US5710370A
Expired / Lapsed
US
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Method for calibrating a differential pressure fluid flow measuring system
Assignee: Dieterich Standard Inc
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Filing: 1996-05-17
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Granted: 1998-01-20
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Expires: 2016-05-17
Abstract
Abstract In a flow measurement system comprising a primary flow sensor and a secondary electronic conversion apparatus for converting high and low fluid pressure signals from the primary flow sensor to an electronic signal output representative of fluid flow, a process for calibrating the system as an integral unit, comprising the steps of applying a plurality of known reference fluid flow rates to the primary flow sensor over the system's operative range of flow conditions, sensing the electrical output of the secondary electronic conversion apparatus for each of the said plurality of reference fluid flow rates, establishing a correction factor for each of said recorded values of electrical output which will tend to linearize the relationship between fluid flow rate and the electrical output of the measuring system, and storing the correction factors in non-volatile memory in a microprocessor which is part of the secondary electronic conversion apparatus.
Inventors
- 👤 Eugene Miles Shanahan
- 👤 John Everett Garnett
- 👤 Robert James Gray
- 👤 Gabriel Dragnea
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 14:36
CPC Classifications
G; G01; G01F; G01F1/00; G01F1/05; G01F1/34; G01F1/50
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
241 words
A system calibration process for a differential pressure flow measuring system for fluid flowing in a confined conduit, where such system comprises a primary flow sensor and a secondary electro-mechanical conversion apparatus, including electronic memory, for converting high and low fluid pressure signals derived from the primary flow sensor to an electric signal output representative of fluid flow, comprising the steps of; calibrating the secondary apparatus against known pressures over the operating range of the apparatus to obtain initial output characterization data and storing the characterization data in the electronic memory, sensing the fluid impact pressure and the fluid static low pressure for a plurality of known reference fluid flows to establish a plurality of high and low pressure signals over a range of flows, with the use of the initial output characterization data, transducing the said high and low pressure signals into measured electrical differential pressure signals representative of the difference between the sensed high and low pressure for each of the plurality of reference flow rates, determining a correction factor for the output of the secondary apparatus for each of the plurality of reference flow rates as a function of the deviation of each value of measured differential pressure from the nominal differential pressure corresponding to each of the said plurality of reference flow rates, modifying the data from the initially characterized secondary apparatus by overwriting, in the electronic memory, the initial characterization data with the calculated correction values.
Claim 2
Independent Claim
241 words
A system calibration process for a differential pressure flow measuring system for fluid flowing in a confined conduit, where such system comprises a primary flow sensor and a secondary electro-mechanical conversion apparatus, including electronic memory, for converting high and low fluid pressure signals derived from the primary flow sensor to an electric signal output representative of fluid flow, comprising the steps of; calibrating the secondary apparatus against known pressures over the operating range of the apparatus to obtain initial output characterization data and storing the characterization data in the electronic memory, sensing the fluid impact pressure and the fluid static low pressure for a plurality of known reference fluid flows to establish a plurality of high and low pressure signals over a range of flows, with the use of the initial output characterization data, transducing the said high and low pressure signals into measured electrical differential pressure signals representative of the difference between the sensed high and low pressure for each of the plurality of reference flow rates, determining a correction factor for the output of the secondary apparatus for each of the plurality of reference flow rates as a function of the deviation of each value of measured differential pressure from the nominal differential pressure corresponding to each of the said plurality of reference flow rates, modifying the data from the initially characterized secondary apparatus by overwriting, in the electronic memory, the initial characterization data with the calculated correction values.
Claim 3
Dependent Claim
50 words
The method of claim 1 wherein the step of determining correction factors for the output of the secondary apparatus for each of the plurality of reference flow rates includes the step of determining the nominal differential pressure output of the system by defining the nominal flow coefficient of the primary.
Claim 4
Dependent Claim
24 words
The method of claim 2 and further including the step of determining the average actual flow coefficient value for the plurality of reference flows.
Claim 5
Dependent Claim
52 words
The method of claim 3 wherein the step of determining correction factors for the output of the secondary apparatus for each of the plurality of reference flow rates includes the step of correcting the measured differential pressure output values for the deviation of the actual flow coefficient from the nominal flow coefficient.
Claim 6
Dependent Claim
58 words
The method of claim 4 wherein the step of determining a correction factor for the output of the secondary apparatus for each of the plurality of reference flow rates includes the step of subjecting the values of the measured differential pressure and the determined nominal differential pressure values to a statistical regression analysis to establish the correction factors.
Claim 7
Dependent Claim
133 words
For a differential pressure flow measuring system comprising a primary flow sensor and a secondary electro-mechanical conversion apparatus for converting high and low fluid pressure signals from the primary flow sensor to an electronic signal output representative of fluid flow, a system calibration process, comprising the steps of; applying a plurality of known reference fluid flow rates to the primary flow sensor over the system's operative range of flow conditions, sensing the electrical output of the secondary electronic conversion apparatus for each of the said plurality of reference fluid flow rates; establishing a correction factor for each of the plurality of reference flow rates which will tend to characterize a desired relationship between the fluid flow rate and the electrical output of the measuring system, and storing the correction factors in non-volatile memory.
