Patent US3713743A successfully refreshed from Google Patents.
US3713743A
Expired / Lapsed
US
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Forward scatter optical turbidimeter apparatus
Assignee: MONITEK Inc A CALIFORNIA Corp
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Filing: 1970-11-25
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Granted: 1973-01-30
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Expires: 1990-11-25
Abstract
Abstract An optical turbidimeter including a light source for generating a ribbon-shaped light beam for transmission through a fluid process stream, a first light detector for measuring the intensity of the light beam after passage through the process stream, a second light detector responsive to light scattered in the forward direction by the direct beam, spatial filtering optics for focusing the scattered light only from a center section of the direct beam onto the second detector and electronic signal processing means responsive to the signals generated by the two detectors for developing an output signal proportional to the ratio of the scattered light to the transmitted light beam.
Inventors
- 👤 R Simms
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 19:37
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/17; G01N21/47; G01N21/49; G01N21/53; G01N21/532
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
243 words
A forward scatter optical turbidimeter comprising: a chamber for containing a liquid fluid sample the turbidity of which is to be evaluated, said chamber having opposite wall portions which are radiation transparent; means for defining a radiation axis through said transparent wall portions; source means disposed on one side of said chamber for developing a beam of radiation and for directing said beam of radiation across said chamber through said wall portions along said radiation axis; first radiation detector means disposed along said radiation axis on the other side of said chamber for receiving said beam of radiation and for generating a first output signal commensurate with the intensity of said beam of radiation after transmission through said fluid sample; second radiation detector means disposed along said radiation axis on the side of said first detector means opposite said chamber; spatial radiation filtering means disposed between said first and second detector means, said spatial radiation filter means being arranged and dimensioned to project only the radiation scattered in the forward direction from a predetermined longitudinal segment of said beam of radiation which lies wholly within said chamber and is spaced inwardly from said wall portions onto said second detector means, said second detector means generating a second output signal commensurate with the intensity of the received forward scattered radiation; and signal processing means responsive to said first and second output signals and operative to provide an indication of the turbidity of said sample.
Claim 2
Dependent Claim
243 words
A forward scatter optical turbidimeter comprising: a chamber for containing a liquid fluid sample the turbidity of which is to be evaluated, said chamber having opposite wall portions which are radiation transparent; means for defining a radiation axis through said transparent wall portions; source means disposed on one side of said chamber for developing a beam of radiation and for directing said beam of radiation across said chamber through said wall portions along said radiation axis; first radiation detector means disposed along said radiation axis on the other side of said chamber for receiving said beam of radiation and for generating a first output signal commensurate with the intensity of said beam of radiation after transmission through said fluid sample; second radiation detector means disposed along said radiation axis on the side of said first detector means opposite said chamber; spatial radiation filtering means disposed between said first and second detector means, said spatial radiation filter means being arranged and dimensioned to project only the radiation scattered in the forward direction from a predetermined longitudinal segment of said beam of radiation which lies wholly within said chamber and is spaced inwardly from said wall portions onto said second detector means, said second detector means generating a second output signal commensurate with the intensity of the received forward scattered radiation; and signal processing means responsive to said first and second output signals and operative to provide an indication of the turbidity of said sample.
Claim 3
Dependent Claim
243 words
A forward scatter optical turbidimeter comprising: a chamber for containing a liquid fluid sample the turbidity of which is to be evaluated, said chamber having opposite wall portions which are radiation transparent; means for defining a radiation axis through said transparent wall portions; source means disposed on one side of said chamber for developing a beam of radiation and for directing said beam of radiation across said chamber through said wall portions along said radiation axis; first radiation detector means disposed along said radiation axis on the other side of said chamber for receiving said beam of radiation and for generating a first output signal commensurate with the intensity of said beam of radiation after transmission through said fluid sample; second radiation detector means disposed along said radiation axis on the side of said first detector means opposite said chamber; spatial radiation filtering means disposed between said first and second detector means, said spatial radiation filter means being arranged and dimensioned to project only the radiation scattered in the forward direction from a predetermined longitudinal segment of said beam of radiation which lies wholly within said chamber and is spaced inwardly from said wall portions onto said second detector means, said second detector means generating a second output signal commensurate with the intensity of the received forward scattered radiation; and signal processing means responsive to said first and second output signals and operative to provide an indication of the turbidity of said sample.
Claim 4
Dependent Claim
243 words
A forward scatter optical turbidimeter comprising: a chamber for containing a liquid fluid sample the turbidity of which is to be evaluated, said chamber having opposite wall portions which are radiation transparent; means for defining a radiation axis through said transparent wall portions; source means disposed on one side of said chamber for developing a beam of radiation and for directing said beam of radiation across said chamber through said wall portions along said radiation axis; first radiation detector means disposed along said radiation axis on the other side of said chamber for receiving said beam of radiation and for generating a first output signal commensurate with the intensity of said beam of radiation after transmission through said fluid sample; second radiation detector means disposed along said radiation axis on the side of said first detector means opposite said chamber; spatial radiation filtering means disposed between said first and second detector means, said spatial radiation filter means being arranged and dimensioned to project only the radiation scattered in the forward direction from a predetermined longitudinal segment of said beam of radiation which lies wholly within said chamber and is spaced inwardly from said wall portions onto said second detector means, said second detector means generating a second output signal commensurate with the intensity of the received forward scattered radiation; and signal processing means responsive to said first and second output signals and operative to provide an indication of the turbidity of said sample.
Claim 5
Dependent Claim
35 words
A forward scatter optical turbidimeter as recited in claim 1 wherein said source means includes beam shaping means for shaping said beam of radiation into a flat ribbon which is substantially uniform along its length.
