Patent US2698430A successfully refreshed from Google Patents.
US5285673A
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US
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Method for in-line calibration verification of mass flow meters
Assignee: DXL International Inc
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Filing: 1991-11-08
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Granted: 1994-02-15
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Expires: 2011-11-08
Abstract
Abstract An apparatus for verifying the calibration of a flow meter contains a flow sensor assembly which has a flow tube defining an axial fluid path through the flow sensor assembly; an upstream temperature sensor in thermal contact with the flow tube; a downstream temperature sensor in thermal contact with the flow tube, the two sensors being operationally connected to a means for producing an output in response to a temperature difference between the first and second sensors; and means for asymmetrically transferring heat to the first and second temperature sensors independently of fluid flow through the flow tube. The calibration of the flow meter's thermal and electronic systems is verified by measuring the flow meter's output in response to a first asymmetric heat transfer to the upstream and downstream temperature sensors when the flow meter is calibrated. The output of the flow meter in response to a second asymmetric transfer to the upstream and downstream sensors is subsequently measured and comparison of the two readings verifies whether the flow meter's thermal and electronic systems remains calibrated.
Inventors
- 👤 Charles F. Drexel
- 👤 Daniel T. Mudd
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 20:57
CPC Classifications
G; G01; G01F; G01F1/00; G01F1/68; G01F1/684; G01F1/6847; G01F1/688; G01F1/6888
Claims Analysis
Total Claims: 31
Claim 1
Independent Claim
129 words
A method for verifying the calibration of a flow meter having a flow tube and means for producing an output in response to temperature difference between first and second temperature sensors comprising: measuring the output of the flow meter in response to a first asymmetric heat transfer to the first and the second temperature sensors produced by a means for asymmetrically transferring heat to the first and second temperature sensors independently of fluid flow through the flow tube, when the flow meter is calibrated; subsequently measuring the output of the flow meter in response to a second asymmetric heat transfer between the two temperature sensors produced by the heat transferring means said first and second heat transfer simulating fluid flow through said flow tube; and comparing the two outputs.
Claim 2
Independent Claim
129 words
A method for verifying the calibration of a flow meter having a flow tube and means for producing an output in response to temperature difference between first and second temperature sensors comprising: measuring the output of the flow meter in response to a first asymmetric heat transfer to the first and the second temperature sensors produced by a means for asymmetrically transferring heat to the first and second temperature sensors independently of fluid flow through the flow tube, when the flow meter is calibrated; subsequently measuring the output of the flow meter in response to a second asymmetric heat transfer between the two temperature sensors produced by the heat transferring means said first and second heat transfer simulating fluid flow through said flow tube; and comparing the two outputs.
Claim 3
Dependent Claim
14 words
The method in accordance with claim 1, wherein the heat transferring means adds heat.
Claim 4
Dependent Claim
18 words
The method in accordance with claim 2, wherein heat is added by resistance heating of the flow tube.
Claim 5
Dependent Claim
19 words
The method in accordance with claim 2, wherein the heat transferring means continuously adds heat at a constant rate.
Claim 6
Dependent Claim
17 words
The method in accordance with claim 4, wherein the first and second heat additions are substantially identical.
Claim 7
Dependent Claim
17 words
The method in accordance with claim 4, wherein the first and second heat additions differ in magnitude.
Claim 8
Dependent Claim
21 words
The method in accordance with claim 2, wherein the heat transferring means adds a fixed quantity of heat in a pulse.
Claim 9
Dependent Claim
22 words
The method in accordance with claim 7, wherein the pulse lasts from about 0 to about 100% of one thermal time constant.
Claim 10
Dependent Claim
20 words
The method in accordance with claim 7, wherein the pulse lasts less than about 5% of one thermal time constant.
Claim 11
Dependent Claim
14 words
The method in accordance with claim 1, wherein the heat transferring means removes heat.
Claim 12
Dependent Claim
19 words
The method in accordance with claim 10, wherein the heat transferring means continuously removes heat at a constant rate.
Claim 13
Dependent Claim
17 words
The method in accordance with claim 11, wherein the first and second heat removals are substantially identical.
Claim 14
Dependent Claim
17 words
The method in accordance with claim 11, wherein the first and second heat removals differ in magnitude.
Claim 15
Dependent Claim
21 words
The method in accordance with claim 10, wherein the heat transferring means removes a fixed quantity of heat in a pulse.
Claim 16
Dependent Claim
22 words
The method in accordance with claim 14, wherein the pulse lasts from about 0 to about 100% of one thermal time constant.
Claim 17
Dependent Claim
20 words
The method in accordance with claim 14, wherein the pulse lasts less than about 5% of one thermal time constant.
