Beer-Lambert law

A demonstration of the Beer–Lambert law: green laser light in a solution of Rhodamine 6B. The beam becomes weaker as it passes through solution.

The Beer–Lambert law, also known as Beer's law, the Lambert–Beer law, or the Beer–Lambert–Bouguer law is a scientific law. It deals with the absorption of light moving through a material. The law is commonly used with chemical analysis measurements. It is used in understanding attenuation in physical optics, for photons, or neutrons. In mathematical physics, this law is a solution of the BGK equation.