Beer’s law is given by the fraction (I/I₀) of x-rays transmitted through a thickness x,

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where,
         x -- The thickness of a material.
         ρ -- The atomic density of the material.
         μ/ρ -- The mass absorption coefficient.

In EDS measurements, the path of X-ray absorption mainly depends on two factors:
         i) The depth of x-ray generation in the specimen.
         ii) The take-off angle.