US20100307220A1 - Flowmeter calibration techniques - Google Patents
Flowmeter calibration techniques Download PDFInfo
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- US20100307220A1 US20100307220A1 US12/721,273 US72127310A US2010307220A1 US 20100307220 A1 US20100307220 A1 US 20100307220A1 US 72127310 A US72127310 A US 72127310A US 2010307220 A1 US2010307220 A1 US 2010307220A1
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- flowmeter
- flowtube
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- calibration
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
- G01F1/00—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow
- G01F1/76—Devices for measuring mass flow of a fluid or a fluent solid material
- G01F1/78—Direct mass flowmeters
- G01F1/80—Direct mass flowmeters operating by measuring pressure, force, momentum, or frequency of a fluid flow to which a rotational movement has been imparted
- G01F1/84—Coriolis or gyroscopic mass flowmeters
- G01F1/8409—Coriolis or gyroscopic mass flowmeters constructional details
- G01F1/8436—Coriolis or gyroscopic mass flowmeters constructional details signal processing
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
- G01F1/00—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow
- G01F1/74—Devices for measuring flow of a fluid or flow of a fluent solid material in suspension in another fluid
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
- G01F1/00—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow
- G01F1/76—Devices for measuring mass flow of a fluid or a fluent solid material
- G01F1/78—Direct mass flowmeters
- G01F1/80—Direct mass flowmeters operating by measuring pressure, force, momentum, or frequency of a fluid flow to which a rotational movement has been imparted
- G01F1/84—Coriolis or gyroscopic mass flowmeters
- G01F1/845—Coriolis or gyroscopic mass flowmeters arrangements of measuring means, e.g., of measuring conduits
- G01F1/8468—Coriolis or gyroscopic mass flowmeters arrangements of measuring means, e.g., of measuring conduits vibrating measuring conduits
- G01F1/8481—Coriolis or gyroscopic mass flowmeters arrangements of measuring means, e.g., of measuring conduits vibrating measuring conduits having loop-shaped measuring conduits, e.g. the measuring conduits form a loop with a crossing point
- G01F1/8486—Coriolis or gyroscopic mass flowmeters arrangements of measuring means, e.g., of measuring conduits vibrating measuring conduits having loop-shaped measuring conduits, e.g. the measuring conduits form a loop with a crossing point with multiple measuring conduits
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
- G01F1/00—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow
- G01F1/76—Devices for measuring mass flow of a fluid or a fluent solid material
- G01F1/78—Direct mass flowmeters
- G01F1/80—Direct mass flowmeters operating by measuring pressure, force, momentum, or frequency of a fluid flow to which a rotational movement has been imparted
- G01F1/84—Coriolis or gyroscopic mass flowmeters
- G01F1/845—Coriolis or gyroscopic mass flowmeters arrangements of measuring means, e.g., of measuring conduits
- G01F1/8468—Coriolis or gyroscopic mass flowmeters arrangements of measuring means, e.g., of measuring conduits vibrating measuring conduits
- G01F1/849—Coriolis or gyroscopic mass flowmeters arrangements of measuring means, e.g., of measuring conduits vibrating measuring conduits having straight measuring conduits
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
- G01F25/00—Testing or calibration of apparatus for measuring volume, volume flow or liquid level or for metering by volume
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N9/00—Investigating density or specific gravity of materials; Analysing materials by determining density or specific gravity
- G01N9/002—Investigating density or specific gravity of materials; Analysing materials by determining density or specific gravity using variation of the resonant frequency of an element vibrating in contact with the material submitted to analysis
Definitions
- This description relates to flowmeters.
- Flowmeters provide information about materials being transferred through a conduit. For example, mass flowmeters provide a measurement of the mass of material being transferred through a conduit. Similarly, density flowmeters, or densitometers, provide a measurement of the density of material flowing through a conduit. Mass flowmeters also may provide a measurement of the density of the material.
- Coriolis-type mass flowmeters are based on the Coriolis effect, in which material flowing through a conduit becomes a radially-travelling mass that is affected by a Coriolis force and therefore experiences an acceleration.
- Many Coriolis-type mass flowmeters induce a Coriolis force by sinusoidally oscillating a conduit about a pivot axis orthogonal to the length of the conduit.
- the Coriolis reaction force experienced by the traveling fluid mass is transferred to the conduit itself and is manifested as a deflection or offset of the conduit in the direction of the Coriolis force vector in the plane of rotation.
- a flowmeter is calibrated.
- a plurality of calibration values are determined, the calibration values corresponding to measurements of material in a flowtube, the flowtube being associated with the flowmeter.
- Each of the calibration values is associated with one of a plurality of operational parameters of the flowmeter, each of the operational parameters being present during the determining of its corresponding calibration value.
- the calibration values are stored in association with their respective operational parameters.
- Implementations may have one or more of the following features. For example, in determining the plurality of calibration values a plurality of zero-flow calibration values corresponding to the measurements may be determined, where the measurements include mass flow measurements erroneously indicated by the flowmeter during a time of substantially zero mass flow through the flowtube. A current operational parameter of the flowmeter may be determined, and a current calibration value for use during an obtaining of a mass flow measurement may be determined, based on the current operational parameter.
- a density of the material in the flowtube may be determined.
- determining the current calibration value of the flowmeter may include measuring a current density of a current material in the flowtube.
- a first calibration value may be associated with a range of densities.
- a current density of a current material in the flowtube may be measured, it may be determined that the current density falls within the range of densities, and the first calibration value may be selected.
- a mathematical relationship between the calibration values and the plurality of operational parameters may be used.
- a current density of a current material in the flowtube may be measured, the current density may be used in conjunction with the mathematical relationship to determine a current calibration value, and the current calibration value may be selected.
- a configuration of flow elements associated with the flowtube may be determined.
- an input may be accepted from a user, the input identifying a current configuration of flow elements.
- a first density of a first material in the flowtube may be measured, a correlation between the first density and a first configuration of flow elements may be accessed, and a first calibration value corresponding to the first configuration may be selected.
- a gas void fraction of the material in the flowtube may be determined.
- an input of the gas void fraction may be received from a gas void fraction measurement system, and the current calibration value may be selected from a pre-determined list of associated calibration values and gas void fractions.
- a calibration system includes a measurement system operable to output measurements of material in a flowtube, where the flowtube is associated with a flowmeter, a calibration system operable to determine calibration values, each based on a corresponding measurement output by the measurement system, and a memory operable to store each of the calibration values in conjunction with an operational parameter associated with an operation of the flowmeter at a time of the corresponding measurement.
- the calibration system may be operable to select a calibration value from the memory, based on a current operational parameter associated with the flowmeter.
- the measurement may include a mass flow rate of the material, and further wherein the calibration values may include zero calibration values corresponding to erroneously-detected mass flow measurements of the material during a time of substantially zero flow.
- the operational parameter may include a density of the material.
- the calibration system may be operable to select a current calibration value based on a current density of material in the flowtube, as measured by the measurement system.
- the calibration system may be operable to select the current calibration value by associating the current density with a pre-selected range of densities that is stored in the memory in association with the current calibration value.
- the calibration system may be operable to select the current calibration value, based on the current density and a mathematical relationship between the calibration values and their corresponding operational parameters
- the operational parameter may include a configuration of flow elements associated with the flowtube.
- the calibration system may be operable to accept a current configuration input by an operator, and to select a current calibration value based on the current configuration.
- the calibration system may be operable to select a current calibration value by determining a current configuration based on a currently-measured density that was previously associated with the current configuration.
- the operational parameter may include a gas void fraction of flow elements within the flowtube.
- the calibration system may be operable to receive a current gas void fraction from a gas void fraction measurement system, and further may be operable to select a corresponding current calibration value from the memory.
- the measurement system, the calibration system, and the memory may be integrated with the flowmeter.
- a flowmeter is operated.
- An operational parameter associated with the flowmeter is determined.
- a zero-flow calibration value based on the operational parameter is determined, based on a plurality of previously-determined zero-flow calibration values.
- a measurement of a property of a material within a flowtube associated with the flowmeter is taken, using the flowmeter. The measurement is adjusted using the zero-flow calibration value.
- Implementations may have one or more of the following features. For example, in determining the operational parameter, determining a configuration of flow elements associated with the flowtube may be determined. In determining the zero-flow calibration value, the zero-flow calibration value may be selected from among the previously-determined zero-flow calibration values as being the zero-flow calibration value that corresponds to one of a set of configurations, where each of the set of configurations existed at a time when its corresponding zero-flow calibration value was previously determined.
- a selection of the configuration may be accepted from a pre-determined set of configurations. Additionally, or alternatively, a density of the material may be measured, and the density may be associated with a first configuration.
- the operational parameter may include a density of the material in the flowtube.
- determining the zero-flow calibration value may include associating the density with a range of densities, and selecting the zero-flow calibration value from among the plurality of previously-determined zero-flow calibration values, based on a pre-determined relationship between the range of densities and the zero-flow calibration value.
