Patent EP0106684A2 successfully refreshed from Google Patents.
EP0106684A2
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Particle diameter measuring device
Assignee: Toshiba Corp
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Filing: 1983-10-14
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Granted: —
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Expires: 2003-10-14
Abstract
Abstract A particle diameter measuring device for measuring the particle diameter distribution of a number of particles (28) to be measured, wherein a laser beam guided through a radiating optical fiber (64) is re-formed by collimator lenses (62) into parallel beams having an adequate diameter and is then irradiated onto the particles (28) to be measured; a plurality of optical fibers (66a, 66b,..., 66z) are arranged along a circle whose center is a point P located in the group of particles (28), the receiving end of any of the optical fibers being directed toward point P. The optical fibers (66b, 66c,..., 66z) receiving scattered light are arranged close to one another in the range of small scattering angles, while they are roughly arranged in the range of large scattering angles. A transmitted light is received by that optical fiber (66a) which is so arranged as to coincide with the laser beam radiating direction, the intensity of this transmitted light being detected by a photo-detector (40). Light scattered at various angles, which angles are formed with reference to the laser beam radiating direction, is received the other optical fibers (66b, 66c,..., 66z), their intensities being detected by the other photo-detectors (40).The transmission factor t= lout/lin is calculated from the intensity of the transmitted light. The particle diameter distribution n(D) is calculated in the form of relative values, using the angular distribution I(θ) of the scattered light intensity. The particle diameter distribution N(υ) is calculated in the form. of absolute values, using t, n(D) and light pass length L. On the while, particle diameter distribution N(D) or n(D) can be measured with high accuracy, independently of the diameter of the particles. Since it is easy to measure the scattered light intensity in a range of scattering angles from 0 to 30°, the particle diameter distribution of particles, the diameter thereof are smaller than 0.1 µm, can be obtained.
Inventors
- 👤 Kyoichi Tatsuno
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-31 16:47
CPC Classifications
G; G01; G01N; G01N15/00; G01N15/02; G01N15/0205; G01N15/0211; G01N21/00; G01N21/17; G01N21/47; G01N2021/4704; G01N2021/4711; G01N2021/4716
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
132 words
A particle diameter measuring device for measuring the particle diameter distribution in a number of particles to be measured comprising: a means (30, 32) for irradiating laser beams onto the particles (28) to be measured; a plurality of photo-detectors (40), each serving to detect the scattered light intensity and convert it into an electric signal; and an arithmetic unit (44) for calculating the particle diameter distribution in the form of relative values of particle densities, using the detected scattered light intensities at the predetermined scattering angles, characterized by comprising a plurality of optical fibers (34), each receiving a light scattered at a predetermined scattering angle in relation to the laser beam incident direction, each of the photo-detectors (40) serving to detect the scattered light intensity guided through each of the optical fibers.
Claim 2
Dependent Claim
132 words
A particle diameter measuring device for measuring the particle diameter distribution in a number of particles to be measured comprising: a means (30, 32) for irradiating laser beams onto the particles (28) to be measured; a plurality of photo-detectors (40), each serving to detect the scattered light intensity and convert it into an electric signal; and an arithmetic unit (44) for calculating the particle diameter distribution in the form of relative values of particle densities, using the detected scattered light intensities at the predetermined scattering angles, characterized by comprising a plurality of optical fibers (34), each receiving a light scattered at a predetermined scattering angle in relation to the laser beam incident direction, each of the photo-detectors (40) serving to detect the scattered light intensity guided through each of the optical fibers.
Claim 3
Dependent Claim
46 words
A particle diameter measuring device according to claim 1, characterized in that each of the scattering angles is increased by a certain increment and the light scattered at any of these scattering angles is received by that optical fiber (34) which corresponds to this scattering angle.
Claim 4
Dependent Claim
87 words
A particle diameter measuring device according to claim 1, characterized in that the light scattered at any of the scattering angles which are increased by a small increment in the range of a small scattering angle is received by that optical fiber (34) which corresponds to the scattering angle, and the light scattered at any of the scattering angles which are increased by a large increment in the range of a large scattering angle is received by that optical fiber (34) which corresponds to the scattering angle.