Claim 18
Independent Claim
133 words
A method for verifying the calibration of a mass fluid flowmeter in-line, the flowmeter including a flow tube having coupled thereto temperature sensors spaced apart along the length of the tube, fluid flow through said tube producing a temperature distribution along the length of the tube, the temperature sensors providing an output indicative of mass flow through the flow tube, the method comprising the steps of: calibrating the flowmeter by measuring the output of the flowmeter for a known mass flow of the fluid; disturbing the temperature distribution along the flow tube by transferring a known quantity of heat to or from the flow tube to simulate fluid flow through the flowmeter; measuring the output of the flowmeter; and comparing the first and second mentioned outputs to verify the calibration of the flowmeter.
Claim 19
Independent Claim
133 words
A method for verifying the calibration of a mass fluid flowmeter in-line, the flowmeter including a flow tube having coupled thereto temperature sensors spaced apart along the length of the tube, fluid flow through said tube producing a temperature distribution along the length of the tube, the temperature sensors providing an output indicative of mass flow through the flow tube, the method comprising the steps of: calibrating the flowmeter by measuring the output of the flowmeter for a known mass flow of the fluid; disturbing the temperature distribution along the flow tube by transferring a known quantity of heat to or from the flow tube to simulate fluid flow through the flowmeter; measuring the output of the flowmeter; and comparing the first and second mentioned outputs to verify the calibration of the flowmeter.
Claim 20
Dependent Claim
22 words
The method in accordance with claim 17, wherein the known quantity of heat is added by resistance heating of the flow tube.
Claim 21
Dependent Claim
20 words
The method in accordance with claim 17, wherein the known quantity of heat is transferred continuously at a constant rate.
Claim 22
Dependent Claim
20 words
The method in accordance with claim 17, wherein the known quantity of heat is in the form of a pulse.
Claim 23
Dependent Claim
21 words
The method in accordance with claim 20, wherein the pulse lasts from about 0 to 100% of one thermal time constant.
Claim 24
Dependent Claim
20 words
The method in accordance with claim 20, wherein the pulse lasts less than about 5% of one thermal time constant.
Claim 25
Independent Claim
156 words
A method for verifying the calibration of a mass fluid flowmeter in-line, the flowmeter including a flow tube having coupled thereto temperature sensors spaced apart along the length of the tube, fluid flow through said tube producing a temperature distribution along the length of the tube, the temperature sensors providing an output indicative of mass flow through the flow tube, the method comprising the steps of: calibrating the flowmeter by measuring the output of the flowmeter for a known mass flow of the fluid; utilizing the flowmeter to measure the mass flow of fluid flowing through the flow tube; discontinuing the flow of fluid through the flowmeter; disturbing the temperature distribution along the flow tube by transferring a known quantity of heat to or from the flow tube to simulate fluid flow through the flowmeter; measuring the output of the flowmeter; and comparing the first and second mentioned outputs to verify the calibration of the flowmeter.
Claim 26
Independent Claim
156 words
A method for verifying the calibration of a mass fluid flowmeter in-line, the flowmeter including a flow tube having coupled thereto temperature sensors spaced apart along the length of the tube, fluid flow through said tube producing a temperature distribution along the length of the tube, the temperature sensors providing an output indicative of mass flow through the flow tube, the method comprising the steps of: calibrating the flowmeter by measuring the output of the flowmeter for a known mass flow of the fluid; utilizing the flowmeter to measure the mass flow of fluid flowing through the flow tube; discontinuing the flow of fluid through the flowmeter; disturbing the temperature distribution along the flow tube by transferring a known quantity of heat to or from the flow tube to simulate fluid flow through the flowmeter; measuring the output of the flowmeter; and comparing the first and second mentioned outputs to verify the calibration of the flowmeter.
Claim 27
Dependent Claim
22 words
The method in accordance with claim 23, wherein the known quantity of heat is added by resistance heating of the flow tube.
Claim 28
Dependent Claim
20 words
The method in accordance with claim 23, wherein the known quantity of heat is transferred continuously at a constant rate.
Claim 29
Dependent Claim
20 words
The method in accordance with claim 23, wherein the known quantity of heat is in the form of a pulse.
Claim 30
Dependent Claim
21 words
The method in accordance with claim 26, wherein the pulse lasts from about 0 to 100% of one thermal time constant.
Claim 31
Dependent Claim
20 words
The method in accordance with claim 26, wherein the pulse lasts less than about 5% of one thermal time constant.
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| 3.5 Years (Year 4) | 1997-02-14 | 1997-08-16 | 1998-02-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-02-14 | 2001-08-16 | 2002-02-15 | $3760.00 | Window Closed / Lapsed |
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