Detecting orientation of vibrometer and correcting measurement value based on detected orientation

Abstract

To provide a meter electronic device for detecting an orientation and correcting a measurement value based on the detected orientation.SOLUTION: A meter electronic device (20) includes an interface (401) configured to communicatively couple to a sensor assembly, and a processing system (402). The processing system (402) is configured to detect an orientation of the sensor assembly based on one or more sensor signals provided by the sensor assembly.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The embodiments described below relate to vibrometer measurements, and more particularly to detecting the orientation of the vibrometer and correcting measurements based on the detected orientation. [Background technology]

[0002] Vibrometers, such as Coriolis mass flow meters, liquid densitometers, gas densitometers, liquid viscometers, gas / liquid specific gravity meters, gas / liquid relative density meters, and gas molecular weight meters, are commonly known and used to measure fluid properties. Generally, a vibrometer comprises a sensor assembly and meter electronics. The material within the sensor assembly may be flowing or stationary. The vibrometer can be used to measure the mass flow rate, density, or other properties of the material within the sensor assembly.

[0003] The vibrometer can be oriented in various directions. For example, if the sensor assembly has two curved conduits containing material, the curved conduits can have an above-the-pipe orientation, a below-the-pipe orientation, or a flag orientation. Additionally, the vibrometer can be calibrated in orientation and installed at the customer site in various orientations. For example, the vibrometer can be calibrated in an above-the-pipe orientation and installed at the customer site in a flag orientation.

[0004] However, due to other effects on the vibration characteristics of the vibrometer (e.g., rotating elements of mode shapes) caused by the density of materials changing with pressure (i.e., head pressure can increase the density of materials) and the relative orientation of gravity, the orientation of the sensor assembly can affect the vibrometer measurements. For example, density measurements from a sensor assembly oriented below the tube may be greater than density measurements from the same sensor assembly oriented above the tube. Therefore, it is necessary to detect the orientation of the vibrometer and correct the vibrometer measurements based on the detected orientation. Summary of the Invention

[0005] Meter electronics are provided for detecting an orientation and correcting measurements based on the detected orientation. According to one embodiment, the meter electronics includes an interface configured to communicatively couple to a sensor assembly and a processing system. The processing system is configured to detect an orientation of the sensor assembly based on one or more sensor signals provided by the sensor assembly.

[0006] A vibrometer is provided that detects an orientation and corrects measurements based on the detected orientation. According to one embodiment, the vibrometer includes a sensor assembly and meter electronics communicatively coupled to the sensor assembly. The meter electronics is configured to detect an orientation of the sensor assembly based on one or more sensor signals provided by the sensor assembly.

[0007] A method is provided for detecting an orientation of a vibrometer and correcting measurements based on the detected orientation. According to one embodiment, the method includes receiving one or more sensor signals from a sensor assembly and detecting an orientation of the sensor assembly based on the one or more sensor signals provided by the sensor assembly.

[0008] Aspects According to one aspect, a method for detecting an orientation and correcting measurements based on the detected orientation is provided. The sensor electronics (20) comprises an interface (401) configured to communicatively couple to the sensor assembly (10) and a processing system (402) configured to detect the orientation of the sensor assembly (10) based on one or more sensor signals provided by the sensor assembly (10).

[0009] Preferably, the processing system (402) configured to detect the orientation of the sensor assembly (10) based on the one or more sensor signals includes a processing system (402) configured to detect the orientation based on the time period of one or more vibrational modes of the sensor assembly (10) as observed in a sensor signal in the one or more sensor signals provided by the sensor assembly (10).

[0010] Preferably, the meter electronics (20) configured to detect orientation based on the time period of the one or more vibration modes includes meter electronics (20) configured to detect orientation based on density values determined from at least two of the one or more vibration modes.

[0011] Preferably, the processing system (402) is further configured to correct the measurements based on the detected orientation of the sensor assembly (10).

[0012] Preferably, the processing system (402) further configured to correct the measurements based on the detected orientation of the sensor assembly (10) includes a processing system (402) further configured to correct the measurements based on a relationship of the detected orientation of the sensor assembly (10) to a reference orientation of the sensor assembly (10).

[0013] Preferably, the reference orientation is the calibration orientation.

[0014] Preferably, the detected orientation of the sensor assembly (10) is one of a tube down orientation (500A), a tube up orientation (500B), and a flag orientation (500C).

[0015] According to one aspect, a vibrometer (5) for detecting an orientation and correcting measurements based on the detected orientation includes a sensor assembly (10) and meter electronics (20) communicatively coupled to the sensor assembly (10). The meter electronics (20) is configured to detect the orientation of the sensor assembly (10) based on one or more sensor signals provided by the sensor assembly (10).

[0016] Preferably, the meter electronics (20) configured to detect an orientation of the sensor assembly (10) based on one or more sensor signals includes meter electronics (20) configured to detect an orientation based on a time period of one or more vibrational modes of the sensor assembly (10) as observed in a sensor signal in the one or more sensor signals provided by the sensor assembly (10).

[0017] Preferably, the meter electronics (20) configured to detect orientation based on the time period of the one or more vibration modes includes meter electronics (20) configured to detect orientation based on density values determined from at least two of the one or more vibration modes.

[0018] Preferably, the meter electronics (20) is further configured to correct the measurement based on the detected orientation of the sensor assembly (10).

[0019] Preferably, the measurements are corrected based on the detected orientation of the sensor assembly (10). The meter electronics (20) is further configured to correct the measurement based on a relationship of the detected orientation of the sensor assembly (10) to a reference orientation of the sensor assembly (10).

[0020] Preferably, the reference orientation is the calibration orientation.

[0021] Preferably, the detected orientation of the sensor assembly (10) is one of a tube down orientation (500A), a tube up orientation (500B), and a flag orientation (500C).

[0022] According to one aspect, a method for detecting an orientation of a vibrometer and correcting measurements based on the detected orientation includes receiving one or more sensor signals from a sensor assembly and detecting an orientation of the sensor assembly based on the one or more sensor signals provided by the sensor assembly.

[0023] Preferably, detecting the orientation of the sensor assembly based on the one or more sensor signals includes detecting the orientation based on a time period of one or more vibrational modes of the sensor assembly as observed in a sensor signal in the one or more sensor signals provided by the sensor assembly.

[0024] Preferably, detecting the orientation based on the time period of the one or more vibration modes comprises detecting the orientation based on density values determined from at least two of the one or more vibration modes.

[0025] Preferably, the method further comprises the step of correcting the measurements based on the detected orientation of the sensor assembly.