Claim 6
Dependent Claim
30 words
A forward scatter optical turbidimeter as recited in claim 2 wherein said beam of radiation has a thickness of less than 5 millimeters along tHe flat portion of said ribbon.
Claim 7
Dependent Claim
39 words
A forward scatter optical turbidimeter as recited in claim 3 wherein said beam of radiation has a transverse width sufficient to occupy at least 50% of the effective cross-sectional area of said chamber through which said light beam passes.
Claim 8
Dependent Claim
42 words
A forward scatter optical turbidimeter as recited in claim 1 and further including a calibration means for permitting a predetermined amount of light, in the form of a calibration beam, to pass through said chamber and only onto said second detector means.
Claim 9
Dependent Claim
68 words
A forward scatter optical turbidimeter as recited in claim 1 in which said spatial radiation filtering means includes, an imaging lens system for imaging the scattered radiation onto said second detector means, and a limiting means cooperating with said second detector means to restrict the imaged radiation to an annulus whose inner and outer diameters correspond, respectively, to the near and far end portion of said longitudinal segment.
Claim 10
Dependent Claim
32 words
A forward scatter optical turbidimeter as recited in claim 6 in which said limiting means includes a central mask overlying said second detector means for defining the inner diameter of said annulus.
Claim 11
Dependent Claim
31 words
A forward scatter optical turbidimeter as recited in claim 6 in which the radiation sensitive portion of said second detector means extends to and defines said outer diameter of said annulus.
Claim 12
Dependent Claim
201 words
A forward scatter optical turbidimeter for monitoring the turbidity of a flowing liquid comprising: a flow channel through which the flowing liquid is passed, said flow channel having opposite wall portions which are optically transparent; means for defining an optical axis through said transparent wall portions transversing said flow channel; light source means disposed on one side of said flow channel for developing and projecting a light beam, having a ribbon-like, substantially uniform cross section along its length, along said optical axis; first light detector means disposed along said optical axis on the other side of said flow channel for receiving the light from said light beam which is directly transmitted and for generating a first output signal commensurate with the intensity such directly transmitted light; second detector means disposed along said optical axis on the side of said first detector means opposite said flow channel for receiving the light from said light beam which is scattered in the forward direction and for generating a second output signal commensurate with the intensity of such forward scattered light; and signal processing means responsive to said first and second output signals and operative to provide an indication of the turbidity of said fluid.
Claim 13
Dependent Claim
201 words
A forward scatter optical turbidimeter for monitoring the turbidity of a flowing liquid comprising: a flow channel through which the flowing liquid is passed, said flow channel having opposite wall portions which are optically transparent; means for defining an optical axis through said transparent wall portions transversing said flow channel; light source means disposed on one side of said flow channel for developing and projecting a light beam, having a ribbon-like, substantially uniform cross section along its length, along said optical axis; first light detector means disposed along said optical axis on the other side of said flow channel for receiving the light from said light beam which is directly transmitted and for generating a first output signal commensurate with the intensity such directly transmitted light; second detector means disposed along said optical axis on the side of said first detector means opposite said flow channel for receiving the light from said light beam which is scattered in the forward direction and for generating a second output signal commensurate with the intensity of such forward scattered light; and signal processing means responsive to said first and second output signals and operative to provide an indication of the turbidity of said fluid.
Claim 14
Dependent Claim
28 words
A forward scatter optical turbidimeter as recited in claim 9 wherein said light source means comprises a laser and a beam expanding means for developing said light beam.
Claim 15
Dependent Claim
76 words
A forward scatter optical turbidimeter is recited in claim 9 which further includes spatial optical filtering means disposed on the side of said first detector means opposite said flow channel portion, said filtering means being operative to project only the light scattered in the forward direction from a predetermined longitudinal segment of said light beam which lies wholly within said flow channel portion and which is spaced inwardly from said walls onto said second detector means.
Claim 16
Dependent Claim
62 words
A forward scatter optical turbidimeter as recited in claim 11 wherein said spatial optical filtering means includes, an imaging lens system for imaging the scattered radiation on said second detector means, and means to limit the area of sensitivity of said second detector means to an annulus whose inner and outer diameters correspond to the desired end portions of said longitudinal segments.
Claim 17
Dependent Claim
43 words
A forward scatter optical turbidimeter as recited in claim 9 which further includes a calibration means for permitting a predetermined amount of light, in the form of a calibration beam, to pass through said flow channel and oNly onto said second detector means.
Claim 18
Dependent Claim
39 words
A forward scatter optical turbidimeter as recited in claim 9 wherein the transverse cross section of said light beam is substantially rectangular and has a thickness in the direction of the flowing liquid which is less then 5 millimeters.
Claim 19
Dependent Claim
34 words
A forward scatter optical turbidimeter as recited in claim 9 wherein the width of said light beam is sufficient to occupy at least 50 percent of the effective cross-sectional area of said flow channel.
Claim 20
Dependent Claim
31 words
A forward scatter optical turbidimeter as recited in claim 9 wherein said signal processing means includes circuit means for electronically rejecting spurious signal excursions caused by bubbles in the flowing liquid.
Claim 21
Dependent Claim
45 words
A forward scatter optical turbidimeter as recited in claim 9 in which said light beam is made as thin in the direction of flow of the flowing liquid as is compatible with the sensitivity of said light detector means to provide a readable output signal.
Claim 22
Dependent Claim
58 words
A forward scatter optical turbidimeter as recited in claim 9 having a pair of side walls parallel to said optical axis and in which said light beam is made as wide in the direction transverse to the flowing liquid as is compatible with the transverse width of the flow channel without coming in contact with said side walls.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-01-30 | 1976-07-31 | 1977-01-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-01-30 | 1980-07-31 | 1981-01-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-01-30 | 1984-07-31 | 1985-01-30 | $7700.00 | Window Closed / Lapsed |