US3676647A
Expired / Lapsed
US
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Particle analyzing apparatus and method
Assignee: Procedyne Corp
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Filing: 1969-12-04
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Granted: 1972-07-11
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Expires: 1989-12-04
Abstract
Abstract On-line, real-time particle analyzing and counting apparatus operating continuously. The particles, suspended in a fluent medium flowing through a transparent chamber of pre-determined cross section, are scanned by a flying spot of minimum practical dimensions. A photodiode adjacent the face of the chamber opposite impingement of the spot is activated in accordance with interruption of the light transmitted through the flowing medium. Activation is proportional to the size and density of the particles and the output of the photodiode is translated into pulses which are measured and counted in accordance with their magnitude and frequency. The pulses are grouped within specified size ranges for convenience of counting.
Inventors
- 👤 Robert Staffin
- 👤 Roy J Ricci
- 👤 Ronald J Juels
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 20:01
CPC Classifications
G; G01; G01N; G01N15/00; G01N15/10; G01N15/14; G01N15/1468; G01N15/147; G06; G06M; G06M11/00; G06M11/02
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
243 words
Apparatus for analyzing the distribution of solid particles contained in a fluent medium and classifying the particles into size ranges and the quantity in each range comprising: a chamber having at least one pair of transparent opposite walls, said chamber having an inlet and an outlet, means to connect the inlet and outlet into a conduit through which the fluid medium is flowing to extract a sample at some predetermined rate, the path of flow through the chamber being in some predetermined direction, a source to emit a beam of light to be transmitted through the walls and medium, a lens system to focus the beam into a spot in the range of about 10 microns measured at a plane transverse to the scan substantially midway of said walls and parallel thereto the spot size being smaller than the smallest particle of interest in the analysis, means to traverse the beam in an oscillating scan across the moving medium and essentially at right angles to the direction of flow, the beam being reduced in intensity in accordance with interruption thereof by the particles, photoelectric means located for activation by the beam following transmission thereof through the medium to provide a train of output pulses containing information indicative of the size and distribution of the particles which are essentially in said plane, and circuit means responsive to the output of said photoelectric means for classifying the pulses into groups corresponding to the selected ranges.
Claim 2
Dependent Claim
243 words
Apparatus for analyzing the distribution of solid particles contained in a fluent medium and classifying the particles into size ranges and the quantity in each range comprising: a chamber having at least one pair of transparent opposite walls, said chamber having an inlet and an outlet, means to connect the inlet and outlet into a conduit through which the fluid medium is flowing to extract a sample at some predetermined rate, the path of flow through the chamber being in some predetermined direction, a source to emit a beam of light to be transmitted through the walls and medium, a lens system to focus the beam into a spot in the range of about 10 microns measured at a plane transverse to the scan substantially midway of said walls and parallel thereto the spot size being smaller than the smallest particle of interest in the analysis, means to traverse the beam in an oscillating scan across the moving medium and essentially at right angles to the direction of flow, the beam being reduced in intensity in accordance with interruption thereof by the particles, photoelectric means located for activation by the beam following transmission thereof through the medium to provide a train of output pulses containing information indicative of the size and distribution of the particles which are essentially in said plane, and circuit means responsive to the output of said photoelectric means for classifying the pulses into groups corresponding to the selected ranges.
Claim 3
Dependent Claim
14 words
Apparatus in accordance with claim 1 in which the source of light is monochromatic.
Claim 4
Dependent Claim
13 words
Apparatus in accordance with claim 1 in which the source is a laser.
Claim 5
Dependent Claim
21 words
Apparatus in accordance with claim 1 in which the direction of flow is vertical and the direction of scan is horizontal.
Claim 6
Dependent Claim
18 words
Apparatus in accordance with claim 1 in which the traversing means provides scan motion which is essentially harmonic.
Claim 7
Dependent Claim
21 words
Apparatus in accordance with claim 5 wherein the classifying means is arranged to utilize a linear portion of the scanning cycle.
Claim 8
Dependent Claim
44 words
Apparatus in accordance with claim 6 further characterized in that the counting means includes gating means, the beam-traversing means includes means to provide a synchronizing signal to initiate and terminate operation of the gating means to derive the linear portion of the scanning cycle.
Claim 9
Dependent Claim
81 words
Apparatus in accordance with claim 1 in which said traversing means includes a mirror mounted for oscillation to receive incident light from the beam and means for oscillating said mirror at the scan frequency and amplitude, the reflected light constituting the scanning spot, the scan frequency providing a linear velocity of the spot which is a substantial multiple of the velocity of the sample stream, whereby the particles as ''''seen'''' by the spot appear static during interception of the beam thereby.
Claim 10
Dependent Claim
26 words
Apparatus in accordance with claim 1 in which the classifying means includes means to count the pulses and to register the number thereof in each group.