- the density may be input into a mathematical relationship derived from a relationship between the previously-determined zero-flow calibration values and corresponding density measurements. Additionally, or alternatively, the zero-flow calibration value may be selected from among the plurality of previously-determined zero-flow calibration values, based on a pre-determined relationship between the operational parameter and the zero-flow calibration value.
- a gas void fraction of the material in the flowtube may be determined.
- a current gas void fraction may be received from a gas void fraction measurement system, and further wherein determining the zero-flow calibration value comprises selecting a current zero-flow calibration value previously associated with the current gas void fraction measurement.
- FIG. 1A is an illustration of a Coriolis flowmeter using a bent flowtube.
- FIG. 1B is an illustration of a Coriolis flowmeter using a straight flowtube.
- FIG. 2 is a block diagram of a Coriolis flowmeter.
- FIG. 3 is a block diagram of a flowmeter operating in conjunction with one or more of a plurality of different-density materials.
- FIG. 4 is a chart comparing zero calibration values calculated at different fluid densities.
- FIG. 5 is a block diagram of a flowmeter operating in conjunction with a plurality of piping and/or pumping configurations.
- FIG. 6 is a flowchart illustrating techniques for selecting a zero calibration value.
- Types of flowmeters include digital flowmeters.
- U.S. Pat. No. 6,311,136 which is hereby incorporated by reference, discloses the use of a digital flowmeter and related technology including signal processing and measurement techniques.
- Such digital flowmeters may be very precise in their measurements, with little or negligible noise, and may be capable of enabling a wide range of positive and negative gains at the driver circuitry for driving the conduit.
- Such digital flowmeters are thus advantageous in a variety of settings.
- commonly-assigned U.S. Pat. No. 6,505,519 which is incorporated by reference, discloses the use of a wide gain range, and/or the use of negative gain, to prevent stalling and to more accurately exercise control of the flowtube, even during difficult conditions such as two-phase flow.
- flowmeters are specifically discussed below with respect to FIGS. 1 and 2 , it should be understood that analog flowmeters also exist. Although such analog flowmeters may be prone to typical shortcomings of analog circuitry, e.g., low precision and high noise measurements relative to digital flowmeters, they also may be compatible with the various techniques and implementations discussed herein. Thus, in the following discussion, the term “flowmeter” or “meter” is used to refer to any type of device and/or system in which a Coriolis flowmeter system uses various control systems and related elements to measure a mass flow, density, and/or other parameters of a material(s) moving through a flowtube or other conduit.
- FIG. 1A is an illustration of a digital flowmeter using a bent flowtube 102 .
- the bent flowtube 102 may be used to measure one or more physical characteristics of, for example, a (traveling) fluid, as referred to above.
- a digital transmitter 104 exchanges sensor and drive signals with the bent flowtube 102 , so as to both sense an oscillation of the bent flowtube 102 , and to drive the oscillation of the bent flowtube 102 accordingly.
- the digital transmitter 104 provides for fast and accurate operation of the bent flowtube 102 . Examples of the digital transmitter 104 being used with a bent flowtube are provided in, for example, commonly-assigned U.S. Pat. No. 6,311,136.
- FIG. 1B is an illustration of a digital flowmeter using a straight flowtube 106 . More specifically, in FIG. 1B , the straight flowtube 106 interacts with the digital transmitter 104 . Such a straight flowtube operates similarly to the bent flowtube 102 on a conceptual level, and has various advantages/disadvantages relative to the bent flowtube 102 . For example, the straight flowtube 106 may be easier to (completely) fill and empty than the bent flowtube 102 , simply due to the geometry of its construction. In operation, the bent flowtube 102 may operate at a frequency of, for example, 50-110 Hz, while the straight flowtube 106 may operate at a frequency of, for example, 300-1,000 Hz.
- a digital mass flowmeter 200 includes the digital transmitter 104 , one or more motion sensors 205 , one or more drivers 210 , a flowtube 215 (which also may be referred to as a conduit, and which may represent either the bent flowtube 102 , the straight flowtube 106 , or some other type of flowtube), and a temperature sensor 220 .
- the digital transmitter 104 may be implemented using one or more of, for example, a processor, a Digital Signal Processor (DSP), a field-programmable gate array (FPGA), an ASIC, other programmable logic or gate arrays, or programmable logic with a processor core.
- DSP Digital Signal Processor
- FPGA field-programmable gate array
- ASIC programmable logic with a processor core
- the digital transmitter 104 generates a measurement of, for example, density and/or mass flow of a material flowing through the flowtube 215 , based at least on signals received from the motion sensors 205 .
- the digital transmitter 104 also controls the drivers 210 to induce motion in the flowtube 215 . This motion is sensed by the motion sensors 205 .
- Density measurements of the material flowing through the flowtube are related to, for example, the frequency of the motion of the flowtube 215 that is induced in the flowtube 215 by a driving force supplied by the drivers 210 , and/or to the temperature of the flowtube 215 .
- mass flow through the flowtube 215 is related to the phase and frequency of the motion of the flowtube 215 , as well as to the temperature of the flowtube 215 .
- the temperature in the flowtube 215 which is measured using the temperature sensor 220 , affects certain properties of the flowtube, such as its stiffness and dimensions.
- the digital transmitter 104 may compensate for these temperature effects. This temperature affects, for example, an operating frequency of the digital transmitter 104 , a sampling rate of an analog-to-digital converter, and/or a crystal frequency associated with a reference clock used by the transmitter 104 .
- a gas void fraction sensor 222 (discussed in more detail below) is included that is operable to determine what percentage of a material in the flowtube 215 , if any, is composed of a gas.
- other sensors may be included, such as, for example, a pressure sensor that is operable to sense a pressure of a material flowing through the flowtube 215 .
- calibration of the flowmeter may be required in order to maintain system performance, particularly over long periods of time and/or extensive operation of the flowmeter.
- One calibration technique is known as “zeroing” or “a zero calibration.”
- a zeroing process a flow of material through the flowtube 215 is stopped (for example, upstream and downstream valves may be closed) during a time when the flowtube 215 is filled with the material. As a result, there is a zero flow of the material, which should lead to a corresponding reading of zero flow output by the flowmeter.
- the flowmeter outputs a non-zero (i.e., erroneous) flowrate during a time of zero flow.
- the (erroneous) non-zero flowrate at zero flow may be used as a calibration factor; that is, for example, it may be subtracted from (or added to) a measured flow, so as to obtain an accurate, i.e., zero-corrected, reading of the flow during future readings.
- the zeroing process might involve, for example, filling the flowtube 215 with a process fluid. Then the flow is brought to zero while keeping the meter full. The resulting non-zero, erroneous flow indicated by the flowmeter may be averaged over a period of time to determine the zero calibration value.
- the zero calibration value also is a function of factors or parameters that are related to the particular operation of whatever flowmeter being used. That is to say, the zero calibration value may be a function of various parameters, such as, for example, a density of the process fluid(s), a configuration of external elements associated with the flowmeter (e.g., valves, pumps, pipes), or a temperature (as measured by the temperature sensor 220 ). As a result, when one or more of these parameters changes, the previously-calculated zero calibration value may be less accurate.
- the zero calibration value may be different for fluids having different densities.
- One reason for this may be that the drive frequency for the flowtube 215 is selected in part based on fluid density, and the mass flow reading at zero flow may be largely dependent on frequency.
- the calculated zero calibration value may not be sufficiently accurate.
- the phrase “batching from empty” refers to a condition in which a flowmeter is completely emptied in between batches of measured materials (i.e., is empty at a start and finish of the measurements).
- the zero calibration value when the flowtube 215 is full may be considerably different than the zero calibration value when the flowtube is empty.
- Other examples in which a zero calibration value may require changing in response to changed (or changing) flowmeter conditions are discussed in more detail below.
- the digital transmitter 104 includes various elements designed to implement the above-described calibration functionality. It should be understood that some or all of these elements (along with other elements of the digital transmitter 104 , not explicitly shown in FIG. 2 ) also may be used during a normal operation of the flowmeter 200 (e.g., after zero calibration values have been determined).
- the digital transmitter 104 includes a measurement system 225 , which is operable to obtain a measurement, such as a mass flow measurement and/or density measurement.
- a calibration determination and correlation system 230 based on at least one measurement output by the measurement system 225 , determines a zero calibration value corresponding to an operational parameter of the flowmeter 200 , at the time of the measurement.
- the measurement system 225 may output an erroneous, non-zero measurement of mass flow of a given material during a time of substantially zero flow of the material through the flowtube 215 , as well as a density of the material.
- the calibration determination and correlation system 230 may then determine a zero calibration value associated with the mass flow measurement and correlate that zero calibration value with the measured density, to be used as a correction factor during future mass flow measurements of material(s) having that density.
- the operational parameter may include, for example, a parameter that is detectable and measurable by the measurement system 225 , such as the density (or temperature) of the material.
- the operational parameter may include a parameter that may be input into the calibration determination and correlation system 230 by an operator, such as a configuration of the flowmeter, or a configuration of various flow elements associated with the flowmeter, such as pipes, valves, or manifolds.
