Particle size and charge measurement in multi-component colloids

PCT No. PCT/AU94/00307 Sec. 371 Date Aug. 31, 1995 Sec. 102(e) Date Aug. 31, 1995 PCT Filed Jun. 7, 1994 PCT Pub. No. WO94/29694 PCT Pub. Date Dec. 22, 1994A method and device is disclosed for determining the distribution of charge and size in a colloidal system. The arrangement disclosed is adapted to measure these characteristics in an inhomogeneous colloid. A colloid is subjected to a steady or slowly varying force which moves the particles at a rate that depends on their radius or charge and thereby sets up spatial inhomogeneities in the suspension, and to either a unsteady mechanical force or an unsteady electrical force, and the resulting electrical or acoustic effects sensed. Monitoring these characteristics over time and subsequent calculation allows the determination of charge and size distribution, for each species present.