Estimation of hydrogen-loading-induced changes in vibrating meters.

Abstract

A method is provided for estimating hydrogen-loading induced changes in a vibrating meter that includes determining a pressure and temperature of hydrogen exposed to a vibrating element of the vibrating meter, calculating a concentration of hydrogen in the vibrating element based on the hydrogen pressure and temperature, and adjusting a calibration factor of the vibrating meter based on the calculated concentration of hydrogen in the vibrating element.

Description

[Technical field]

[0001] The embodiments described below relate to estimating changes in a vibratory meter, and more particularly, to estimating hydrogen-loading induced changes in a vibratory meter. [Background technology]

[0002] Vibratory meters, such as, for example, Coriolis mass flow meters, liquid density meters, gas density meters, liquid viscosity meters, gas / liquid specific gravity meters, gas / liquid relative density meters, and gas molecular weight meters, are commonly known and used to measure fluid parameters. Generally, vibratory meters include a sensor assembly and meter electronics. The sensor assembly may be communicatively coupled to the meter electronics and provide a sensor signal to the meter electronics. The sensor assembly may include a conduit configured to vibrate in response to a driving force imposed by an actuator that receives a drive signal from the meter electronics. The actuator may be referred to as a driver.

[0003] When a conduit is used in a sensor assembly, the conduit may be filled with a material having a property to be measured. The material in one or more conduits of the sensor assembly may be flowing or stationary. The sensor assembly may be used to measure one or more fluid parameters, such as mass flow rate, density, or other properties of the material in the sensor assembly. More specifically, there may be one or more transducers attached to one or more conduits that are configured to convert vibrational motion into a sensor signal. These transducers may be referred to as pick-off sensors. Pick-off sensors are generally located at the inlet and outlet portions of one or more conduits.

[0004] As mentioned above, the vibratory meter may be a Coriolis flow meter. A Coriolis flow meter includes one or more conduits connected in line in a pipeline or other transport system to carry materials, such as fluids, slurries, and / or the like, in the system. Each conduit may be considered to have a set of natural vibration modes, including, for example, simple bending, torsional, radial, and coupled modes. In a Coriolis flow measurement application, the conduit is excited in one or more vibration modes as material flows through the conduit, and the motion of the conduit is measured at points spaced along the conduit. During flow, the vibrating tube and the flowing mass couple to each other due to the Coriolis force, which induces a vibration phase difference between the ends of the tube. The phase difference may be directly proportional to the mass flow rate and may be measured as the phase difference between two sensor signals provided by pick-off sensors.

[0005] For example, the mass flow rate of a material may be proportional to the phase difference or time delay between the two sensor signals, where the time delay may include the phase difference divided by the frequency. Thus, the mass flow rate may be determined, for example, by multiplying the time delay by a proportionality constant or calibration factor, sometimes referred to as a flow calibration factor (FCF). The FCF may reflect the material and mechanical properties of the flow tube. The FCF may be determined by a calibration process prior to incorporating the flow meter into a pipeline or other conduit. In the calibration process, a material is flowed through the conduit at a known flow rate, and the proportionality constant between the phase difference or time delay and the flow rate is calculated and recorded as the FCF. A similar procedure may be used to calibrate a density meter when duration is the independent variable instead of time delay.

[0006] Vibratory meters may be used in processes where the process fluid contains hydrogen, such as hydrogen-rich or pure fluids. It is known that hydrogen can diffuse into metal lattices, for example steel lattices, under certain conditions. Diffusion of hydrogen into metal lattices can have a significant effect on the material properties of the metal. Some of the changes can be an increase in the elastic modulus (e.g., stress to strain ratio). If the increase in elastic modulus becomes significant, the result can be hydrogen-assisted cracking of the metal. This problem may alternatively be referred to as hydrogen induced cracking, embrittlement, etc.

[0007] Metals may be manufactured that are sufficiently resistant to hydrogen loading so that they do not undergo hydrogen assisted cracking. However, such metals may still undergo sufficient hydrogen loading to change the material properties of the metal. The change in material properties may be significant enough to cause errors in the vibratory meter measurements. More specifically, vibratory meters may use calibration coefficients that relate parameter values ​​of the vibrating element (e.g., time delay, frequency, etc.) to measurements of fluid properties of the fluid being measured, such as mass flow rate, density, viscosity, etc. If the material properties of the vibrating element change, the calibration coefficients may no longer accurately relate the parameter values ​​of the vibrating element to the measurements of the fluid properties.

[0008] Such changes may be accounted for by recalibrating the vibratory meter, however, calibration may be undesirable for a variety of reasons, such as the manual labor required in hazardous environments or the costs associated with taking the vibratory meter offline. Such risks and costs may be minimized, and therefore the return on investment maximized, by accurately assessing whether calibration is necessary. Furthermore, the calibration factor may be adjusted by quantifying changes to material properties that have a known relationship to the calibration factor. Thus, there is a need to estimate hydrogen loading induced changes in the vibratory meter. Summary of the Invention

[0009] A method for estimating hydrogen loading induced changes in a vibrating meter is provided, according to one embodiment, the method includes determining a pressure and temperature of hydrogen exposed to a vibrating element of the vibrating meter, calculating a concentration of hydrogen in the vibrating element based on the hydrogen pressure and temperature, and adjusting a calibration factor of the vibrating meter based on the calculated concentration of hydrogen in the vibrating element.

[0010] A vibratory meter configured to estimate hydrogen loading induced changes in a vibratory meter is provided. According to one embodiment, the vibratory meter comprises a sensor assembly having a vibrating element configured to be exposed to hydrogen in a process fluid, and meter electronics communicatively coupled to the sensor assembly. The meter electronics is configured to determine a pressure and a temperature of the hydrogen, calculate a concentration of hydrogen in the vibrating element based on the hydrogen pressure and temperature, and adjust a calibration factor of the vibratory meter based on the calculated concentration of hydrogen in the vibrating element.

[0011] [Aspects] According to one aspect, a method for estimating hydrogen loading induced changes in a vibrating meter includes determining a pressure and temperature of hydrogen exposed to a vibrating element of the vibrating meter, calculating a concentration of hydrogen in the vibrating element based on the hydrogen pressure and temperature, and adjusting a calibration factor of the vibrating meter based on the calculated concentration of hydrogen in the vibrating element.

[0012] Preferably, the vibrating element is one of a conduit and a tine.

[0013] Preferably, the process fluid is one of a pure fluid of hydrogen and a mixture containing hydrogen.

[0014] Preferably, the step of determining the pressure of the hydrogen comprises determining one of the total pressure of a pure fluid of hydrogen and the partial pressure of hydrogen in the mixture.

[0015] Preferably, the hydrogen is in at least one of a gas and liquid phase and / or in at least one of a molecular and atomic form.

[0016] Preferably, the step of calculating the concentration of hydrogen in the vibrating element comprises calculating an average concentration as a percentage of the equilibrium concentration.

[0017] Preferably, the step of adjusting the calibration factor of the vibration meter includes the steps of calculating a change in elastic modulus of the vibration element based on the concentration of hydrogen in the vibration element, and calculating a calibration factor converted to elastic modulus based on the change in elastic modulus.

