US3817623A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for measuring visibility in a fluid
Assignee: Impulsphysik GmbH
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Filing: 1973-02-15
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Granted: 1974-06-18
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Expires: 1993-02-15
Abstract
Abstract A light source has an outlet opening for emitted light and a light detector is spaced from the light source and has an inlet opening to receive emitted light. The path between these two openings leads through the fluid which is to be measured. A baffle is interposed between the two openings in such a manner that light cannot move from the outlet opening into the inlet opening in a straight path. A pair of omni-directionally lightdiffusing cover plates of light-transmissive material are provided, each overlying and closing one of the openings and having an active surface area which is at most slightly larger than the area of the respective opening.
Inventors
- 👤 F Fruengel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 13:17
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/17; G01N21/47; G01N21/49; G01N21/53; G01N21/538; G01W; G01W1/00; G01W1/14
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
134 words
In an apparatus for measuring visibility in a fluid, a combination comprising light source means having an outlet opening for emitted light; light detecting means spaced from said light source means and having an inlet opening positioned to receive light emitted by said light source and travelling from said outlet opening to said inlet opening along a path leading through the fluid to be measured; baffle means interposed between said outlet opening and said inlet opening and positioned to continuously prevent direct incidence of the emitted light into said inlet opening; heating means for heating said baffle means; and a pair of omni-directionally light-diffusing cover plates of light-transmissive material, each overlying one of said openings and having an active surface area which is at most slightly larger than the area of the respective opening.
Claim 2
Dependent Claim
134 words
In an apparatus for measuring visibility in a fluid, a combination comprising light source means having an outlet opening for emitted light; light detecting means spaced from said light source means and having an inlet opening positioned to receive light emitted by said light source and travelling from said outlet opening to said inlet opening along a path leading through the fluid to be measured; baffle means interposed between said outlet opening and said inlet opening and positioned to continuously prevent direct incidence of the emitted light into said inlet opening; heating means for heating said baffle means; and a pair of omni-directionally light-diffusing cover plates of light-transmissive material, each overlying one of said openings and having an active surface area which is at most slightly larger than the area of the respective opening.
Claim 3
Dependent Claim
24 words
A combination as defined in claim 1, wherein said cover plates are substantially circular and have a diameter of up to substantially 25 mm.
Claim 4
Dependent Claim
30 words
A combination as defined in claim 1; and further comprising a potting material embedding and fluid-tightly encapsulating said light source and light detecting means and part of said baffle means.
Claim 5
Dependent Claim
50 words
A combination as defined in claim 1, said light source means comprising a laser diode operative for emitting constant-amplitude light pulses; and further comprising an optical narrow-bandpass filter inwardly of the cover plate associated with said inlet so as to permit entry of only the light pulses of said diode.
Claim 6
Dependent Claim
14 words
A combination as defined in claim 1, wherein said cover plates are ground-glass plates.
Claim 7
Dependent Claim
28 words
A combination as defined in claim 1, wherein said fluid is water; and wherein said plates are of a material resistant to the formation of marine growths thereon.
Claim 8
Dependent Claim
20 words
A combination as defined in claim 6, wherein said material is boron-silicate glass with a vapor-deposited heavy-metal ion film thereon.
Claim 9
Dependent Claim
22 words
A combination as defined in claim 1, wherein said baffle means is at least in part composed of optically blackened heavy metal.
Claim 10
Dependent Claim
16 words
A combination as defined in claim 8, wherein said metal is selected from copper and brass.
Claim 11
Dependent Claim
79 words
A combination as defined in claim 1, wherein said baffle means comprises a U-shaped baffle element having side walls provided with free edges, and a transverse wall; and wherein said heating means is provided on said transverse wall so as to heat said free edges via said transverse and said side walls; and further comprising potting material fluid-tightly encapsulating said light source means, said light detecting means and said baffle means except for at least said free edges thereof.
Claim 12
Dependent Claim
59 words
A combination as defined in claim 1, said baffle means comprising a baffle element of a heavy metal having anti-fouling properties in water; and wherein said heating means includes at least one heating transistor in heat-exchanging contact with said baffle element, and further comprising a thermistor control associated with said transistor, and thermostat means also associated with said transistor.
Claim 13
Dependent Claim
74 words
A combination as defined in claim 1, wherein said baffle means is arranged symmetrically about an axis of said apparatus, such that the volume of space traversed by said path surrounds an outer periphery of said baffle means; and further comprising mounting means for mounting said baffle means, light source means and detecting means, said mounting means extending into a bi-conical volume of space defined by the shortest unobstructed light path between said openings.
Claim 14
Dependent Claim
51 words
A combination as defined in claim 1; further comprising a chargeable source of electrical energy operatively associated with said light source means; and photoelectric charging means connected with said energy source and operative for charging the same in response to the incidence of light of requisite brightness onto said charging means.
Claim 15
Dependent Claim
62 words
In an apparatus for measuring visibility in a fluid, a combination comprising a source of diffuse emitted light; a non-focused light receiver spaced from said source; and a heated baffle unit of thermally conductive material having anti-fouling properties in at least some fluids, interposed between said source and said receiver for preventing direct passage of light from the former to the latter.
Claim 16
Dependent Claim
62 words
In an apparatus for measuring visibility in a fluid, a combination comprising a source of diffuse emitted light; a non-focused light receiver spaced from said source; and a heated baffle unit of thermally conductive material having anti-fouling properties in at least some fluids, interposed between said source and said receiver for preventing direct passage of light from the former to the latter.
References Cited (Backward Citations)
US3672775A
Cited
US3694936A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-06-17 | 1977-12-17 | 1978-06-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-17 | 1981-12-17 | 1982-06-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-17 | 1985-12-17 | 1986-06-18 | $7700.00 | Window Closed / Lapsed |