[0026] Preferably, correcting the measurements based on the detected orientation of the sensor assembly includes correcting the measurements based on a relationship of the detected orientation of the sensor assembly to a reference orientation of the sensor assembly.

[0027] Preferably, the reference orientation is the calibration orientation.

[0028] Preferably the detected orientation of the sensor assembly is one of a tube down orientation, a tube up orientation, and a flag orientation. [Brief explanation of the drawings]

[0029] Like reference numbers represent like elements in all drawings. It should be understood that the drawings are not necessarily to scale. [Figure 1] FIG. 1 shows a vibrometer 5 for detecting an orientation and correcting measurements based on the detected orientation. [Figure 2] FIG. 1 shows a block diagram of a vibrometer 5 including a block diagram representation of the meter electronics 20. [Figure 3A] FIG. 1 shows a diagram of a conduit to illustrate vibration modes of a conduit, such as conduit 130 described above. [Figure 3B] FIG. 1 shows a diagram of a conduit to illustrate vibration modes of a conduit, such as conduit 130' described above. [Figure 4] FIG. 2 illustrates meter electronics 20 for detecting the orientation of the vibrometer and correcting measurements based on the detected orientation. [Figure 5A] 1A-1C show various exemplary orientations of a vibrometer 5. [Figure 5B] 1A-1C show various exemplary orientations of a vibrometer 5. [Figure 5C] 1A-1C show various exemplary orientations of a vibrometer 5. [Figure 6] FIG. 6 shows a frequency spectrum graph 600 of a vibrometer. [Figure 7] FIG. 7 shows a calibration graph 700 illustrating vibrometer orientation detection. [Figure 7A] FIG. 7 shows a detailed view of a portion of the calibration graph 700. [Figure 8] FIG. 8 illustrates a method 800 for detecting the orientation of a vibrometer. DETAILED DESCRIPTION OF THE INVENTION

[0030] 1 through 8 and the following description provide specific examples to teach those skilled in the art how to make and use the best mode embodiments for detecting orientation and correcting measurements based on the detected orientation. Some conventional aspects have been simplified or omitted for the purpose of teaching inventive principles. Those skilled in the art will appreciate variations from these examples that fall within the scope of the present disclosure. Those skilled in the art will appreciate that the features described below can be combined in various ways to form multiple variations for detecting orientation and correcting measurements based on the orientation. Consequently, the embodiments described below are not limited to the specific examples described below, but only by the claims and their equivalents.

[0031] FIG. 1 illustrates a vibrometer 5 for detecting orientation and correcting measurements based on the detected orientation. As shown in FIG. 1, the vibrometer 5 includes a sensor assembly 10 and meter electronics 20. The sensor assembly 10 responds to the mass flow rate and density of a process material. The meter electronics 20 connects to the sensor assembly 10 via leads 100 and provides density, mass flow, and temperature information, as well as other information, via port 26.

[0032] The sensor assembly 10 includes a pair of manifolds 150 and 150′, flanges 103 and 103′ with flange necks 110 and 110′, a pair of parallel conduits 130 and 130′, a driver 180, a resistance temperature detector (RTD) 190, and a pair of pickoff sensors 170l and 170r. The conduits 130 and 130′ have two essentially straight inlet legs 131 and 131′ and outlet legs 134 and 134′ that converge toward each other at the conduit mounting blocks 120 and 120′. The conduits 130 and 130′ bend at two symmetrical locations along their lengths and are essentially parallel throughout their entire lengths. Brace bars 140 and 140′ serve to define axes W and W′ about which each conduit 130 and 130′ oscillates. Legs 131, 131′ and 134, 134′ of conduits 130, 130′ are securely attached to conduit mounting blocks 120 and 120′, which are in turn securely attached to manifolds 150 and 150′. This provides a continuous, closed material path through sensor assembly 10.

[0033] When flanges 103 and 103', having holes 102 and 102', are connected via inlet end 104 and outlet end 104' to a process line (not shown) carrying the process material being measured, the material enters the meter at inlet end 104 through orifice 101 in flange 103 and is directed through manifold 150 to conduit mounting block 120, having surface 121. Within manifold 150, the material is split and directed through conduits 130, 130'. Upon exiting conduits 130, 130', the process material is recombined into a single stream within block 120', having surface 121' and manifold 150', before being directed to outlet end 104', which is connected to the process line (not shown) by flange 103', having hole 102'.

[0034] The conduits 130, 130' are selected and appropriately mounted to the conduit mounting blocks 120, 120' so as to have substantially the same mass distribution, moment of inertia, and Young's modulus about the bending axes W-W and W'-W', respectively. These bending axes are aligned with the brace bars 140. and 140'. To the extent that the Young's modulus of the conduit changes with temperature, this change affects flow and density calculations, an RTD 190 is attached to the conduit 130' to continuously measure the temperature of the conduit 130'. The temperature of the conduit 130', and therefore the voltage appearing across the RTD 190 for a given current passing therethrough, is governed by the temperature of the material passing through the conduit 130'. The temperature-dependent voltage appearing across the RTD 190 is used in a well-known manner by the meter electronics 20 to compensate for changes in the modulus of elasticity of the conduits 130, 130' due to any changes in the conduit temperature. The RTD 190 is connected to the meter electronics 20 by leads 195.

[0035] Both conduits 130, 130' are driven in opposite directions about their respective bending axes W and W' and in the so-called first out-of-phase bending mode of the flow meter by a driver 180. This driver 180 may comprise any one of many well-known configurations, such as a magnet attached to conduit 130' and opposing coils attached to conduit 130 through which an alternating current flows, causing both conduits 130, 130' to vibrate. An appropriate drive signal 185 is applied to driver 180 by meter electronics 20 via leads.

[0036] Meter electronics 20 receives sensor signal 165 appearing on lead 100, which carries the RTD temperature signal on lead 195 and left and right sensor signals 165l, 165r, respectively. Meter electronics 20 generates drive signal 185 appearing on lead to driver 180, causing conduits 130, 130' to vibrate. Meter electronics 20 processes left and right sensor signals 165l, 165r and RTD signal 195 to calculate the mass flow rate and density of the material passing through sensor assembly 10. This information, along with other information, is applied by meter electronics 20 as a signal over path 26. A more detailed description of meter electronics 20 follows.

[0037] 2 shows a block diagram of the vibrometer 5, including a block diagram representation of the meter electronics 20. As shown in FIG. 2, the meter electronics 20 is communicatively coupled to the sensor assembly 10. As described above with reference to FIG. 1, the sensor assembly 10 includes left and right pickoff sensors 170l, 170r, a driver 180, and a temperature sensor 190, which are communicatively coupled to the meter electronics 20 via a set of leads 100 through a communication channel 112.

