Investigation On Sizing Of Particle Potpourri And Determining Refractive Index Of Solution

Optical means in metrology territory outperforms others in numerous merits such as not-contact with the probed, high precision, non-electrical interrogation, excellent reproducibility and great compactness. It is, henceforth, burgeoning in applications in industry, agriculture and people's daily life. The presented dissertation focuses on sizing particulate ensemble by fully employing Gustav Mie's theory of light scattering, and tackling the problem of extracting the refractive index of solution with high precision by employing Fabry-Perot interferometry. The research work of this thesis encapsulates the following aspects:I. In Particle Sizing:1. We built, with our hands, a set-up of particle sizer with an all-solid-state Nd:YAG laser replacing the more conventional large-frame He-He laser, and a linear CCD array instead of the traditional concentric semi-ring shaped photoelectric detector. The robustness of this sizing system and the accompanying mathematical algorithm was tested by successfully retrieving the diameters of the standard monodisperse potpourri of polystyrene beads provided by the State Center for Standard Substances.2. For the first time, the refractive index of these beads was determined with fairly good precision. The measured value adds a non-trivial constant to the optics bank for quotations like in sizer calibration.3. Theoretically, we constructed a math model for sizing polydisperse particle system satisfying the well-celebrated R-R distribution within the realm of light scattering technique. Extensive numerical simulations were performed with PC computer. We studied, in the presence of random error, the influence of the variation of particle diameter distribution on the fitting precision which was universal to all static light scattering based particle sizers.4. The feasibility of our instrument was corroborated by determining the diameter distribution of domestic humidifier-generated aqueous spray. The obtained value was in good agreement with the data-sheets of all humidifier vendors.