- the calibration determination and correlation system 230 correlates particular zero calibration values with particular, corresponding operational parameters, and stores these values and correlations in a memory 235 .
- a calibration selection system 240 may select or otherwise determine an appropriate zero calibration value, using the memory 235 .
- the calibration system determines the appropriate zero calibration value automatically, whereas, in another implementation, an operator selects the appropriate zero calibration value directly from the memory 235 .
- an appropriate zero calibration value is made available to the measurement system 225 , so that the measurement system 225 , during normal operation of the flowmeter 200 , may output highly-accurate, zero-adjusted measurements.
- the calibration selection system 240 may select a zero calibration value from the memory 235 in a variety of ways. For example, when zero calibration values and operational parameters that include a corresponding number of fluid densities are stored in the memory 235 , the calibration selection system 240 may interact with the measurement system 225 to determine a density of a material currently in the flowtube 215 . Then, the calibration selection system may select a zero calibration value corresponding to that density. In this way, highly-accurate, customized mass flow measurements may be obtained during future use of the flowmeter, even when a plurality of different-density materials are measured by the flowmeter.
- FIG. 3 is a block diagram 300 of a flowmeter operating in conjunction with one or more of a plurality of different-density materials.
- a liquid material is fed into a valve 302 , and thereby into a meter 304 .
- a vapor or gas material is fed through a valve 306 and into the meter 304 .
- the meter 304 may include, for example, all of the features described above with respect to the flowmeter 200 and further described in U.S. Pat. Nos. 6,311,136 and/or 6,505,519.
- valve 302 may be opened while the valve 306 is closed, so that the meter 304 measures only the liquid material.
- the valve 306 may be opened while the valve 302 is closed, so that the meter 304 measures only the gaseous material.
- the valves 302 and 306 may each be partially or alternately open, so that both of the liquid and gaseous materials travel through the meter 304 during a given period of time.
- a density of the liquid and a density of the gas may be associated with an appropriate zero calibration value. Then, during subsequent measurements, the meter 304 may determine a density of the material currently flowing therethrough, and select the corresponding zero calibration value accordingly.
- a mixture of the same two fluids is passed through the meter 304 , where proportions of the fluids relative to one another may vary.
- the liquid and the gas may be passed through the meter 304 simultaneously, rather than consecutively, and the percentage of the gas (i.e., the “void fraction”) may vary over time.
- the void fraction increases, the density of the liquid/gas mixture will generally decrease, possibly resulting in the need for a different zero calibration value.
- a venturi tube i.e., a tube with a constricted throat that determines fluid pressures and velocities by measurement of differential pressures generated at the throat as a fluid traverses the tube
- a pressure gradient may be used to determine a pressure gradient and thereby allow a determination of the gas void fraction.
- measurements of gas void fractions may be obtained using equipment (e.g., the gas void fraction sensor 222 ) that is wholly external to the flowtube.
- equipment e.g., the gas void fraction sensor 222
- sonar measurements may be taken to determine gas void fraction.
- the SONARtracTM gas void fraction monitoring system produced by CiDRA Corporation of Wallingford, Conn. may be used.
- the situation of a void fraction arises, for example, when the meter 304 measures a liquid and gas flow simultaneously (e.g., when measuring a combination of oil and hydrocarbon-related gas that is output by an oil well), or when a meter is used in a “batching from empty” application, as referred to above.
- the user might, for example, zero the meter 304 while full of liquid, and store the zero calibration value and density. This process may be repeated with the meter 304 being empty (e.g. full of air). Then, during operation, the meter 304 would use the zero calibration value associated with gas when it is predominantly gas and would use the zero calibration value associated with liquid when it is closer to being full. This process could be further extended to store zero calibration values for a variety of void fractions.
- any of the various techniques discussed above for determining gas void fractions may be used to determine gas void fractions, which may then be associated with corresponding zero calibration values.
- a gas void fraction measurement system such as, for example, an external sensor or probe similar to those discussed above, may output a signal directly to an input of the transmitter 104 , to be processed in the transmitter 104 to determine a gas void fraction (i.e., may be positioned and connected similarly to the temperature sensor 220 of FIG. 2 ).
- the signal from such an external sensor or probe may be connected to a separate computing resource, such as, for example, a control system or flow computer, with the determination of a gas void fraction carried out therein.
- the sensor or probe itself may have an integrally-formed computing resource that is operable to determine a gas void fraction for direct output to the transmitter 104 .
- FIG. 4 is a chart 400 comparing zero calibration values calculated at different fluid densities.
- a first data point 402 corresponds to a zero calibration value determined (by the calibration determination and correlation system 230 ) for a material having a first density, as measured by the measurement system 225 .
- second and third data points 404 and 406 correspond to zero calibration values determined for materials having second and third densities, respectively.
- the data points 402 , 404 , and 406 may then be associated with their respective density values by the calibration determination and correlation system 230 , and stored in the memory 225 , so that an appropriate zero calibration value may be chosen by the calibration selection system 240 during future measurements.
- the calibration selection system 240 might simply select a zero calibration value corresponding to a measured one of the three densities, perhaps from a table relating the zero calibration and density values and stored in the memory 235 .
- a fluid may be used having a density that does not directly correspond to one of the data points 402 , 404 , or 406 .
- the three data points 402 , 404 , and 406 may nonetheless be used to obtain an appropriate zero calibration value.
- a number of density bands 408 , 410 , 412 , 414 , 416 , and 418 might be defined within a relevant density range, so that the zero calibration values corresponding to the data points 402 , 404 , and 406 may be associated with a corresponding one of the density bands.
- the bands may be established in the calibration determination and correlation system 230 and/or the calibration selection system 240 , and stored in the memory 235 .
- the bands may be based on, for example, a manufacturer's determination, or could be a configurable parameter that is adjusted by a user of the flowmeter.
- an appropriate zero calibration value may be chosen. For example, if a fluid having a density falling within the density band 410 is processed by the flowmeter, then the zero calibration value corresponding to the data point 402 may be used.
- the calibration determination and correlation system 230 may interpolate (e.g., linearly interpolate) between the data points. In this way, a fluid having a density anywhere within the relevant range could be correlated with a corresponding zero calibration value that would produce an improved-accuracy measurement.
- the memory 235 may be used to store a mathematical relationship or algorithm derived by the calibration determination and correlation system 230 , rather than (or in addition to) a table of related values.
- FIG. 5 is a block diagram 500 of a flowmeter 502 operating in conjunction with a plurality of piping and/or pumping configurations.
- a first material or product 504 is pumped through a pump 506 and a valve 508 before reaching the meter 502 .
- a second product 510 is pumped through a pump 512 and a valve 514 before reaching the meter 502 .
- a third product 516 is sent to the meter 502 after being fed to a valve 518 by way of a gravity feed 520 .
- first product 504 , the pump 506 , and the valve 508 form a first configuration 522
- second product 510 , the pump 512 , and the valve 514 form a second configuration 524
- third product 516 , valve 518 , and the gravity feed 520 form a third configuration 526 .
- the three products 504 , 510 , and 516 may or may not have the same density as one another. Even in the case where two or more of the densities are the same (or even where two of the products are the same), however, zero calibration values associated with each of the configurations 522 , 524 , and 526 may be different from one another, due to, for example, the configuration elements (e.g., the valves 508 , 514 , 518 , the pumps 506 and 512 , or the gravity feed 520 ) that are used, and/or the manner in which the configuration elements are connected to one another.
- the configuration elements e.g., the valves 508 , 514 , 518 , the pumps 506 and 512 , or the gravity feed 520
- a zero calibration value is determined for (and associated with) each of the configurations 522 , 524 , and 526 , and stored for future use. Selection of an appropriate zero calibration value is then determined during measurements by way of discrete input from an operator of the flowmeter 502 , e.g., by input into the calibration determination and correlation system 230 and/or the calibration selection system 240 of a currently-used configuration.
- the various zero calibration values are associated with their respective configurations in the above-described manner, and the configurations and corresponding zero calibration values are then displayed on an output screen associated with the digital transmitter 104 . In this way, a user may simply scroll through the stored configurations to select an appropriate zero calibration value.
- the flowmeter determines a density of a currently-measured product, and thereby determines the appropriate zero calibration value automatically.
- the meter 502 determines that, based on a given density of a current product, a particular configuration exists. Then, based on that density and configuration, the appropriate zero calibration value may be selected.
- FIG. 6 is a flowchart 600 illustrating techniques for selecting a zero calibration value, as described above.
- FIG. 6 it is assumed that a particular flowtube or flowtube type is being used. Thus, if a new or different flowtube were used, the process(es) described below may require repeating to ensure accuracy of the flowmeter in conjunction with the new flowtube.
- a user performs a zero calibration for each condition, i.e., for each operational parameter ( 602 ).
- this might include performing zero calibrations for materials having multiple, different densities ( 604 ), or might include performing zero calibrations for multiple, different configurations ( 606 ), or both.