[0018] Preferably, the step of calculating the change in elastic modulus of the vibrating element comprises calculating a change in elastic modulus of the vibrating element using the formula:

number

number

number

[0019] Preferably, the step of calculating a modulus-converted calibration factor based on the change in modulus of elasticity comprises calculating a calibration factor based on the change in modulus of elasticity using the formula:

number

[0020] Preferably, the step of calculating a modulus-converted calibration factor based on the change in modulus of elasticity comprises calculating a calibration factor based on the change in modulus of elasticity using the formula:

number

[0021] A vibratory meter configured to estimate hydrogen-loading induced changes in a vibratory meter includes a sensor assembly having a vibrating element configured to be exposed to hydrogen in a process fluid, and meter electronics communicatively coupled to the sensor assembly, the meter electronics configured to determine a pressure and temperature of the hydrogen, calculate a concentration of hydrogen in the vibrating element based on the hydrogen pressure and temperature, and adjust a calibration factor of the vibratory meter based on the calculated concentration of hydrogen in the vibrating element.

[0022] Preferably, the vibrating element is one of a conduit and a tine.

[0023] Preferably, the hydrogen-containing process fluid is one of a hydrogen pure fluid and a hydrogen-containing mixture.

[0024] Preferably, the meter electronics being configured to determine the pressure of the hydrogen includes the meter electronics being configured to determine one of a total pressure of a pure fluid of hydrogen and a partial pressure of hydrogen in a mixture.

[0025] Preferably, the hydrogen is in at least one of a gas and liquid phase and / or in at least one of a molecular and atomic form.

[0026] Preferably, the meter electronics being configured to calculate the concentration of hydrogen in the vibrating element includes the meter electronics being configured to calculate a modulus of elasticity of the vibrating element based on a pressure and a temperature of hydrogen in the process fluid.

[0027] Preferably, configuring the meter electronics to adjust the calibration factor of the vibratory meter includes configuring the meter electronics to calculate a change in elastic modulus of the vibrating element based on a concentration of hydrogen in the vibrating element, and to calculate a modulus-converted calibration factor based on the change in elastic modulus.

[0028] Preferably, the meter electronics is configured to calculate the change in elastic modulus of the vibrating element according to the formula:

number

number

number

[0029] Preferably, the meter electronics is configured to calculate a modulus-converted calibration factor based on the change in modulus of elasticity by calculating a modulus-converted calibration factor based on the change in modulus of elasticity by the meter electronics according to the formula:

number

[0030] Preferably, the meter electronics is configured to calculate a modulus-converted calibration factor based on the change in modulus of elasticity by calculating a modulus-converted calibration factor based on the change in modulus of elasticity by the meter electronics according to the formula:

number

[0031] Like reference numbers refer to like elements in all drawings. It should be understood that the drawings are not necessarily to scale. [Figure 1] 1 shows a vibratory meter 5 configured to estimate hydrogen-loading induced changes in the vibratory meter. [Diagram 2] 1 shows a vibratory meter 5a comprising a Coriolis meter configured to estimate hydrogen induced changes in the vibratory meter 5a. [Diagram 3] 3 shows a block diagram of the vibratory meter 5a described in connection with FIG. 2, including a block diagram representation of meter electronics 20a configured to estimate hydrogen-loading induced changes in the vibratory meter 5a. [Figure 4] 1 shows a vibratory meter 5b with a fork meter configured to estimate hydrogen-loading induced changes in the fork meter. [Diagram 5] Meter electronics 20 configured to estimate hydrogen-loading induced changes in a vibrating meter 5 is shown. [Figure 6] A method 600 for estimating hydrogen loading induced changes in a vibrating meter is shown. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0032] 1-6 and the following description provide specific examples to teach those skilled in the art how to make and use the best mode of the embodiments for estimating hydrogen-loading-induced changes in a vibrating meter. For the purpose of teaching the principles of the invention, some conventional aspects have been simplified or omitted. Those skilled in the art may appreciate variations from these examples that fall within the scope of the present disclosure. As will be appreciated by those skilled in the art, the features described below can be combined in various ways to form multiple variations of the embodiments for estimating hydrogen-loading-induced changes in a vibrating meter. As a result, the embodiments described below are not limited to the specific examples described below, but are limited only by the claims and their equivalents.

[0033] FIG. 1 illustrates a vibratory meter 5 configured to estimate hydrogen loading induced changes in a vibratory meter. As illustrated in FIG. 1, the vibratory sensor 5 is comprised of a sensor assembly 10 and meter electronics 20 communicatively coupled to the sensor assembly 10. The sensor assembly 10 may include the fluid to be measured, may be immersed in the fluid to be measured, may be exposed to the fluid to be measured, etc. The sensor assembly 10 provides information regarding the sensing characteristic to the meter electronics 20. The information may be provided by an electrical signal, an optical signal, etc. The information may be provided by any suitable means, such as, for example, modulating a characteristic (e.g., voltage, current, power, etc.) of the electrical signal. The modulation may be digital, analog, mixed signal, etc. The meter electronics 20 may use the information to convert the information to a measurement. This conversion typically utilizes one or more calibration factors that may offset and / or scale the information to the measurement. The fluid measurement may be comprised of one or more fluid measurements. Thus, the meter electronics 20 may provide the fluid measurements via a port 26 to a communication terminal, interface, etc. As will be explained in more detail below, if the characteristics of the sensor assembly 10 change relative to a baseline or reference calibration, the fluid measurements may be affected.

[0034] The sensor assembly 10 may be configured to sense a property of a fluid. More specifically, the vibrating element 130 may be configured to be exposed to a fluid to measure a property of the fluid. The vibrating element 130 may include a conduit that contains the fluid, such as a conduit of a Coriolis meter, the tines of a fork meter that are immersed in the fluid, as described in more detail below. The property or properties of the fluid may include flow rate, e.g., mass or volumetric flow rate, density, viscosity, etc. The property of the fluid may also include temperature, pressure, and / or the like of the fluid.

[0035] The sensor assembly 10 may also be configured to sense non-fluid properties, such as temperature, contained pressure of the housing, and / or vibration frequency of one or more vibrating elements. The sensor assembly 10 may provide information regarding the properties of the fluid via the communication channel 100. The sensor assembly 10 may also receive drive signals, etc., from the meter electronics 20 via the communication channel 100.

[0036] Additionally or alternatively, although not shown in FIGURE 1, transducers such as temperature and / or pressure transducers may be mechanically coupled to a vessel, pipeline, etc. coupled with the sensor assembly 10 for sensing the fluid supplied to the sensor assembly 10. Such transducers, which may be referred to as external transducers, may be communicatively coupled to the meter electronics 20 in addition to the sensor assembly 10. The external transducers may provide such information to the meter electronics 20 via, for example, port 26 shown in FIGURE 1, although additional ports, etc. may be used.

[0037] [Coriolis meter] FIG. 2 illustrates a vibratory meter 5a comprising a Coriolis meter configured to estimate hydrogen-induced changes in the vibratory meter 5a. As illustrated in FIG. 1, the vibratory meter 5a is a Coriolis meter comprising a sensor assembly 10a and meter electronics 20a. The sensor assembly 10a is responsive to mass flow rate and density of a process material. The meter electronics 20a is connected to the sensor assembly 10a via a communication channel 100a, which may be comprised of leads, although any suitable channel may be used. As may be appreciated, the communication channel 100a includes an RTD signal, a drive signal, and left and right sensor signals. The meter electronics 20a may be configured to use the communication channel 100a to calculate and provide density, mass flow rate, temperature information, and the like, via port 26a.

