US3765771A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Liquid borne particle sensing method using aerosolizing techniques
Assignee: Coulter Electronics Inc
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Filing: 1971-10-27
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Granted: 1973-10-16
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Expires: 1991-10-27
Abstract
Abstract A sample in a liquid is nebulized into an aerosol so that the particles in the sample are continuously aerosolized. The aerosol is then run through an optical particle sensor to count the particles.
Inventors
- 👤 C Shaw
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 16:43
CPC Classifications
G; G01; G01N; G01N15/00; G01N15/06; G01N15/065
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
243 words
A method for counting and determining the cencentration of particles in a liquid sample comprising the steps of: introducing the liquid sample into a calibrated sample input means having an outlet which opens into a chamber at a point spaced from the walls of the chamber; passing a warm, dry, gaseous jet flow stream into the chamber and adjacent to said outlet of said input means for drawing a given amount of the liquid sample into the chamber, for nebulizing the given amount of liquid sample and thereafter for evaporating liquid on the particles in the given amount of sample so nebulized and also for drying liquid drops not containing particles to reduce the size thereof to a size below the size of drops detectable by a sensor to separate the particles in the given amount of liquid sample from the liquid thereof; transporting by means of said warm, dry, jet flow stream, the thus separated particles, in their thus separated form, directly into a beam of focused light, generating as a result of said transporting a quantum of forward light scattered energy which is directly proportional to the number and concentration of the particles in the given amount of liquid sample; measuring the given amount of the liquid sample drawn into the chamber from said sample input means; and measuring photoelectrically the generated quantum of light energy to determine the number and concentration of particles in the given amount of liquid sample.
Claim 2
Independent Claim
243 words
A method for counting and determining the cencentration of particles in a liquid sample comprising the steps of: introducing the liquid sample into a calibrated sample input means having an outlet which opens into a chamber at a point spaced from the walls of the chamber; passing a warm, dry, gaseous jet flow stream into the chamber and adjacent to said outlet of said input means for drawing a given amount of the liquid sample into the chamber, for nebulizing the given amount of liquid sample and thereafter for evaporating liquid on the particles in the given amount of sample so nebulized and also for drying liquid drops not containing particles to reduce the size thereof to a size below the size of drops detectable by a sensor to separate the particles in the given amount of liquid sample from the liquid thereof; transporting by means of said warm, dry, jet flow stream, the thus separated particles, in their thus separated form, directly into a beam of focused light, generating as a result of said transporting a quantum of forward light scattered energy which is directly proportional to the number and concentration of the particles in the given amount of liquid sample; measuring the given amount of the liquid sample drawn into the chamber from said sample input means; and measuring photoelectrically the generated quantum of light energy to determine the number and concentration of particles in the given amount of liquid sample.
Claim 3
Dependent Claim
35 words
The method defined in claim 1 including sheathing in a gaseous flow stream the thus separated particles for thereby shielding the particles from the chamber and any other related structure used for accomplishing said method.
Claim 4
Dependent Claim
44 words
The method defined in claim 2 including establishing isokinetic flow between the thus separate particles and the stream of sheathing gas to prevent turbulence in said chamber which would detract from the efficiency of said introducing, passing, drawing, separating, aerosolizing, drying, transporting, and generating.
Claim 5
Dependent Claim
52 words
The method defined in claim 3 including controlling the duration of said passing of the jet stream and the flow rate of the jet stream for determining the total amount of sample being introduced into the chamber, whereby a precise count of the thus separated particles can be attained by said measuring.
Claim 6
Dependent Claim
32 words
The method of claim 1 including the step of measuring the intensity of the forward scattered light to determine the size of said particles and thereby the type of particles being sensed.
Claim 7
Independent Claim
169 words
A method for counting and determining the concentration of particles in a liquid sample comprising the steps of: introducing the liquid sample into a chamber; separating said particles from the liquid portion of said liquid sample by subjecting the sample to ultrasonic waves to produce liquid drops and by drying the thus separated liquid drops to reduce the size of any liquid drops containing only liquid to a size below the size of drops detectable by a sensor and to evaporate liquid on particles in drops containing liquid and particles by introducing into the chamber a warm, dry, jet flow stream; transporting by means of said warm, dry, jet flow stream, the thus separated particles, in their thus separated form, directly into a beam of focused light, generating as a result of said transporting a quantum of forward light scattered energy which is directly proportional to the number and concentration of the particles in a known measurement of the liquid sample; and measuring photoelectrically such quantum of light energy.