- the zero calibration values are related to their corresponding operational parameters by the calibration determination and correlation system 230 , and these values and their relations to one another (including, possibly, a mathematical relationship between the values) are recorded in the memory 235 ( 608 ).
- the appropriate zero calibration value is selected by the calibration selection system 240 ( 612 ).
- the flowmeter may be used to measure a density of the currently-flowing fluid, whereupon the density is correlated with a particular zero calibration value in one or more of the manners described above ( 614 ).
- the zero calibration value may be selected based on a current configuration/product being used, as input by a user, perhaps by way of a scrolling, input/output display ( 616 ).
- Measurements are then performed for some period of time ( 618 ). If characteristics of a new material(s) and/or configuration are to be measured ( 620 ), then flow of that material (in that configuration) is initiated ( 610 ), and the zero calibration value is adjusted accordingly. Otherwise, the process flow ends ( 622 ).
- a zero calibration value may be temperature dependent for wide swings in temperature of, for example, approximately 40 or 50 C or greater. The various procedures described above can be done with such variations in temperature, since temperature also is measured (specifically, using the temperature sensor 220 ).
- the techniques described above can be performed, for example, by a manufacturer, during installation of the flowmeter. Alternatively, the techniques can be performed by a user of the flowmeter, periodically or during routine measurements. The techniques may be advantageous during cleaning of the flowmeter, during which cleaning materials may be processed through the flowmeter.
- the flowmeter zeroing techniques may be used to measure a density and/or mass flow of liquids such as petroleum oil (e.g., Naphtha, natural or distilled) or other hydrocarbon materials, food and food-related materials, as well as cleaning materials.
- the flowmeter and zeroing techniques may be used to measure density and/or mass flow of various gasses, including air, natural gas, and elemental gasses such as Helium.
- the implementations discussed above consider the direct integration of zeroing techniques with a flowmeter, such as implementing the techniques in a software module associated with the digital transmitter 104 , it is also possible to determine zero calibration values independently of the particular transmitter or control system being used. In this case, the zero calibration values could be externally subtracted from (or added to) a measurement output of the digital transmitter 104 .
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Abstract
Descriptions are provided for implementing flowmeter zeroing techniques. In operating a flowmeter, it may be the case that, if not properly calibrated, the flowmeter will produce erroneous measurements, e.g., will indicate a non-zero flow during a period of zero flow. By determining a magnitude of such erroneous measurements, calibration values may be determined, which may later be used to adjust a measurement that is output by the flowmeter and thereby improve an accuracy of the flowmeter. Such calibration values may be determined for a plurality of operational conditions associated with the flowmeter, such as densities of materials being measured, and/or configurations of flow elements associated with transporting material to the flowmeter. Then, the calibration values may be correlated with the relevant operational conditions, and stored for later use. In this way, during an actual operation of the flowmeter, a number of calibration values may be made available, and an optimal calibration value may be selected for an existing operational condition of the flowmeter.
Description
- This application is a continuation of U.S. application Ser. No. 11/304,698 filed on Dec. 16, 2005 and titled “FLOWMETER CALIBRATION TECHNIQUES,” which is in turn a continuation of U.S. application Ser. No. 10/729,990 filed Dec. 9, 2003 and titled “FLOWMETER ZEROING TECHNIQUES,” which claims priority to U.S. Provisional Application Ser. No. 60/460,817 filed on Apr. 8, 2003 and titled “FLOWMETER ZEROING TECHNIQUES.” All of these applications are incorporated herein in their entirety.
- This description relates to flowmeters.
- Flowmeters provide information about materials being transferred through a conduit. For example, mass flowmeters provide a measurement of the mass of material being transferred through a conduit. Similarly, density flowmeters, or densitometers, provide a measurement of the density of material flowing through a conduit. Mass flowmeters also may provide a measurement of the density of the material.
- For example, Coriolis-type mass flowmeters are based on the Coriolis effect, in which material flowing through a conduit becomes a radially-travelling mass that is affected by a Coriolis force and therefore experiences an acceleration. Many Coriolis-type mass flowmeters induce a Coriolis force by sinusoidally oscillating a conduit about a pivot axis orthogonal to the length of the conduit. In such mass flowmeters, the Coriolis reaction force experienced by the traveling fluid mass is transferred to the conduit itself and is manifested as a deflection or offset of the conduit in the direction of the Coriolis force vector in the plane of rotation.
- According to one general aspect, a flowmeter is calibrated. A plurality of calibration values are determined, the calibration values corresponding to measurements of material in a flowtube, the flowtube being associated with the flowmeter. Each of the calibration values is associated with one of a plurality of operational parameters of the flowmeter, each of the operational parameters being present during the determining of its corresponding calibration value. The calibration values are stored in association with their respective operational parameters.
- Implementations may have one or more of the following features. For example, in determining the plurality of calibration values a plurality of zero-flow calibration values corresponding to the measurements may be determined, where the measurements include mass flow measurements erroneously indicated by the flowmeter during a time of substantially zero mass flow through the flowtube. A current operational parameter of the flowmeter may be determined, and a current calibration value for use during an obtaining of a mass flow measurement may be determined, based on the current operational parameter.
- In determining the current operational parameter, a density of the material in the flowtube may be determined. In this case, determining the current calibration value of the flowmeter may include measuring a current density of a current material in the flowtube.
- In associating each of the calibration values with one of the plurality of operational parameters, a first calibration value may be associated with a range of densities. In this case, in determining the current calibration value, a current density of a current material in the flowtube may be measured, it may be determined that the current density falls within the range of densities, and the first calibration value may be selected.
- In associating each of the calibration values with one of the plurality of operational parameters, a mathematical relationship between the calibration values and the plurality of operational parameters may be used. In this case, in determining the current calibration value, a current density of a current material in the flowtube may be measured, the current density may be used in conjunction with the mathematical relationship to determine a current calibration value, and the current calibration value may be selected.
- In determining the current operational parameter, a configuration of flow elements associated with the flowtube may be determined. In this case, in determining the current calibration value, an input may be accepted from a user, the input identifying a current configuration of flow elements. Additionally, or alternatively, in determining the current calibration value, a first density of a first material in the flowtube may be measured, a correlation between the first density and a first configuration of flow elements may be accessed, and a first calibration value corresponding to the first configuration may be selected.
- In determining the current operational parameter, a gas void fraction of the material in the flowtube may be determined. In this case, in determining the current calibration value, an input of the gas void fraction may be received from a gas void fraction measurement system, and the current calibration value may be selected from a pre-determined list of associated calibration values and gas void fractions.
- According to another general aspect, a calibration system includes a measurement system operable to output measurements of material in a flowtube, where the flowtube is associated with a flowmeter, a calibration system operable to determine calibration values, each based on a corresponding measurement output by the measurement system, and a memory operable to store each of the calibration values in conjunction with an operational parameter associated with an operation of the flowmeter at a time of the corresponding measurement.
- Implementations may have one or more of the following features. For example, the calibration system may be operable to select a calibration value from the memory, based on a current operational parameter associated with the flowmeter. The measurement may include a mass flow rate of the material, and further wherein the calibration values may include zero calibration values corresponding to erroneously-detected mass flow measurements of the material during a time of substantially zero flow.
- The operational parameter may include a density of the material. The calibration system may be operable to select a current calibration value based on a current density of material in the flowtube, as measured by the measurement system. The calibration system may be operable to select the current calibration value by associating the current density with a pre-selected range of densities that is stored in the memory in association with the current calibration value. The calibration system may be operable to select the current calibration value, based on the current density and a mathematical relationship between the calibration values and their corresponding operational parameters
- The operational parameter may include a configuration of flow elements associated with the flowtube. The calibration system may be operable to accept a current configuration input by an operator, and to select a current calibration value based on the current configuration. The calibration system may be operable to select a current calibration value by determining a current configuration based on a currently-measured density that was previously associated with the current configuration.
- The operational parameter may include a gas void fraction of flow elements within the flowtube. The calibration system may be operable to receive a current gas void fraction from a gas void fraction measurement system, and further may be operable to select a corresponding current calibration value from the memory.
- The measurement system, the calibration system, and the memory may be integrated with the flowmeter.
- According to another general aspect, a flowmeter is operated. An operational parameter associated with the flowmeter is determined. A zero-flow calibration value based on the operational parameter is determined, based on a plurality of previously-determined zero-flow calibration values. A measurement of a property of a material within a flowtube associated with the flowmeter is taken, using the flowmeter. The measurement is adjusted using the zero-flow calibration value.
- Implementations may have one or more of the following features. For example, in determining the operational parameter, determining a configuration of flow elements associated with the flowtube may be determined. In determining the zero-flow calibration value, the zero-flow calibration value may be selected from among the previously-determined zero-flow calibration values as being the zero-flow calibration value that corresponds to one of a set of configurations, where each of the set of configurations existed at a time when its corresponding zero-flow calibration value was previously determined.
- In determining the operational parameter, a selection of the configuration may be accepted from a pre-determined set of configurations. Additionally, or alternatively, a density of the material may be measured, and the density may be associated with a first configuration.