[0038] The sensor assembly 10a includes a pair of manifolds 150a and 150a', flanges 103a and 103a' having flange necks 110a and 110a', a pair of conduits 130a and 130a', a driver 180a, a resistance temperature detector (RTD) 190a, and a pair of pick-off sensors 170al and 170ar. The conduits 130a and 130a' have two inlet legs 131a, 131a' and outlet legs 134a, 134a' that converge towards each other at the conduit mounting blocks 120a and 120a'. The conduits 130a, 130a' bend at two symmetrical locations along their lengths and are essentially parallel throughout their lengths. Brace bars 140a and 140a' serve to define axes W and W' about which each conduit 130a, 130a' oscillates. The inlet and outlet legs 131a, 131a' and 134a, 134a' of conduits 130a, 130a' are fixedly attached to conduit mounting blocks 120a and 120a', which are fixedly attached to manifolds 150a and 150a'. This provides a continuous closed material path through sensor assembly 10a.

[0039] When flanges 103a and 103a' having holes 102a and 102a' are connected via inlet end 104a and outlet end 104a' to a process line (not shown) carrying the process material being measured, the material enters the meter at inlet end 104a through orifice 101a in flange 103a and is directed through manifold 150a to conduit mounting block 120a having surface 121a. Within manifold 150a, the material is split and directed through conduits 130a, 130a'. Upon exiting conduits 130a, 130a', the process material is recombined into a single stream at block 120a' having surface 121a' and manifold 150a' before being directed to outlet end 104a' which is connected to the process line (not shown) by flange 103a' having holes 102a'.

[0040] The conduits 130a, 130a' are selected to have substantially the same mass distribution, moment of inertia, and Young's modulus about bending axes W--W and W'--W', respectively, and are appropriately mounted in the conduit mounting blocks 120a, 120a'. These bending axes pass through the brace bars 140a, 140a'. Insofar as the Young's modulus of the conduit changes with temperature and this change affects the flow rate and density calculations, an RTD 190a is mounted in the conduit 130a' to continuously measure the temperature of the conduit 130a'. The temperature of the conduit 130a', and therefore the voltage appearing across the RTD 190a for a given current passing through the conduit, is governed by the temperature of the material passing through the conduit 130'. The temperature dependent voltage appearing across the RTD 190a is used in a known manner by the meter electronics 20a to compensate for changes in the elastic modulus of the conduits 130a, 130a' due to any changes in the conduit temperature. The RTD 190a is connected to the meter electronics 20a by a lead 195a.

[0041] Both conduits 130a, 130a' are driven in opposite directions about their respective bending axes W and W' in what is called the first out-of-phase bending mode of the vibratory meter by a driver 180a. This driver 180a may comprise any one of a number of well known configurations, such as a magnet mounted in conduit 130a' and opposing coils mounted in conduit 130a through which an alternating current flows to vibrate both conduits 130a, 130a'. An appropriate drive signal 185a is applied to driver 180a by meter electronics 20a via leads.

[0042] Meter electronics 20a receives the RTD temperature signal on lead 195a and the sensor signal 165a, or more specifically the left and right sensor signals 165al, 165ar, appearing over communication channel 100a. Meter electronics 20a generates a drive signal 185a appearing on a lead to driver 180a, causing conduits 130a, 130a' to vibrate. Meter electronics 20a processes the left and right sensor signals 165al, 165ar and the RTD signal from lead 195a to calculate the mass flow rate and density of the material passing through sensor assembly 10a. This information, along with other information, is applied by meter electronics 20a as a signal via port 26a.

[0043] Figure 3 illustrates a block diagram of the vibratory meter 5a described in connection with Figure 2, including a block diagram representation of meter electronics 20a configured to estimate hydrogen loading induced changes to the vibratory meter 5a. As shown in Figure 3, the meter electronics 20a is communicatively coupled to the sensor assembly 10a. As previously described in connection with Figure 2, the sensor assembly 10a includes left and right pickoff sensors 170al, 170ar, driver 180a, and RTD 190a, which are communicatively coupled to the meter electronics 20a via a set of leads over communication channel 112a.

[0044] The meter electronics 20a provides the drive signal 185a via a lead having the communication channel 100a. More specifically, the meter electronics 20a provides the drive signal 185a to a driver 180a in the sensor assembly 10a. Additionally, the sensor signals 165a, including a left sensor signal 165al and a right sensor signal 165ar, are provided by the sensor assembly 10a. More specifically, in the illustrated embodiment, the sensor signals 165a are provided by left and right pickoff sensors 170al, 170ar in the sensor assembly 10a. As can be appreciated, the sensor signals 165a are provided to the meter electronics 20a via the communication channel 112a, respectively.

[0045] Meter electronics 20a includes a processor 210a communicatively coupled to one or more signal processors 220a and one or more memories 230a. Processor 210a is also communicatively coupled to user interface 30a. Processor 210a is communicatively coupled to a host via a communication port over port 26a and receives power via power port 250a. Processor 210a may be a microprocessor, although any suitable processor may be used. For example, processor 210a may be comprised of sub-processors, such as a multi-core processor, a serial communication port, a peripheral interface (e.g., a serial peripheral interface), on-chip memory, I / O ports, and the like. In these and other embodiments, processor 210a is configured to perform operations on received and processed signals, such as digitized signals.

[0046] The processor 210a may receive the digitized sensor signal from one or more signal processors 220a. The processor 210a may also be configured to provide information such as a phase difference, a property of the fluid in the sensor assembly 10a, etc. The processor 210a may provide the information to a host via a communication port. The processor 210a may also be configured to communicate with one or more memories 230a to receive information and / or store information in one or more memories 230a. For example, the processor 210a may receive a calibration factor and / or a sensor assembly zero (e.g., a phase difference when the flow is zero) from one or more memories 230a. Each of the calibration factor and / or the sensor assembly zero may be associated with the vibratory meter 5a and / or the sensor assembly 10a, respectively. The processor 210a may use the calibration factor to process the digitized sensor signal received from one or more signal processors 220a.

[0047] The one or more signal processors 220a are shown as being comprised of an encoder / decoder (CODEC) 222a and an analog-to-digital converter (ADC) 226a. The one or more signal processors 220a may condition an analog signal, digitize a conditioned analog signal, and / or provide a digitized signal. The CODEC 222a is configured to receive the sensor signal 165a from the left and right pickoff sensors 170al, 170ar. The CODEC 222a is also configured to provide a drive signal 185a to the driver 180a. In alternative embodiments, more or fewer signal processors may be used.

