Particle length and volume comeasurement with controlled orientation
AssigneeParticle Data, Inc.
InventorsRobert H. Berg, Richard F. Karuhn
Life of this patent
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Abstract
A method of and means for controlling orientation of particles through a sensing zone in a particle analyzing system, which facilitates particle shape determination, comprises laminar flow orientation of the particles in a stream moving through an elongate straight passage coaxially aligned with an elongate sensing zone longer than the longest particle to be sensed and analyzed. The particles are carried through the sensing zone in an isokinetic laminar flow sheath of fluid.
Claims20
A method of controlling the presentation and traverse of elongated particles in fluid suspension to and through a sensing zone of greater length than the longest particle to be analyzed, to facilitate particle shape or size determination in a particle analysis system of a type responsive to electrical signals generated by particles passing through said sensing zone during an analytical time span, comprising:
- effecting in a fluid-filled circuit all of the following steps in a manner effectively free from turbulence, continuously and sequentially in isokinetic laminar flow;
- (a) transporting the particles through a first elongate passage of sufficient length to cause stable longitudinal orientation of the particles in a filamentary stream in said passage;
- p1 (b) transferring said filamentary stream of longitudinally oriented particles as a core stream enveloped in a particle-free cotraveling fluid sheath from the downstream end of said first passage and smoothly, and without disturbing the stable longitudinal orientation of the elongated particles, receiving said stream through the entrance end of a coaxially aligned sensing zone passage;
- (c) advancing said fluid sheathed core stream through said sensing zone passage and maintaining the particles in said stable longitudinal orientation for particle shape or size determination as the particles generate signals while traversing the length of said sensing zone;
- (d) discharging said fluid sheathed core stream of now waste particles from an exit end of said sensing zone passage into a continuation of said fluid filled circuit;
- (e) controlling the flow of the stream of waste particles in movement away from the said exit end and thus avoiding straying, hangup or recycling of the waste particles relative to said exit end;
- (f) and applying a constant differential pressure throughout said fluid filled circuit in effecting all of the foregoing steps during said analytical time span.
Apparatus for controlling the presentation and traverse of elongated particles in fluid suspension to and through a sensing zone passage of greater length than the longest particle to be analyzed, to facilitate particle shape or size determination in a particle analysis system of a type response to electrical signals generated by particles passing through said sensing zone during an analytical time span, comprising:
- a fluid-filled circuit for effecting turbulence-free continuous and sequential isokinetic laminar flow, and having:
- (a) means defining a first elongate passage of sufficient length for transporting the particles therethrough in stable longitudinal orientation in a filamentary particle stream in said passage;
- (b) means for enveloping said filamentary particle stream as a core stream in a particle-free cotraveling fluid sheath;
- (c) said sensing zone passage having an entrance end coaxially aligned with a downstream end of said first passage for transference of said sheathed core stream smoothly from said first passage into said sensing zone passage, said entrance end being shaped for avoiding any disturbance in the stable longitudinal orientation of the elongated particles during said transference;
- (d) means responsive to the particles for generating electrical signals for particle shape or size determination while the particles advance in said fluid sheathed core stream through said sensing zone passage in said stable longitudinal orientation;
- (e) means providing a continuation of said fluid filled circuit into which said fluid sheathed core stream of now waste particles is discharged from an exit end of said sensing zone passage;
- (f) means for controlling the flow of the stream of waste particles in movement away from said exit end for avoiding straying, hangup or recycling of the waste particles relative to said exit end;
- (g) and means for applying a constant differential pressure throughout said fluid filled circuit during said analytical time span.
Dependencies are inferred from the claim text.