The light scattering method measures turbidity by the extent to which light is obstructed and scatters when it passes through water. Suspended solids in water obstruct or scatter light. When light is passed through from one side of the water to be measured, light weakened by obstruction (transmitted light S) reaches the opposite side, and scattered light (scattered light T) reaches the sides. S/T derived from the light is proportional to the concentration of suspended solids, so turbidity can be measured with S/T. This measurement method is less susceptible to external factors such as fluctuations in light source intensity, liquid color, or dirt on light-transmitting windows.
Field-installation type turbidity meter