Patent US3521311A successfully refreshed from Google Patents.
Patent US3758211A successfully refreshed from Google Patents.
US3758211A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Atmospheric visibility measuring apparatus
Assignee: UK Secretary of State for Defence
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Filing: 1972-01-13
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Granted: 1973-09-11
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Expires: 1992-01-13
Abstract
Abstract The apparatus comprises a light projection means for projecting a beam of light into the atmosphere along a prescribed beam path, an optical detection means arranged to respond to light scattered by particles in the atmosphere from within another beam path surrounding an optical axis of the detector, and control apparatus for turning the light beam and the optical axis of the detection means in unison about a horizontal axis which extends substantially from the projection means to the detection means. The light projection means and the optical detection means are relatively mounted so that the optical axis of the detection means always intersects the light beam at a constant angle and at a constant range from the detection means. The control apparatus may comprise a rotatable horizontal shaft supporting the light projection means and the optical detection means. Alternatively a fixed light projector and detector may be arranged to co-operate with two mirrors provided on a rotatable horizontal shaft the mirrors being arranged to direct the light beam into the prescribed beam path and to reflect the scattered light onto the detector. The projection means and the detection means, or just the mirrors which form a part thereof, may be mounted separately and maintained in relative alignment by a follow-up servo system.
Inventors
- 👤 D Bateman
- 👤 G Burrell
- 👤 D Killick
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 13:14
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/17; G01N21/47; G01N21/49; G01N21/53; G01N21/538
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
139 words
Apparatus for measuring the visibility conditions of the atmosphere comprising projection means for projecting a beam of light along a first beam path, detection means capable of providing measurable output signals representing the amount of light incident on the detection means from within a second beam path, wherein the projection means and the detection means are mounted relative to each other so that the first and second beam paths will intersect at a predetermined constant angle and at a predetermined constant range from the detection means, and the detection means will receive light scattered from the part of the beam of light where the two beam paths intersect, and wherein the apparatus also comprises control means for turning the said two beam paths in unison about a substantially horizontal axis extending from the projection means to the detection means.
Claim 2
Dependent Claim
139 words
Apparatus for measuring the visibility conditions of the atmosphere comprising projection means for projecting a beam of light along a first beam path, detection means capable of providing measurable output signals representing the amount of light incident on the detection means from within a second beam path, wherein the projection means and the detection means are mounted relative to each other so that the first and second beam paths will intersect at a predetermined constant angle and at a predetermined constant range from the detection means, and the detection means will receive light scattered from the part of the beam of light where the two beam paths intersect, and wherein the apparatus also comprises control means for turning the said two beam paths in unison about a substantially horizontal axis extending from the projection means to the detection means.
Claim 3
Dependent Claim
60 words
Apparatus as claimed in claim 1 and wherein the control means includes a shaft mounted rotatably such that its longitudinal axis is co-linear with the said substantially horizontal axis and on which the projection means and the detection means are rigidly mounted, and means for turning the said shaft about its longitudinal axis through a predetermined range of angular positions.
Claim 4
Dependent Claim
47 words
Apparatus as claimed in claim 1 and wherein the control means comprises a follow-up servo system connected to the projection means and the detection means so as to maintain the relative alignment of the two beam paths when they are turned about the said substantially horizontal axis.
Claim 5
Dependent Claim
80 words
Apparatus as claimed in claim 1 where the projection meanS includes a light projector and a first mirror mounted to direct light from the light projector into the first beam path, wherein the detection means includes a light detector and a second mirror mounted to direct light from the second beam path onto the light detector, and wherein the control means comprises means for turning the first mirror and the second mirror in unison about the said substantially horizontal axis.
Claim 6
Dependent Claim
63 words
Apparatus as claimed in claim 4 and wherein the control means comprises a shaft mounted rotatably such that its longitudinal axis is a co-linear extension of the said substantially horizontal axis and means for turning the shaft through a predetermined range of angular positions about its longitudinal axis, and wherein the first and second mirrors are mounted on opposite ends of the shaft.
Claim 7
Dependent Claim
45 words
Apparatus as claimed in claim 4 and wherein the mirrors are mounted on separate mountings and the control means comprises a follow-up servo system connected to maintain the relative alignment of the two beam paths when they are turned about the said substantially horizontal axis.
Claim 8
Dependent Claim
30 words
Apparatus as claimed in claim 1 wherein the detection means comprises at least one part which is duplicated so as to enable measurements to be made over different path lengths.
Claim 9
Dependent Claim
64 words
Apparatus as claimed in claim 1 and also comprising an additional detection means, responsive to light from within a third beam path, and mounted so that the third beam path intersects the first beam path at a constant angle and at a constant range from the additional detector means, and is turned in unison with the first beam path and the second beam path.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-09-10 | 1977-03-12 | 1977-09-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-09-10 | 1981-03-12 | 1981-09-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-09-10 | 1985-03-12 | 1985-09-11 | $7700.00 | Window Closed / Lapsed |