Unit of turbidity is calculated by ?

Ans: A. Measuring the scattered light at 90degIT is involved with measuring the amount of transmitted light (and calculating the absorbed light) by paicles in suspension to determine the concentration of the substance in question.Amount of absorbed light, and therefore, concentration is dependent on, Number of paicles, Size of paicleS, Measurements are made using light spectrophotometersTurbidity Unit is the International Standard Unit. Both measure the light scattered at 90o. NTU uses white light with peak spectral output at 400 to 680nm as light source. FTU uses Infrared monochromatic light with peak output at 780 to 900nm as light source.