[0038] Meter electronics 20 provides drive signals 185 via leads 100. More specifically, meter electronics 20 provides drive signals 185 to drivers 180 within sensor assembly 10. Additionally, sensor signals 165, including left sensor signal 165l and right sensor signal 165r, are provided by sensor assembly 10. More specifically, in the embodiment shown, sensor signals 165 are provided by left and right pickoff sensors 170l, 170r within sensor assembly 10. As can be seen, sensor signals 165 are each provided to meter electronics 20 through communication channel 112.

[0039] Meter electronics 20 includes a processor 210 communicatively coupled to one or more signal processors 220 and one or more memories 230. Processor 210 is also communicatively coupled to user interface 30. Processor 210 is communicatively coupled to a host via a communication port over port 26 and receives power via power port 250. Processor 210 may be a microprocessor, although any suitable processor may be used. For example, processor 210 may comprise 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, etc. In these and other embodiments, processor 210 may be a digitized The signal processing unit is configured to perform an operation on the received and processed signal, such as a signal generated by a signal processing unit.

[0040] The processor 210 may receive digitized sensor signals from one or more signal processors 220. The processor 210 is also configured to provide information such as a phase difference, a property of the fluid in the sensor assembly 10, etc. The processor 210 may provide the information to a host through a communication port. The processor 210 may also be configured to communicate with one or more memories 230 to receive and / or store information in the one or more memories 230. For example, the processor 210 may receive calibration coefficients and / or a sensor assembly zero (e.g., a phase difference when there is zero flow) from the one or more memories 230. Each of the calibration coefficients and / or the sensor assembly zero may be associated with the flow meter 5 and / or the sensor assembly 10, respectively. The processor 210 may use the calibration coefficients to process the digitized sensor signals received from the one or more signal processors 220.

[0041] The one or more signal processors 220 are shown as including an encoder / decoder (CODEC) 222 and an analog-to-digital converter (ADC) 226. The one or more signal processors 220 may condition analog signals, digitize the conditioned analog signals, and / or provide digitized signals. The CODEC 222 is configured to receive the sensor signals 165 from the left and right pickoff sensors 170l, 170r. The CODEC 222 is also configured to provide the drive signals 185 to the driver 180. In alternative embodiments, more or fewer signal processors may be used.

[0042] As shown, the sensor signal 165 is provided to the CODEC 222 via a signal conditioner 240. The drive signal 185 is provided to the driver 180 via the signal conditioner 240. Although the signal conditioner 240 is shown as a single block, the signal conditioner 240 may comprise signal conditioning components such as filters, such as two or more operational amplifiers, low-pass filters, voltage-to-current amplifiers, etc. For example, the sensor signal 165 may be amplified by a first amplifier, and the drive signal 185 may be amplified by a voltage-to-current amplifier. The amplification can ensure that the magnitude of the sensor signal 165 is an approximation of the full-scale range of the CODEC 222.

[0043] In the illustrated embodiment, the one or more memories 230 comprise read-only memory (ROM) 232, random access memory (RAM) 234, and ferroelectric random access memory (FRAM®) 236. However, in alternative embodiments, the one or more memories 230 may comprise more or less memory. Alternatively or additionally, the one or more memories 230 may comprise 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 used in place of the FRAM® 236. The one or more memories 230 may be storage devices configured to store process data, such as drive or sensor signals, mass flow or density measurements, etc.

[0044] The mass flow measurement (dot m) is calculated using the formula:

[0045]

number

[0046] With respect to density, the resonant frequency at which each conduit 130, 130' vibrates may be a function of the square root of the spring constant of the conduit 130, 130' divided by the total mass of the conduit 130, 130' containing the material. The total mass of the conduit 130, 130' containing the material may be the mass of the conduit 130, 130' plus the mass of the material inside the conduit 130, 130'. The mass of the material within the conduit 130, 130' is directly proportional to the density of the material. Therefore, the density of the material is proportional to the square of the period at which the conduit 130, 130' containing the material vibrates multiplied by the spring constant of the conduit 130, 130'. Therefore, by determining the period at which the conduit 130, 130' vibrates and scaling the result appropriately, an accurate measure of the density of the material contained in the conduit 130, 130' can be obtained. The meter electronics 20 can determine the period or resonant frequency using the sensor signal 165 and / or the drive signal 185. The conduits 130, 130' may vibrate in more than one vibration mode.

[0047] Vibration Mode 3A and 3B show diagrams of a conduit, such as conduits 130 and 130′ described above, to illustrate vibration modes of the conduit. As shown in FIGS. 3A and 3B, the conduit is represented by line 310. Line 310 has a U-shape to reflect a U-shaped conduit, which may include a left conduit and a right conduit. As shown in FIGS. 3A and 3B, line 310 includes left and right rest lines 312a and 312b. Also shown in FIGS. 3A and 3B are bending axes W-W and W′-W′, which are aligned with the vibration nodes of line 310. In FIG. 3A, line 310 also includes left and right primary bending mode lines 314a and 314b. Also shown are left and right secondary bending mode lines 316a and 316b. In FIG. 3B, line 310 includes a left-hand first-order torsional mode 318a and a right-hand first-order torsional mode 318b.

[0048] The left and right primary bending mode lines 314a, 314b are indicated by arrows that are 180 degrees out of phase with each other. That is, they move in opposite directions. This can be beneficial in various ways, such as reducing vibrations of the vibrometer due to unequal displacements of the conduit. The left and right primary bending mode lines 314a, 314b are also indicated as having a single node that is aligned with the bending axes W-W and W'-W'. The left and right secondary bending mode lines 316a, 316b are also indicated by arrows that are 180 degrees out of phase with each other. However, the left and right secondary bending mode lines 316a, 316b have two vibration nodes, hence the term "secondary." The natural frequency of the left and right secondary bending mode lines 316a, 316b may be higher than the natural frequency of the left and right primary bending mode lines 314a, 314b. The left and right primary torsional modes 318a, 318b are shown as having asymmetric displacements along their respective lengths relative to the left and right lines of rest 312a, 312b, with the arrows indicating that the left and right primary torsional modes 318a, 318b are out of phase with each other.

[0049] Although the vibration modes represented by line 310 are shown as separate, they may be superimposed on the conduit modeled by line 310. That is, the conduit modeled by line 310 may have multiple vibration modes. For example, the conduit to the left of the conduit may have a primary bending mode, a secondary bending mode, and a torsional mode. Thus, The conduit may have a first out-of-phase bending mode, a second out-of-phase bending mode, and a first torsional mode. The conduit may have additional modes, such as higher order bending modes (e.g., third order, fourth order, fifth order, etc.), in-phase bending modes, and higher order torsional modes (e.g., second order, third order, fourth order, etc.).

