Patent Publication Number: US-9851242-B2

Title: Collocated sensor for a vibrating fluid meter

Description:
TECHNICAL FIELD 
     The embodiments described below relate to, vibrating meters, and more particularly, to a collocated sensor for a vibrating fluid meter. 
     BACKGROUND OF THE INVENTION 
     Vibrating meters, such as for example, vibrating densitometers and Coriolis flow meters are generally known and are used to measure mass flow and other information for materials within a conduit. The material may be flowing or stationary. Exemplary Coriolis flow meters are disclosed in U.S. Pat. No. 4,109,524, U.S. Pat. No. 4,491,025, and Re. 31,450 all to J. E. Smith et al. These flow meters have one or more conduits of straight or curved configuration. Each conduit configuration in a Coriolis mass flow meter has a set of natural vibration modes, which may be of simple bending, torsional, or coupled type. Each conduit can be driven to oscillate at a preferred mode. 
     Material flows into the flow meter from a connected pipeline on the inlet side of the flow meter, is directed through the conduit(s), and exits the flow meter through the outlet side of the flow meter. The natural vibration modes of the vibrating, material filled system are defined in part by the combined mass of the conduits and the material flowing within the conduits. 
     When there is no flow through the flow meter, a driving force applied to the conduit(s) causes all points along the conduit(s) to oscillate with identical phase or a small “zero offset”, which is a time delay measured at zero flow. As material begins to flow through the flow meter, Coriolis forces cause each point along the conduit(s) to have a different phase. For example, the phase at the inlet end of the flow meter lags the phase at the centralized driver position, while the phase at the outlet leads the phase at the centralized driver position. Pick-off sensors on the conduit(s) produce sinusoidal signals representative of the motion of the conduit(s). Signals output from the pick-off sensors are processed to determine the time delay between the pick-off sensors. The time delay between the two or more pick-off sensors is proportional to the mass flow rate of material flowing through the conduit(s). 
     Meter electronics connected to the driver generates a drive signal to operate the driver and determines a mass flow rate and other properties of a material from signals received from the pick-off sensors. The driver may comprise one of many well-known arrangements; however, a magnet and an opposing drive coil have received great success in the vibrating meter industry. Examples of suitable drive coil and magnet arrangements are provided in U.S. Pat. No. 7,287,438 as well as U.S. Pat. No. 7,628,083, which are both assigned on their face to Micro Motion, Inc. and are hereby incorporated by reference. An alternating current is passed to the drive coil for vibrating the conduit(s) at a desired flow tube amplitude and frequency. It is also known in the art to provide the pick-off sensors as a magnet and coil arrangement very similar to the driver arrangement. However, while the driver receives a current, which induces a motion, the pick-off sensors can use the motion provided by the driver to induce a voltage. The magnitude of the time delay measured by the pick-off sensors is very small; often measured in nanoseconds. Therefore, it is necessary to have the transducer output be very accurate. 
       FIG. 1  illustrates an example of a prior art vibrating meter  5  in the form of a Coriolis flow meter comprising a sensor assembly  10  and a meter electronics  20 . The meter electronics  20  is in electrical communication with the sensor assembly  10  to measure characteristics of a flowing material, such as, for example, density, mass flow rate, volume flow rate, totalized mass flow, temperature, and other information. 
     The sensor assembly  10  includes a pair of flanges  101  and  101 ′, manifolds  102  and  102 ′, and conduits  103 A and  103 B. Manifolds  102 ,  102 ′ are affixed to opposing ends of the conduits  103 A,  103 B. Flanges  101  and  101 ′ of the prior art Coriolis flow meter are affixed to opposite ends of the spacer  106 . The spacer  106  maintains the spacing between manifolds  102 ,  102 ′ to prevent undesired vibrations in the conduits  103 A and  103 B. The conduits  103 A and  103 B extend outwardly from the manifolds in an essentially parallel fashion. When the sensor assembly  10  is inserted into a pipeline system (not shown) which carries the flowing material, the material enters sensor assembly  10  through flange  101 , passes through the inlet manifold  102  where the total amount of material is directed to enter conduits  103 A and  103 B, flows through the conduits  103 A and  103 B and back into the outlet manifold  102 ′ where it exits the sensor assembly  10  through the flange  101 ′. 
     The prior art sensor assembly  10  includes a driver  104 . The driver  104  is affixed to conduits  103 A and  103 B in a position where the driver  104  can vibrate the conduits  103 A,  103 B in the drive mode, for example. More particularly, the driver  104  includes a first driver component  104 A affixed to the conduit  103 A and a second driver component  104 B affixed to the conduit  103 B. The driver  104  may comprise one of many well-known arrangements such as a coil mounted to the conduit  103 A and an opposing magnet mounted to the conduit  103 B. 
