US5048323A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fluid metering
Assignee: Gemalto Terminals Ltd
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Filing: 1988-08-11
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Granted: 1991-09-17
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Expires: 2008-08-11
Abstract
Abstract A gas flow correction sensor for producing an output signal proportional to the ratio between line pressure and line temperature for gas flowing in a line, for use in correcting the output of a volumetric flow meter connected in the line, comprises a sealed chamber containing a fixed mass of a reference gas. The sealed chamber includes a bellows portion subjected to line pressure, thus maintaining the reference gas at line pressure. Additionally, the sealed chamber is thermally insulated and includes at least a portion disposed in a thermowell immersed in the line, so as to maintain the reference gas at line temperature. A vibrating quartz density sensor is also mounted in the thermowell, so as to produce an output signal whose frequency is proportional to the density of the reference gas, which can be shown also to be proportional to the desired line pressure to line temperature ratio.
Inventors
- 👤 James W. Stansfeld
- 👤 David I. H. Atkinson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 02:56
CPC Classifications
G; G01; G01F; G01F15/00; G01F15/02; G01F15/04; G01F15/043; G01N; G01N9/00; G01N9/002
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
114 words
A gas flow correction sensor for sensing a pressure-temperature function of gas flowing in a line for use in correcting the output of a volumetric flow meter connected in the line, the sensor comprising: a sealed gas-containing chamber having at least a portion thereof in a thermowell entering the line, said chamber including a bellows subjected to line pressure and said portion comprising a capillary tube connected with a sub-chamber, whereby the contained gas will be maintained at line temperature and pressure; and a vibrating element density sensing means for producing an output signal whose frequency is dependent upon the density of the contained gas, the density sensing means being mounted in said sub-chamber.
Claim 2
Dependent Claim
114 words
A gas flow correction sensor for sensing a pressure-temperature function of gas flowing in a line for use in correcting the output of a volumetric flow meter connected in the line, the sensor comprising: a sealed gas-containing chamber having at least a portion thereof in a thermowell entering the line, said chamber including a bellows subjected to line pressure and said portion comprising a capillary tube connected with a sub-chamber, whereby the contained gas will be maintained at line temperature and pressure; and a vibrating element density sensing means for producing an output signal whose frequency is dependent upon the density of the contained gas, the density sensing means being mounted in said sub-chamber.
Claim 3
Dependent Claim
18 words
A sensor as claimed in claim 1, wherein the density sensing means comprises a resonant quartz density sensor.
Claim 4
Dependent Claim
41 words
A sensor as claimed in claim 1, further comprising a second density sensing means similar to the first mentioned sensing means but arranged to be subjected only to line temperature, for cancelling intrinsic temperature dependent errors of the first sensing means.
Claim 5
Dependent Claim
23 words
A sensor as claimed in claim 1, wherein the contained gas is chosen to be of comparable compressibility with the gas being metered.
Claim 6
Dependent Claim
21 words
A sensor as claimed in claim 1, wherein the capillary and sub-chamber are formed within an elongate probe in said thermowell.
Claim 7
Dependent Claim
23 words
A sensor as claimed in claim 1, wherein the bellows volume is large compared with the volume of any capillary and sub-chamber portions.
Claim 8
Dependent Claim
41 words
A sensor as claimed in claim 2, further comprising a second density sensing means similar to the first mentioned sensing means but arranged to be subjected only to line temperature, for cancelling intrinsic temperature dependent errors of the first sensing means.
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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) | 1994-09-16 | 1995-03-18 | 1995-09-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-09-16 | 1999-03-18 | 1999-09-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-09-16 | 2003-03-18 | 2003-09-17 | $7700.00 | Window Closed / Lapsed |