[0048] As shown, the sensor signal 165a is provided to the CODEC 222a via a signal conditioner 240a. The drive signal 185 is provided to the driver 180a via a signal conditioner 240a. Although the signal conditioner 240a is shown as a single block, the signal conditioner 240a may be comprised of signal conditioner components such as two or more op-amps, filters such as low-pass filters, voltage-to-current amplifiers, etc. For example, the sensor signal 165a may be amplified by a first amplifier and the drive signal 185a may be amplified by a voltage-to-current amplifier. The amplification may be such that the magnitude of the sensor signal 165a is close to the full-scale range of the CODEC 222a.

[0049] In the illustrated embodiment, the one or more memories 230a are comprised of a read-only memory (ROM) 232a, a random access memory (RAM) 234a, and a ferroelectric random access memory (FRAM®) 236a. However, in other embodiments, the one or more memories 230a may be comprised of more or less memory. Additionally or alternatively, the one or more memories 230a may be comprised of different types of memory (e.g., volatile, non-volatile, etc.). For example, a different type of non-volatile memory, such as an erasable programmable read-only memory (EPROM), may be employed in place of the FRAM 236a. The one or more memories 230a may be a storage device configured to store process data, such as drive signals or sensor signals, mass flow or density measurements, etc.

[0050] The mass flow measurement is calculated according to the formula:

number

number

[0051] The measured time delay Δt includes operationally derived (i.e., measured) time delay values ​​that include the time delay that exists between the pickoff sensor signals, for example, where the time delay is due to the Coriolis effect associated with the mass flow rate through the vibratory meter 5a. The measured time delay Δt is a direct measure of the mass flow rate of the flowing material as it flows through the vibratory meter 5a. The zero flow time delay Δt 0 includes the time delay at zero flow. The zero flow time delay Δt 0is a zero flow value that can be determined at the factory and programmed into the vibratory meter 5a. The zero flow time delay Δt 0 is an exemplary zero flow value. Other zero flow values, such as phase difference, time difference, etc., determined at the zero flow condition may be used. The zero flow time delay Δt 0 The value of may not change even when flow conditions are changing. The mass flow value of the material flowing through the vibratory meter 5a is calculated by multiplying the measured time delay Δt by the reference zero flow value Δt 0 The flow rate is determined by multiplying the difference between and by a flow calibration factor, FCF, which is proportional to the physical stiffness of the vibratory meter.

[0052] With respect to density, the resonant frequency at which each conduit 130a, 130a' may vibrate may be a function of the square root of the spring constant of the conduit 130a, 130a' divided by the total mass of the conduit 130a, 130a' with the material. The total mass of the conduit 130a, 130a' with the material may be the mass of the conduit 130a, 130a' plus the mass of the material in the conduit 130a, 130a'. The mass of the material in the conduit 130a, 130a' is directly proportional to the density of the material. Thus, the density of the material may be proportional to the square of the period at which the conduit 130a, 130a' containing the material vibrates multiplied by the spring constant of the conduit 130a, 130a'. Thus, by determining the period at which the conduit 130a, 130a' vibrates and appropriately scaling the result, an accurate measurement of the density of the material contained by the conduit 130a, 130a' can be obtained. The meter electronics 20a can determine the period or resonant frequency using the sensor signal 165a and / or the drive signal 185a. The conduit 130a, 130a' can vibrate in multiple vibration modes. As previously mentioned, the vibratory meter 5 can be a fork meter, an example of which is described below.

[0053] [Fork Meter] FIG. 4 illustrates a vibratory meter 5b that includes a fork meter configured to estimate hydrogen-loading-induced changes in the fork meter. As illustrated in FIG. 4, the vibratory meter 5b includes meter electronics 20b that is communicatively coupled to a sensor assembly 10b. The meter electronics 20b is also mechanically coupled to the sensor assembly 10b by a shaft 115b. The shaft 115b may be of any desired length. The shaft 115b may be at least partially hollow. Wires or other conductors may extend between the meter electronics 20b and the vibrating element 130b through the shaft 115b. The meter electronics 20b includes circuit components such as a receiver circuit 134b, an interface circuit 136b, and a driver circuit 138b. In the illustrated embodiment, the receiver circuit 134b and the driver circuit 138b are directly coupled to the leads of the vibrating element 130b. Alternatively, the meter electronics 20b may comprise a component or device separate from the vibrating element 130b, with the receiver circuitry 134b and the driver circuitry 138b coupled to the vibrating element 130b via the communication channel 100b.

[0054] In the illustrated embodiment, the vibrating element 130b of the vibrating meter 5b is a tuning fork structure, and the vibrating element 130b is at least partially immersed in the process fluid being measured. The vibrating element 130b includes a housing 105b that can be attached to other structures, such as a pipe, a conduit, a tank, a receptacle, a manifold, or any other fluid handling structure. The housing 105b holds the vibrating element 130b while the vibrating element 130b remains at least partially exposed to the process fluid. Thus, the vibrating element 130b is configured to be immersed in the fluid.

[0055] The vibrating element 130b in the illustrated embodiment includes first and second tines 130bd and 130bs configured to extend at least partially into the fluid. The first and second tines 130bd and 130bs comprise elongate elements that may have any desired cross-sectional shape. The first and second tines 130bd and 130bs may be at least partially flexible or resilient in nature. The vibrating meter 5b further includes corresponding first and second piezoelectric elements 122b and 124b comprising piezoelectric crystal elements. The first and second piezoelectric elements 122b and 124b are positioned adjacent the first and second tines 130bd and 130bs, respectively. The first and second piezoelectric elements 122b and 124b are configured to contact and mechanically interact with the first and second tines 130bd and 130bs.

[0056] The first piezoelectric element 122b is in contact with at least a portion of the first tine 130bd. The first piezoelectric element 122b is also electrically connected to a driver circuit 138b. The driver circuit 138b provides a generated drive signal to the first piezoelectric element 122b. The first piezoelectric element 122b expands and contracts when exposed to the generated drive signal. As a result, the first piezoelectric element 122b can deform and displace the first tine 130bd alternately back and forth in an oscillatory motion (see dashed lines) to disturb the fluid in a periodic back and forth manner.

[0057] The second piezoelectric element 124b is shown coupled to a receiver circuit 134b that generates a vibration signal corresponding to the deformation of the second tine 130bs in the fluid. The movement of the second tine 130bs causes a corresponding electrical vibration signal to be generated by the second piezoelectric element 124b. The second piezoelectric element 124b transmits the vibration signal to the meter electronics 20b. The meter electronics 20b includes an interface circuit 136b. The interface circuit 136b can be configured to communicate with an external device. The interface circuit 136b can communicate one or more vibration measurement signals and can communicate determined fluid properties to one or more external devices. The meter electronics 20b can transmit vibration signal characteristics, such as a vibration signal frequency and a vibration signal amplitude of the vibration signal, via the interface circuit 136b. The meter electronics 20b can transmit fluid measurements, such as the density and / or viscosity of the fluid, via the interface circuit 136b, among others. Other fluid measurements are contemplated and are within the scope of this specification and claims. Additionally, the interface circuit 136b may receive communications from external devices, including, for example, commands and data for generating measurements. In some embodiments, the receiver circuit 134b is coupled to a driver circuit 138b, which provides a vibration signal to the driver circuit 138b. The driver circuit 138b generates a drive signal for the vibration element 130b. The driver circuit 138b may modify characteristics of the generated drive signal. The vibration element 130b is generally maintained at a resonant frequency under the influence of the surrounding fluid.