     In the present example of the prior art Coriolis flow meter, the drive mode is the first out of phase bending mode and the conduits  103 A,  103 B are selected and appropriately mounted to inlet manifold  102  and outlet manifold  102 ′ so as to provide a balanced system having substantially the same mass distribution, moments of inertia, and elastic modules about bending axes W-W and W′-W′, respectively. In the present example, where the drive mode is the first out of phase bending mode, the conduits  103 A and  103 B are driven by the driver  104  in opposite directions about their respective bending axes W-W and W′-W′. A drive signal in the form of an alternating current can be provided by the meter electronics  20 , such as for example via pathway  110 , and passed through the coil to cause both conduits  103 A,  103 B to oscillate. Those of ordinary skill in the art will appreciate that other drive modes may be used by the prior art Coriolis flow meter. 
     The sensor assembly  10  shown includes a pair of pick-offs  105 ,  105 ′ that are affixed to the conduits  103 A,  103 B. More particularly, first pick-off components  105 A and  105 ′A are located on the first conduit  103 A and second pick-off components  105 B and  105 ′B are located on the second conduit  103 B. In the example depicted, the pick-offs  105 ,  105 ′ may be electromagnetic detectors, for example, pick-off magnets and pick-off coils that produce pick-off signals that represent the velocity and position of the conduits  103 A,  103 B. For example, the pick-offs  105 ,  105 ′ may supply pick-off signals to the meter electronics  20  via pathways  111 ,  111 ′. Those of ordinary skill in the art will appreciate that the motion of the conduits  103 A,  103 B is generally proportional to certain characteristics of the flowing material, for example, the mass flow rate and the density of the material flowing through the conduits  103 A,  103 B. However, the motion of the conduits  103 A,  103 B also includes a zero-flow delay or offset that can be measured at the pick-offs  105 ,  105 ′. The zero-flow offset can be caused by a number of factors such as non-proportional damping, residual flexibility response, electromagnetic crosstalk, or phase delay in instrumentation. 
     In many prior art fluid meters, the zero-flow offset is typically corrected for by measuring the offset at zero-flow conditions and subtracting the measured offset from subsequent measurements made during flow. While this approach provides an adequate flow measurement when the zero-flow offset remains constant, in actuality the offset changes due to a variety of factors including small changes in the ambient environment (such as temperature) or changes in the piping system through which the material is flowing. As can be appreciated any change in the zero-flow offset results in an error in the determined flow characteristics. During normal operations, there may be long periods of time between no-flow conditions. The changes in the zero-flow offset over time may cause significant errors in the measured flow. 
     The present applicants have developed a method for determining and correcting for changes in the zero-flow offset during flow, which is described in U.S. Pat. No. 7,706,987 entitled “In-Flow Determination Of Left And Right Eigenvectors In A Coriolis Flowmeter” and is hereby incorporated by reference. This so-called “Direct Coriolis Measurement” (DICOM) used in the &#39;987 patent explains that if two or more drivers are used rather than the typical single driver system, the left and right eigenvectors of the Coriolis flow meter system can be determined. In the physical sense, the right eigenvectors determine the phase between response points (pick-offs) when a particular mode is excited. The right eigenvectors are the values typically measured and determined in vibrating flow meters, such as the prior art flow meter  5 . The left eigenvectors determine the phase between drivers that optimally excite a particular mode. Without a zero-flow offset, these two phases are the same. Consequently, as outlined in the &#39;987 patent, if the left and right eigenvectors can be determined, the zero-flow offset can be distinguished from the fluid flow. 
     Although DICOM allows for increased accuracy in flow measurements by allowing in-flow determination of the zero-flow offset, the present applicants have discovered that the DICOM requires collocated sensor components. Although the &#39;987 patent describes the use of collocated sensor components, in actuality, the &#39;987 patent utilizes two separate and distinct driver sensor components and two separate and distinct pick-off sensor components. The &#39;987 patent attempts to position the driver and pick-off sensor components directly across from one another on the flow conduit to provide collocation. However, because the driver and pick-off sensor components are individually attached to the flow conduits  103 A,  103 B, precise collocation is impractical and even a small misplacement can result in errors propagating throughout the flow measurement. 
     U.S. Pat. No. 6,230,104, which is assigned on its face to the present applicants, discloses a combined driver and pick-off sensor. The combined driver and pick-off sensor disclosed in the &#39;104 patent can be used to reduce the number of sensor components, which reduces the wiring and consequently, the cost. Additionally, the combined driver and pick-off sensor can be used to perform DICOM. However, due to the configuration of the combined sensor component disclosed in the &#39;104 patent, measurements are complex and require an excessive amount of power. Further, the configuration disclosed in the &#39;104 patent is easily rendered inaccurate. The &#39;104 patent uses the same coil to apply the drive signal and receive the pick-off signal. This dual use of the coil requires a complex separation of the back electromotive force (back-EMF), which is the desired velocity measurement, from the measured transducer voltage applied by the drive signal. The determination of the back-EMF with the combined sensor component shown in the &#39;104 patent requires at least two compensations. The back-EMF can be characterized by equation (1). 
     