- The operational parameter may include a density of the material in the flowtube. In this case, determining the zero-flow calibration value may include associating the density with a range of densities, and selecting the zero-flow calibration value from among the plurality of previously-determined zero-flow calibration values, based on a pre-determined relationship between the range of densities and the zero-flow calibration value.
- In determining the zero-flow calibration value, the density may be input into a mathematical relationship derived from a relationship between the previously-determined zero-flow calibration values and corresponding density measurements. Additionally, or alternatively, the zero-flow calibration value may be selected from among the plurality of previously-determined zero-flow calibration values, based on a pre-determined relationship between the operational parameter and the zero-flow calibration value.
- In determining the operational parameter, a gas void fraction of the material in the flowtube may be determined. In determining the gas void fraction, a current gas void fraction may be received from a gas void fraction measurement system, and further wherein determining the zero-flow calibration value comprises selecting a current zero-flow calibration value previously associated with the current gas void fraction measurement.
- The details of one or more implementations are set forth in the accompanying drawings and the description below. Other features will be apparent from the description and drawings, and from the claims.
-
FIG. 1A is an illustration of a Coriolis flowmeter using a bent flowtube. -
FIG. 1B is an illustration of a Coriolis flowmeter using a straight flowtube. -
FIG. 2 is a block diagram of a Coriolis flowmeter. -
FIG. 3 is a block diagram of a flowmeter operating in conjunction with one or more of a plurality of different-density materials. -
FIG. 4 is a chart comparing zero calibration values calculated at different fluid densities. -
FIG. 5 is a block diagram of a flowmeter operating in conjunction with a plurality of piping and/or pumping configurations. -
FIG. 6 is a flowchart illustrating techniques for selecting a zero calibration value. - Types of flowmeters include digital flowmeters. For example, U.S. Pat. No. 6,311,136, which is hereby incorporated by reference, discloses the use of a digital flowmeter and related technology including signal processing and measurement techniques. Such digital flowmeters may be very precise in their measurements, with little or negligible noise, and may be capable of enabling a wide range of positive and negative gains at the driver circuitry for driving the conduit. Such digital flowmeters are thus advantageous in a variety of settings. For example, commonly-assigned U.S. Pat. No. 6,505,519, which is incorporated by reference, discloses the use of a wide gain range, and/or the use of negative gain, to prevent stalling and to more accurately exercise control of the flowtube, even during difficult conditions such as two-phase flow.
- Although digital flowmeters are specifically discussed below with respect to
FIGS. 1 and 2 , it should be understood that analog flowmeters also exist. Although such analog flowmeters may be prone to typical shortcomings of analog circuitry, e.g., low precision and high noise measurements relative to digital flowmeters, they also may be compatible with the various techniques and implementations discussed herein. Thus, in the following discussion, the term “flowmeter” or “meter” is used to refer to any type of device and/or system in which a Coriolis flowmeter system uses various control systems and related elements to measure a mass flow, density, and/or other parameters of a material(s) moving through a flowtube or other conduit. -
FIG. 1A is an illustration of a digital flowmeter using abent flowtube 102. Specifically, thebent flowtube 102 may be used to measure one or more physical characteristics of, for example, a (traveling) fluid, as referred to above. InFIG. 1A , adigital transmitter 104 exchanges sensor and drive signals with thebent flowtube 102, so as to both sense an oscillation of thebent flowtube 102, and to drive the oscillation of thebent flowtube 102 accordingly. By quickly and accurately determining the sensor and drive signals, thedigital transmitter 104, as referred to above, provides for fast and accurate operation of thebent flowtube 102. Examples of thedigital transmitter 104 being used with a bent flowtube are provided in, for example, commonly-assigned U.S. Pat. No. 6,311,136. -
FIG. 1B is an illustration of a digital flowmeter using astraight flowtube 106. More specifically, inFIG. 1B , thestraight flowtube 106 interacts with thedigital transmitter 104. Such a straight flowtube operates similarly to thebent flowtube 102 on a conceptual level, and has various advantages/disadvantages relative to thebent flowtube 102. For example, thestraight flowtube 106 may be easier to (completely) fill and empty than thebent flowtube 102, simply due to the geometry of its construction. In operation, thebent flowtube 102 may operate at a frequency of, for example, 50-110 Hz, while thestraight flowtube 106 may operate at a frequency of, for example, 300-1,000 Hz. - Referring to
FIG. 2 , a digitalmass flowmeter 200 includes thedigital transmitter 104, one ormore motion sensors 205, one ormore drivers 210, a flowtube 215 (which also may be referred to as a conduit, and which may represent either thebent flowtube 102, thestraight flowtube 106, or some other type of flowtube), and atemperature sensor 220. Thedigital transmitter 104 may be implemented using one or more of, for example, a processor, a Digital Signal Processor (DSP), a field-programmable gate array (FPGA), an ASIC, other programmable logic or gate arrays, or programmable logic with a processor core. - The
digital transmitter 104 generates a measurement of, for example, density and/or mass flow of a material flowing through theflowtube 215, based at least on signals received from themotion sensors 205. Thedigital transmitter 104 also controls thedrivers 210 to induce motion in theflowtube 215. This motion is sensed by themotion sensors 205. - Density measurements of the material flowing through the flowtube are related to, for example, the frequency of the motion of the
flowtube 215 that is induced in theflowtube 215 by a driving force supplied by thedrivers 210, and/or to the temperature of theflowtube 215. Similarly, mass flow through theflowtube 215 is related to the phase and frequency of the motion of theflowtube 215, as well as to the temperature of theflowtube 215. - The temperature in the
flowtube 215, which is measured using thetemperature sensor 220, affects certain properties of the flowtube, such as its stiffness and dimensions. Thedigital transmitter 104 may compensate for these temperature effects. This temperature affects, for example, an operating frequency of thedigital transmitter 104, a sampling rate of an analog-to-digital converter, and/or a crystal frequency associated with a reference clock used by thetransmitter 104. Also inFIG. 2 , a gas void fraction sensor 222 (discussed in more detail below) is included that is operable to determine what percentage of a material in theflowtube 215, if any, is composed of a gas. Although not shown inFIG. 2 , other sensors may be included, such as, for example, a pressure sensor that is operable to sense a pressure of a material flowing through theflowtube 215. - In performing measurements of mass flow (and/or density), calibration of the flowmeter may be required in order to maintain system performance, particularly over long periods of time and/or extensive operation of the flowmeter. One calibration technique is known as “zeroing” or “a zero calibration.” In a zeroing process, a flow of material through the
flowtube 215 is stopped (for example, upstream and downstream valves may be closed) during a time when theflowtube 215 is filled with the material. As a result, there is a zero flow of the material, which should lead to a corresponding reading of zero flow output by the flowmeter. - For various reasons, however, it may be the case that the flowmeter outputs a non-zero (i.e., erroneous) flowrate during a time of zero flow. In these cases, the (erroneous) non-zero flowrate at zero flow may be used as a calibration factor; that is, for example, it may be subtracted from (or added to) a measured flow, so as to obtain an accurate, i.e., zero-corrected, reading of the flow during future readings.
- The zeroing process might involve, for example, filling the
flowtube 215 with a process fluid. Then the flow is brought to zero while keeping the meter full. The resulting non-zero, erroneous flow indicated by the flowmeter may be averaged over a period of time to determine the zero calibration value. - In performing such a zeroing process, a type of flowtube currently being used may be relevant in obtaining and using the zero calibration value. Additionally, it may be the case that the zero calibration value also is a function of factors or parameters that are related to the particular operation of whatever flowmeter being used. That is to say, the zero calibration value may be a function of various parameters, such as, for example, a density of the process fluid(s), a configuration of external elements associated with the flowmeter (e.g., valves, pumps, pipes), or a temperature (as measured by the temperature sensor 220). As a result, when one or more of these parameters changes, the previously-calculated zero calibration value may be less accurate.
- For example, in a Coriolis mass flowmeter, the zero calibration value may be different for fluids having different densities. One reason for this may be that the drive frequency for the
flowtube 215 is selected in part based on fluid density, and the mass flow reading at zero flow may be largely dependent on frequency. Thus, in applications where fluids of greatly varying density are involved, or applications where multiple fluids are passed through the same meter, the calculated zero calibration value may not be sufficiently accurate. - As another example, the phrase “batching from empty” refers to a condition in which a flowmeter is completely emptied in between batches of measured materials (i.e., is empty at a start and finish of the measurements). In this situation, the zero calibration value when the
flowtube 215 is full may be considerably different than the zero calibration value when the flowtube is empty. Other examples in which a zero calibration value may require changing in response to changed (or changing) flowmeter conditions are discussed in more detail below. - In order to provide an accurate zero calibration value in a wide variety of settings, separate zero calibration values are determined in different environments, and correlated with the environment in which they were obtained. Then, during subsequent use of the flowmeter, an appropriate zero calibration value is determined for the environment at hand, based on the previously-obtained values.