[0058] The vibratory meter 5b with fork meter can measure fluid properties such as density, viscosity, etc. The density can be determined from the period of the vibrating element 130b as expressed in the following equation [2], similar to the density determined using the conduits 130a, 130a' described above. ρ fluid = C 1 τ 2 +C 2 [2] During the ceremony, ρ fluid is the fluid density, C1 and C 2 is a constant, and τ is the period of the fork vibration.

[0059] As shown, the fluid density ρ fluid is the period of the fork and two constants C 1 ,C 2 These two constants scale and offset the information received from vibrating element 130b to obtain density.

[0060] The sensor assembly 10 of the vibrating meter 5 may be adversely affected by hydrogen loading of the vibrating element. For example, the sensor assembly 10a described in relation to Figures 2 and 3 includes conduits 130a, 130a' that may contain and transport a fluid containing hydrogen. Thus, hydrogen in the fluid may separate and adsorb into the lattice of the conduits 130a, 130a'. Similarly, the vibrating element 130b of the vibrating meter 5b may be immersed in a process fluid containing hydrogen. Thus, hydrogen in the process fluid may adsorb into the lattice of the vibrating element 130b.

[0061] Hydrogen loading of the vibrating element can change material properties, such as the elastic modulus of the vibrating element. As a result, vibrational properties of the vibrating element, such as the resonant frequency, period, and displacement of the vibrating element, can change correspondingly. Hydrogen loading can be estimated by determining one or more thermodynamic properties, such as the temperature and pressure of hydrogen in the process fluid, using the thermodynamic properties to determine the change in material properties of the vibrating element. This change in material properties can be used to adjust the calibration factor of the vibrating meter, as described in more detail below.

[0062] [Effect of hydrogen loading on material properties] Hydrogen diffusion into the lattice of a metal can affect the material properties of the metal. Typically, metals can be selected to reduce or mitigate the effect and / or amount of hydrogen loading in the metal. This can help prevent catastrophic failures such as hydrogen-induced cracking, but some hydrogen may still diffuse into the lattice and affect the material properties of the metal. This effect on the material properties of the metal can correspondingly affect parameters such as frequency, relative displacement, and period of the vibrating element of the vibration sensor. Furthermore, hydrogen loading may increase the "internal friction" of the metal and therefore the damping coefficient of the vibrating element. This can increase the drive power required to drive the dynamic element.

[0063] The amount (e.g., concentration) of hydrogen in the metal and the correlation between the amount of hydrogen in the metal and the change in material properties can be used to estimate the change in material properties. This estimated change in material properties can be used to determine a modulus adjusted calibration factor. The hydrogen loading adjusted calibration factor can be used to determine if a measurement is invalid, a hydrogen loading corrected measurement, etc., as described in more detail below.

[0064] [Table 1]

[0065] In the "Sample" column, 316L-n and XM-19-n (where "n" represents the sample number) are samples of 316L and XM-19 steels, respectively. These may be suitable for use in vibrating elements in vibratory meters measuring hydrogen process fluids, such as hydrogen gas, due to their resistance to hydrogen-assisted cracking mechanisms. As shown, there is a large overall shift in the elastic modulus of the steel samples due to the diffusion of hydrogen into the lattice of the steel samples, which may be referred to herein as hydrogen loading. The XM-19 steel sample exhibits a significantly larger change in elastic modulus than the 316L steel sample. As can be seen from the Concentration C' column, this difference in elastic modulus change may be due to the greater diffusion of hydrogen into the lattice of the XM-19 steel sample. This greater diffusion may be due to the XM-19 steel containing nitrogen, which may result in a larger lattice strain compared to the 316L steel. As can also be seen from Table 1, the change in elastic modulus may range from 0.30% to 0.50%. In the context of mass flow measurements, this change in elastic modulus can correspond to an error contribution that is at least the mass flow accuracy specification of the vibratory meter. For example, some vibratory meters that measure mass flow may have a liquid mass flow accuracy specification of 0.1% or less and a gas mass flow accuracy specification of 0.5% or less. Thus, the measurement error caused by hydrogen loading alone may be large enough to invalidate the vibratory meter calibration.

[0066] The diffusion of a gas such as hydrogen into a metal such as steel can be understood by Fick's second law of diffusion. Assuming a one-dimensional problem, Fick's second law in cylindrical coordinates may be expressed as:

number

[0067] When a one-dimensional problem is situated in linear coordinates, Fick's second law may be expressed as:

number

[0068] For Sievert's law, which predicts the solubility of gases in metals, the equilibrium concentration of hydrogen may be related to the pressure of hydrogen gas by:

number

number

[0069] As can be seen, by knowing the temperature and pressure of the hydrogen, the equilibrium concentration of hydrogen

number

[0070] The temperature may be the temperature of a process fluid, such as a mixture containing hydrogen, although any suitable temperature may be used. The temperature of the hydrogen may be obtained by any suitable means, such as measurement, calculation, estimation, input by a user, inference from process information, obtained from an external transducer, etc. The temperature of the hydrogen may be considered to drive the kinetics of hydrogen diffusion and solubility. Thus, the higher the temperature, the faster hydrogen will diffuse through the lattice and the higher the total hydrogen solubility.

[0071] The hydrogen pressure may be the pressure of a substantially pure fluid of hydrogen. Thus, the measured pressure or total pressure may be the hydrogen pressure. A fluid composed almost entirely of hydrogen may be considered substantially pure if the measured pressure or total pressure can be used as the hydrogen pressure in equation [5] above to accurately predict, for example, the change in elastic modulus. For example, a small amount of non-hydrogen components may be removed if such components are not within the calculated equilibrium concentration of, for example, hydrogen.

number

[0072] The hydrogen pressure may be the partial pressure of the hydrogen component in the mixture. The partial pressure may be determined, for example, by Dalton's law of partial pressure, where the number of moles of a gas component is multiplied by the pressure of the mixture to determine the partial pressure. By way of example, the mixture in the closed vessel, as measured by a fork meter, may have a known mass ratio of the components. This mass ratio may be converted to the number of moles of each gas component. Thus, the total pressure of the mixture in the closed vessel may be multiplied by the number of moles of hydrogen to determine the partial pressure of hydrogen in the mixture. Alternative methods may be used to determine the partial pressure of hydrogen in the mixture.

[0073] A linear relationship that may be referred to as the elastic modulus vs. concentration change ratio μ can be developed from the information in Table 1 relating hydrogen concentration to the change in elastic modulus, although any suitable data or relationship may be used. The elastic modulus vs. concentration change ratio μ may have dimensions in parts per million of elastic modulus (E / ppm). Furthermore, the average incremental shift in elastic modulus over a given time frame can be calculated by:

number

number

number

[0074] Since the effect of the change in the elastic modulus of the vibrating element is integrated over time, the accumulated effect may preferably be summed over time, which may be expressed as:

number

[0075] Here, the concentration is calculated over a period a. The cumulative change in the elastic modulus of the vibrating element, ΔE, is expressed as total is integrated over a number n of time increments a. Thus, although the above may be applied to any suitable material, the change in elastic modulus of a vibrating element comprising the steels of Table 1 may be determined.