       
         
           
             
               
                 
                   
                     
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     The resistive load varies with temperature, thereby requiring on-line resistance calculation. Errors in this compensation affect both drive stability and flow measurement. Further, the resistive load is typically larger than the other terms in equation (1). Consequently, even small errors in the resistive load can translate to large flow errors. The inductive load is typically much smaller than the resistive load, but small errors here still become significant flow measurement offsets. 
     Therefore, as can be appreciated, the combined driver and pick-off sensor disclosed in the &#39;104 patent does not provide a suitable solution. There exists a need in the art for a combined driver and pick-off sensor that is collocated and can determine measurements with reduced complexity. The embodiments described below overcome these and other problems and an advance in the art is achieved. 
     SUMMARY OF THE INVENTION 
     A combined driver and pick-off sensor component for a vibrating meter is provided according to an embodiment. The combined driver and pick-off sensor component comprises a magnet portion comprising at least a first magnet and a coil portion. According to an embodiment, the coil portion comprises a coil bobbin, a driver wire wound around the coil bobbin, and a pick-off wire wound around the coil bobbin. 
     A vibrating meter is provided according to an embodiment. The vibrating meter comprises a meter electronics and a sensor assembly in electrical communication with the meter electronics. According to an embodiment, the sensor assembly includes one or more flow conduits and one or more combined driver and pick-off sensor components coupled to at least one of the one or more flow conduits. Each of the combined driver and pick-off sensor components comprises a magnet portion and a coil portion. According to an embodiment, the coil portion includes a coil bobbin, a driver coil wound around the coil bobbin, and a pick-off wire wound around the coil bobbin. 
     A method for forming a vibrating meter including a sensor assembly with one or more flow conduits is provided according to an embodiment. The method comprises steps of winding a driver wire around a coil bobbin and winding a pick-off wire around the coil bobbin. According to an embodiment, the method further comprises coupling the coil bobbin to one of the one or more flow conduits. According to an embodiment, the method further comprises electrically coupling the driver wire to a meter electronics for communicating a drive signal and electrically coupling the pick-off wire to the meter electronics for communicating a pick-off signal. 
     Aspects 
     According to an aspect, a combined driver and pick-off sensor component for a vibrating meter comprises: 
     a magnet portion comprising at least a first magnet; 
     a coil portion including:
         a coil bobbin;   a driver wire wound around the coil bobbin; and   a pick-off wire wound around the coil bobbin.       

