A turbidimeter or sometimes called a turbidimeter (turbidity meter) is a common name for an instrument that measures turbidity. Measuring low-level turbidity requires an accurate measurement of the scattered light in water
Turbidity is the measure of the relative clarity of a liquid. It is an optical characteristic of water and is a measurement of the amount of light that is scattered by material in the water when a light is shined through the water sample. The higher the intensity of scattered light, the higher the turbidity.