Patent US2388567A successfully refreshed from Google Patents.
US3694936A
Expired / Lapsed
US
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Apparatus for determining visibility including a pulsed light source, a plurality of spaced reflectors, and a detector
Assignee: ABB Norden Holding AB
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Filing: 1971-10-21
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Granted: 1972-10-03
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Expires: 1991-10-21
Abstract
Abstract To determine visibility in varying weather conditions, a lightemitting source is arranged to emit light pulses in the direction of reflectors arranged at known constant distances or with consecutively increasing or decreasing distances between them, the size and reflexibility being unique for each one of them, and a receiving unit of which the amplification can be variable according to the time, is arranged to receive echoes from the reflectors, the number of echoes the amplitude of which exceeds a certain value are registered and counted and the number of echoes actually accepted by the receiver unit constitutes a measurement of visibility.
Inventors
- 👤 Bernt Ling
- 👤 Anders Persson
- 👤 Olof Svensson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 14:35
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/17; G01N21/47; G01N21/49; G01N21/53; G01N21/538
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
126 words
Means for determining visibility in varying weather conditions, comprising a radiation source (1), a plurality of reflectors (2,3,4,5) arranged at different distances from the radiation source to receive radiation emitted thereby, a receiving unit (7) including amplifying means (8) arranged to receive echoes of radiation from said source reflected by said reflectors, the reflective surfaces areas and reflectivity of said reflectors and the amplification factor of the receiving unit being so related that at a predetermined reference visibility the output of the amplifying means is the same for echoes from each of the reflectors, the receiving unit including means to emit output signals only in response to signals from said amplifying means exceeding a predetermined value, whereby the number of such output signals determines the visibility.
Claim 2
Dependent Claim
126 words
Means for determining visibility in varying weather conditions, comprising a radiation source (1), a plurality of reflectors (2,3,4,5) arranged at different distances from the radiation source to receive radiation emitted thereby, a receiving unit (7) including amplifying means (8) arranged to receive echoes of radiation from said source reflected by said reflectors, the reflective surfaces areas and reflectivity of said reflectors and the amplification factor of the receiving unit being so related that at a predetermined reference visibility the output of the amplifying means is the same for echoes from each of the reflectors, the receiving unit including means to emit output signals only in response to signals from said amplifying means exceeding a predetermined value, whereby the number of such output signals determines the visibility.
Claim 3
Dependent Claim
37 words
Means according to claim 1, in which the reflectors (2,3,4,5) have substantially equal reflectivity whereas the reflecting surface of each of the reflectors increases with increasing distance between the radiation source (1) and the reflectors (2, 3,4,5).
Claim 4
Dependent Claim
26 words
Means according to claim 1, in which the reflectivity of the reflectors (2,3,4,5) increases with increasing distance between the radiation source (1) and the reflectors (2,3,4,5).
Claim 5
Dependent Claim
21 words
Means according to claim 1, in which the amplification factor of the receiving unit (7) is variable depending on the time.
Claim 6
Dependent Claim
28 words
Means according to claim 1, in which said receiving unit (7) comprises members (10) arranged to count the number of echoes (11) accepted by the receiving unit (7).
Claim 7
Dependent Claim
28 words
Means according to claim 1, in which the light cross-section of the radiation source (1) is arranged to illuminate the total reflecting surface of all the reflectors (2,3,4,5).
Claim 8
Dependent Claim
15 words
Means according to claim 1, in which the radiation source (1) is a laser emitter.
References Cited (Backward Citations)
US3393321A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-10-03 | 1976-04-03 | 1976-10-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-10-03 | 1980-04-03 | 1980-10-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-10-03 | 1984-04-03 | 1984-10-03 | $7700.00 | Window Closed / Lapsed |