Enhancement of Linearity of Optical Density

The value of absorption of light energy is dependent on the number of molecules present in absorbing material and the thickness of the medium. Thus, intensity of light energy leaving the absorbing substance is used as an indication of concentration of that particular substance. If the thickness i.e. path length of the light energy in the sample holder, normally the flow through cell and intensity of incident light energy are kept constant, then the amount of light energy transmitted out of the absorbing media is proportional to the concentration of the media. Usually the transmitted light energy and concentration are related to Lambert’s and Beer’s law of photometry. However, the Lambert’s and Beer’s law of photometry is valid or linear up to the optical density of 2.0. In the presented work, it is proposed to facilitate the Lambert’s and Beer’s law of photometry to go beyond optical density of 2.0 and measure the concentrations of sample at high value.