[0050] As the foregoing indicates, a vibration mode may have a shape, amplitude, and natural frequency. The shape of the vibration mode can be detected by comparing sensor signals, such as sensor signal 165, to one another. The phase difference between the sensor signal provided by left pickoff sensor 170l and the sensor signal provided by right pickoff sensor 170r indicates torsional mode excitation caused by Coriolis forces due to flow through the vibrometer when the tube vibrates in a bending mode or other mode, and may be proportional to the phase difference between conduits 130, 130′. The amplitude of the vibration mode may be proportional to the amplitude of sensor signal 165.

[0051] The frequencies of the vibration modes can be determined from the sensor signal 165 and / or the drive signal 185. More specifically, for each vibration mode having a natural modal frequency, the sensor signal 165 may have a component corresponding to the vibration mode of the conduit 130, 130′. Accordingly, filtering may be used to separate the components to determine the frequency of each component. The frequency of each component corresponds to the frequency of a vibration mode. The frequencies of the vibration modes may individually be referred to as modal frequencies. That is, modal frequencies are the natural frequencies of the vibration modes, each of which corresponds to a component in the sensor signal 165 and / or the drive signal 185.

[0052] Vibration modes may have a relationship. For example, the relationship between two vibration modes, referred to herein as a modal relationship, may be based on the phase, amplitude, and frequency of the two vibration modes. In one example, the modal relationship may be the difference in frequency between the left and right secondary bending mode lines 316a, 316b and the difference in frequency between the left and right primary bending mode lines 314a, 314b. The modal relationship may be quantified as a modal difference. For example, the modal relationship may be the difference between the time period of the left and right secondary bending mode lines 316a, 316b relative to the time period of the left and right primary bending mode lines 314a, 314b.

[0053] Meter electronics for detecting orientation 4 illustrates meter electronics 20 for detecting the orientation of a vibrometer and correcting measurements based on the detected orientation. As shown in FIG. 4, meter electronics 20 includes an interface 401 and a processing system 402. Meter electronics 20 receives a vibration response, such as from sensor assembly 10. Meter electronics 20 processes the vibration response to obtain flow characteristics of the flowable material flowing through sensor assembly 10.

[0054] The interface 401 can receive the sensor signal 165 from one of the pickoff sensors 170l, 170r shown in FIGS. 1 and 2. The interface 401 can perform any necessary or desired signal conditioning, such as formatting, amplification, buffering, or the like. Alternatively, some or all of the signal conditioning can be performed by the processing system 402. Additionally, the interface 401 can enable communication between the meter electronics 20 and an external device. The interface 401 can be capable of any method of electronic, optical, or wireless communication. The interface 401 can provide information based on the vibration response. The interface 401 can be coupled to a digitizer, such as the CODEC 222 shown in FIG. 2, where the sensor signal includes an analog sensor signal. The digitizer samples and digitizes the analog sensor signal to generate a digitized sensor signal.

[0055] The processing system 402 performs the operations of the meter electronics 20 and processes the flow measurements from the sensor assembly 10. The processing system 402 executes one or more processing routines, thereby processing the flow measurements to generate one or more flow characteristics. The processing system 402 is communicatively coupled to the interface 401 and configured to receive information from the interface 401.

[0056] Processing system 402 can comprise a general-purpose computer, a microprocessing system, a logic circuit, or any other general-purpose or customized processing device. Alternatively, or additionally, processing system 402 can be distributed among multiple processing devices. Processing system 402 can also include any manner of integrated or stand-alone electronic storage media, such as storage system 404.

[0057] The storage system 404 can store flow meter parameters and data, software routines, constant values, and variable values. In one embodiment, the storage system 404 includes routines executed by the processing system 402, such as an operation routine 410 and a correction routine 420 for the vibrometer 5. The storage system can also store statistics such as standard deviations, confidence intervals, etc.

[0058] The compensation routine 420 may compensate measurements, such as mass flow measurements, for the orientation of the vibrometer. For example, as described in more detail below, the compensation routine 420 may detect the orientation of a sensor assembly of a vibrometer, such as the sensor assembly 10 described above, based on one or more sensor signals provided by the sensor assembly 10. The compensation routine 420 may compensate measurements, such as mass flow measurements, based on a relationship of the detected orientation of the sensor assembly to a reference orientation of the sensor assembly. The reference orientation may be a calibration orientation.

[0059] 4, the calibration information 430 includes a calibration orientation 432 and a calibration signal 434. The calibration orientation 432 may be a value from a list of orientations, such as tube up, tube down, or flag orientation. The calibration orientation 432 may be detected from the calibration signal 434, may be input by a user, or may be automatically detected by an accelerometer or the like. The calibration orientation 432 is associated with the calibration signal 434.

[0060] The calibration signal 434 may be measured and stored during calibration of the vibrometer 5. The calibration signal 434 may be a time domain sampling of the sensor signal 165, a frequency spectrum signal indicative of the frequencies of vibration modes, a list of component frequencies where each component frequency is associated with a vibration mode frequency, a list of relationships between components, any suitable combination of the foregoing, etc. The calibration signal 434 is associated with a calibration orientation 432.

[0061] The storage system 404 can also store operational information 440, which can include data related to the installation of the vibrometer 5. As shown in FIG. 4, the operational information 440 includes a detected orientation 442, an operational signal 444, an uncorrected measurement value 446, and a corrected measurement value 448. The detected orientation 442 can be a value taken from or indicative of a list of orientations, such as a tube-up orientation, a tube-down orientation, or a flag orientation. The detected orientation 442 can be detected from the operational signal 444, can be input by a user, or can be automatically detected, such as by an accelerometer. The detected orientation 442 can be an installation orientation. The detected orientation 442 is associated with the operational signal 444.

[0062] The motion signal 444 may be measured and stored during calibration of the vibrometer 5. The motion signal 444 may be obtained by time domain sampling of the sensor signal 165 and / or the drive signal 185, vibration monitoring, etc. The motion signal 444 may be a frequency spectrum signal indicative of the frequencies of the vibration modes, a list of component frequencies where each component frequency is associated with a vibration mode frequency, a list of relationships between the components, any suitable combination of the foregoing, etc. The motion signal 444 may be associated with the detected orientation 442.