Claim 8
Dependent Claim
133 words
For a differential pressure flow measuring system comprising a primary flow sensor and a secondary electro-mechanical conversion apparatus for converting high and low fluid pressure signals from the primary flow sensor to an electronic signal output representative of fluid flow, a system calibration process, comprising the steps of; applying a plurality of known reference fluid flow rates to the primary flow sensor over the system's operative range of flow conditions, sensing the electrical output of the secondary electronic conversion apparatus for each of the said plurality of reference fluid flow rates; establishing a correction factor for each of the plurality of reference flow rates which will tend to characterize a desired relationship between the fluid flow rate and the electrical output of the measuring system, and storing the correction factors in non-volatile memory.
Claim 9
Dependent Claim
39 words
The method of claim 6 and further including the step of initially linearizing the secondary electro-mechanical apparatus against known pressures over the operating range of the apparatus to obtain data for linearizing the output of the said electro-mechanical apparatus.
Claim 10
Independent Claim
170 words
A system calibration process for differential pressure flow measurement in a system having fluid flowing in a confined conduit, and having a primary flow sensor and a secondary electro-mechanical conversion apparatus, including electronic memory, for converting high and low fluid pressure signals derived from the primary flow sensor to an electric signal representative of fluid flow, comprising the steps of; sensing the fluid impact pressure and the fluid static low pressure for a plurality of known reference fluid flows to establish a plurality of high and low pressure signals over a range of fluid flows, transducing the said high and low pressure signals into measured electrical differential pressure signals representative of the difference between the sensed high and low pressure for each of the plurality of reference flow rates, establishing a desired relationship between the reference flow rates and the electrical output of the secondary apparatus for each of the plurality of the reference flow rates, overwriting into the electronic memory the said established desired relationship of the secondary apparatus.
Claim 11
Independent Claim
170 words
A system calibration process for differential pressure flow measurement in a system having fluid flowing in a confined conduit, and having a primary flow sensor and a secondary electro-mechanical conversion apparatus, including electronic memory, for converting high and low fluid pressure signals derived from the primary flow sensor to an electric signal representative of fluid flow, comprising the steps of; sensing the fluid impact pressure and the fluid static low pressure for a plurality of known reference fluid flows to establish a plurality of high and low pressure signals over a range of fluid flows, transducing the said high and low pressure signals into measured electrical differential pressure signals representative of the difference between the sensed high and low pressure for each of the plurality of reference flow rates, establishing a desired relationship between the reference flow rates and the electrical output of the secondary apparatus for each of the plurality of the reference flow rates, overwriting into the electronic memory the said established desired relationship of the secondary apparatus.
Claim 12
Dependent Claim
39 words
The method of claim 8 and further including the step of initially characterizing the secondary electro-mechanical apparatus against known pressures over the operating range of the apparatus to obtain data for characterizing the output of the said electro-mechanical apparatus.
Claim 13
Dependent Claim
17 words
The method of claim 8 where the step of establishing a desired relationship includes that of linearization.
Claim 14
Dependent Claim
187 words
For a differential pressure flow measuring system comprising a primary flow sensor and a secondary electro-mechanical conversion apparatus for convening high and low fluid pressure signals from the primary flow sensor to an electronic signal output representative of fluid flow, a system calibration process, comprising the steps of; applying a plurality of known reference fluid flow rates to the primary flow sensor over the system's operative range of flow conditions, sensing the electrical output of the secondary electronic conversion apparatus for each of the said plurality of reference fluid flow rates; establishing a correction factor for each of the plurality of reference flow rates which will tend to linearize the relationship between fluid flow rate and the electrical output of the measuring system as a function of the deviation of each value of measured differential pressure from the nominal differential pressure corresponding to each of the plurality of reference flow rates, storing the correction factors in non-volatile memory, and initially linearizing the secondary electro-mechanical apparatus against known pressure over the operating range of the apparatus to obtain data for linearizing the output of the said electro-mechanical apparatus.
Claim 15
Dependent Claim
187 words
For a differential pressure flow measuring system comprising a primary flow sensor and a secondary electro-mechanical conversion apparatus for convening high and low fluid pressure signals from the primary flow sensor to an electronic signal output representative of fluid flow, a system calibration process, comprising the steps of; applying a plurality of known reference fluid flow rates to the primary flow sensor over the system's operative range of flow conditions, sensing the electrical output of the secondary electronic conversion apparatus for each of the said plurality of reference fluid flow rates; establishing a correction factor for each of the plurality of reference flow rates which will tend to linearize the relationship between fluid flow rate and the electrical output of the measuring system as a function of the deviation of each value of measured differential pressure from the nominal differential pressure corresponding to each of the plurality of reference flow rates, storing the correction factors in non-volatile memory, and initially linearizing the secondary electro-mechanical apparatus against known pressure over the operating range of the apparatus to obtain data for linearizing the output of the said electro-mechanical apparatus.