- In
FIG. 2 , then, thedigital transmitter 104 includes various elements designed to implement the above-described calibration functionality. It should be understood that some or all of these elements (along with other elements of thedigital transmitter 104, not explicitly shown inFIG. 2 ) also may be used during a normal operation of the flowmeter 200 (e.g., after zero calibration values have been determined). - Thus, the
digital transmitter 104 includes ameasurement system 225, which is operable to obtain a measurement, such as a mass flow measurement and/or density measurement. A calibration determination andcorrelation system 230, based on at least one measurement output by themeasurement system 225, determines a zero calibration value corresponding to an operational parameter of theflowmeter 200, at the time of the measurement. For example, themeasurement system 225 may output an erroneous, non-zero measurement of mass flow of a given material during a time of substantially zero flow of the material through theflowtube 215, as well as a density of the material. The calibration determination andcorrelation system 230 may then determine a zero calibration value associated with the mass flow measurement and correlate that zero calibration value with the measured density, to be used as a correction factor during future mass flow measurements of material(s) having that density. - Thus, as in the example just given, the operational parameter may include, for example, a parameter that is detectable and measurable by the
measurement system 225, such as the density (or temperature) of the material. As another example, the operational parameter may include a parameter that may be input into the calibration determination andcorrelation system 230 by an operator, such as a configuration of the flowmeter, or a configuration of various flow elements associated with the flowmeter, such as pipes, valves, or manifolds. - The calibration determination and
correlation system 230 correlates particular zero calibration values with particular, corresponding operational parameters, and stores these values and correlations in amemory 235. During a subsequent operation of theflowmeter 200, acalibration selection system 240 may select or otherwise determine an appropriate zero calibration value, using thememory 235. In one implementation, the calibration system determines the appropriate zero calibration value automatically, whereas, in another implementation, an operator selects the appropriate zero calibration value directly from thememory 235. Thus, an appropriate zero calibration value is made available to themeasurement system 225, so that themeasurement system 225, during normal operation of theflowmeter 200, may output highly-accurate, zero-adjusted measurements. - The
calibration selection system 240 may select a zero calibration value from thememory 235 in a variety of ways. For example, when zero calibration values and operational parameters that include a corresponding number of fluid densities are stored in thememory 235, thecalibration selection system 240 may interact with themeasurement system 225 to determine a density of a material currently in theflowtube 215. Then, the calibration selection system may select a zero calibration value corresponding to that density. In this way, highly-accurate, customized mass flow measurements may be obtained during future use of the flowmeter, even when a plurality of different-density materials are measured by the flowmeter. -
FIG. 3 is a block diagram 300 of a flowmeter operating in conjunction with one or more of a plurality of different-density materials. InFIG. 3 , a liquid material is fed into avalve 302, and thereby into ameter 304. Further inFIG. 3 , a vapor or gas material is fed through avalve 306 and into themeter 304. It should be understood that, although not explicitly shown inFIG. 3 , themeter 304 may include, for example, all of the features described above with respect to theflowmeter 200 and further described in U.S. Pat. Nos. 6,311,136 and/or 6,505,519. - In
FIG. 3 , thevalve 302 may be opened while thevalve 306 is closed, so that themeter 304 measures only the liquid material. Conversely, thevalve 306 may be opened while thevalve 302 is closed, so that themeter 304 measures only the gaseous material. Further, thevalves meter 304 during a given period of time. - Thus, as described above, a density of the liquid and a density of the gas (e.g., air) may be associated with an appropriate zero calibration value. Then, during subsequent measurements, the
meter 304 may determine a density of the material currently flowing therethrough, and select the corresponding zero calibration value accordingly. - It should be understood that many variations exist for the configuration shown in
FIG. 3 . For example, more than two materials could be measured in this way by themeter 304. Also, multiple types of liquids (or gasses) could simultaneously be included (as opposed to one or more of each). - In one implementation, a mixture of the same two fluids is passed through the
meter 304, where proportions of the fluids relative to one another may vary. For example, inFIG. 3 , the liquid and the gas may be passed through themeter 304 simultaneously, rather than consecutively, and the percentage of the gas (i.e., the “void fraction”) may vary over time. As the void fraction increases, the density of the liquid/gas mixture will generally decrease, possibly resulting in the need for a different zero calibration value. - Various techniques exist for measuring the gas void fraction. For example, various sensors or probes exist that may be inserted into the flow to determine a gas void fraction. As another example, a venturi tube (i.e., a tube with a constricted throat that determines fluid pressures and velocities by measurement of differential pressures generated at the throat as a fluid traverses the tube), relying on the fact that gas generally moves with a higher velocity than liquid(s) through a restriction, may be used to determine a pressure gradient and thereby allow a determination of the gas void fraction. In some systems, as referred to above with respect to
FIG. 2 , measurements of gas void fractions may be obtained using equipment (e.g., the gas void fraction sensor 222) that is wholly external to the flowtube. For example, sonar measurements may be taken to determine gas void fraction. As a specific example of such a sonar-based system, the SONARtrac™ gas void fraction monitoring system produced by CiDRA Corporation of Wallingford, Conn. may be used. - The situation of a void fraction arises, for example, when the
meter 304 measures a liquid and gas flow simultaneously (e.g., when measuring a combination of oil and hydrocarbon-related gas that is output by an oil well), or when a meter is used in a “batching from empty” application, as referred to above. In these and similar situations, the user might, for example, zero themeter 304 while full of liquid, and store the zero calibration value and density. This process may be repeated with themeter 304 being empty (e.g. full of air). Then, during operation, themeter 304 would use the zero calibration value associated with gas when it is predominantly gas and would use the zero calibration value associated with liquid when it is closer to being full. This process could be further extended to store zero calibration values for a variety of void fractions. - Additionally, or alternatively, any of the various techniques discussed above for determining gas void fractions (or any other technique) may be used to determine gas void fractions, which may then be associated with corresponding zero calibration values. In one implementation, a gas void fraction measurement system, such as, for example, an external sensor or probe similar to those discussed above, may output a signal directly to an input of the
transmitter 104, to be processed in thetransmitter 104 to determine a gas void fraction (i.e., may be positioned and connected similarly to thetemperature sensor 220 ofFIG. 2 ). In another implementation, the signal from such an external sensor or probe may be connected to a separate computing resource, such as, for example, a control system or flow computer, with the determination of a gas void fraction carried out therein. In yet another implementation, the sensor or probe itself may have an integrally-formed computing resource that is operable to determine a gas void fraction for direct output to thetransmitter 104. -
FIG. 4 is achart 400 comparing zero calibration values calculated at different fluid densities. In the chart ofFIG. 4 , afirst data point 402 corresponds to a zero calibration value determined (by the calibration determination and correlation system 230) for a material having a first density, as measured by themeasurement system 225. Similarly, second andthird data points correlation system 230, and stored in thememory 225, so that an appropriate zero calibration value may be chosen by thecalibration selection system 240 during future measurements. - For example, similarly to the implementation of
FIG. 3 , it may be the case that (in this case, three) different fluids are alternately processed through the same flowmeter, where each of the three different fluids has a density corresponding to one of the data points 402, 404, and 406. In one implementation, then, thecalibration selection system 240 might simply select a zero calibration value corresponding to a measured one of the three densities, perhaps from a table relating the zero calibration and density values and stored in thememory 235. - In another example, a fluid may be used having a density that does not directly correspond to one of the data points 402, 404, or 406. In this case, the three
data points density bands correlation system 230 and/or thecalibration selection system 240, and stored in thememory 235. The bands may be based on, for example, a manufacturer's determination, or could be a configurable parameter that is adjusted by a user of the flowmeter. - Once the bands are established for a fluid having a density within one of the bands, an appropriate zero calibration value may be chosen. For example, if a fluid having a density falling within the
density band 410 is processed by the flowmeter, then the zero calibration value corresponding to thedata point 402 may be used. - Somewhat similarly, if the data points 402, 404, and 406 have some type of relationship to one another, such as a linear, quasi-linear, or tractable relationship, the calibration determination and
correlation system 230 may interpolate (e.g., linearly interpolate) between the data points. In this way, a fluid having a density anywhere within the relevant range could be correlated with a corresponding zero calibration value that would produce an improved-accuracy measurement. In this case, thememory 235 may be used to store a mathematical relationship or algorithm derived by the calibration determination andcorrelation system 230, rather than (or in addition to) a table of related values. -
FIG. 5 is a block diagram 500 of a flowmeter 502 operating in conjunction with a plurality of piping and/or pumping configurations. InFIG. 5 , a first material or product 504 is pumped through a pump 506 and a valve 508 before reaching the meter 502. A second product 510 is pumped through a pump 512 and a valve 514 before reaching the meter 502. Finally inFIG. 5 , a third product 516 is sent to the meter 502 after being fed to a valve 518 by way of a gravity feed 520. Thus, the first product 504, the pump 506, and the valve 508 form a first configuration 522, the second product 510, the pump 512, and the valve 514 form a second configuration 524, and the third product 516, valve 518, and the gravity feed 520 form a third configuration 526. - In
FIG. 5 , the three products 504, 510, and 516 may or may not have the same density as one another. Even in the case where two or more of the densities are the same (or even where two of the products are the same), however, zero calibration values associated with each of the configurations 522, 524, and 526 may be different from one another, due to, for example, the configuration elements (e.g., the valves 508, 514, 518, the pumps 506 and 512, or the gravity feed 520) that are used, and/or the manner in which the configuration elements are connected to one another. - Thus, in one exemplary case, and similar to the chart of
FIG. 4 , a zero calibration value is determined for (and associated with) each of the configurations 522, 524, and 526, and stored for future use. Selection of an appropriate zero calibration value is then determined during measurements by way of discrete input from an operator of the flowmeter 502, e.g., by input into the calibration determination andcorrelation system 230 and/or thecalibration selection system 240 of a currently-used configuration. - In a more specific example, the various zero calibration values are associated with their respective configurations in the above-described manner, and the configurations and corresponding zero calibration values are then displayed on an output screen associated with the
digital transmitter 104. In this way, a user may simply scroll through the stored configurations to select an appropriate zero calibration value. - In a further example, if the three products have different densities, then these densities are correlated with a specific configuration and corresponding zero calibration value. Then, during measurements, the flowmeter determines a density of a currently-measured product, and thereby determines the appropriate zero calibration value automatically. In other words, the meter 502 determines that, based on a given density of a current product, a particular configuration exists. Then, based on that density and configuration, the appropriate zero calibration value may be selected.
