Patent US4008601A successfully refreshed from Google Patents.
US4008601A
Expired / Lapsed
US
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Fluidic partial pressure sensor
Assignee: United States Department of the Army
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Filing: 1975-06-16
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Granted: 1977-02-22
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Expires: 1995-06-16
Abstract
Abstract A fluidic partial pressure sensor for measuring the partial pressure of a s constituent in a mixture relative to a reference gas. The pressure drop output of a fluidic bridge concentration sensor is connected to the aspirated input of a fluidic aspirator which is operated in its sonic or saturated region. By virtue thereof, the vacuum created in the aspirated input is directly proportional to the ambient pressure at the output of the aspirator. Since the ratio of the bridge pressure drop is therefore made constant, the output pressure of the bridge sensor is thereby directly proportional to the partial pressure of the gas constituent of interest.
Inventors
- 👤 Robert L. Woods
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 12:06
CPC Classifications
G; G01; G01N; G01N7/00
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
151 words
A method for obtaining a direct indication of partial pressure of a first gas in a reference gas, comprising the steps of: supplying a fluidic bridge concentration sensor with said reference gas in a first input channel of said sensor and with a sample mixture comprising said first gas whose partial pressure is desired to be measured in said reference gas in a second input channel of said sensor; exhausting said sample mixture and said reference gas through a reference output which ensures that said pressure drop across said fluidic bridge concentration is proportional to the ambient pressure by application of a vacuum, wherein said vacuum is achieved by means of a fluidic aspirator operated in its sonic region; and measuring the pressure difference across said input channels thereby obtaining a signal output which provides a pressure directly proportional to the partial pressure of said first gas in said reference gas.
Claim 2
Independent Claim
151 words
A method for obtaining a direct indication of partial pressure of a first gas in a reference gas, comprising the steps of: supplying a fluidic bridge concentration sensor with said reference gas in a first input channel of said sensor and with a sample mixture comprising said first gas whose partial pressure is desired to be measured in said reference gas in a second input channel of said sensor; exhausting said sample mixture and said reference gas through a reference output which ensures that said pressure drop across said fluidic bridge concentration is proportional to the ambient pressure by application of a vacuum, wherein said vacuum is achieved by means of a fluidic aspirator operated in its sonic region; and measuring the pressure difference across said input channels thereby obtaining a signal output which provides a pressure directly proportional to the partial pressure of said first gas in said reference gas.
Claim 3
Independent Claim
148 words
A method for obtaining a direct indication of partial pressure of a first gas in a reference gas over varying pressures, comprising the steps of: supplying a fluidic bridge concentration sensor with said reference gas in a first input channel of said sensor and with a sample mixture comprising said first gas whose partial pressure is desired to be measured in said reference gas in a second input channel of said sensor; exhausting said sample mixture and said reference gas through a reference output which ensures that said pressure drop across said fluidic bridge concentration sensors is proportional to the ambient pressure by operating an aspirator in the choked flow condition in the region wherein ##EQU4## and measuring the pressure difference across said input channels thereby obtaining a signal output which provides a pressure directly proportional to the partial pressure of said first gas in said reference gas.
Claim 4
Independent Claim
148 words
A method for obtaining a direct indication of partial pressure of a first gas in a reference gas over varying pressures, comprising the steps of: supplying a fluidic bridge concentration sensor with said reference gas in a first input channel of said sensor and with a sample mixture comprising said first gas whose partial pressure is desired to be measured in said reference gas in a second input channel of said sensor; exhausting said sample mixture and said reference gas through a reference output which ensures that said pressure drop across said fluidic bridge concentration sensors is proportional to the ambient pressure by operating an aspirator in the choked flow condition in the region wherein ##EQU4## and measuring the pressure difference across said input channels thereby obtaining a signal output which provides a pressure directly proportional to the partial pressure of said first gas in said reference gas.
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) | 1980-02-22 | 1980-08-23 | 1981-02-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-02-22 | 1984-08-23 | 1985-02-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-02-22 | 1988-08-23 | 1989-02-22 | $7700.00 | Window Closed / Lapsed |