Steven K Richter

US Patent:

7187441, Mar 6, 2007

Filed:

Nov 7, 1997

Appl. No.:

09/297895

Inventors:

Joseph Pierce - Appleton WI, US
Steven Richter - Brunswick GA, US
Rajesh Shinde - West Lafayette IN, US
Ganesh Balgi - Lebanon IN, US
Jeffrey Kao - Lake Jackson TX, US
Huabei Jiang - Clemson SC, US

Assignee:

The Texas A&M University System - College Station TX

International Classification:

G01N 21/51

US Classification:

356336, 356342

Abstract:

A system () and method are disclosed for the self-calibrating, on-line determination of size distribution f(x) and volume fraction φ of a number of particles (P) dispersed in a medium () by detecting one or more propagation characteristics of multiply scattered light from the particles (P). The multiply scattered light is re-emitted in response to exposure to a light source () configured to provide light at selected wavelengths. The determination includes calculating the isotropic scattering and absorption coefficients for the particles (P) by comparing the incident and detected light to determine a measurement corresponding to the propagation time through the scattering medium (), and iteratively estimating the size distribution f(x) and volume fraction φ as a function of the coefficients for each of the wavelengths. An estimation approach based on an expected form of the distribution and the mass of the particles is also disclosed. Furthermore, techniques to determine a particle structure factor indicative of particle-to-particle interactions which vary with particle concentration and influence light scattering at high concentrations is disclosed.