actually, I think chemical types more often use the base 10 [common
logs] rather than e [natural logs]  in these definitions)

Hope this helps.

Bob Sciamanda
Physics, Edinboro Univ of PA (ret)
trebor@velocity.net
http://www.velocity.net/~trebor

-----Original Message-----
From: Herbert H. Gottlieb <herbgottlieb@juno.com>
To: phys-l@atlantis.uwf.edu <phys-l@atlantis.uwf.edu>
Cc: phys-l@atlantis.uwf.edu <phys-l@atlantis.uwf.edu>
Date: Monday, June 15, 1998 10:19 PM
Subject: Beer-Lambert Law


> In Optics, the Beer Lambert Law gives the relation between the thickness
> of a color filter and the attenustion of transmitted light.
>
> Is anyone familiar with the equations and application of this
> Law in modern technology?
>
> Herb Gottlieb from New York City
> (Where our ignorance of a law is not an acceptable excuse)
>
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