Patent US3695765A successfully refreshed from Google Patents.
US3695765A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for measuring and/or monitoring the size of particles in suspension
Assignee: Tronox Pigment UK Ltd
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Filing: 1970-04-22
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Granted: 1972-10-03
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Expires: 1990-04-22
Abstract
Abstract A method for measuring the diameter of particles in a suspension wherein a particle-free layer having substantially the same refractive index as the suspending medium is provided directly above the suspension and the upper surface of the suspension is illuminated at a large angle of incidence by a beam of radiation passing through the particle-free layer and the intensity of radiation that is scattered by the suspended particles and then re-enters the layer is measured for one or more small scattering angles. These measurements of scattered radiation provide a measure of the mean particle diameter of the suspended particles that is substantially independent of the concentration of particles in the suspension.
Inventors
- 👤 Jan Paul Bol
- 👤 Joseph Gebhart
- 👤 Gunther Seger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 07:11
CPC Classifications
G; G01; G01J; G01J3/00; G01J3/28; G01J3/44; G01J3/4412; G01N; G01N15/00; G01N15/02; G01N15/0205; B; B65; B65G; B65G2814/00; B65G2814/03; B65G2814/0301; B65G2814/0314; B65G2814/0316; B65G2814/0317
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
86 words
A method for measuring, and/or detecting changes in, the diameter of particles in suspension in a fluid medium, which comprises causing a beam of radiation to enter the upper surface of the suspension at a large angle of incidence through a particle-free layer located directly above the suspension and comprising a material having substantially the same refractive index as the suspending medium, and measuring the intensity of radiation that is scattered by the suspended particles and reenters the layer for at least one small scattering angle.
Claim 2
Independent Claim
86 words
A method for measuring, and/or detecting changes in, the diameter of particles in suspension in a fluid medium, which comprises causing a beam of radiation to enter the upper surface of the suspension at a large angle of incidence through a particle-free layer located directly above the suspension and comprising a material having substantially the same refractive index as the suspending medium, and measuring the intensity of radiation that is scattered by the suspended particles and reenters the layer for at least one small scattering angle.
Claim 3
Dependent Claim
37 words
A method according to claim 1, wherein the incident beam consists of polychromatic radiation and the intensity of the scattered radiation is measured for each of a series of wavelengths at a single small forward scattering angle.
Claim 4
Dependent Claim
42 words
A method according to claim 1, wherein the wavelength of the incident radiation is so selected that the ratio of the particle radius to the wavelength of the radiation in the suspending medium is in the range of from 0.3:1 to 5:1.
Claim 5
Dependent Claim
19 words
A method according to claim 3, wherein the said ratio is in the range of from 1:1 to 5:1.
Claim 6
Dependent Claim
27 words
A method according to claim 1, wherein the beam of radiation enters the upper surface of the suspension at an angle of incidence of at least 65*.
Claim 7
Dependent Claim
16 words
A method according to claim 5, wherein the said angle of incidence is at least 80*.
Claim 8
Dependent Claim
37 words
A method according to claim 1, wherein the illuminating beam enters the particle-free layer through a surface thereof that is not parallel to the upper surface of the suspension, and that is substantially perpendicular to said beam.
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) | 1975-10-03 | 1976-04-03 | 1976-10-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-10-03 | 1980-04-03 | 1980-10-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-10-03 | 1984-04-03 | 1984-10-03 | $7700.00 | Window Closed / Lapsed |