     Preferably, the pick-off wire is wound on top of at least a portion of the driver wire. 
     Preferably, the coil bobbin comprises a first winding area for receiving the driver wire and a second winding area for receiving the pick-off wire. 
     Preferably, the first and second winding areas are spaced apart from one another. 
     Preferably, the combined driver and pick-off sensor component further comprises a flux directing ring positioned between the first and second winding areas. 
     Preferably, the coil bobbin comprises a magnet receiving portion for receiving at least a portion of the magnet. 
     Preferably, the first magnet corresponds to the driver wire and the magnet portion further comprises a second magnet coupled to the first magnet corresponding to the pick-off wire. 
     According to another aspect, a vibrating meter comprises:
         a meter electronics;   a sensor assembly in electrical communication with the meter electronics and including:
           one or more flow conduits; and   one or more combined driver and pick-off sensor components coupled to at least one of the one or more flow conduits with each of the combined driver and pick-off sensor components comprising a magnet portion and a coil portion, wherein the coil portion includes a coil bobbin, a driver wire wound around the coil bobbin, and a pick-off wire wound around the coil bobbin.   
               

     Preferably, the vibrating meter further comprises a first electrical lead coupled to the driver wire and in electrical communication with the meter electronics for communicating a drive signal and a second electrical lead coupled to the pick-off wire and in electrical communication with the meter electronics for communicating a pick-off signal. 
     Preferably, the magnet portion comprises at least a first magnet. 
     Preferably, the coil bobbin comprises a magnet receiving portion for receiving at least a portion of the first magnet. 
     Preferably, the pick-off wire is wound on top of at least a portion of the driver wire. 
     Preferably, the coil bobbin comprises a first winding area for receiving the driver wire and a second winding area for receiving the pick-off wire. 
     Preferably, the first and second winding areas are spaced apart from one another. 
     Preferably, the vibrating meter further comprises a flux directing ring positioned between the first and second winding areas. 
     According to another aspect, a method for forming a vibrating meter including a sensor assembly with one or more flow conduits comprises steps of:
         winding a driver wire around a coil bobbin;   winding a pick-off wire around the coil bobbin;   coupling the coil bobbin to one of the one or more flow conduits;   electrically coupling the driver wire to a meter electronics for communicating a drive signal; and   electrically coupling the pick-off wire to the meter electronics for communicating a pick-off signal.       

