Patent ID: 7924431
Filing Date: 2011-04-12
Classification: G01N

Abstract:
1. A method of measuring properties of particles, comprising the steps of: generating a beam of radiation which is propagated along an optical axis; illuminating with the beam an observation region which is transited by a particle, a portion of the beam giving rise to radiation which is scattered by scattering interaction of the portion of the beam with the particle, and another portion being transmitted substantially undisturbed along the optical axis through the observation region; and detecting, in a detection plane disposed along the optical axis, a plurality of radiation intensity values which are determined by the interference between the scattered radiation and the transmitted radiation; wherein said detection of the radiation intensity values in the detection plane is carried out according to a time sequence of acquisitions corresponding to successive transit positions of said particle through the observation region, and wherein on the basis of said time sequence of acquisitions, the trend of a parameter of asymmetry of the distribution of the plurality of radiation intensity values with respect to the optical axis, due to the successive transit positions of the particle, is determined as a function of time, depending on the trend of the parameter of asymmetry which has been determined as a function of time, the trends of phase delay and amplitude of the scattered radiation with respect to the transmitted radiation are determined as a function of time, and the properties of the particle are determined on the basis of the trends of the phase delay and amplitude of the scattered radiation as a function of time.