Claim 5
Dependent Claim
96 words
A particle diameter measuring device according to claim 3, characterized in that the range of the scattering angle at which the scattered light intensities are to be measured is divided into a plurality of ranges of scattering angles, the light scattered at any of the divided ranges of scattering angles which is increased by a certain increment is received by that optical fiber (34) which corresponds to the scattering angle, and the increment in the divided range of small scattering angles is set to be smaller than that in the divided range of large scattering angles.
Claim 6
Dependent Claim
38 words
A particle diameter measuring device according to claim 3, characterized in that the light scattered at any of the scattering angles which is gradually increased is received by that optical fiber (34) which corresponds to the scattering angle.
Claim 7
Dependent Claim
105 words
A particle diameter measuring device according to claim 4, characterized in that each of the optical fibers (34) has a receiving end (36) which is located on a circle whose center is a point located in the particles (28), the range of the scattering angle at which the scattered light intensities are to be measured is divided into two ranges, and the receiving ends (36) of the optical fibers (34) are arranged close to one another in two layers in one range of small scattering angles, while they are arranged close to one another in one layer in the other range of large scattering angles.
Claim 8
Dependent Claim
34 words
A particle diameter measuring device according to claim 3, characterized in that the scattering angles at which the scattered light intensities are to be measured are in the range of from 0 to 30°.
Claim 9
Dependent Claim
34 words
A particle diameter measuring device according to claim 3, characterized in that the scattering angles at which the scattered light intensities are to be measured are in the range of from 0 to 60°.
Claim 10
Dependent Claim
260 words
A particle diameter measuring device for measuring the particle diameter distribution of a number of particles to be measured, comprising: a means (64, 62) for irradiating laser beams onto a number of particles to be measured; a plurality of photo-detectors (40) for scattered light, each serving to detect the scattered light intensity and convert it into an electric signal; and a means (76) for calculating the particle diameter distribution n(D) in the form of relative values of particle densities, using the scattered light intensity at the scattering angles, said being intensity being detected by the photo-detectors (40); characterized by comprising an optical fiber (66a) for transmitted light, receiving a light advancing straight in the laser beam incident direction and passing through the particles (28); a photo-detector (40) for transmitted light, which serves to detect the scattered light intensity guided through the optical fiber (66a) and convert it into an electric signal; a plurality of optical fibers (66b, 66c,..., 66z) for scattered light, each receiving a light scattered at a predetermined scattering angles in relation to the laser beam incident direction, each of the photo-detectors (40) serving to detect the scattered light intensity guided through each of the optical fibers (66b, 66c,..., 66z) for scattered beams; a means (70) for calculating a transmission factor t using intensity of transmitted light detected by the photo-detectors (40); and a means (72, 74) for calculating the particle diameter distribution N(D) in the form of absolute values of particle densities, using both the particle diameter distribution n(D) of relative values and the transmission factor t.
Claim 11
Dependent Claim
260 words
A particle diameter measuring device for measuring the particle diameter distribution of a number of particles to be measured, comprising: a means (64, 62) for irradiating laser beams onto a number of particles to be measured; a plurality of photo-detectors (40) for scattered light, each serving to detect the scattered light intensity and convert it into an electric signal; and a means (76) for calculating the particle diameter distribution n(D) in the form of relative values of particle densities, using the scattered light intensity at the scattering angles, said being intensity being detected by the photo-detectors (40); characterized by comprising an optical fiber (66a) for transmitted light, receiving a light advancing straight in the laser beam incident direction and passing through the particles (28); a photo-detector (40) for transmitted light, which serves to detect the scattered light intensity guided through the optical fiber (66a) and convert it into an electric signal; a plurality of optical fibers (66b, 66c,..., 66z) for scattered light, each receiving a light scattered at a predetermined scattering angles in relation to the laser beam incident direction, each of the photo-detectors (40) serving to detect the scattered light intensity guided through each of the optical fibers (66b, 66c,..., 66z) for scattered beams; a means (70) for calculating a transmission factor t using intensity of transmitted light detected by the photo-detectors (40); and a means (72, 74) for calculating the particle diameter distribution N(D) in the form of absolute values of particle densities, using both the particle diameter distribution n(D) of relative values and the transmission factor t.
