Instrumentation for Turbidimetry and Nephelometry

Turbidimetry and nephelometry are two techniques based on the elastic scattering of radiation by a suspension of colloidal particles: (a) in turbidimetry the detector is placed in line with the source and the decrease in the radiation’s transmitted power is measured.; (b) in nephelometry scattered radiation is measured at an angle of 90^o to the source. The similarity of turbidimetry to the measurement of absorbance and of nephelometry to the measurement of fluorescence is evident in these instrumental designs . In fact, turbidity can be measured using a UV/Vis spectrophotometer and a spectrofluorimeter is suitable for nephelometry.