[0076] The elastic modulus may be related to one or more calibration factors of the vibratory meter, and thus, as described in more detail below, a change in the calibration factor of the vibratory meter may be estimated, thereby allowing for an adjusted calibration factor based on changes in the elastic modulus of the vibratory element.

[0077] [Vibration meter with conduit] For a conduit with a cylindrical tube with thin walls and long diffusion times, the solution to Fick's second law of diffusion can be expressed as:

number

number

[0078] The flow calibration factor of a conduit can be directly related to the elastic modulus. Thus, the elastic modulus-reduced flow calibration factor FCF' can be expressed as:

number

[0079] Therefore, the hydrogen-loading corrected mass flow rate may be determined by modifying equation [1] above as follows:

number

number

number

[0080] [Fork Meter] For the vibrating element 130b with the first and second tines 130bd, 130bs, the average concentration of hydrogen may be calculated using the following formula:

number

[0081] Referring to equation [2] above, the second calibration factor C 2 does not depend on the elastic modulus of the vibration element 130b, but the first calibration coefficient C 1 Similar to the previously mentioned flow calibration factor FCF, the first calibration factor C 1 The relationship between the elastic modulus and the strain is linear.

[0082] Therefore, the first calibration factor C 1 may be adjusted as follows:

number

[0083] Therefore, the hydrogen-loading corrected density can be determined by modifying equation [2] as follows: ρ HLcorr = C 1 'τ 2 +C 2

[13] In the formula, ρ HLcorr is the hydrogen-loading corrected density.

[0084] As will be appreciated, the above Table 1 and equations, as well as any other suitable data, equations, relationships, etc., may be used in routines executed in electronic circuitry such as the aforementioned meter electronics 20. Exemplary configurations of meter electronics 20 are described below.

[0085] 5 illustrates meter electronics 20 configured to estimate hydrogen-loading induced changes in a vibrating meter 5. As illustrated in FIG. 5, meter electronics 20 includes an interface 501 and a processing system 502. Meter electronics 20 receives a vibration response from a sensor assembly, such as sensor assembly 10 described above. Meter electronics 20 may process the vibration response to obtain flow characteristics of the flowing material flowing through sensor assembly 10. Meter electronics 20 may perform checks, verifications, calibration routines, etc. to ensure that the flow characteristics of the flowing material are accurately measured.

[0086] With reference to the vibratory meter 5a described above in connection with Figures 2 and 3, the interface 501 may receive the sensor signal 165a from one of the pick-off sensors 170al, 170ar shown in Figures 2 and 3. The interface 501 may also be configured to receive the drive signal 185a, for example, from the signal conditioner 240a. Although the drive signal 185a is shown as being provided by the signal conditioner 240a, a back EMF may be provided from the sensor assembly 10a to the meter electronics 20 due to vibrations of the conduit 130a in the sensor assembly 10a. Thus, the interface 501 may be configured to receive the communication channel 100a shown in Figures 2 and 3. With respect to the vibratory meter 5b shown in Figure 4, the interface 501 may provide a drive signal to the first piezoelectric element 122b and receive a sensor signal from the second piezoelectric element 124b.

[0087] The interface 501 may perform any necessary or desired signal conditioning, such as formatting, amplification, buffering, etc. in any manner. Alternatively, some or all of the signal conditioning may be performed in the processing system 502. Additionally, the interface 501 may enable communication between the meter electronics 20 and an external device. The interface 501 may be capable of any manner of electronic, optical, or wireless communication. The interface 501 may provide information based on the vibration response. The interface 501 may be coupled to a digitizer, such as the CODEC 222a shown in FIG. 3, where the sensor signal includes an analog sensor signal. The digitizer samples and digitizes the analog sensor signal to generate a digitized sensor signal.

[0088] The processing system 502 performs operations of the meter electronics 20 and processes the fluid measurements from the sensor assembly 10. The processing system 502 executes one or more processing routines, thereby processing the fluid measurements to generate one or more fluid characteristics. The processing system 502 is communicatively coupled to the interface 501 and configured to receive information from the interface 501.

[0089] Processing system 502 may comprise a general purpose computer, a microprocessing system, a logic circuit, or some other general purpose or customized processing device. Additionally or alternatively, processing system 502 may be distributed across multiple processing devices. Processing system 502 may also include any type of integrated or stand-alone electronic storage medium, such as storage system 504.

[0090] The storage system 504 can store vibratory meter parameters and data, software routines, constant values, and variable values. In one embodiment, the storage system 504 includes routines executed by the processing system 502, such as operational routines 510. The processing system 502 may be further configured to execute other routines, such as zero calibration and zero verification routines for the vibratory meter 5. The storage system may also store statistics, such as the mean, standard deviation, confidence intervals, etc.

[0091] The operating routine 510 may determine mass flow rate 512, density 514, and drive gain 516 based on the sensor signals received by interface 501. Mass flow rate 512 may consist of a directly measured mass flow rate value, as described above. Mass flow rate 512 may be determined from the sensor signals, such as the time delay between the left and right pick-off sensor signals. Density 514 may also be determined from the sensor signals, for example, by determining a frequency from one or both of the left and right pick-off sensor signals, as described above. A separate storage system, such as meter electronics 20b described in connection with FIG. 4, may not include the mass flow rate.

[0092] The term drive gain may refer to a measure of the amount of power required to drive a vibrating element to a specified amplitude, although any suitable definition may be used. For example, the term drive gain may refer in some embodiments to a drive current, a pick-off voltage, or any measured or derived signal that indicates the amount of power required to drive a vibrating element at a particular amplitude. Drive gain may be used to detect multiphase flow by utilizing characteristics of the drive gain, such as, for example, noise level, standard deviation of the signal, damping-related measurements, and any other means known in the art for detecting mixed-phase flow. In the vibratory meter 5a described in connection with Figures 2 and 3, these metrics may be compared across pick-off sensors 170al and 170ar to detect mixed-phase flow.

[0093] The storage system 504 is also shown as storing process parameters 520. The process parameters 520 include pressure 522 and temperature 524, although other more or less process parameters may be stored. As shown in FIG. 5, the pressure 522 may be the pressure of the process fluid in the conduit 130a, 130a'. The pressure may be provided, for example, by a pressure sensor that is part of the sensor assembly 10 or is external to the sensor assembly 10. By way of example, with reference to FIG. 2, the pressure sensor may be mechanically coupled to a pipeline that is mechanically coupled to the inlet end 104a or the outlet end 104a'. With reference to FIG. 4, the pressure sensor may be mechanically coupled to a vessel having the process fluid being sensed by the vibratory meter 5b. Regardless of location, the pressure sensor may be communicatively coupled to the meter electronics 20. Similarly, the temperature 524 may be provided by a temperature sensor inside or outside the vibration sensor 10. For example, with reference to the vibration sensor 10 described in connection with FIGS. 2 and 3, the temperature 524 may be provided by an RTD 190a.

