Method and apparatus for studying particles having widely different sizes

Claim 1

A method for studying particles of widely different sizes wherein the particles are suspended in a liquid medium in a vessel and settle through the medium from top to bottom at a rate determined by their size, said method including the steps of: detecting the concentration at a particular height in said vessel of particles suspended in said liquid medium in excess of a particular size, allowing the liquid medium and particles suspended therein to pass through a first aperture in a first tube positioned at said particular height in said vessel in response to said concentration at said particular height decreasing below a first detected concentration, and allowing the liquid medium and particles suspended therein to pass into a second tube, at a second particular height on said beaker through a second aperture substantially greater in size than said first aperture.

Claim 2

A method for studying particles of widely different sizes wherein the particles are suspended in a liquid medium in a vessel and settle through the medium from top to bottom at a rate determined by their size, said method including the steps of: detecting the concentration at a particular height in said vessel of particles suspended in said liquid medium in excess of a particular size, allowing the liquid medium and particles suspended therein to pass through a first aperture in a first tube positioned at said particular height in said vessel in response to said concentration at said particular height decreasing below a first detected concentration, and allowing the liquid medium and particles suspended therein to pass into a second tube, at a second particular height on said beaker through a second aperture substantially greater in size than said first aperture.

Claim 10

An apparatus for studying particles of widely different sizes suspended in a fluid by passage of said fluid from a vessel to one of a plurality of tubes positioned in said vessel wherein each of said plurality of tubes has an aperture therein for passage of said fluid therethrough, said apparatus comprising, at least a first and second of said plurality of tubes positioned at a first height in said vessel, said first tube having a first aperture of a first particular size therein and said second tube having a second aperture of a second particular size greater than said first particular size, at least a third of said plurality of tubes at a second, lower height in said vessel, said third tube having a third aperture therein substantially larger than said first particular size of said first aperture, first control means for controlling passage of said fluid from said vessel to said first tube, first sensing means coupled to said second tube and said first control means for sensing the rate of particles entering said second tube from said vessel through said second aperture, said first sensing means operative in response to a reduction in the rate of particles in excesS of a particular size entering said second tube to actuate said control means for allowing fluid to flow from said vessel into said first tube, and second control means for controlling passage of said fluid from said vessel to said third tube.

Claim 11

An apparatus for studying particles of widely different sizes suspended in a fluid by passage of said fluid from a vessel to one of a plurality of tubes positioned in said vessel wherein each of said plurality of tubes has an aperture therein for passage of said fluid therethrough, said apparatus comprising, at least a first and second of said plurality of tubes positioned at a first height in said vessel, said first tube having a first aperture of a first particular size therein and said second tube having a second aperture of a second particular size greater than said first particular size, at least a third of said plurality of tubes at a second, lower height in said vessel, said third tube having a third aperture therein substantially larger than said first particular size of said first aperture, first control means for controlling passage of said fluid from said vessel to said first tube, first sensing means coupled to said second tube and said first control means for sensing the rate of particles entering said second tube from said vessel through said second aperture, said first sensing means operative in response to a reduction in the rate of particles in excesS of a particular size entering said second tube to actuate said control means for allowing fluid to flow from said vessel into said first tube, and second control means for controlling passage of said fluid from said vessel to said third tube.

Claim 22

An apparatus for studying particles of widely different sizes by use of the Coulter principle comprising, a first vessel carrying a body of fluid having particles of widely varying size suspended therein, at least first, second and third tubes suspended in said vessel and having first, second and third apertures respectively therein for enabling flow of fluid from said vessel to said tubes, said first and second tubes and apertures being at substantially the same depth in said vessel and said third tube and aperture being at a lower depth, said second and third apertures being substantially the same in size, and said first aperture being substantially smaller than said second and third apertures, first, second and third fluid control means coupled to said apertures for causing said fluid to flow through said apertures, means for actuating said second and third fluid control means for enabling flow of fluid through said second and third apertures, first, second and third scanning means coupled to said first, second and third apertures respectively, said scanning means each being responsive to the passage of particles through said apertures to produce an electric signal for each passing particle, the value of which is related to the dimensions of respective particles, threshold means coupled to said second scanning means and operative in response to the reduction in the repetition rate of said electric signals in excess of a particular value to develop a control signal, and means for actuating said first fluid control means coupled to said threshold means and said first fluid control means and operative in response to said control signal to enable flow of fluid through said first aperture, and pulse analysis means, coupled to said first and third scanning means for analyzing the electric signals produced thereby.

Claim 23

An apparatus for studying particles of widely different sizes by use of the Coulter principle comprising, a first vessel carrying a body of fluid having particles of widely varying size suspended therein, at least first, second and third tubes suspended in said vessel and having first, second and third apertures respectively therein for enabling flow of fluid from said vessel to said tubes, said first and second tubes and apertures being at substantially the same depth in said vessel and said third tube and aperture being at a lower depth, said second and third apertures being substantially the same in size, and said first aperture being substantially smaller than said second and third apertures, first, second and third fluid control means coupled to said apertures for causing said fluid to flow through said apertures, means for actuating said second and third fluid control means for enabling flow of fluid through said second and third apertures, first, second and third scanning means coupled to said first, second and third apertures respectively, said scanning means each being responsive to the passage of particles through said apertures to produce an electric signal for each passing particle, the value of which is related to the dimensions of respective particles, threshold means coupled to said second scanning means and operative in response to the reduction in the repetition rate of said electric signals in excess of a particular value to develop a control signal, and means for actuating said first fluid control means coupled to said threshold means and said first fluid control means and operative in response to said control signal to enable flow of fluid through said first aperture, and pulse analysis means, coupled to said first and third scanning means for analyzing the electric signals produced thereby.