     Preferably, the method further comprises a step of coupling a magnet to a second flow conduit of the one or more flow conduits such that the coil bobbin receives at least a portion of the magnet. 
     Preferably, the step of winding the pick-off wire comprises winding the pick-off wire on top of the driver wire. 
     Preferably, the step of winding the driver and pick-off wires comprises winding the driver wire in a first winding area and winding the pick-off wire in a second winding area spaced from the first winding area. 
     Preferably, the method further comprises a step of coupling a flux directing ring to the coil bobbin between the first and second winding areas. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a prior art fluid meter. 
         FIG. 2  shows a cross-sectional view of a combined sensor component according to an embodiment. 
         FIG. 3  shows a cross-sectional view of a combined sensor component according to another embodiment. 
         FIG. 4  shows a vibrating meter  400  according to an embodiment. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIGS. 2-3  and the following description depict specific examples to teach those skilled in the art how to make and use the best mode of embodiments of a support member. For the purpose of teaching inventive principles, some conventional aspects have been simplified or omitted. Those skilled in the art will appreciate variations from these examples that fall within the scope of the present description. Those skilled in the art will appreciate that the features described below can be combined in various ways to form multiple variations of the fluid meter. As a result, the embodiments described below are not limited to the specific examples described below, but only by the claims and their equivalents. 
       FIG. 2  shows a cross-sectional view of a combined sensor component  200  according to an embodiment. According to the embodiment shown, the combined sensor component  200  comprises a combined driver and a pick-off sensor component. According to an embodiment, the combined driver and pick-off sensor component can be coupled to the first and second flow conduits  103 A,  103 B. In the embodiment shown, the combined sensor component  200  is coupled to the first and second flow conduits  103 A,  103 B using mounting brackets  210 A,  210 B. Therefore, the combined sensor component  200  can replace one or more of the sensor components  104 ,  105 ,  105 ′ of the prior art flow meter  5  shown in  FIG. 1 . In some embodiments, two combined sensor components  200  may be used to replace the pick-off sensors  105 ,  105 ′ while the driver  104  can be eliminated. Thus, the use of the combined sensor component  200  can reduce the number of total sensor components required for an operational fluid meter. 
     According to an embodiment, the combined sensor component  200  comprises a coil portion  204 A and a magnet portion  104 B. The magnet portion  104 B comprises a magnet  211  that is held onto the mounting bracket  210 B using a bolt  212 B. The magnet  211  can be positioned within a magnet keeper  213  that can help direct the magnetic field. According to an embodiment, the magnet portion  104 B comprises a typical magnet portion of prior art sensor components. The mounting bracket  210 B is shown coupled to the second flow conduit  103 B. The mounting bracket  210 B may be coupled to the flow conduit  103 B according to well-known techniques such as welding, brazing, bonding, etc. 
     According to an embodiment, the coil portion  204 A is coupled to the first flow conduit  103 A with the mounting bracket  210 A. The mounting bracket  210 A may be coupled to the flow conduit  103 A according to well-known techniques such as welding, brazing, bonding, etc. The coil portion  204 A also comprises a coil bobbin  220 . The coil bobbin  220  can include a magnet receiving portion  220 ′ for receiving at least a portion of the magnet  211 . The coil bobbin  220  can be held onto the mounting bracket  210 A with a bolt  212 A or similar fastening device. The particular method used to couple the coil portion  204 A to the flow conduit  103 A should in no way limit the scope of the present embodiment. 
     Additionally, while the combined driver and pick-off sensor component  200  is shown being coupled to a dual flow conduit sensor assembly, in other embodiments, one of the portions  104 B,  204 A may be coupled to a stationary component or a dummy tube, for example. This may be the case in situations where the combined driver and pick-off sensor component  200  is utilized in a single flow conduit sensor assembly. 
     According to an embodiment, the coil portion  204 A collocates the driver wire  221  and the pick-off wire  222 . Unlike the prior art combined sensor component described in the &#39;104 patent, the combined sensor component of the present embodiment provides separate and distinct wires  221 ,  222 . However, according to the embodiment shown in  FIG. 2 , the driver wire  221  and the pick-off wire  222  are both wound around the same coil bobbin  220 . Winding the driver wire  221  and the pick-off wire  222  around the coil bobbin  220  creates a driver coil  221 ′ and a pick-off coil  222 ′, which are collocated. In the embodiment shown, the wires  221 ,  222  are stacked on top of one another, i.e., one wire is wound on top of the other. While the embodiment shows the driver wire  221  being wound on the bobbin  220  prior to the pick-off wire  222 , the reverse could also be utilized, wherein the pick-off wire  222  is positioned radially inward of the driver wire  221 . 
     According to an embodiment, an insulating layer (not shown) may be provided between the driver wire  221  and the pick-off wire  222 . However, such an insulating layer is not necessary. 
     As shown, both coils share a single magnet  211  and a single magnet keeper  213 . Consequently, the number of components required to form a combined sensor component  200  is substantially reduced. 
     The combined sensor component  200  provides a significant advantage over the combined sensor shown in the &#39;104 patent. The combined sensor component  200  substantially eliminates the resistive compensation that is required by the &#39;104 patent as the driver wire  221  is different from the pick-off wire  222 . Therefore, the back-EMF calculation has been simplified to equation (2). 
     
