Patent ID: 6177983
Filing Date: 2001-01-23
Classification: G01N

Abstract:
A method for producing measurements of specific key characteristic parameters of small particles suspended within a scattering medium, comprising the steps of:directing a beam of light into the scattering medium;detecting the Doppler-shifted components of light scattered by the movement of the suspended particles and the unscattered source light and generating a first signal representative of the power spectral density of the Doppler-shifted components and the unscattered source light;passing said first signal into a plurality of bandpass filters, each bandpass filter generating a second signal, the magnitude of which is representative of the power spectral density integrated over the bandpass for a specific key characteristic parameter;passing said first signal through a low pass filter to generate a third signal, the magnitude of which represents a measurement of the concentration of the particles in the scattering medium;normalizing each second signal of said plurality of second signals with said third signal, thereby developing a plurality of individual ratiometric signals whose magnitudes are representative of a measurement of specific key characteristic parameters of the particles in the scattering medium.