[0063] The uncorrected measurements 446 and the corrected measurements 448 may be values of a parameter of the material measured by the vibrometer 5. The parameter may be any suitable parameter, such as density, mass flow rate, or any derived value, such as porosity, mixture density, or mixture component density. The uncorrected measurements 446 may not be corrected for the detected orientation of the vibrometer 5. For example, if the calibration orientation 432 is a tube-up orientation and the detected orientation is a tube-down orientation, the value of the uncorrected measurements 446 may not be equal to the measurement of the vibrometer 5 in the tube-up orientation. However, as described in more detail below, the uncorrected measurements 446 may be corrected to equal the measurement of the vibrometer 5 in the tube-up orientation by using the corrected measurements 448.

[0064] The storage system 404 may also store reference information 450, which may include reference-related data that can be used to determine the orientation of the vibration sensor 5. As shown in FIG. 4, the reference information 450 includes a reference signal 452 and an orientation correlation 454. The reference signal 452 may be a sensor signal associated with a known orientation. For example, the reference signal 452 may be a list of component frequencies, each of which is associated with a given vibration mode that is associated with an orientation. This list may be used to determine an orientation signature, such as one of the orientation correlations 454 shown in FIG. 4. The reference orientation 456 may be, for example, a list of orientations that can be used during calibration that are associated with the reference signal 452. Thus, the reference signal 452 may be the same as the calibration signal 434.

[0065] Orientation correlation 454 may be a list of modal relationships associated with the orientation of vibrometer 5. For example, orientation correlation 454 may be a list of modal relationships correlated with the orientation of sensor assembly 10. Modal relationships may be quantitative relationships such as differences and ratios of two or more vibration parameter values each associated with a mode, as described below with respect to FIG. 7, which depend on tube periods and observed density values, although any suitable parameters may be used.

[0066] 4, the storage system 404 may also include correction information 460. The correction information 460 is shown as including a correction value 462, a correction orientation 464, and an orientation relationship 466. The correction value 462 may be associated with an orientation of the vibrometer 5. For example, the correction value 462 may include a list of values, each associated with an orientation of the vibrometer 5, such as the correction orientation 464 shown in FIG. 4. The correction orientation 464 may include a list of orientations, such as a tube up orientation, a tube down orientation, or a flag orientation.

[0067] As can be appreciated, the correction value 462 may be associated with a corrected orientation 464 depending on the relationship between the orientations, such as the relationship between the calibrated orientation 432 and the detected orientation 442. These and other relationships may be in the orientation relationship 466. For example, if the calibrated orientation 432 is a tube-up orientation and the detected orientation is a tube-down orientation, the orientation relationship may be a tube-up to tube-down relationship. The orientation relationship 466 may associate the tube-up to tube-down relationship with a correction value in the correction value 462. Thus, the uncorrected measurement value 446 may be corrected to the corrected measurement value 448 using the correction value.

[0068] The orientation relationship 466 may also include a relationship between two of the correction values 462 and the orientation relationship. For example, a first correction value in the correction values 462 may be associated with the relationship between the top of the tube and the bottom of the tube, and a second correction value may be associated with the relationship between the bottom of the tube and the top of the tube. The difference between the first and second correction values may be associated with the relationship between the bottom of the tube and the flag. That is, the calibration orientation 432 may be the tube down orientation and the detected orientation 442 may be the flag orientation. Thus, the uncorrected measurement 446 may be corrected to a corrected measurement 448 using the difference between the first and second correction values.

[0069] As can be appreciated, calibration orientation 432 may always be in a particular orientation, such as a tube-down orientation. Thus, correction values 462 may have only three values, each associated with correction orientations 464 tube-up, tube-down, and flag orientations by orientation relationships 466. However, orientation relationships 466 may include relationships between correction value relationships, such as a relationship between two of the correction values and the orientation relationships.

[0070] As can also be appreciated, the correction value associated with an orientation relationship without a difference (e.g., a tube-top-to-tube-top relationship, a tube-bottom-to-tube-bottom relationship, a flag-to-flag relationship, etc., see FIGS. 5A-5C ) may be null, zero, etc. For example, if the uncorrected measurement 446 is corrected by adding a correction value, the correction value may be zero for an orientation relationship without a difference. If the uncorrected measurement 446 is corrected by multiplying it by a correction value, the correction value may be null to indicate that a multiplication operation should not be performed. Thus, the corrected measurement 448 may be the same as the uncorrected measurement 446. The correction may need to be made based on the detected orientation of the vibrometer, which means that an orientation may need to be defined, as shown below with reference to FIGS. 5A-5C .

[0071] Exemplary Orientation 5A-5C illustrate various exemplary orientations of the vibrometer 5. As shown in FIG. 5A, the vibrometer 5 has a down-the-pipe orientation 500A, and in FIG. 5B, the vibrometer 5 has an up-the-pipe orientation 500B. The vibrometer 5 is shown in FIG. 5C as having a flag orientation 500C. In FIGS. 5A-5C, the vibrometer 5 includes a horizontal axis 510, which may be defined as being transverse to the direction of material flow. The vibrometer 5 also includes a vertical axis 520. The material flow direction may be considered to be collinear with the vertical axis from flange 103 to flange 103′, even if the material flows in other directions between flanges 103, 103′.

[0072] Also shown in Figures 5A-5C are the center of gravity 530a below the tube, the center of gravity 530b above the tube, and the flag center of gravity 530c. The center of gravity for the vibrometer may be the center of mass of the fluid and conduit material between the brackets, although any suitable center of mass may be used. As shown in Figures 5A-5C, the horizontal length 532a below the tube corresponds to the center of gravity 530a below the tube, the horizontal length 532b above the tube corresponds to the center of gravity 530b above the tube, and the horizontal length 532c of the flag corresponds to the flag center of gravity 530c. The vertical length 534c of the flag also corresponds to the flag center of gravity 530c. As can be seen from Figures 5A-5C, the location of the center of gravity relative to the position of the bracket varies depending on the orientation of the vibrometer 5. More specifically, head pressure can cause the density of the material to be greater when the vibrometer 5 is in the bottom-of-the-tube orientation 500A relative to the top-of-the-tube orientation 500B. This can lead to inaccurate measurements of the material within the vibrometer 5. Therefore, the measurements may be corrected by detecting the orientation of the vibrometer.

[0073] Orientation detection As described in more detail below, the orientation of the vibrometer may be detected by measuring sensor signal parameters of two or more vibration modes. For example, the time period of the conduit in the vibrometer may be measured for the first bending mode and the second bending mode. These two time periods may be used to determine observed density values, i.e., a first observed density value and a second observed density value, respectively. The difference between the first observed density value and the second observed density value may be compared to a predetermined correlation for the orientation of the vibrometer to detect the orientation of the vibrometer. Other sensor signal parameters may be used. may be used.