Claim 12
Dependent Claim
130 words
A particle diameter measuring device according to claim 9, characterized by comprising: a means (90, 58, 60) for defining the optical length L in which laser beams are scattered by the particles (28), and a means (55) for adjusting the optical length L, based on the transmission factor t, in such a way that detected values of the scattered light intensities are not influenced by multiple scattering; wherein the absolute value particle diameter distribution calculating means (72, 74) calculates the particle diameter distribution N(D) in the form of absolute values, using the transmission factor t and the relative value particle diameter distribution n(D) which are calculated from the intensity of transmitted light and scattered light intensity detected after the light pass length L is adjusted by the adjusting means (55).
Claim 13
Dependent Claim
93 words
A particle diameter measuring device according to claim 10, characterized in that the defining means comprises a first glass plate (58) arranged to shield the radiating means from the outside and allow laser beams to pass therethrough; and a second glass plate (60), arranged opposite the first glass plate, to shield the optical fibers from the outside and allow laser beams to pass therethrough; the particles (28) to be measured being between the first and second glass plates, and the light pass length L being defined by the distance between these glass plates.
Claim 14
Dependent Claim
124 words
A particle diameter measuring device according to claim 11, characterized in that the radiating means includes a laser beam generator (30); a radiating optical fiber (64), one end of which is connected to the laser beam generator to guide a laser beam therethrough; collimator lenses (62) arranged in front of the other end of the radiating optical fiber; and a radiating section (54) which houses the collimator lenses and is capable of reciprocating in conjunction with the collimator along the optical axis of the collimator lenses; with the first glass plate (58) of the defining means being arranged in front of the radiating section and the adjusting means reciprocating the radiating section in such a way as to adjust the light pass length L.
Claim 15
Dependent Claim
64 words
A particle diameter measuring device according to claim 10, characterized in that the adjusting means (55) adjusts the optical length L in such a way that the pass-through ratio t becomes larger than 0.6 in the case where it is smaller than 0.6 when expressed as a value obtained by dividing the intensity of the transmitted light by the intensity of the incident beams.
Claim 16
Dependent Claim
48 words
A particle diameter measuring device according to claim 9, characterized in that each of the optical fibers (66b, 66c,..., 66z) for scattered light is so arranged as to receive the light scattered at any of the scattering angles, each of which angles is increased by a certain increment.
Claim 17
Dependent Claim
73 words
A paritcle diameter measuring device according to claim 9, characterized in that each of the optical fibers (66b, 66c,..., 66z) for scattered light is so arranged as to receive the light scattered at any of the small scattering angles, each of which angles is increased by a small increment; and, also, to receive the light scattered at any of the large diffracting angles, each of which angles is increased by a large increment.
Claim 18
Dependent Claim
101 words
A particle diameter measuring device according to claim 15, characterized in that the range of the scattering angle at which the scattered light intensities are to be measured is divided into a plurality of ranges of scattering angles, the light scattered at any of the divided ranges of scattering angles which is increased by a certain increment is received by that optical fiber (66b, 66c,..., 66z) for scattered beams which corresponds to the scattering angle, and the increment in the divided range of small scattering angles is set to be smaller than that in the divided range of large diffracting angles.
Claim 19
Dependent Claim
43 words
A particle diameter measuring device according to claim 15, characterized in that the light scattered at any of the scattering angles which is gradually increased is received by that optical fiber (66b, 66c,..., 66z) for scattered beams which corresponds to the scattering angle.
Claim 20
Dependent Claim
107 words
A particle diameter measuring device according to claim 16, characterized in that each of the optical fibers (66b, 66c,..., 66z) for scattered light has a receiving end which is located on a circle whose center is a point located in the particles (28), the range of the scattering angle at which the scattered light intensities are to be measured is divided into two ranges, and the receiving ends of the optical fibers are arranged close to one another in two layers in one range of small scattering angles, while they are arranged close to one another in one layer in the other range of large scattering angles.
Claim 21
Dependent Claim
35 words
. A particle diameter measuring device according to claim 16, characterized in that the scattering angles at which the scattered light intensities are to be measured are in the range of from 0 to 30°.
Claim 22
Dependent Claim
34 words
A particle diameter measuring device according to claim 16, characterized in that the scattering angles at which the scattered light intensities are to be measured are in the range of from 0 to 60°.
References Cited (Backward Citations)
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