Beer-Lambert Law

Definition: Beer-Lambert Law is the linear relationship between absorbance of electromagnetic radiation and the concentration of an absorber in the medium through which the radiation travels. The general Beer-Lambert Law would be: where A is the measured absorbance (i.e. -log_{10}frac{I}{I_0}, I is the intensity of the measured light and I_0 is the intensity of the incident light), epsilon_{lambda} is the wavelength-dependent molar (decadic) absorption coefficient (formerly molar decadic extinction coefficient) with units of M^{-1}cm^{-1} , c is the concentration of the absorber (M^{-1}) and d is the pathlength of light (cm). Please note that the subscript lambda is often dropped with the understanding that the value for epsilon is for a specific wavelength.

Alternative definition:

Synonym: Beer-Lambert-Bouguer Law

References:

Related terms: modified Beer Lambert law, optical density, molar absorption coefficient  

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