[0094] 5, the storage system 504 also includes a hydrogen loading estimation 530. The hydrogen loading estimation 530 may include a routine used to calculate a value of a hydrogen loading parameter. As shown, the hydrogen loading estimation 530 includes a concentration routine 532 and a concentration parameter 534. The concentration routine 532 may be an algorithm that calculates one or more values ​​of the concentration parameter 534. For example, the concentration routine 532 may obtain the pressure 522 and temperature 524 of hydrogen in the process fluid and perform the calculations described above to determine the concentration of hydrogen in the vibrating element. For example, the concentration of hydrogen may be determined using Table 1 and equation [5] above, although any suitable data and routines may be used.

[0095] The storage system 504 may also include material properties 540. The material properties 540 may include any suitable material properties of the vibration element of the sensor assembly 10. As shown, the material properties 540 include a modulus of elasticity 542 of the vibration sensor 10, although alternative and / or additional material properties may be used. For example, it may be advantageous to store temperature vs. strain data, stress vs. strain data, etc. The modulus of elasticity 542 in FIG. 5 may be in units of gigapascals, although any suitable units may be used. The modulus of elasticity 542 may be an original modulus provided in any suitable manner, such as, for example, input from a data sheet associated with the vibration element, inferred from a meter verification, etc. The material properties 540 also include a modulus of elasticity change 544. The modulus of elasticity change 544 may be determined from the concentration parameter 534 as described above. For example, the processing system 502 may be configured to calculate the modulus of elasticity change 544 by using equations [5]-[7] above, although any suitable equation may be used.

[0096] The storage system 504 also includes a modulus-adjusted calibration factor 550. As shown in FIG. 5, the modulus-adjusted calibration factor 550 includes a modulus-adjusted FCF 552 and a modulus-adjusted first calibration factor 554. The modulus-adjusted FCF 552 may be a value determined using equation [9]. That is, the modulus-adjusted FCF 552 may be a modulus-scaled flow calibration factor. Similarly, the modulus-adjusted first calibration factor 554 may be a value determined using equation

[12] above. That is, the modulus-adjusted first calibration factor 554 may be the modulus-scaled first calibration factor of equation

[12] above. Although equations [9] and

[12] above use modulus-scaled changes, any suitable adjusted flow rate or first calibration factor may be used. For example, routines other than scaling may be used to adjust the flow calibration factor determined prior to hydrogen loading of the vibrating element of the vibrating meter 5. For example, a non-linear equation may be employed.

[0097] Thus, mass flow 512 and density 514 may include corrected mass flow and density values. For example, mass flow 512 may include an uncorrected or raw mass flow value and a hydrogen-loading corrected mass flow value. The hydrogen-loading corrected mass flow value may be determined using equation

[10] above. Similarly, density 514 may include an uncorrected or raw density value and a hydrogen-loading corrected density value. The hydrogen-loading corrected density value may be determined using equation

[13] above, although any suitable relationship, routine, etc. may be employed.

[0098] FIG 6 illustrates a method 600 for estimating hydrogen loading induced changes in a vibrating meter. Method 600 may be performed by meter electronics 20 described above, although any suitable meter electronics may be used. As shown in FIG 6, method 600 determines, at step 610, the pressure and temperature of hydrogen exposed to a vibrating element of the vibrating meter. At step 620, method 600 calculates the concentration of hydrogen in the vibrating element based on the hydrogen pressure and temperature. Method 600 adjusts, at step 630, a calibration factor of the vibrating meter based on the calculated concentration of hydrogen in the vibrating element.

[0099] The method 600 may be applied to any suitable vibratory meter, such as the vibratory meter 5 described above. For example, the vibratory element 130 may be one of the conduits 130a, 130a' containing a process fluid. Alternatively, the vibratory element 130 may be a tine, such as the first and second tines 130bd, 130bs described above, immersed in the process fluid. Furthermore, Fick's second law may have different solutions depending on the thickness of the conduit wall or tine and the period selected for integration. Thus, Fick's second law may have alternative forms depending on the geometry of the vibratory element 130.

[0100] The process fluid exposed to the vibrating element may be a substantially pure fluid of hydrogen. For example, the process fluid may be comprised of 99.99% pure hydrogen, although any suitable purity may be used with the substantially pure hydrogen fluid. Alternatively, the process fluid may be a mixture containing hydrogen. By way of example, the mixture may be comprised of an inert gas, such as helium, and hydrogen gas, although any suitable mixture may be used.

[0101] The step 610 of determining the pressure of hydrogen may include determining the total pressure of a substantially pure fluid of hydrogen or the partial pressure of hydrogen in a mixture. For example, if the process fluid is a substantially pure fluid of hydrogen, the measured pressure of the process may be used. Alternatively, if the process fluid is a mixture that includes hydrogen, the measured pressure may be used to determine the partial pressure of hydrogen, as described above. This partial pressure may be used as the pressure of hydrogen when determining the concentration of hydrogen in the vibrational element.

[0102] The hydrogen may be in any suitable phase or form. For example, the hydrogen may be in a gas phase or a liquid phase. By way of example, the process fluid may be a substantially pure fluid of gaseous hydrogen. The hydrogen may be in molecular or atomic form. The molecular form of hydrogen may be defined as two hydrogen atoms in diatomic form. Additionally or alternatively, the process fluid may include atomic hydrogen. Atomic hydrogen may be defined as an atom of hydrogen. The hydrogen that diffuses to the vibrating element may be in molecular or atomic form, and may be in the same or different form than that of the process fluid.

[0103] Calculating 620 the concentration of hydrogen in the vibrating element may include calculating an average concentration of hydrogen as a percentage of the equilibrium concentration. For example, the average concentration of the percentage of equilibrium concentration in the conduits 130a, 130a' described in connection with Figure 2 may be calculated using equation [8] above. Similarly, the average concentration of the equilibrium concentration of hydrogen in the first and second tines 130bd, 130bs described in connection with Figure 4 may be calculated using equation

[11] above.

[0104] The step of adjusting the calibration factor 630 may include calculating a change in the elastic modulus of the vibrating element based on the concentration of hydrogen in the vibrating element, and calculating a modulus-equivalent calibration factor based on the change in elastic modulus. By way of example, values ​​obtained from equations [8] and

[11] may be used in equation [5] above to determine the change in elastic modulus. This change in elastic modulus may be accumulated according to equation [7]. Calculating the modulus-equivalent calibration factor based on the change in elastic modulus may include using equations [9] and

[12] above, although any suitable equation may be used.

[0105] The vibratory meter 5, meter electronics 20, and method 600 described above estimate hydrogen loading induced changes in the vibratory meter 5. In particular, the vibratory meter 5, meter electronics 20, and method 600 may obtain the pressure and temperature of hydrogen in the process fluid to calculate the concentration of hydrogen in the lattice of the vibrating element. The change in elastic modulus is determined using data or a relationship relating the change in elastic modulus to the concentration of hydrogen in the lattice. Because the elastic modulus of the vibrating element is directly related to the calibration factor of the vibrating element, the change in the calibration factor may be determined from the change in elastic modulus.

[0106] Thus, the change in the calibration factor may be estimated without calibrating the vibratory meter 5. This can be used to determine whether a reference calibration factor still results in measurements within specification. Additionally or alternatively, hydrogen-loading corrected measurements may be obtained. For example, hydrogen-loading corrected mass flow values ​​and / or hydrogen-loading corrected density values ​​may be obtained.