[0074] FIG. 6 illustrates a frequency spectrum graph 600 of a vibrometer. As shown in FIG. 6, the frequency spectrum graph 600 includes a frequency axis 610 in Hertz (Hz) and a magnitude axis 620 in decibels (dB). As can be seen, the frequency axis 610 ranges from 0 Hz to 1000 Hz, and the magnitude axis 620 ranges from -150 dB to 0 dB, although any suitable units and numerical ranges may be used. The frequency spectrum graph 600 also includes a spectral plot 630. The spectral plot 630 is shown as having a primary drive peak 632 and a secondary drive peak 634. Also shown are a primary torsional mode peak 636 and an in-phase bending mode peak 638. The primary drive peak 632 is at approximately 127 Hz, and the secondary drive peak 634 is at approximately 675 Hz.

[0075] The spectral plot 630 may be generated by sweeping from 0 Hz to 1000 Hz and measuring the resulting vibration. Referring to the vibrometer 5 described above as an example, the drive signal 185 may be a sinusoidal signal supplied to the conduits 130, 130′ at a fixed amplitude over a frequency range of 0 Hz to 1000 Hz. The amplitudes of the left and right sensor signals 165l, 165r may be measured as the drive signal 185 is swept from 0 Hz to 1000 Hz. As can be seen, the primary drive peak 632 is centered at the natural frequency of the vibrometer 5. However, as can be seen in the spectral plot 630, both the primary and secondary drive peaks 632, 634 are above the noise floor of the spectral plot 630 and may therefore be filtered and measured.

[0076] The primary drive peak 632 may correspond to a first bending mode of the conduits 130, 130′. Similarly, the secondary drive peak 634 may correspond to a second bending mode of the conduits 130, 130′. Thus, during operation, the drive signal 185 may have two sinusoidal components centered at approximately 127 Hz and 675 Hz, respectively. The sensor signals 165l, 165r may be filtered by two bandpass filters centered at approximately 127 Hz and 675 Hz, respectively. The CODEC 222 may track the primary and secondary drive peaks 632, 634 as their frequencies change with the material flowing through the conduits 130, 130′.

[0077] Thus, sensor signal parameters for each vibration mode may be measured and correlated to properties of the material within the conduits 130, 130'. For example, the time period and frequency of the drive signal 185 and / or the sensor signals 165l, 165r may vary according to the density of the material within the conduits 130, 130'. Similarly, the amplitude of the drive signal 185 and / or the sensor signals 165l, 165r may vary. As can be appreciated, other parameters of the material may be determined, such as viscosity, flow rate, composition, etc.

[0078] As can be appreciated, these sensor signal parameters may correspond to modes of vibration. For example, the first bending mode corresponding to the first drive peak 632 may have a lower frequency than the second bending mode corresponding to the second drive peak 634. Thus, the first bending mode may be used to generate a first density value, and the second bending mode may be used to generate a second density value. As can be appreciated, these density values should be equal to each other, but may not be equal to each other due to the orientation of the vibrometer. Thus, as the following discussion illustrates, the difference in density values, or other measurements or sensor signal parameters, may be used to detect the orientation of the vibrometer.

[0079] 7 shows a calibration graph 700 illustrating the orientation detection of the vibrometer. As shown in FIG. 7, the calibration graph 700 is plotted in grams per cubic centimeter (g / cm3 ) and the density axis 710 in units of squared microseconds (μs 2 ) and the axis of the square of the time period 720. As shown, calibration graph 700 is for a vibrometer in a down-the-tube orientation. Calibration graph 700 includes a calibrated density value 702. That is, if an unknown material having the same density value as calibration density value 702 is measured in a down-the-tube orientation (which is the same as the calibration orientation), the observed density value will be equal to calibration density value 702.

[0080] As can be seen, the calibration graph 700 includes a first-order graph 730 and a second-order graph 740. The first-order and second-order graphs 730, 740 were obtained by measuring the tube periods of the first and second bending modes, respectively, during calibration. More specifically, the first-order and second-order graphs 730, 740 were obtained by measuring the tube periods when the vibrometer was alternately filled with water and air. Air has a viscosity of approximately 0.001 g / cm 3 and water has a density of about 0.9982 g / cm 3 , which are shown as D1 and D2 in the calibration graph 700, respectively.

[0081] 7, primary graph 730 includes a primary calibration plot 732, and secondary graph 740 includes a secondary calibration plot 742. Primary and secondary calibration plots 732, 742 each have a primary air coordinate 732a and a primary water coordinate 732b, and a secondary air coordinate 742a and a secondary water coordinate 742b. Primary air coordinate 732a and secondary air coordinate 742a are determined by measuring the pipe periods of the primary and secondary bending modes, respectively, while air is present in the conduit of the vibratory flow meter. Similarly, primary water coordinate 732b and secondary water coordinate 742b are determined by measuring the pipe periods of the primary and secondary bending modes, respectively, while water is present in the conduit of the vibratory flow meter.

[0082] In most vibrometers, there is a linear relationship between the density of the material and the square of the pipe period of the conduit containing the material. Therefore, the primary air coordinate 732a and the primary water coordinate 732b are each a function of the square of the primary air pipe period K1. 2 and air density value D1 and square of primary water pipe period K2 2 and Similarly, the secondary air coordinate 742a and the secondary water coordinate 742b are calculated by the square of the secondary air pipe period K3 2 and air density value D1 and square of secondary water pipe period K4 2 and water density value D2. A linear relationship between the density of the material and the square of the pipe period is relied upon to generate the first-order and second-order calibration plots 732, 742 between their respective primary air coordinates 732a and primary water coordinates 732b, and secondary air coordinates 742a and secondary water coordinates 742b. For other vibrometers that exhibit non-linear relationships, the calibration plots can be defined as polynomials or other curves that fit two or more coordinates similarly determined at other densities with other fluid materials or fluid temperatures.

[0083] The primary and secondary calibration plots 732, 742 may be used to determine the density of an unknown material. For example, if the vibrometer is installed in a tube-down orientation and the material has a density equal to the calibrated density value 702, the observed density value may be equal to the calibrated density value 702 determined from the primary and secondary calibration plots 732, 742. That is, the primary and secondary calibration plots 732, 742 will produce the same calibrated density value 702. Associated with the calibrated density value 702 is a primary calibration tube period squared 736a, which is a coordinate on the primary calibration plot 732, and a secondary calibration tube period squared 746a, which is a coordinate on the secondary calibration plot 742.

[0084] However, the vibrometer may be installed in an orientation other than the orientation down the tube used during calibration. If the vibrometer is installed in an orientation other than the same as the calibration orientation, the primary and secondary calibration plots 732, 742 may not produce the calibrated density value 702. Additionally, the primary and secondary calibration plots 732, 742 may produce unequal primary and secondary density values 734, 744, respectively. This difference between the observed density values may be used to determine the orientation of the vibrometer during measurement, as described below.

