Patent US3790289A successfully refreshed from Google Patents.
US3790289A
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US
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Gas turbidity measuring apparatus
Assignee: Robert Bosch GmbH
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Filing: 1973-02-05
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Granted: 1974-02-05
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Expires: 1993-02-05
Abstract
Abstract The turbidity of exhaust gases of an internal combustion engine is measured by comparing light transmission through the gases with light transmission through an equivalent body of clean air. In order to prevent accumulation of dirt or soot on the light source, photocell, and optical path element, a pair of transparent rotating discs is used to close off the opening through which light enters and leaves the test chamber, allowing a small gap for a laminar boundary layer of clean air. One of the discs has opaque sectors and functions also as a shutter,so that the light may pass alternately through the test chamber and through another chamber containing clean air.
Inventors
- 👤 U Schmidt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 05:11
CPC Classifications
F; F02; F02D; F02D41/00; F02D41/02; F02D41/14; F02D41/1438; F02D41/1444; F02D41/1451; G; G01; G01N; G01N21/00; G01N21/17; G01N21/47; G01N21/49; G01N21/53; G01N21/534; G01N21/84; G01N21/85
Claims Analysis
Total Claims: 30
Claim 1
Independent Claim
118 words
Apparatus for evaluating turbidity in gases, such as exhaust gases of diesel motors, by measuring the attenuation of a light beam passing through a chamber filled with the gas to be measured, comprising: a pair of rotationally driven transparent discs disposed on opposite ends of said chamber closely adjacent openings in said chamber facing said discs through which said light beam passes in, at one end, and out, at the other end, so that said discs close off said chamber in such a manner that a boundary layer of clean air entrained by said discs on their surfaces acts to prevent, or to reduce greatly, direct conact between said discs (21,22) and the said gases to be examined.
Claim 2
Dependent Claim
118 words
Apparatus for evaluating turbidity in gases, such as exhaust gases of diesel motors, by measuring the attenuation of a light beam passing through a chamber filled with the gas to be measured, comprising: a pair of rotationally driven transparent discs disposed on opposite ends of said chamber closely adjacent openings in said chamber facing said discs through which said light beam passes in, at one end, and out, at the other end, so that said discs close off said chamber in such a manner that a boundary layer of clean air entrained by said discs on their surfaces acts to prevent, or to reduce greatly, direct conact between said discs (21,22) and the said gases to be examined.
Claim 3
Dependent Claim
54 words
Apparatus as defined in claim 1 in which a gap is provided between the respective ends of the chamber (10) and the facing surfaces of said discs (21,22) which approximately corresponds to the thickness of said clean air boundary layer and has a gap width of approximately 0.2 mm, but not exceeding 0.4 mm.
Claim 4
Dependent Claim
28 words
Apparatus as defined in claim 1 in which the axis of rotation (23) of said discs (21,22) passes outside of said chamber (10) through which said gases flow.
Claim 5
Dependent Claim
32 words
Apparatus as defined in claim 3 in which said gases flow through said chamber (10) in a direction parallel to the surface of said discs (21,22) and in their direction of rotation.
Claim 6
Dependent Claim
37 words
Apparatus as defined in claim 4 in which the velocity of flow of said gases is approximately equal to the velocity of rotation of said discs (21,22) in the neighborhood of said openings of said chamber (10).
Claim 7
Dependent Claim
33 words
Apparatus as defined in claim 4 in which a second measuring chamber (11) filled with clean air is arranged parallel to the aforesaid chamber (10) through which flow the gases to be examined.
Claim 8
Dependent Claim
31 words
Apparatus as defined in claim 6 in which said second chamber (11) is bounded at its ends by the same transparent and rotating discs (21,22) as said first mentioned chamber (10),
Claim 9
Dependent Claim
30 words
Apparatus as defined in claim 7 in which said second chamber (11) filled with clean air is subjected to a pressure above atmospheric pressure by means of a pump (12).
Claim 10
Dependent Claim
18 words
Apparatus as defined in claim 6 in which said second chamber (11) is closed off on all sides.
Claim 11
Dependent Claim
36 words
Apparatus as defined in claim 6 in which a light beam is passed through said second chamber (11) coming from the same source (25) which provides the light beam passing through said first mentioned chamber (10).