       
         
           
             
               
                 
                   
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     Where: 
     M is the mutual inductance between the two coils  221 ′,  222 ′. 
     As can be appreciated, with the resistive compensation removed from the equation, the determination of the back-EMF is substantially simplified. Further, an online temperature measurement is no longer required. Also, recall from above that the resistive compensation is typically much larger than the inductive compensation. Therefore, the compensation required by equation (2) results in smaller flow measurement errors. 
     Although not shown in  FIG. 2 , it should be appreciated that the meter electronics  20  can communicate with the driver wire  221  with a wire lead (See  FIG. 4 ) similar to the wire lead  110  shown in  FIG. 1 . Therefore, when in electrical communication with the meter electronics, the driver wire  221  can be provided with a drive signal in order to create motion between the coil portion  204 A and the magnet portion  104 B. Likewise, the pick-off wire  221  can communicate with the meter electronics  20  with a wire lead (See  FIG. 4 ) similar to one of the wire leads  111 ,  111 ′. Therefore, when in electrical communication with the meter electronics, the pick-off wire  222  can sense motion between the coil portion  204 A and the magnet portion  104 B and provide a pick-off signal to the meter electronics. Therefore, the combined sensor component  200  does not require the complex circuitry and mimetic circuit as required by the system disclosed in the &#39;104 patent. 
       FIG. 3  shows a cross-sectional view of a combined sensor component  300  according to an embodiment. The embodiment shown in  FIG. 3  is similar to the embodiment shown in  FIG. 2  except that rather than winding the pick-off wire  222  on top of the driver wire  221 , the two wires are spaced from one another, while remaining wound around the same bobbin  222 . Therefore, the bobbin  222  comprises a first winding area  322  and a second winding area  322 ′. According to an embodiment, the first and second winding areas  322 ,  322 ′ are spaced from one another. The winding areas  322 ,  322 ′ may comprise grooves formed in the coil bobbin  222  in order to receive a wire. According to the embodiment shown, the driver and pick-off wires  221 ,  222  are further separated by a flux directing ring  330 . The flux directing ring  330  may be formed from carbon steel or some other mu metal and coupled to the coil bobbin  222  between the first and second winding areas  322 ,  322 ′. The flux directing ring  330  can help in isolating the electric fields associated with the individual wires  221 ,  222 . The flux directing ring  330  can direct the flux lines from the driver wire  221  away from the pick-off wire  222 . 
     Although the driver wire  221  is shown positioned closer to the magnet portion  104 B, in other embodiments, the pick-off wire  222  can be positioned closer to the magnet portion  104 B. Therefore, the present embodiment should not be limited to the configuration shown in  FIG. 3 . 
     According to an embodiment, the combined sensor component  300  eliminates the resistive compensation as in the combined sensor component  200 , but also with the combined sensor component  300 , the mutual inductance from equation (2) is small enough that any errors in the compensation of equation (2) are minimal. Consequently, the back-EMF of the pick-off wire  222  can be measured directly as if the pick-off wire  222  were located on a separate sensor component as in the prior art. 
     Advantageously, the combined sensor component  300  provides a collocated sensor component with the measurement simplicity of a stand-alone sensor component. The combined sensor components  200 ,  300  may be used in Coriolis flow meter in order to reduce the number of sensor components required. With the combined sensor components, the number of sensor components can be reduced from three ( FIG. 1 ) to two. This results in a reduction in material costs, assembly time, and less wiring. Additionally, the use of the combined sensor components  200 ,  300  ensure collocation of a driver wire  221  and a pick-off wire  222 . Therefore, use of either the combined sensor component  200  or the combined sensor component  300  improves the accuracy of measurements obtained using DICOM. 
