Patent ID: 7336358

Claim:
A method for evaluating one or more materials in accordance with size of particles therein, comprising: evaluating a first plurality of spectra of light reflected from a first group of particles by varying distance between a first light conductor for conducting light to said particles and a second light conductor for conducting light from said particles, and analyzing spectra of light received from said first group of particles at a plurality of distances between said first light conductor and said second light conductor; evaluating a second plurality of spectra of light reflected from a second group of particles by varying distance between said first light conductor and said second light conductor, and analyzing spectra of light received from said second group of particles at a plurality of distances between said first light conductor and said second light conductor; comparing results of said evaluating of said first group with results of said evaluating of said second group; and providing an indication of a state of said material when said comparing produces a predetermined comparison result.