Nephelometry - method for the quantitative analysis, based on measurement of intensity of the light scattered by the particles of turbid media. Turbid media form of suspensions, emulsions, colloidal solutions.
Measurement of the intensity of scattered light (the degree of turbidity) is done usually by means of turbidity meters. Light dispersion is observed in the direction perpendicular to the light flow through the investigated liquid. In certain conditions, the intensity of scattering light is proportional to the number of suspended particles, and therefore their total mass per unit volume of turbid media. The method of analysis based on the measurement of attenuation of the intensity of the light flux passing through a dark environment, called turbidimetry.
Nephelometry and turbidimetry widely used for analysis of water, some food, drugs and fluids and tissues of organisms.