Claim 16
Dependent Claim
202 words
For a differential pressure flow measuring system comprising a primary flow sensor and a secondary electro-mechanical conversion apparatus for converting high and low fluid pressure signals from the primary flow sensor to an electronic signal output representative of fluid flow, a system calibration process, comprising the steps of; applying a plurality of known reference fluid flow rates to the primary flow sensor over the system's operative range of flow conditions, sensing the electrical output of the secondary electronic conversion apparatus for each of the said plurality of reference fluid flow rates; establishing a correction factor for each of the plurality of reference flow rates which will tend to linearize the relationship between fluid flow rate and the electrical output of the measuring system as a function of the deviation of each value of measured differential pressure from the nominal differential pressure corresponding to each of the plurality of reference flow rates, storing the correction factors in non-volatile memory, initially linearizing the secondary electro-mechanical apparatus against known pressure over the operating range of the apparatus to obtain data for linearizing the output of the said electro-mechanical apparatus, and modifying the initial linearization data for the secondary electro-mechanical apparatus with the determined correction factors.
Claim 17
Dependent Claim
202 words
For a differential pressure flow measuring system comprising a primary flow sensor and a secondary electro-mechanical conversion apparatus for converting high and low fluid pressure signals from the primary flow sensor to an electronic signal output representative of fluid flow, a system calibration process, comprising the steps of; applying a plurality of known reference fluid flow rates to the primary flow sensor over the system's operative range of flow conditions, sensing the electrical output of the secondary electronic conversion apparatus for each of the said plurality of reference fluid flow rates; establishing a correction factor for each of the plurality of reference flow rates which will tend to linearize the relationship between fluid flow rate and the electrical output of the measuring system as a function of the deviation of each value of measured differential pressure from the nominal differential pressure corresponding to each of the plurality of reference flow rates, storing the correction factors in non-volatile memory, initially linearizing the secondary electro-mechanical apparatus against known pressure over the operating range of the apparatus to obtain data for linearizing the output of the said electro-mechanical apparatus, and modifying the initial linearization data for the secondary electro-mechanical apparatus with the determined correction factors.
Claim 18
Independent Claim
227 words
A system calibration process for differential pressure flow measurement in a system having fluid flowing in a confined conduit, and having a primary flow sensor and a secondary electro-mechanical conversion apparatus, including electronic memory, for converting high and low fluid pressure signals derived from the primary flow sensor to an electric signal representative of fluid flow, comprising the steps of; sensing the fluid impact pressure and the fluid static low pressure for a plurality of known reference fluid flows to establish a plurality of high and low pressure signals over a range of fluid flows, transducing the said high and low pressure signals into measured electrical differential pressure signals representative of the difference between the sensed high and low pressure for each of the plurality of reference flow rates, establishing a desired relationship between the reference flow rates and the electrical output of the secondary apparatus for each of the plurality of the reference flow rates at a function of the deviation of each value of measured differential pressure from the nominal differential pressure corresponding to each of the plurality of reference flow rates, overwriting into the electronic memory the said established desired relationship of the secondary apparatus, and initially characterizing the secondary electro-mechanical apparatus against known pressures over the operating range of the apparatus to obtain data for characterizing the output of the said electro-mechanical apparatus.
Claim 19
Independent Claim
227 words
A system calibration process for differential pressure flow measurement in a system having fluid flowing in a confined conduit, and having a primary flow sensor and a secondary electro-mechanical conversion apparatus, including electronic memory, for converting high and low fluid pressure signals derived from the primary flow sensor to an electric signal representative of fluid flow, comprising the steps of; sensing the fluid impact pressure and the fluid static low pressure for a plurality of known reference fluid flows to establish a plurality of high and low pressure signals over a range of fluid flows, transducing the said high and low pressure signals into measured electrical differential pressure signals representative of the difference between the sensed high and low pressure for each of the plurality of reference flow rates, establishing a desired relationship between the reference flow rates and the electrical output of the secondary apparatus for each of the plurality of the reference flow rates at a function of the deviation of each value of measured differential pressure from the nominal differential pressure corresponding to each of the plurality of reference flow rates, overwriting into the electronic memory the said established desired relationship of the secondary apparatus, and initially characterizing the secondary electro-mechanical apparatus against known pressures over the operating range of the apparatus to obtain data for characterizing the output of the said electro-mechanical apparatus.
Claim 20
Dependent Claim
27 words
The method of claim 13 and further including the step of modifying the data obtained by initially characterizing the secondary electro-mechanical apparatus with the determined correction factors.
Claim 21
Dependent Claim
18 words
The method of claim 14 and further including the step of storing the correction factors in non-volatile memory.
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) | 2001-01-19 | 2001-07-21 | 2002-01-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-01-19 | 2005-07-21 | 2006-01-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-01-19 | 2009-07-21 | 2010-01-20 | $7700.00 | Window Closed / Lapsed |