[0085] When the vibrometer is oriented in the flag direction, the primary and secondary calibration plots 732, 742 may produce primary and secondary flag density values 734b, 744b, respectively, corresponding to the square of the tube period of the primary flag 736b and the square of the tube period of the secondary flag 746b, respectively. When the vibrometer is oriented above the tube, the primary and secondary calibration plots 732, 742 may produce primary and secondary tube density values 734c, 744c, respectively, corresponding to the square of the tube period of the primary tube 736c and the square of the tube period of the secondary tube 746c, respectively. As can be seen, the primary and secondary flag density values 734b, 744b are not equal to one another. Also, the primary and secondary tube density values 734c, 744c are not equal to one another. The difference between the primary density value 734 and the secondary density value 744 is explained in more detail below with reference to FIG. 7A.

[0086] 7A shows a detailed view of a portion of the calibration graph 700. As shown in FIG. 7A, the density axis of the secondary graph 740 intersects with lines representing the density value of the primary flag 734b, the density value above the primary tube 734c, the secondary flag density value 744b, and the density value above the secondary tube 744c. As expected because the vibrometer is calibrated in the down-the-tube orientation, the density difference below the tube Δ ρdown is equal to zero. As can be seen, the flag density difference Δ ρflag is the density difference above the tube, Δ ρflag Also, as can be seen, the density difference above the tube, Δ ρflag is the flag density difference Δ ρflagThe size is about twice that of the vibration meter, so the orientation of the vibration meter can be detected.

[0087] For example, the meter electronics 20 may measure the density difference Δ ρup The difference in the density of the flags is Δ ρflag An orientation correlation 454 may be stored that correlates the density difference Δ over the tube with the flag orientation. The correlation may be indexed, for example, by operating frequency, tube period, etc. ρup or flag density difference Δ ρflag The value of may vary proportionally with the operating frequency of the vibrometer 5. The orientation correlation 454 may be relative to other parameters, such as the operating frequency of the vibrometer 5, the observed density value, or may be in any suitable form, such as a percentage, ratio, or the like operating against or relative to other parameters. Values other than density may be used for the orientation correlation 454. For example, the orientation correlation 454 may correlate the time period, or the square of the time period, or the difference thereof, of the conduit 130 within the vibrometer 5 with the orientation of the vibrometer 5. These and other correlations may be used to determine the orientation of a vibrometer, such as the vibrometer 5 described above, which may then be used to correct measurements.

[0088] The correlation may be generalized to sensor signal parameters or other material parameters. For example, the time period of the vibration is t MO where "MO" denotes the mode (m) and the order (O). The modes can be denoted by β and ζ as bending and torsional modes, respectively. The orders can be denoted by 1, 2, and 3. Thus, the first bending and torsional modes can be denoted as β1 and ζ1, respectively. The first bending and second bending modes may be denoted as β1 and β2. Thus, the difference is t β -t β This can be defined as Δt β1βThis nomenclature may be used for material parameters such as density. The density difference between the densities determined using the first and second bending modes is ρ β -ρ β which may be defined by Δρ β1β can be shortened to

[0089] Orientation-based measurement correction The following table shows how to correct measurements based on the orientation of the vibrometer. In the table below, the columns and rows are headed by the three orientations: under the tube, over the tube, and flag, however, any suitable orientation and / or orientation description may be used. The table below also includes correction values, indicated by the letters "A" and "B," which are percentages of the uncorrected measurements. As shown, correction values A and B are associated with the change from the calibrated orientation to the current orientation. That is, A is the correction (% of reading) from calibration below the tube to flag operation. B is the correction (% of reading) from calibration below the tube to operation above the tube.

[0090] Calibration of the below-the-tube motion to the above-the-tube motion may be a relationship between a reference orientation and a detected orientation of the vibrometer. That is, the reference orientation may be a calibration orientation, and the detected orientation may be a current orientation. Additionally, with reference to FIG. 4 above, the calibration orientation may be a value within reference orientation 456, the current orientation may be a value within correction orientation 464, and the relationship between the reference orientation and the detected orientation may be a value within orientation relationship 466.

[0091] [Table 1] Therefore, if the current orientation is the same as the calibrated orientation, the above table returns a null value, indicating that the uncorrected measurement can be corrected. Therefore, the uncorrected measurement can be provided as an accurate measurement. If the calibrated orientation is tube down and the current orientation is tube up, the correction value can be B. The uncorrected measurement can be corrected with B, for example, by adding a value obtained by multiplying the uncorrected measurement by B. As can be seen from the above table, the calibrated orientation of tube up relative to the flag orientation has a correction value of AB. That is, the uncorrected measurement can be corrected by adding the uncorrected measurement multiplied by the difference between A and B.

[0092] method FIG. 8 illustrates a method 800 for detecting the orientation of a vibrometer. As shown in FIG. 8, the method 800, at step 810, receives one or more sensor signals from a sensor assembly. The sensor assembly may be the same as the sensor assembly 10 described above, although any suitable sensor assembly may be used. The one or more sensor signals may be received, for example, by the interface 401 described above. The interface 401 and / or the processing system 402 may condition, sample, digitize, compress, and / or expand, decimate, etc., the one or more received sensor signals. At step 820, the method 800 detects the orientation of the sensor assembly based on the one or more sensor signals provided by the sensor assembly. The processing system 402 described above may detect the orientation.

[0093] The method 800 may, at step 820, detect an orientation based on the time period of one or more vibrational modes of the sensor assembly as observed in one or more sensor signals provided by the sensor assembly. For example, the orientation may be detected based on the time period of one or more vibrational modes, which may include one or more vibrational modes. Detecting an orientation based on density values determined from at least two of the modes. In one example described above with reference to FIGS. 7 and 7A, the method 800 can compare the primary flag density value 734b to the secondary flag density value 744b to determine that the sensor assembly is in a flag orientation. This comparison can be the difference between the two density values or can be performed against the calibration density value 702. For example, the difference between the primary flag density value 734b and the calibration density value 702 can be compared to the difference between the secondary flag density value 744b and the calibration density value 702. Other methods, such as comparing time periods, frequencies, etc., can also be used to detect orientation. Additionally, more than two vibration modes can be used.

