Patent US4561932A successfully refreshed from Google Patents.
US4375334A
Expired / Lapsed
US
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Nephelometer
Assignee: United States Department of the Navy
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Filing: 1981-06-18
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Granted: 1983-03-01
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Expires: 2001-06-18
Abstract
Abstract A nephelometer and method for measuring optical quality of a marine atmosphere and particularly characterizing its aerosol particle size distribution, visual range and aerosol optical effects in the visible and infrared. There is provided a housing for entrapping a momentary aerosol sampling, a laser source for providing a narrow collimated beam of radiant energy (usually light) through the sample, and plural spaced-apart cosine sensors facing across the radiant energy illuminated sample, with one reading a slightly greater angle than the other, for receiving aerosol particle scattered light. Integrated outputs from the sensors when compared with laser output intensity as a reference signal provide an indication of aerosol particle size distribution and concentration.
Inventors
- 👤 Hermann E. Gerber
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 11:56
CPC Classifications
G; G01; G01N; G01N15/00; G01N15/02; G01N15/0205; G01N21/00; G01N21/17; G01N21/47; G01N21/49; G01N21/51
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
181 words
A nephelometer for monitoring optical quality of a marine atmosphere comprising: a housing including an elongate chamber for containing a sampling of marine atmosphere including aerosol particles; a laser providing pulses of collimated electromagnetic radiation through the sampling longitudinally of the elongate chamber; plural cosine sensors in the chamber longitudinally spaced along the radiated sampling and looking generally transverse to the elongate chamber; means admitting scattered radiation to one of the sensors over an angular range from about 170° downstream to about 13° upstream of the radiation, and to the other sensor over an angular range from about 170° downstream to about 3° upstream of the radiation whereby said other sensor receives more forward radiation than the one; a third sensor receiving radiation from the laser through the sampling for monitoring laser output intensity and producing a reference signal in response thereto; said pair of sensors providing respective output signals in relation to the intensity of scattered radiation received by each over its entire angular ranges; and, means comparing the sensor output signals and reference signal; thereby providing scattered radiation information.
Claim 2
Dependent Claim
181 words
A nephelometer for monitoring optical quality of a marine atmosphere comprising: a housing including an elongate chamber for containing a sampling of marine atmosphere including aerosol particles; a laser providing pulses of collimated electromagnetic radiation through the sampling longitudinally of the elongate chamber; plural cosine sensors in the chamber longitudinally spaced along the radiated sampling and looking generally transverse to the elongate chamber; means admitting scattered radiation to one of the sensors over an angular range from about 170° downstream to about 13° upstream of the radiation, and to the other sensor over an angular range from about 170° downstream to about 3° upstream of the radiation whereby said other sensor receives more forward radiation than the one; a third sensor receiving radiation from the laser through the sampling for monitoring laser output intensity and producing a reference signal in response thereto; said pair of sensors providing respective output signals in relation to the intensity of scattered radiation received by each over its entire angular ranges; and, means comparing the sensor output signals and reference signal; thereby providing scattered radiation information.
Claim 3
Dependent Claim
36 words
The invention according to claim 1 wherein the means admitting scattered radiation to the sensors is further defined as a fence on either side thereof for admitting more or less upstream scattered light to a sensor.
Claim 4
Dependent Claim
24 words
The invention according to claim 2 further defined by the fences adapted to also selectively admit more or less scattered light to respective sensors.
Claim 5
Dependent Claim
29 words
The invention according to claims 1 or 2 wherein the means admitting light to the sensors includes a rotatably mounted disc adapted to provide different fence heights upon rotation.
Claim 6
Dependent Claim
16 words
The invention according to claim 4 wherein the disc is eccentrically mounted about its rotation axis.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-02-28 | 1986-08-30 | 1987-03-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-02-28 | 1990-08-30 | 1991-03-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-02-28 | 1994-08-30 | 1995-03-01 | $7700.00 | Window Closed / Lapsed |