Patent US3701283A successfully refreshed from Google Patents.
US3701283A
Expired / Lapsed
US
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Pressure-subtracting hypsometric apparatus
Assignee: United States Department of the Navy
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Filing: 1970-10-26
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Granted: 1972-10-31
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Expires: 1990-10-26
Abstract
Abstract A hypsometric liquid such as water is supported in a closed chamber on a tubular column of mercury, the mercury being exposed in a manometric manner to atmospheric pressure so that variations in the atmospheric pressure increase or reduce the height of the mercury column. Also, an increase in pressure applied to the hypsometric liquid reduces the height of the mercury column since the liquid rests directly on the mercury. The hypsometric liquid is heated in a controlled manner to produce a vapor that exerts pressure on the liquid and the mercury column. As the temperature is increased by the heater, the mercury moves down the tube until it reaches a constant or fixed level at which sensor electronics adjust the power to the heater so that the top of the mercury column remains exactly at this fixed level. The pressure on the liquid is determined by measuring the temperature inside the hypsometric chamber. Atmospheric pressure is essentially equal to the hypsometric chamber pressure plus the pressure equivalent of the mercury column. The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.
Inventors
- 👤 Ernest W Lichfield
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 14:55
CPC Classifications
G; G01; G01L; G01L9/00; G01L9/0091; G01L9/0097
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
192 words
Pressure-subtracting hypsometric apparatus comprising: an elongate member having a manometric-type tubular column portion open to the atmosphere at one of its ends, said elongate member also having a closed hypsometric chamber portion communicating with the other end of said manometric tubular portion, a column of manometric liquid carried by said tubular portion, a volatile hypsometric liquid partially filling said chamber portion and having an interface resting on and immiscible with said manometric liquid, heating means for vaporizing said hypsometric liquid for producing a vapor pressure in said partially filled chamber sufficient to move said interface against atmospheric pressure to a predetermined fixed level, heat control means for continuously maintaining said fixed level, said control means being responsive to transitory pressureinduced fluctuating movements of said interface in either direction from said fixed level for selectively energizing or deenergizing said heating means sufficiently to promptly return the interface to said fixed level, and means for detecting the temperature of said hypsometric liquid when said interface is at said fixed level, whereby the atmospheric pressure is derivable by adding the pressure equivalent of said detected temperature to the pressure equivalent of the fixed-level manometric column.
Claim 2
Dependent Claim
192 words
Pressure-subtracting hypsometric apparatus comprising: an elongate member having a manometric-type tubular column portion open to the atmosphere at one of its ends, said elongate member also having a closed hypsometric chamber portion communicating with the other end of said manometric tubular portion, a column of manometric liquid carried by said tubular portion, a volatile hypsometric liquid partially filling said chamber portion and having an interface resting on and immiscible with said manometric liquid, heating means for vaporizing said hypsometric liquid for producing a vapor pressure in said partially filled chamber sufficient to move said interface against atmospheric pressure to a predetermined fixed level, heat control means for continuously maintaining said fixed level, said control means being responsive to transitory pressureinduced fluctuating movements of said interface in either direction from said fixed level for selectively energizing or deenergizing said heating means sufficiently to promptly return the interface to said fixed level, and means for detecting the temperature of said hypsometric liquid when said interface is at said fixed level, whereby the atmospheric pressure is derivable by adding the pressure equivalent of said detected temperature to the pressure equivalent of the fixed-level manometric column.
Claim 3
Dependent Claim
30 words
The apparatus of claim 1 wherein: said hypsometric chamber portion is evacuated to minimize the effects of atmospheric pressure acting on its liquid contents, and said manometric liquid is mercury.
Claim 4
Dependent Claim
33 words
The apparatus of claim 1 wherein said temperature detecting means includes: a thermistor mounted on said hypsometric chamber portion, a remotely disposed recorder, and means electrically coupling the thermistor output to said recorder.
Claim 5
Dependent Claim
131 words
The apparatus of claim 1 wherein said manometric liquid is mercury and said heat control means includes: a light source, electrical circuit means for energizing said heating means, and light responsive switching means for opening and closing said circuit, said light source having a beam intersecting said tubular column at said fixed level and said switching means being disposed in the path of said beam, said switching means closing saiD circuit at a preselected light intensity level and said hypsometric fluid being sufficiently light-transmissive to transmit said intensity level, said mercury alternating the light intensity sufficiently to open the circuit and interupt energization of the heating means, whereby movement of said interface through the beam path is capable of maintaining said fixed level by responsively energizing and deenergizing the heating means.
Claim 6
Dependent Claim
45 words
The apparatus of claim 1 further including temperature control means for insulating the apparatus for environmental temperature conditions, said temperature control means comprising: a metal container encasing the apparatus, heating means for maintaining the container at a preselected temperature, and heat-insulating means encasing the container.
Claim 7
Dependent Claim
41 words
The apparatus of claim 4 wherein said heat control means further includes: means for controlling the intensity of said light source for causing said heating means to be alternately switched on and off when said interface is intersected by the beam.
Claim 8
Dependent Claim
57 words
The apparatus of claim 5 wherein said means for controlling the light source intensity includes: light-responsive circuit means for producing a light beam having an intensity varying between fixed intensity levels, said light responsive switching means of said heat control circuit being responsive to said light beam intensity for alternately switching said heating means on or off.
References Cited (Backward Citations)
US2459268A
Cited
US2758476A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-10-31 | 1976-05-01 | 1976-10-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-10-31 | 1980-05-01 | 1980-10-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-10-31 | 1984-05-01 | 1984-10-31 | $7700.00 | Window Closed / Lapsed |