VISIBLE AND NEAR INFRARED BACKSCATTERING SPECTROSCOPY FOR SIZING SPHERICAL MICROPARTICLES

L. B. SCAFFARDI; F. VIDELA; D. C. SCHINCA

APPLIED OPTICS

OSA

Lugar: Washington; Año: 2007 vol. 46 p. 67 - 75

0003-6935

Scattering is a useful tool for the determination of particle size in solution. Particularly, spectroscopic analysis of backscattering render the possibility of a simplified experimental setup and a direct data processing using Mie theory. This work shows that a simple endoscopic technique based on NIR backscattering spectroscopy together with the development of a corresponding algorithm based on Fourier Transform and Mie Theory, is a powerful tool for sizing microparticles in the range from 25 to 60 mm diameter, with a coarse mean error of about 3 mm.  Cross-correlation between experimental and theoretical spectra allows to reduce the mean error to about 1 mm. These results extend previous work restricted to visible backscattering spectroscopy applied for sizing microparticles in the range between 1 to 24 mm of diameter.  This technique could be the basis for the construction of a portable and practical instrument.