Nephelometry is based on the principle of

Light attenuated in intensity by scattering [Ref: nephelonzetyy and turbidimetry methods are based on the phenomenon whereby light, passing through a medium with dispersed paicles of a different refractive index from that of the medium, is attenuated in intensity by scattering.In turbidimetry, the intensity of light transmitted through the medium, the unscattered light, is measured.In nephelometry, the intensity of the scattered light is measured, usually, but not necessarily, at right angles to the incident light beam.The intensity of the scattered radiation depends on several factors, including the wavelength of the incident radiation and the paicle size; however, in a given system, the scattering is directly propoional to the concentration of the paiculate matter.