     As with the combined sensor component  200  shown in  FIG. 2 , the driver wire  221  and the pick-off wire  222  can share the same magnet  211 . However, in the embodiment shown, the magnet portion  104 B comprises a second magnet  311 . The second magnet  311  can be coupled to the first magnet  211  and can be used to primarily interact with the pick-off wire  222 . This is because in the combined sensor component  300 , the pick-off wire  222  is positioned further away from the first magnet  211  and consequently, better performance can be achieved if the second magnet  311  is used that is positioned closer to the pick-off wire  222  during use. 
       FIG. 4  shows a vibrating meter  400  according to an embodiment. The vibrating meter  400  is similar to the meter  5  shown in  FIG. 1  and like components share the same reference number. The vibrating meter  400  may comprise a Coriolis flow meter or some other fluid meter. Therefore, the vibrating meter  400  comprises a sensor assembly  40  and the meter electronics  20 . The sensor assembly  40  can receive a fluid. The fluid may be flowing or stationary. The fluid may comprise a gas, a liquid, a gas with suspended particulates, a liquid with suspended particulates, or a combination thereof. 
     The sensor assembly  40  is in electrical communication with the meter electronics  20  via leads  415 . According to the embodiment shown, the vibrating meter  400  utilizes the combined sensor components  300 ; however, in other embodiments, the combined sensor components  200  may be used. As shown in  FIG. 4 , the vibrating meter  400  has reduced the number of sensor components from three to two. Therefore, the manufacturing process is substantially simplified. Further, the vibrating meter  400  may be used for DICOM operations. 
     According to the embodiment shown, a first combined sensor component  300  is coupled at the inlet end of the flow conduits  103 A,  103 B while a second combined sensor component  300  is shown coupled at the outlet end of the flow conduits  103 A,  103 B. In the embodiment shown, the first combined sensor component  300  is in electrical communication with the meter electronics  20  via a first wire lead  411  and a second wire lead  411 ′. More specifically, the driver wire  221  of the first combined sensor component  300  is coupled to the first wire lead  411  while the pick-off wire  222  is coupled to the second wire lead  411 ′. Similarly, the second combined sensor component  300  is in electrical communication with the meter electronics  20  via a third wire lead  412  and a fourth wire lead  412 ′. More specifically, the driver wire  221  of the second combined sensor component  300  is coupled to the third wire lead  412  while the pick-off wire  222  is coupled to the fourth wire lead  412 ′. 
     Advantageously, the meter electronics  20  can provide a drive signal to one or both of the driver coils via leads  411 ,  412  and receive pick-off signals from the pick-off coils via leads  411 ′,  412 ′ as is generally known in the art. 
     The embodiments described above provide an improved collocated sensor component for a vibrating meter. The improved collocated sensor component comprises a combined driver and pick-off sensor component. In order to ensure collocation of the driver and pick-off coils  221 ′,  222 ′, the driver and pick-off wires  221 ,  222  are wound around the same coil bobbin  220 . Advantageously, in embodiments where the collocated sensor component is used for DICOM, collocation of the driver and sensor components does not have to be assumed or estimated. Rather, the combined driver and pick-off sensor components  200 ,  300  ensure that collocation is achieved. 
     The detailed descriptions of the above embodiments are not exhaustive descriptions of all embodiments contemplated by the inventors to be within the scope of the present description. Indeed, persons skilled in the art will recognize that certain elements of the above-described embodiments may variously be combined or eliminated to create further embodiments, and such further embodiments fall within the scope and teachings of the present description. It will also be apparent to those of ordinary skill in the art that the above-described embodiments may be combined in whole or in part to create additional embodiments within the scope and teachings of the present description. 
     Thus, although specific embodiments are described herein for illustrative purposes, various equivalent modifications are possible within the scope of the present description, as those skilled in the relevant art will recognize. The teachings provided herein can be applied to other fluid meters, and not just to the embodiments described above and shown in the accompanying figures. Accordingly, the scope of the embodiments should be determined from the following claims.