GB1417691A - Methods of measuring sizes of particles - Google Patents
Methods of measuring sizes of particlesInfo
- Publication number
- GB1417691A GB1417691A GB3929871A GB3929871A GB1417691A GB 1417691 A GB1417691 A GB 1417691A GB 3929871 A GB3929871 A GB 3929871A GB 3929871 A GB3929871 A GB 3929871A GB 1417691 A GB1417691 A GB 1417691A
- Authority
- GB
- United Kingdom
- Prior art keywords
- particles
- particle
- laser
- light
- circuit
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N15/00—Investigating characteristics of particles; Investigating permeability, pore-volume, or surface-area of porous materials
- G01N15/02—Investigating particle size or size distribution
- G01N15/0205—Investigating particle size or size distribution by optical means, e.g. by light scattering, diffraction, holography or imaging
Abstract
1417691 Photo-electric investigation of size distribution of particles CAMBRIDGE CONSULTANTS Ltd and WELWYN HALL RESEARCH ASSOCIATION 21 Nov 1972 [21 Aug 1971] 39298/71 Heading G1A Size and size distribution of particles moving through a liquid are investigated by utilizing the Doppler change in frequency when electromagnetic radiation is scattered by the particle(s). In the arrangement of Fig. 1, a helium-neon laser and beam-splitter, 3, provide two coherent beams 5, 7 to be focused on a volume 11 within a jar. The particles in the contained liquid are investigated when settling under gravity such that Stoke's law is applicable. The light scattered from volume 11 is detected at 13 and analyzed by processing circuit 17 which may be as in Figs. 1 A or 1B (not shown). In the former, used when one particle is being scanned at a time, the output is applied to a bank of ten narrow pass filters 21 coupled to respective counters. The detector 13 produces an output at a frequency f equivalent to the Doppler change in frequency of the laser beam, this being dependent on the particle velocity V, which itself is proportional (under Stoke's law) to D<SP>2</SP>, the diameter of the particle. The counters in circuit 17 as in Fig. 1A (not shown), therefore provide the numbers of particles in a plurality of size ranges. In the second case, Fig.1B (not shown), circuit 17 comprises a time compression spectrum analyzer coupled to a normalizing circuit; this provides a continuous size distribution spectrum to be displayed on a cathode ray tube, pen recorder &c. In the arrangement of Fig. 2 (not shown), a single beam from a laser is focused by a lens on to a small volume within the sample. The emergent light is allowed to pass through two apertures in a mask, and the resultant narrow beams focused on the detector. In a further arrangement, Fig. 3 (not shown), light from the laser is divided into two beams by a beam-splitter, one beam being applied to the sample and the other reflected from a mirror to a further beam-splitter where it is combined with scattered (and Doppler shifted) light from the sample.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB3929871A GB1417691A (en) | 1971-08-21 | 1971-08-21 | Methods of measuring sizes of particles |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB3929871A GB1417691A (en) | 1971-08-21 | 1971-08-21 | Methods of measuring sizes of particles |
Publications (1)
Publication Number | Publication Date |
---|---|
GB1417691A true GB1417691A (en) | 1975-12-17 |
Family
ID=10408807
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB3929871A Expired GB1417691A (en) | 1971-08-21 | 1971-08-21 | Methods of measuring sizes of particles |
Country Status (1)
Country | Link |
---|---|
GB (1) | GB1417691A (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2521294A1 (en) * | 1982-02-05 | 1983-08-12 | Bajard Jean | GLOBAL INTERFERENTIAL GRANULOMETRY METHOD APPLICABLE IN PARTICULAR TO POLYDISPERSE BIOLOGICAL PARTICLES |
EP0253669A2 (en) * | 1986-07-18 | 1988-01-20 | Btg International Limited | Method and apparatus for the measurement of the size of particles entrained in a gas |
-
1971
- 1971-08-21 GB GB3929871A patent/GB1417691A/en not_active Expired
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0086170A1 (en) * | 1982-02-03 | 1983-08-17 | Jean Bajard | Method for analyzing particle size distribution of global samples with use of interferences, especially for polydispersed biological particles |
US4622642A (en) * | 1982-02-03 | 1986-11-11 | Jean Bajard | Batch interference granulometric process particularly applicable to poly-dispersed biological particles |
FR2521294A1 (en) * | 1982-02-05 | 1983-08-12 | Bajard Jean | GLOBAL INTERFERENTIAL GRANULOMETRY METHOD APPLICABLE IN PARTICULAR TO POLYDISPERSE BIOLOGICAL PARTICLES |
EP0253669A2 (en) * | 1986-07-18 | 1988-01-20 | Btg International Limited | Method and apparatus for the measurement of the size of particles entrained in a gas |
EP0253669A3 (en) * | 1986-07-18 | 1989-05-31 | National Research Development Corporation | Method and apparatus for the measurement of the size of particles entrained in a gas |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
PS | Patent sealed | ||
PCNP | Patent ceased through non-payment of renewal fee |