Explain Principle of Turbidimetry and Nephelometry.

When the light is incident on a solution containing suspended particles. The fraction of the light it scattered and the remaining is transmitted. If we know the intensity of transmitted radiations then we can have quantitative analysis of sample. That phenomenon is known as Turbidimetry.

But if we know intensity of scattered radiations then we can also have quantitative analysis. This phenomenon is Known as Nephelometry.

The scattered radiation is always observed at the angle of either 45°, 90° or at 135° to the incident light.

Turbidimetry and Nephelometry involve the use of Very dilute Solutions Therefore suspended particles must have negligible solubility. Such particles scatter the light considerably and therefore great care must he taken that samples are free of dust particles. The particles of the disperse phase must be very fine so that they do not settle down rapidly.