-
FIG. 6 is aflowchart 600 illustrating techniques for selecting a zero calibration value, as described above. InFIG. 6 , it is assumed that a particular flowtube or flowtube type is being used. Thus, if a new or different flowtube were used, the process(es) described below may require repeating to ensure accuracy of the flowmeter in conjunction with the new flowtube. - To begin, a user performs a zero calibration for each condition, i.e., for each operational parameter (602). As in the examples above, this might include performing zero calibrations for materials having multiple, different densities (604), or might include performing zero calibrations for multiple, different configurations (606), or both. The zero calibration values are related to their corresponding operational parameters by the calibration determination and
correlation system 230, and these values and their relations to one another (including, possibly, a mathematical relationship between the values) are recorded in the memory 235 (608). - Then, flow of a particular material (in a particular configuration) is commenced (610). The appropriate zero calibration value is selected by the calibration selection system 240 (612). For example, the flowmeter may be used to measure a density of the currently-flowing fluid, whereupon the density is correlated with a particular zero calibration value in one or more of the manners described above (614). As another example, the zero calibration value may be selected based on a current configuration/product being used, as input by a user, perhaps by way of a scrolling, input/output display (616).
- Measurements are then performed for some period of time (618). If characteristics of a new material(s) and/or configuration are to be measured (620), then flow of that material (in that configuration) is initiated (610), and the zero calibration value is adjusted accordingly. Otherwise, the process flow ends (622).
- Although density and mechanical configurations are primarily discussed above as examples of operational parameters that may affect zero calibration value selection, other factors may affect selection of an appropriate zero calibration value. For example, a zero calibration value may be temperature dependent for wide swings in temperature of, for example, approximately 40 or 50 C or greater. The various procedures described above can be done with such variations in temperature, since temperature also is measured (specifically, using the temperature sensor 220).
- The techniques described above can be performed, for example, by a manufacturer, during installation of the flowmeter. Alternatively, the techniques can be performed by a user of the flowmeter, periodically or during routine measurements. The techniques may be advantageous during cleaning of the flowmeter, during which cleaning materials may be processed through the flowmeter.
- Many types of materials may be used in conjunction with the implementations described herein. For example, the flowmeter zeroing techniques may be used to measure a density and/or mass flow of liquids such as petroleum oil (e.g., Naphtha, natural or distilled) or other hydrocarbon materials, food and food-related materials, as well as cleaning materials. Similarly, the flowmeter and zeroing techniques may be used to measure density and/or mass flow of various gasses, including air, natural gas, and elemental gasses such as Helium. As a result, applications for these and related techniques are far-ranging, including food industries, drug production, oil and gas processing, and various other industries.
- Moreover, although the implementations discussed above consider the direct integration of zeroing techniques with a flowmeter, such as implementing the techniques in a software module associated with the
digital transmitter 104, it is also possible to determine zero calibration values independently of the particular transmitter or control system being used. In this case, the zero calibration values could be externally subtracted from (or added to) a measurement output of thedigital transmitter 104. - A number of implementations have been described. Nevertheless, it will be understood that various modifications may be made. Accordingly, other implementations are within the scope of the following claims.
Claims (2)
1. A method of calibrating a flowmeter having a vibratable flowtube and at least one sensor associated with the vibratable flowtube, the method comprising:
vibrating the flowtube while a first operational parameter of the flowtube is present;
receiving a first sensor signal from the sensor, the sensor signal representative of the vibration of the flowtube while the first operational parameter of the flowtube is present;
determining a first calibration value based on the first sensor signal, wherein the first calibration value is a first zero-flow calibration value;
storing the first calibration value in association with the first operational parameter;
vibrating the flowtube while a second operational parameter of the flowtube is present;
receiving a second sensor signal from the sensor, the second sensor signal representative of the vibration of the flowtube while the second operational parameter of the flowtube is present;
determining a second calibration value based on the second sensor signal, wherein the second calibration value is a second zero-flow calibration value; and
storing the second calibration value in association with the second operational parameter.
2-38. (canceled)
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US12/721,273 US20100307220A1 (en) | 2003-04-08 | 2010-03-10 | Flowmeter calibration techniques |
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US46081703P | 2003-04-08 | 2003-04-08 | |
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US11/304,698 US7185526B2 (en) | 2003-04-08 | 2005-12-16 | Flowmeter calibration techniques |
US11/681,574 US7690240B2 (en) | 2003-04-08 | 2007-03-02 | Flowmeter calibration techniques |
US12/721,273 US20100307220A1 (en) | 2003-04-08 | 2010-03-10 | Flowmeter calibration techniques |
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US11/681,574 Continuation US7690240B2 (en) | 2003-04-08 | 2007-03-02 | Flowmeter calibration techniques |
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US11/681,574 Active 2024-08-25 US7690240B2 (en) | 2003-04-08 | 2007-03-02 | Flowmeter calibration techniques |
US12/721,273 Abandoned US20100307220A1 (en) | 2003-04-08 | 2010-03-10 | Flowmeter calibration techniques |
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US11/681,574 Active 2024-08-25 US7690240B2 (en) | 2003-04-08 | 2007-03-02 | Flowmeter calibration techniques |
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Families Citing this family (40)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6997032B2 (en) * | 2003-04-08 | 2006-02-14 | Invensys Systems, Inc. | Flowmeter zeroing techniques |
DE10351313A1 (en) * | 2003-10-31 | 2005-05-25 | Abb Patent Gmbh | Method for zero point correction of a measuring device |
US7302356B2 (en) * | 2004-09-15 | 2007-11-27 | Endress + Hauser Flowtec Ag | Coriolis flowmeter |
US7337084B2 (en) * | 2005-06-21 | 2008-02-26 | Invensys Systems, Inc. | Switch-activated zero checking feature for a Coriolis flowmeter |
US8021469B2 (en) * | 2005-07-14 | 2011-09-20 | Access Business Group International Llc | Control methods for an air treatment system |
US7212953B1 (en) * | 2005-12-09 | 2007-05-01 | Dresser, Inc. | Portable diagnostic analysis of gas meter and electronic corrector |
WO2008013545A1 (en) * | 2006-07-28 | 2008-01-31 | Micro Motion, Inc. | Three pickoff sensor flow meter |
WO2008024112A1 (en) * | 2006-08-24 | 2008-02-28 | Micro Motion, Inc. | Multiple flow conduit flow meter |
KR20100029070A (en) * | 2007-02-19 | 2010-03-15 | 브룩스 인스트러먼트, 엘엘씨, | Valve leakby diagnostics |
US7516034B1 (en) * | 2007-09-18 | 2009-04-07 | Rosemount Inc. | Magnetic flow transmitter having multiple flowtube data sets |
JP5613766B2 (en) | 2009-08-12 | 2014-10-29 | マイクロ モーション インコーポレイテッド | Method and apparatus for determining and compensating for changes in differential zero offset of vibratory flow meter |
RU2502963C2 (en) * | 2009-08-12 | 2013-12-27 | Майкро Моушн, Инк. | Method and device to determine zero shift in vibration flow metre |