Claim 11
Dependent Claim
37 words
Apparatus in accordance with claim 9 further characterized by means in the output-circuit means to de-activate the counting means upon acquisition of the leading edge of a particle pulse to avoid spurious pulses derived from adjacent particles.
Claim 12
Dependent Claim
25 words
Apparatus in accordance with claim 1 in which the classifying means includes means to distinguish between particles in the plane and those outside the plane.
Claim 13
Dependent Claim
52 words
Apparatus in accordance with claim 1 in which the cross-sectional area of the medium flowing through the chamber is so determined by the configuration of the chamber as to direct the medium past the scanning spot in a thin sheet, the mid-plane of the sheet being substantially coincident with the focal plane.
Claim 14
Dependent Claim
25 words
Apparatus in accordance with claim 1 further characterized in that the output-responsive means includes electrical components to clip the pulses to some predetermined voltage level.
Claim 15
Independent Claim
154 words
The method of measuring the distribution of particles contained in a fluent medium as a function of time, comprising: a. extracting a sample of the medium, b. continuously flowing the sample through a chamber defined in part by a pair of opposite transparent walls, c. transmitting a beam of light through the walls and sample, d. converging the beam to a spot, on the order of about 10 microns at a focal plane which is essentially midway of said walls, e. causing the spot to oscillate in a plane substantially at right angles to the direction of flow through the chamber, f. translating the varying intensity of the transmitted light occasioned by the constantly changing distribution of particles presented by flow of the sample into voltage pulses, g. analyzing the pulses for amplitude and periodicity, h. sorting the pulses into a plurality of predetermined size groups, and i. registering the count in each group.
Claim 16
Independent Claim
154 words
The method of measuring the distribution of particles contained in a fluent medium as a function of time, comprising: a. extracting a sample of the medium, b. continuously flowing the sample through a chamber defined in part by a pair of opposite transparent walls, c. transmitting a beam of light through the walls and sample, d. converging the beam to a spot, on the order of about 10 microns at a focal plane which is essentially midway of said walls, e. causing the spot to oscillate in a plane substantially at right angles to the direction of flow through the chamber, f. translating the varying intensity of the transmitted light occasioned by the constantly changing distribution of particles presented by flow of the sample into voltage pulses, g. analyzing the pulses for amplitude and periodicity, h. sorting the pulses into a plurality of predetermined size groups, and i. registering the count in each group.
Claim 17
Dependent Claim
30 words
The method in accordance with claim 14 further characterized in that the linear rate of scan is a substantial multiple of the flow rate of the sample through the chamber.
Claim 18
Dependent Claim
37 words
The method in accordance with claim 14 in which the volumetric rate of flow of the sample is constant and the sorting of the pulses is determined in terms of particles per unit volume of the sample.
Claim 19
Dependent Claim
23 words
The method in accordance with claim 14 characterized by the further step of limiting the diffraction time, the spot at the focal plane.
Claim 20
Independent Claim
154 words
The method of measuring the distribution of particles contained in a fluent medium as a function of time comprising: a. extracting a sample of the medium, b. continuously flowing the sample through a chamber defined in part by a pair of opposite transparent walls, c. transmitting a beam of light through the walls and sample, d. converging the beam to a spot on the order of about 10 microns, e. causing the spot to oscillate in essentially harmonic motion in a plane substantially at right angles to the direction of flow through the chamber, f. translating the varying intensity of the transmiTted light occasioned by the constantly changing distribution of particles presented by flow of the sample into pulses modulating the sine wave representing the harmonic motion, g. analyzing the pulses for amplitude and periodicity, h. sorting the pulses into a plurality of predetermined size groups, and i. registering the count in each group.
Claim 21
Independent Claim
154 words
The method of measuring the distribution of particles contained in a fluent medium as a function of time comprising: a. extracting a sample of the medium, b. continuously flowing the sample through a chamber defined in part by a pair of opposite transparent walls, c. transmitting a beam of light through the walls and sample, d. converging the beam to a spot on the order of about 10 microns, e. causing the spot to oscillate in essentially harmonic motion in a plane substantially at right angles to the direction of flow through the chamber, f. translating the varying intensity of the transmiTted light occasioned by the constantly changing distribution of particles presented by flow of the sample into pulses modulating the sine wave representing the harmonic motion, g. analyzing the pulses for amplitude and periodicity, h. sorting the pulses into a plurality of predetermined size groups, and i. registering the count in each group.
Claim 22
Dependent Claim
26 words
The method in accordance with claim 18 further characterized in that only an essentially linear portion of the modulated sine wave is utilized in the analysis.
References Cited (Backward Citations)
US2920525A
Cited
US3436139A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-07-11 | 1976-01-10 | 1976-07-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-11 | 1980-01-10 | 1980-07-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-11 | 1984-01-10 | 1984-07-11 | $7700.00 | Window Closed / Lapsed |