Claim 12
Dependent Claim
62 words
Apparatus as defined in claim 10 in which at least one of said two rotationally driven transparent discs (21,22) is partly covered with opaque material in such a way that as the result of rotation of said discs, the light beams passing through said chambers (10,11) are alternately blocked off and the aggregate cross section of the two light beams remains constant.
Claim 13
Dependent Claim
31 words
Apparatus as defined in claim 11 in which the light which passes through said chambers (10,11) iS in each case concentrated into a parallel or weakly convergent beam by a collimator.
Claim 14
Dependent Claim
47 words
Apparatus as defined in claim 12 in which the path of light prior to reaching each of the said chambers (10,11) is controlled by a diaphragm, which limits the passage of light coming out of each of said collimators to a light beam of the same magnitude.
Claim 15
Dependent Claim
27 words
Apparatus as defined in claim 13 in which the light coming out of each of said chambers (10,11) is gathered in each case by a lens (33).
Claim 16
Dependent Claim
19 words
Apparatus as defined in claim 14 in which a diaphragm is provided behind each of said gathering lenses (33).
Claim 17
Dependent Claim
40 words
Apparatus as defined in claim 15 in which an optical device is provided behind each of said diaphragms on the exit side of said light beams, which is adapted to project the diaphragm openings onto a common light sensitive element.
Claim 18
Dependent Claim
41 words
Apparatus as defined in claim 16 in which the light gathered by said lenses is in each case transmitted by an optical fiber (35,36) onto a final cross sectional surface which corresponds to the cross section of the combined light beam.
Claim 19
Dependent Claim
45 words
Apparatus as defined in claim 17 in which the path of light through each of said chambers (10,11) passes in each case through a polarization filter, which makes possible the regulation of the light flowing through each of said chambers (10,11) to any desired degree.
Claim 20
Dependent Claim
17 words
Apparatus as defined in claim 10 in which said light source (25) delivers light similar to sunlight.
Claim 21
Dependent Claim
41 words
Apparatus as defined in claim 16 in which the color sensitivity of said light sensitive device (37) is made to correspond to that of the human eye in its response properties either directly or by the interposition of suitable color filters.
Claim 22
Dependent Claim
15 words
Apparatus as defined in claim 10 in which said light source (25) provides monochromatic light.
Claim 23
Dependent Claim
20 words
Apparatus as defined in claim 21 in which said light source (25) provides light in the short wave ultraviolet region.
Claim 24
Dependent Claim
45 words
Apparatus as defined in claim 10 in which said light source provides heterochromatic light and in which a filter is used in the path of said light which allows only a light of a narrow range of wave lengths in the ultraviolet region to pass.
Claim 25
Dependent Claim
45 words
Apparatus as defined in claim 10 in which a regulating device is interposed in the path of light which is passed through said second chamber (11) filled with clean air, said regulating device being provided with means for reading off its position at any time.
Claim 26
Dependent Claim
43 words
Apparatus as defined in claim 24 in which said regulating device is adjustable by automatically operative means (38) in such a manner that illumination of said light sensitive device (37) through said two chambers together remains constant during rotation of said discs (21,22).
Claim 27
Dependent Claim
23 words
Apparatus as defined in claim 25 in which an electrical indicator is provided for detecting and indicating the position of said regulating device.
Claim 28
Dependent Claim
30 words
Apparatus as defined in claim 6 in which said chamber (10) filled with said gases to be examined is provided with a temperature sensor for measuring the average gas temperature.
Claim 29
Dependent Claim
45 words
Apparatus as defined in claim 5 in which guide vanes are provided at the entrance end of said chamber (10) through which said gases to be examined flow, which vanes are adapted to promote even distribution of said gases over the length of said chamber.
Claim 30
Dependent Claim
53 words
Apparatus as defined in claim 28 in which the portions of the apparatus which guide the gases to be examined are at least in part surrounded by a covering and that the space between these portions and said covering are arranged to provide for the passage therethrough of a heating or cooling medium.
References Cited (Backward Citations)
US2966092A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-02-04 | 1977-08-06 | 1978-02-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-04 | 1981-08-06 | 1982-02-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-04 | 1985-08-06 | 1986-02-05 | $7700.00 | Window Closed / Lapsed |