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MX2013014108A (en) * | 2011-06-27 | 2014-01-20 | Micro Motion Inc | Vibratory flow meter and zero check method. |
RU2568950C2 (en) | 2011-07-07 | 2015-11-20 | Майкро Моушн, Инк. | Method and device to determine differential parameters of fluid flow for system of fluid flow measurement with multiple meters |
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US9562427B2 (en) * | 2012-11-19 | 2017-02-07 | Invensys Systems, Inc. | Net oil and gas well test system |
US9360406B2 (en) * | 2013-04-17 | 2016-06-07 | Thermo Fisher Scientific Inc. | Method and apparatus for self-calibration of density profiler |
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WO2017069749A1 (en) * | 2015-10-21 | 2017-04-27 | Micro Motion, Inc. | In situ transducer calibration |
SG11201805599XA (en) * | 2016-01-13 | 2018-07-30 | Micro Motion Inc | Multi-phase coriolis measurement device and method |
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US11920971B2 (en) | 2020-08-14 | 2024-03-05 | Honeywell International Inc. | Gas flowmeter having inline calibrating |
DE102020129074A1 (en) | 2020-11-04 | 2022-05-05 | Krohne Messtechnik Gmbh | Flow meter, method for operating a flow meter, system and method for operating a system |
US11754429B2 (en) | 2020-11-11 | 2023-09-12 | Honeywell International Inc. | Multifunctional dust trap |
WO2022256001A1 (en) * | 2021-06-02 | 2022-12-08 | Micro Motion, Inc. | Detecting a measurement bias of a reference zero-flow value |
WO2022255999A1 (en) * | 2021-06-02 | 2022-12-08 | Micro Motion, Inc. | Selecting a zero-verification criteria for a zero verification of a vibratory meter |
CN113776575A (en) * | 2021-08-16 | 2021-12-10 | 深圳市睿联技术股份有限公司 | Zero point calibration method, device, apparatus, electronic device, and computer-readable storage medium |
Citations (18)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4733569A (en) * | 1985-12-16 | 1988-03-29 | K-Flow Division Of Kane Steel Co., Inc. | Mass flow meter |
US4817448A (en) * | 1986-09-03 | 1989-04-04 | Micro Motion, Inc. | Auto zero circuit for flow meter |
US4845989A (en) * | 1987-09-04 | 1989-07-11 | Titlow Joseph D | Method and apparatus for determining elastic constants in tubes |
US4852409A (en) * | 1988-06-09 | 1989-08-01 | Fischer & Porter Company | Signal recovery system for mass flowmeter |
US5228327A (en) * | 1991-07-11 | 1993-07-20 | Micro Motion, Inc. | Technique for determining a mechanical zero value for a coriolis meter |
US5295084A (en) * | 1991-10-08 | 1994-03-15 | Micromotion, Inc. | Vibrating tube densimeter |
US5357811A (en) * | 1992-02-11 | 1994-10-25 | Exac Corporation | Single tube coriolis flow meter with floating intermediate section |
US5524084A (en) * | 1994-12-30 | 1996-06-04 | Hewlett-Packard Company | Method and apparatus for improved flow and pressure measurement and control |
US5796012A (en) * | 1996-09-19 | 1998-08-18 | Oval Corporation | Error correcting Coriolis flowmeter |
US6272438B1 (en) * | 1998-08-05 | 2001-08-07 | Micro Motion, Inc. | Vibrating conduit parameter sensors, methods and computer program products for generating residual-flexibility-compensated mass flow estimates |
US6311136B1 (en) * | 1997-11-26 | 2001-10-30 | Invensys Systems, Inc. | Digital flowmeter |
US6367336B1 (en) * | 1998-12-29 | 2002-04-09 | Hugo Gabriel Martina | Process mass flow apparatus and method for measuring the mass flow of powdered and granulated solids as well as the accumulated weight of material passed during a specified time |
US6374190B2 (en) * | 1998-06-29 | 2002-04-16 | Siemens Aktiengesellschaft | Method for calibrating an angle sensor and navigation system having an angle sensor |
US6378354B1 (en) * | 2000-07-21 | 2002-04-30 | Micro Motion, Inc. | System for calibrating a drive signal in a coriolis flowmeter to cause the driver to vibrate a conduit in a desired mode of vibration |
US6505519B2 (en) * | 2000-03-23 | 2003-01-14 | Invensys Systems, Inc. | Correcting for two-phase flow in a digital flowmeter |
US6557422B1 (en) * | 2000-01-21 | 2003-05-06 | Krohne A.G. | Mass flow rate measuring device |
US6687635B2 (en) * | 2002-06-13 | 2004-02-03 | Mks Instruments, Inc. | Apparatus and method for compensated sensor output |
US6997032B2 (en) * | 2003-04-08 | 2006-02-14 | Invensys Systems, Inc. | Flowmeter zeroing techniques |
Family Cites Families (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE4226391C2 (en) | 1992-08-10 | 1995-07-20 | Flowtec Ag | Method for detecting a zero point drift of a Coriolis mass flow sensor |
JP3265859B2 (en) | 1994-10-18 | 2002-03-18 | 富士電機株式会社 | Mass flow meter |
US6962164B2 (en) | 2001-04-24 | 2005-11-08 | Celerity Group, Inc. | System and method for a mass flow controller |
-
2003
- 2003-12-09 US US10/729,990 patent/US6997032B2/en not_active Expired - Lifetime
-
2004
- 2004-03-30 DE DE112004000612.0T patent/DE112004000612B4/en not_active Expired - Lifetime
- 2004-03-30 WO PCT/US2004/009916 patent/WO2004092680A2/en active Application Filing
-
2005
- 2005-12-16 US US11/304,698 patent/US7185526B2/en not_active Expired - Lifetime
-
2007
- 2007-03-02 US US11/681,574 patent/US7690240B2/en active Active
-
2010
- 2010-03-10 US US12/721,273 patent/US20100307220A1/en not_active Abandoned
Patent Citations (19)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4733569A (en) * | 1985-12-16 | 1988-03-29 | K-Flow Division Of Kane Steel Co., Inc. | Mass flow meter |
US4817448A (en) * | 1986-09-03 | 1989-04-04 | Micro Motion, Inc. | Auto zero circuit for flow meter |
US4845989A (en) * | 1987-09-04 | 1989-07-11 | Titlow Joseph D | Method and apparatus for determining elastic constants in tubes |
US4852409A (en) * | 1988-06-09 | 1989-08-01 | Fischer & Porter Company | Signal recovery system for mass flowmeter |
US5228327A (en) * | 1991-07-11 | 1993-07-20 | Micro Motion, Inc. | Technique for determining a mechanical zero value for a coriolis meter |
US5295084A (en) * | 1991-10-08 | 1994-03-15 | Micromotion, Inc. | Vibrating tube densimeter |
US5357811A (en) * | 1992-02-11 | 1994-10-25 | Exac Corporation | Single tube coriolis flow meter with floating intermediate section |
US5524084A (en) * | 1994-12-30 | 1996-06-04 | Hewlett-Packard Company | Method and apparatus for improved flow and pressure measurement and control |
US5796012A (en) * | 1996-09-19 | 1998-08-18 | Oval Corporation | Error correcting Coriolis flowmeter |
US6311136B1 (en) * | 1997-11-26 | 2001-10-30 | Invensys Systems, Inc. | Digital flowmeter |
US6374190B2 (en) * | 1998-06-29 | 2002-04-16 | Siemens Aktiengesellschaft | Method for calibrating an angle sensor and navigation system having an angle sensor |
US6272438B1 (en) * | 1998-08-05 | 2001-08-07 | Micro Motion, Inc. | Vibrating conduit parameter sensors, methods and computer program products for generating residual-flexibility-compensated mass flow estimates |
US6367336B1 (en) * | 1998-12-29 | 2002-04-09 | Hugo Gabriel Martina | Process mass flow apparatus and method for measuring the mass flow of powdered and granulated solids as well as the accumulated weight of material passed during a specified time |
US6557422B1 (en) * | 2000-01-21 | 2003-05-06 | Krohne A.G. | Mass flow rate measuring device |
US6505519B2 (en) * | 2000-03-23 | 2003-01-14 | Invensys Systems, Inc. | Correcting for two-phase flow in a digital flowmeter |
US6378354B1 (en) * | 2000-07-21 | 2002-04-30 | Micro Motion, Inc. | System for calibrating a drive signal in a coriolis flowmeter to cause the driver to vibrate a conduit in a desired mode of vibration |
US6687635B2 (en) * | 2002-06-13 | 2004-02-03 | Mks Instruments, Inc. | Apparatus and method for compensated sensor output |
US6997032B2 (en) * | 2003-04-08 | 2006-02-14 | Invensys Systems, Inc. | Flowmeter zeroing techniques |
US7185526B2 (en) * | 2003-04-08 | 2007-03-06 | Invensys Systems, Inc. | Flowmeter calibration techniques |
Also Published As
Publication number | Publication date |
---|---|
US20060090537A1 (en) | 2006-05-04 |
US20070144234A1 (en) | 2007-06-28 |
US7690240B2 (en) | 2010-04-06 |
WO2004092680A3 (en) | 2005-04-28 |
US7185526B2 (en) | 2007-03-06 |
DE112004000612T5 (en) | 2006-04-06 |
DE112004000612B4 (en) | 2023-05-04 |
US6997032B2 (en) | 2006-02-14 |
US20040200259A1 (en) | 2004-10-14 |
WO2004092680A2 (en) | 2004-10-28 |
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