[0094] The method 800 may also correct measurements based on a detected orientation of the sensor assembly. For example, measurements may be corrected based on the relationship of the detected orientation of the sensor assembly to a reference orientation of the sensor assembly. Referring to the example in the table above, the relationship between the detected orientation and the reference orientation may be the relationship between a current orientation, such as a flag orientation, and a calibration orientation, such as a tube-down orientation. This relationship determines a correction value, A. This value may be applied to correct measurements, for example, of the density or volumetric flow measurements of a material within the sensor assembly. As can be seen in the table above, the current and / or calibration orientation of the sensor assembly may be a tube-down orientation, a tube-up orientation, and a flag orientation. However, other orientations may be used.

[0095] The vibrometer 5, meter electronics 20, and method 800 described above can detect the orientation of the sensor assembly 10 and correct measurements. As a result, the corrected measurements can be accurate. Orientation can be detected based on the sensor signal provided by the sensor assembly 10, thus eliminating the need for additional hardware. Therefore, orientation can be detected with any vibrometer that can be configured to vibrate the sensor assembly 10 in two or more vibration modes, for example. This can include a vibrometer installed in the field. Orientation can be detected by any suitable parameter of the sensor signal, such as using density values determined from two or more vibration modes, or can be determined from the sensor signal, and can thus be configured as needed to reduce computational resources while retaining a desired amount of accuracy. While any suitable parameter, such as tube period or frequency, can be used, density values for the first and second bending modes can be more accurate, for example, due to temperature compensation that can be used to determine the density values.

[0096] The detailed description of the above-described embodiments is not an exhaustive description of all embodiments contemplated by the inventors within the scope of the present specification. Indeed, those skilled in the art will recognize that certain elements of the above-described embodiments may be variously combined or omitted to create further embodiments, and such further embodiments will fall within the scope and teachings of the present specification. It will also be apparent to those skilled in the art that the above-described embodiments can be combined, in whole or in part, to create additional embodiments within the scope and teachings of the present specification.

[0097] Thus, while specific embodiments have been described herein for illustrative purposes, those skilled in the art will recognize that various equivalent modifications are possible within the scope of the present disclosure. The teachings provided herein may be applied to other meter electronics, vibrometers, and methods for detecting and correcting the orientation of a vibrometer, as well as the embodiments described above and illustrated in the accompanying drawings. Accordingly, the scope of the above-described embodiments should be determined from the following claims.

Claims

1. 1. Meter electronics (20) for detecting orientation and correcting measurements based on the detected orientation, comprising: an interface (401) configured to communicatively couple to the sensor assembly (10); a processing system (402) configured to detect an orientation of the sensor assembly (10) based on one or more sensor signals provided by the sensor assembly (10); The meter electronics (20) comprises:

2. 2. The meter electronics of claim 1, wherein the processing system configured to detect an orientation of the sensor assembly based on the one or more sensor signals comprises the processing system configured to detect the orientation based on a time period of one or more vibrational modes of the sensor assembly as observed in a sensor signal in the one or more sensor signals provided by the sensor assembly.

3. 3. The meter electronics of claim 2, wherein the meter electronics configured to detect the orientation based on a time period of the one or more vibration modes comprises the meter electronics configured to detect the orientation based on density values determined from at least two of the one or more vibration modes.

4. The meter electronics (20) of any one of claims 1 to 3, wherein the processing system (402) is further configured to correct measurements based on a detected orientation of the sensor assembly (10).

5. 5. The meter electronics of claim 4, wherein the processing system further configured to correct the measurement based on a detected orientation of the sensor assembly comprises the processing system further configured to correct the measurement based on a relationship of the detected orientation of the sensor assembly to a reference orientation of the sensor assembly.

6. The meter electronics (20) of claim 5, wherein the reference orientation is a calibration orientation.

7. 7. The meter electronics (20) of any one of claims 1 to 6, wherein the detected orientation of the sensor assembly (10) is one of a down-the-tube orientation (500A), an up-the-tube orientation (500B), and a flag orientation (500C).

8. A vibrometer (5) that detects an orientation and corrects measurements based on the detected orientation, a sensor assembly (10); meter electronics (20) communicatively coupled to the sensor assembly (10), meter electronics (20) configured to detect an orientation of the sensor assembly (10) based on one or more sensor signals provided by the sensor assembly (10); A vibrometer (5) comprising:

9. The meter electronics (20) configured to detect the orientation of the sensor assembly (10) based on the one or more sensor signals is 9. The vibrometer (5) of claim 8, wherein the meter electronics (20) is configured to detect orientation based on a time period of one or more vibration modes of the sensor assembly (10) as observed in one or more sensor signals provided by a vibration meter (10) connected to a power supply (12).

10. 10. The vibrometer of claim 9, wherein the meter electronics configured to detect an orientation based on a time period of one or more vibration modes comprises the meter electronics configured to detect an orientation based on density values determined from at least two of the one or more vibration modes.

11. 11. The vibrometer (5) of any one of claims 8 to 10, wherein the meter electronics (20) is further configured to correct measurements based on a detected orientation of the sensor assembly (10).

12. 12. The vibrometer of claim 11, wherein the meter electronics further configured to correct the measurement based on a detected orientation of the sensor assembly comprises the meter electronics further configured to correct the measurement based on a relationship of the detected orientation of the sensor assembly to a reference orientation of the sensor assembly.

13. 13. The vibrometer (5) according to claim 12, wherein the reference orientation is a calibration orientation.

14. 14. The vibrometer (5) of any one of claims 8 to 13, wherein the detected orientation of the sensor assembly (10) is one of a tube down orientation (500A), a tube up orientation (500B), and a flag orientation (500C).

15. 1. A method for detecting an orientation of a vibrometer and correcting measurements based on the detected orientation, comprising: receiving one or more sensor signals from a sensor assembly; detecting an orientation of the sensor assembly based on the one or more sensor signals provided by the sensor assembly; A method comprising:

16. 16. The method of claim 15, wherein detecting an orientation of the sensor assembly based on the one or more sensor signals comprises detecting an orientation based on a time period of one or more vibrational modes of the sensor assembly as observed in a sensor signal in the one or more sensor signals provided by the sensor assembly.

17. 17. The method of claim 16, wherein detecting an orientation based on a time period of the one or more vibration modes comprises detecting an orientation based on density values determined from at least two of the one or more vibration modes.

18. 18. The method of claim 15, further comprising correcting measurements based on the detected orientation of the sensor assembly.

19. 20. The method of claim 18, wherein correcting the measurement based on the detected orientation of the sensor assembly comprises correcting the measurement based on a relationship of the detected orientation of the sensor assembly to a reference orientation of the sensor assembly.

20. The method of claim 19 , wherein the reference orientation is a calibration orientation.

21. 21. The method of any one of claims 15 to 20, wherein the detected orientation of the sensor assembly is one of a tube down orientation, a tube up orientation, and a flag orientation.

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