Monday, 10 September 2018

NEPHLOMETRY and TURBIDIMETRY

WONDERFUL DISCUSSION WITH SHRI JKP SIR,

NEPHELOMETRY    ANDTURBIDIMETRY
INTRODUCTION• When electromagnetic radiation (light) strikes a  particle in solution, some of the light will be  absorbed ...

THEORY  Scattered light may be measured by• Turbidimetry• Nephelometry• In turbidimetry, the intensity of light transmitte...




• Turbidometric measurements are made at 180o  from the incident light beam.• In Nephelometry, the intensity of the scatte...


• The two techniques differs only in the manner of  measuring the scattered radiation.



• Turbidity can be measured on most routine  analysers by a spectrophotometer (absorbed light)         • Reduced sensitivi...

• Light scattering is the physical phenomenon  resulting from the interaction of light with a  particles in solution.  Dep...

Tyndall Effect• Scattering of light- by particles in a colloid or  suspension.• the longer-wavelength light is more transm...


Light Scattering Phenomenon• The blue color of the sky and the red color of the  sun at sunset result from scattering of l...

• NEPHELOMETRY• ↓ concentration, uniform scattering, intensity of  scatted light proportional to conc. measured at 900    ...
Turbidimetry                          ↨                   Colorimetry• Measurement of the intensity of light transmitted  ...
COLORIMETER                    TURBIDIMETERSimilarity:                    Similarity: transmitted light measured   trans...

FLOURIMETRY                       NEPHELOMETRYSimilarity:                       Similarity: Emergent radiation           ...


CHOICE OF THE METHOD• depends upon the amount of light scattered by  suspended particles present in solution.• TURBIDIMETR...

INSTRUMENTATION• The basic instrument contains• Light Source:Tungsten lamp,  White light - nephelometers• Filters - Turbid...

• CELLS• cylindrical cells - flat faces to minimize reflections &  multiple scatterings

FACTORS AFFECTING MEASUREMENTS• The amount of radiation removed or deviated from  the primary radiation beam depends on th...





•   Nephelometry:•   Is = Ks Io C•   Is = scattered intensity•   Ks= empirical constant•   Io = Incident intensity• c = co...
2. Effect of Particle Size on Scattering• Size and the shape of the particles responsible for   the scattering.• Because m...
• Turbidimetry-Practical Considerations• Selecting λ: Important. It is necessary to avoid  radiation that is absorbed by t...

APPLICATIONS1. Analysis of water   clarity, conc. of ions2. Determination of CO23. Determination of inorganic substances  ...


6. Miscellaneous   Water treatment plants, sewage work, refineries, paper   industry7. Atmospheric pollution   smokes & fo...












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