US3632209A
Expired / Lapsed
US
⏱️ 0.0 years remaining
System for measuring light transmittance through absorptive or diffusive media
Assignee: Susquehanna Corp
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Filing: 1970-04-28
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Granted: 1972-01-04
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Expires: 1990-04-28
Abstract
Abstract A system and process are disclosed for measuring the transmittance or opacity of a smoke plume discharged from a smokestack or diesel engine exhaust. Measurement is accomplished by passing light pulses through the smoke plume and detecting the remaining energy with a photoelectric detector. The effect of scattered light is eliminated. An electrical signal proportional to the unabsorbed light received at the detector is displayed on a calibrated opacity meter.
Inventors
- 👤 Edward F Kingman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 22:23
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/17; G01N21/47; G01N21/49; G01N21/53; G01N21/534; F; F02; F02B; F02B3/00; F02B3/06
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
179 words
A system for measuring the opacity or transmittance of a medium comprising, a light transmitter, including, a. a light source for emitting light, b. a target for providing an optical contrast to said light source, c. and means for causing said light to be emitted from said light transmitter as pulses of light; a receiver, including, a. a photosensitive detector spaced from said light source and target and positioned to have its field of view filled thereby, for providing an output in proportion to the intensity of light received through said medium, b. a processing circuit connected to said detector for providing an electrical signal proportional to the detector output, said processing circuit including, i. means for substantially eliminating the effect of scattered light caused by said medium and Received at said detector, c. and means connected to said processing circuit for providing a sensible indication of opacity or transmittance of the medium; said light source and said detector defining the sole light path between said transmitter and receiver through said medium for receipt of light by said detector.
Claim 2
Independent Claim
179 words
A system for measuring the opacity or transmittance of a medium comprising, a light transmitter, including, a. a light source for emitting light, b. a target for providing an optical contrast to said light source, c. and means for causing said light to be emitted from said light transmitter as pulses of light; a receiver, including, a. a photosensitive detector spaced from said light source and target and positioned to have its field of view filled thereby, for providing an output in proportion to the intensity of light received through said medium, b. a processing circuit connected to said detector for providing an electrical signal proportional to the detector output, said processing circuit including, i. means for substantially eliminating the effect of scattered light caused by said medium and Received at said detector, c. and means connected to said processing circuit for providing a sensible indication of opacity or transmittance of the medium; said light source and said detector defining the sole light path between said transmitter and receiver through said medium for receipt of light by said detector.
Claim 3
Dependent Claim
30 words
A system as claimed in claim 1 wherein, a. said causing means comprises means for intermittently energizing said light source to cause said light source to emit pulses of light.
Claim 4
Dependent Claim
35 words
A system as claimed in claim 2 wherein, a. said medium is a smoke plume, and b. said providing means is a meter for providing a direct reading in percent opacity of said smoke plume.
Claim 5
Independent Claim
165 words
A method for measuring the opacity or transmittance of a medium by the use of a light source and an optically contrasting target and a detector spaced therefrom, and a measuring circuit connected to the detector, comprising: a. calibrating said circuit so that the difference in luminance between said light source and contrasting target when viewed by the detector clear of the medium is a fixed value, b. pulsing said light source to provide alternately to the detector a source of light and an optically contrasting target as viewed through the medium, c. causing said medium to flow in a path between said light source and contrasting target and said detector, d. detecting the apparent luminances between said light source and contrasting target when viewed by said detector through said medium, e. electrically processing the detected apparent luminances to provide a difference signal, and f. referencing said difference signal to said fixed value to give an indication of the opacity or transmittance of said medium.
Claim 6
Independent Claim
165 words
A method for measuring the opacity or transmittance of a medium by the use of a light source and an optically contrasting target and a detector spaced therefrom, and a measuring circuit connected to the detector, comprising: a. calibrating said circuit so that the difference in luminance between said light source and contrasting target when viewed by the detector clear of the medium is a fixed value, b. pulsing said light source to provide alternately to the detector a source of light and an optically contrasting target as viewed through the medium, c. causing said medium to flow in a path between said light source and contrasting target and said detector, d. detecting the apparent luminances between said light source and contrasting target when viewed by said detector through said medium, e. electrically processing the detected apparent luminances to provide a difference signal, and f. referencing said difference signal to said fixed value to give an indication of the opacity or transmittance of said medium.
Claim 7
Dependent Claim
29 words
A method as claimed in claim 4 further comprising the step of: a. Eliminating the effect of scattered light through the medium while electrically processing said detected apparent luminances.
Claim 8
Dependent Claim
35 words
A method as claimed in claim 5 where said medium is a smoke plume and further comprising the step of: a. Providing for said indication a direct reading in percent opacity of said smoke plume.
Claim 9
Independent Claim
155 words
A system for measuring the opacity or transmittance of a medium comprising, a light transmitter, including, a. a light source for emitting light, b. a target for providing an optical contrast to said light source, c. means for causing said light to be emitted from said light transmitter as pulses of light; a receiver, including, a. a photosensitive detector spaced from said light source and target and positioned to have its field of view filled thereby, for providing an output in proportion to the intensity of light received through said medium, b. a processing circuit connected to said detector for providing an electrical signal proportional to the detector output, said processing circuit including, i. means for calibrating said receiver with reference to said light source and contrasting target clear of the effect of said medium, c. and means connected to said processing circuit for providing a sensible indication of opacity or transmittance of the medium.
Claim 10
Independent Claim
155 words
A system for measuring the opacity or transmittance of a medium comprising, a light transmitter, including, a. a light source for emitting light, b. a target for providing an optical contrast to said light source, c. means for causing said light to be emitted from said light transmitter as pulses of light; a receiver, including, a. a photosensitive detector spaced from said light source and target and positioned to have its field of view filled thereby, for providing an output in proportion to the intensity of light received through said medium, b. a processing circuit connected to said detector for providing an electrical signal proportional to the detector output, said processing circuit including, i. means for calibrating said receiver with reference to said light source and contrasting target clear of the effect of said medium, c. and means connected to said processing circuit for providing a sensible indication of opacity or transmittance of the medium.
Claim 11
Dependent Claim
30 words
A system as claimed in claim 7 wherein, a. said causing means comprises means for intermittently energizing said light source to cause said light source to emit pulses of light.
Claim 12
Dependent Claim
54 words
A system as claimed in claim 8 wherein, a. said processing circuit includes means for substantially eliminating the effect of steady-state components received at said detector, and b. said light source and said detector define the sole light path between said transmitter and receiver through said medium for receipt of light by said detector.
Claim 13
Dependent Claim
35 words
A system as claimed in claim 9 wherein, a. said target is black, and b. said light source is approximately centered in said black target with reference to the field of view of said detector.
Claim 14
Dependent Claim
35 words
A system as claimed in claim 10, wherein a. said medium is a sMoke plume, and b. said providing means is a meter for providing a direct reading in percent opacity of said smoke plume.
References Cited (Backward Citations)
US2198971A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-01-03 | 1975-07-05 | 1976-01-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-03 | 1979-07-05 | 1980-01-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-03 | 1983-07-05 | 1984-01-04 | $7700.00 | Window Closed / Lapsed |