A method and apparatus for measuring birefringent particles is provided comprising
a source lamp, a grating, a first polarizer having a first transmission axis, a
sample cell and a second polarizer having a second polarization axis. The second
polarizer has a second polarization axis that is set to be perpendicular to the
first polarization axis, and thereby blocks linearly polarized light with the orientation
of the beam of light passing through the first polarizer. The beam of light passing
through the second polarizer is measured using a detector.