Patent ID: 6412359
Filing Date: 2002-07-02
Classification: G01N,G01P

Abstract:
A device for determining one or more particle physical characteristics, the device comprising:(a) a force field device for subjecting at least one particle to at least one force field, the force field device comprising: (1) a first force field producing assembly comprising: (i) a first force field producing device; and (ii) a first pole piece for concentrating the force field flux produced by the first force field producing device; (2) a second force field producing assembly comprising: (i) a second force field producing device; and (ii) a second pole piece for concentrating the force field flux produced by the second force field producing device; (3) the first and second pole pieces each comprising a flux concentrating portion having a curved end portion for producing a region of space having a substantially constant force field and wherein the flux concentrating portions are displaced substantially opposite each other with an inter-polar air gap therebetween and wherein the curved end portions comprise: (i) a first distal end having a substantially curved surface; (ii) a second distal end having a substantially curved surface; (iii) wherein the first and second distal ends are configured so as to be contiguous with each other; and (iv) wherein the substantially curved surface of the first distal end comprises a portion having a substantially constant radius and wherein the radius is in the range of approximately 3 mm; and (v) wherein the substantially curved surface of the second distal end comprises a portion which is substantially hyperbolic and wherein the hyperbolic portion is approximately defined as y(x)=9.544/x2âˆ’12.719, wherein x and y are Cartesian coordinates with the origin placed at the intersection of the plane of symmetry separating the pole pieces and a plane tangent to the radial portion of the distal ends of the pole pieces; (b) a substantially transparent flow channel positioned at least partially within the region of space having a substantially constant force magnitude and direction and for allowing the introduction of at least one particle; and (c) a computer system for gathering and analyzing data associated with the at least one particle.