[0107] The detailed description of the above embodiments is not an exhaustive description of all embodiments that the inventors contemplate within the scope of the present specification. Indeed, as will be appreciated by those skilled in the art, certain elements of the above-described embodiments can be combined or removed in various ways to produce further embodiments, which are within the scope and teachings of the present specification. Also, as will be appreciated by those skilled in the art, the above-described embodiments may be combined in whole or in part to produce additional embodiments within the scope and teachings of the present specification.

[0108] Thus, while specific embodiments are described herein for illustrative purposes, various equivalent modifications are possible within the scope of the present disclosure, as those skilled in the art will recognize. The teachings provided herein may be applied to other embodiments for estimating hydrogen-induced changes in a vibratory meter, as well as the embodiments described above and illustrated in the accompanying drawings. Thus, the scope of the above embodiments should be determined from the following claims.

Claims

1. 1. A method for estimating hydrogen loading induced changes in a vibrating meter, comprising: determining the pressure and temperature of hydrogen exposed to a vibrating element of the vibrating meter; calculating a concentration of the hydrogen within the vibrating element based on the pressure and the temperature of the hydrogen; adjusting a calibration factor of the vibratory meter based on the calculated concentration of the hydrogen in the vibrating element; The method includes:

2. The method of claim 1 , wherein the vibrating element is one of a conduit and a tine.

3. 2. The method of claim 1, wherein the process fluid is one of a pure fluid of said hydrogen and a mixture containing said hydrogen.

4. 4. The method of claim 3, wherein determining the pressure of the hydrogen comprises determining one of a total pressure of the pure fluid of the hydrogen and a partial pressure of the hydrogen in the mixture.

5. 10. The method of claim 1, wherein the hydrogen is in at least one of a gas phase and a liquid phase and / or in at least one of a molecular form and an atomic form.

6. The method of claim 1 , wherein calculating the concentration of the hydrogen in the vibrating element comprises calculating an average concentration as a percentage of an equilibrium concentration.

7. 2. The method of claim 1 , wherein adjusting the calibration factor of the vibratory meter comprises: calculating a change in elastic modulus of the vibrating element based on the concentration of the hydrogen in the vibrating element; and calculating a modulus-converted calibration factor based on the change in elastic modulus.

8. The step of calculating the change in the elastic modulus of the vibrating element may be performed using the formula: [0030] using During the ceremony, ΔE is the change in elastic modulus of the metal, μ is the ratio of elastic modulus to concentration change; [0031] is the equilibrium concentration of hydrogen, and [0032] 8. The method of claim 7, wherein: is the fraction of the equilibrium concentration of hydrogen in a metal.

9. Calculating the elastic modulus-reduced calibration factor based on the change in the elastic modulus may be accomplished by calculating the elastic modulus-reduced calibration factor based on the change in the elastic modulus according to the formula: [Equation 33] using During the ceremony, FCF is the reference flow calibration factor, FCF' is the elastic modulus converted flow calibration factor, E is the reference elastic modulus or modulus that yielded the reference flow calibration factor; and 8. The method of claim 7, wherein ΔE is the change in elastic modulus of the vibrating element from the reference elastic modulus E.

10. Calculating the elastic modulus-reduced calibration factor based on the change in the elastic modulus may be accomplished by calculating the elastic modulus-reduced calibration factor based on the change in the elastic modulus according to the formula: [0034] using During the ceremony, C 1 is the first calibration factor of the standard, C 1 ' is the first calibration coefficient converted to elastic modulus, E is the reference modulus or modulus that provided the first calibration factor for the standard; and 8. The method of claim 7, wherein ΔE is the change in elastic modulus of the vibrating element from the reference elastic modulus E.

11. A vibratory meter (5) configured to estimate hydrogen-loading-induced changes in the vibratory meter (5); a sensor assembly (10) having a vibrating element (130) configured to be exposed to hydrogen in a process fluid; meter electronics (20) communicatively coupled to the sensor assembly (10); Equipped with The meter electronics (20) determining the hydrogen pressure and temperature; Calculating a concentration of the hydrogen within the vibration element (130) based on the pressure and the temperature of the hydrogen; and adjusting a calibration factor of the vibratory meter based on the calculated concentration of the hydrogen in the vibrating element (130); A vibration meter (5).

12. The vibratory meter (5) of claim 11, wherein the vibrating element (130) is one of a conduit (130a, 130a') and a tine (130bd, 130bs).

13. 12. The vibratory meter (5) of claim 11, wherein the process fluid containing hydrogen is one of a pure fluid of hydrogen and a mixture containing hydrogen.

14. 14. The vibratory meter of claim 13, wherein the meter electronics (20) configured to determine the pressure of the hydrogen includes the meter electronics (20) configured to determine one of a total pressure of the pure fluid of the hydrogen and a partial pressure of the hydrogen in the mixture.

15. The vibratory meter (5) according to claim 11, wherein the hydrogen is in at least one of a gaseous and liquid phase and / or in at least one of a molecular and atomic form.

16. 12. The vibratory meter of claim 11, wherein the meter electronics (20) configured to calculate the concentration of the hydrogen in the vibrating element (130) comprises the meter electronics (20) configured to calculate a modulus of elasticity of the vibrating element (130) based on the pressure and the temperature of the hydrogen in the process fluid.

17. 12. The vibratory meter of claim 11, wherein the meter electronics (20) configured to adjust the calibration factor of the vibratory meter (5) includes the meter electronics (20) configured to calculate a change in elastic modulus of the vibratory element (130) based on the concentration of the hydrogen in the vibratory element (130) and to calculate a modulus-converted calibration factor based on the change in elastic modulus.

18. The meter electronics (20) is configured to calculate the change in elastic modulus of the vibratory element based on the equation: [Equation 35] including the use of During the ceremony, ΔE is the change in elastic modulus of the metal, μ is the ratio of elastic modulus to concentration change; [0036] is the equilibrium concentration of hydrogen, and [Equation 37] 18. The vibratory meter (5) of claim 17, wherein R is the fraction of equilibrium concentration of hydrogen in a metal.

19. The meter electronics (20) being configured to calculate the elastic modulus-converted calibration factor based on the change in elastic modulus means that the meter electronics (20) is configured to calculate the elastic modulus-converted calibration factor based on the change in elastic modulus by the formula: [Equation 38] configured to use During the ceremony, FCF is the reference flow calibration factor, FCF' is the elastic modulus converted flow calibration factor, E is the reference elastic modulus or modulus that yielded the reference flow calibration factor; and 18. The vibratory meter (5) of claim 17, wherein ΔE is the change in elastic modulus of the vibrating element from the reference elastic modulus E.

20. The meter electronics (20) being configured to calculate the elastic modulus-converted calibration factor based on the change in elastic modulus means that the meter electronics (20) is configured to calculate the elastic modulus-converted calibration factor based on the change in elastic modulus by the formula: [0039] configured to use During the ceremony, C 1 is the first calibration factor of the standard, C 1 ' is the first calibration coefficient converted to elastic modulus, E is the reference modulus or modulus that provided the first calibration factor for the standard; and 18. The vibratory meter (5) of claim 17, wherein ΔE is a calculated shift in the elastic modulus of the vibrating element from the reference elastic modulus E.

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