Claim 8
Independent Claim
169 words
A method for counting and determining the concentration of particles in a liquid sample comprising the steps of: introducing the liquid sample into a chamber; separating said particles from the liquid portion of said liquid sample by subjecting the sample to ultrasonic waves to produce liquid drops and by drying the thus separated liquid drops to reduce the size of any liquid drops containing only liquid to a size below the size of drops detectable by a sensor and to evaporate liquid on particles in drops containing liquid and particles by introducing into the chamber a warm, dry, jet flow stream; transporting by means of said warm, dry, jet flow stream, the thus separated particles, in their thus separated form, directly into a beam of focused light, generating as a result of said transporting a quantum of forward light scattered energy which is directly proportional to the number and concentration of the particles in a known measurement of the liquid sample; and measuring photoelectrically such quantum of light energy.
Claim 9
Dependent Claim
27 words
The method defined in claim 6 including selecting the frequency of the ultrasonic sound waves to drive off certain predetermined sizes of particles from the liquid sample.
Claim 10
Dependent Claim
70 words
The method defined in claim 7 including sheathing in a gaseous flow stream the thus separated particles for thereby shielding the particles from the chamber and any other related structure used for accomplishing said method, and establishing isokinetic flow between the thus separated particles and the stream of sheathing gas to prevent turbulence in said chamber which would detract from the efficiency of said introducing, separating, drying, transporting, and generating.
Claim 11
Dependent Claim
189 words
An optical particle sensor for determining the size and concentration of particles carried in a liquid sample by measuring the forward scattering of a focused light beam projected through an aerosol of the liquid sample, said sensor comprising: a sample input chamber; fluid metering means arranged for introducing at its output a metered amount of the fluid sample into said input chamber; separating means for freeing the particles from the carrier liquid, said separating means including structure for producing a jet stream of warm, dry gas, and structure for passing said jet stream closely adjacent to said metering means output, whereupon a metered amount of the liquid sample is drawn into said input chamber and the liquid carrier thereof is separated from the particles and evaporated, leaving an aerosol stream of the particleS in said input chamber; means for focusing an illuminating beam of light on a small portion of said warm, dry aerosol stream of particles; and photoelectric means for receiving and measuring the light forward scattered by the illuminated particles and for producing an output proportional to the size and concentration of the particles in the sample.
Claim 12
Dependent Claim
189 words
An optical particle sensor for determining the size and concentration of particles carried in a liquid sample by measuring the forward scattering of a focused light beam projected through an aerosol of the liquid sample, said sensor comprising: a sample input chamber; fluid metering means arranged for introducing at its output a metered amount of the fluid sample into said input chamber; separating means for freeing the particles from the carrier liquid, said separating means including structure for producing a jet stream of warm, dry gas, and structure for passing said jet stream closely adjacent to said metering means output, whereupon a metered amount of the liquid sample is drawn into said input chamber and the liquid carrier thereof is separated from the particles and evaporated, leaving an aerosol stream of the particleS in said input chamber; means for focusing an illuminating beam of light on a small portion of said warm, dry aerosol stream of particles; and photoelectric means for receiving and measuring the light forward scattered by the illuminated particles and for producing an output proportional to the size and concentration of the particles in the sample.
Claim 13
Dependent Claim
57 words
The sensor defined in claim 9 wherein said fluid metering means includes a pipette having its open outlet arranged as said metering means output so that the jet stream draws sample from the pipette to nebulize the liquid, and the amount of liquid sample withdrawn from the pipette can be determined visually by calibrations on the pipette.
Claim 14
Dependent Claim
83 words
The sensor defined in claim 9 including sheath means for introducing a gaseous flow stream between the aerosol stream of suspended particles and the walls of said input chamber to act as a sheath to shield the particles from contact with the walls of the chamber, said sheath means including a plenum upstream of said metering means output, means for introducing warm, dry gas into said plenum, and means for generating and projecting an annular sheath of such gas around the aerosol stream.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-10-15 | 1977-04-16 | 1977-10-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-15 | 1981-04-16 | 1981-10-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-15 | 1985-04-16 | 1985-10-16 | $7700.00 | Window Closed / Lapsed |