US20050087235A1 - Sensor assembly, system including RFID sensor assemblies, and method - Google Patents

Abstract

A system comprises a valve; a plurality of RFID sensor assemblies coupled to the valve to monitor a plurality of parameters associated with the valve; a control tag configured to wirelessly communicate with the respective tags that are coupled to the valve, the control tag being further configured to communicate with an RF reader; and an RF reader configured to selectively communicate with the control tag, the reader including an RF receiver. Other systems and methods are also provided.

Description

GOVERNMENT RIGHTS
• This invention was made with government support under contract number DE-AC0676RL01830 awarded by the U.S. Department of Energy. The Government has certain rights in the invention.
TECHNICAL FIELD
• The invention relates to sensors. The invention also relates to valves and process control.
BACKGROUND OF THE INVENTION
• Industrial process control environments typically require physical sensing of parameters such as temperature, pressure, flow rate, strain, displacement, humidity, vibration, etc. Adapting a sensor network and its cabling infrastructure to existing plant environments is usually cost prohibitive.
• Various sensors that incorporate transmitters are known in the art. For example, U.S. Pat. No. 5,774,048 (incorporated herein by reference) relates to a valve that generates a wireless transmittable signal if pressure drops within vehicle tires. U.S. Pat. No. 6,005,480 to Banzhof et al. relates to similar subject matter.
• U.S. Pat. No. 6,199,575 to Widner (incorporated herein by reference) discloses a valve system that includes a MEMS pressure sensor that senses pressure and functions as a mechanical actuator for a valve. A transmitter is integrated with the valve and a receiver is located at a remote location. A transmitter may be formed on the MEMS along with a pressure transducer and its associated circuitry. An alternative embodiment is disclosed in which a digital modulator is included in a transducer valve.
• U.S. Pat. No. 6,445,969 to Kenney et al. (incorporated herein by reference) discloses a system and method of monitoring process parameters associated with a manufacturing or testing process. This reference discloses that radio frequency identification tags may be used to transmit an event signal. If an event trigger is detected, a command is sent to a particular sensor to measure a specified process parameter.
• U.S. Pat. No. 6,484,080 to Breed discloses an acceleration sensor including an RFID unit. U.S. Pat. No. 6,563,417 to Shaw discloses an RFID tag including a temperature sensor.
• Pneumatic or fluid controlled valves are known in the art and used in a variety of applications, such as to control water and other fluids in nuclear reactors. Such valves are discussed in U.S. Pat. No. 5,197,328 to Fitzgerald; U.S. Pat. No. 6,026,352 to Burns et al.; U.S. Pat. No. 5,329,956 to Marriott et al.; and U.S. Pat. No. 5,774,048 to Achterholt, all of which are incorporated by reference. In a typical pneumatic operated valve, a current to pressure (I/P) transducer is coupled to a valve positioner which supplies an operating pneumatic pressure to a valve diaphragm actuator. The diaphragm actuator in turn is coupled to a sliding valve stem and plug. Feedback is provided by a mechanical linkage, such as by a valve positioner arm having one end connected to the actuator/valve stem and the other end coupled to the positioner so as to track movement of the valve stem. Alternatively, electrical signal feedback is provided from installed valve positioner instrumentation.
• The value of sensor for providing both diagnostics and prognostics is readily accepted; however, innovative technical developments are needed to facilitate the implementation.
SUMMARY OF THE INVENTION
• Some aspects of the invention provide a system comprising a valve; a plurality of RFID sensor assemblies coupled to the valve to monitor a plurality of parameters associated with the valve; a control tag configured to wirelessly communicate with the respective tags that are coupled to the valve, the control tag being further configured to communicate with an RF reader; and an RF reader configured to selectively communicate with the control tag, the reader including an RF receiver:
• Other aspects of the invention provide a suite of RFID sensor assemblies for use in industrial process control. The suite can include, for example, sensors configured to sense one or more of temperature, pressure, strain, or other process control parameters. In some aspects of the invention, a tailored mechanical package is provided to allow the RFID tag to be readily adapted to a particular process component or parameter.
BRIEF DESCRIPTION OF THE DRAWINGS
• Preferred embodiments of the invention are described below with reference to the following accompanying drawings.
• FIG. 1 is a block diagram of a system including a pneumatically operated valve and a plurality of RFID sensor assemblies embodying various aspects of the invention.
• FIG. 2A is a circuit schematic of a RFID sensor assembly.
• FIG. 2B is a reader embodying various aspects of the invention.
• FIG. 3 is a perspective view of an RFID sensor assembly in accordance with some embodiments.
• FIG. 4 is a perspective view of an RFID sensor assembly in accordance with other embodiments.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
• FIG. 1 shows a system embodying various aspects of the invention. Thesystem9 includes a fluid control or pneumatically operatedvalve10. The air operatedvalve10 includes acontrol valve11, apneumatic diaphragm actuator12, astem coupler13, avalve positioner14, a pressure orvolume booster15, a controller and I/P or E/P converter16, asensor17, anair regulator18, and a pneumaticfluid supply line19. Thevalve11 controls fluid flow through amain fluid line20. Themain fluid line20 transfers fluid in connection with an industrial process. For example, the main fluid line could transfer fluid used in a power plant (e.g., water or other fluids used in a nuclear power plant). Thefluid line20 may be any other sort of fluid line in an industrial process facility.
• In the illustrated embodiment, a condition of thefluid line20 is sensed (e.g., temperature, pressure, flow) and this information is sent to thevalve positioner14. For example, in the illustrated embodiment, thesensor17 is a pressure transducer that senses pressure upstream of thevalve11. In alternative embodiments, different parameters can be sensed either upstream or downstream of thevalve11. In the illustrated embodiment, an electro-pneumatictype valve positioner47 is shown, includingpneumatic positioner14 and I/P converter16. Thesensor17 provides an output, which is an electrical output in the illustrated embodiment. More particularly, in the illustrated embodiment, thesensor17 provides a current output. Theconverter16 is coupled to the sensor (transducer)17 and converts an electrical signal (current in the illustrated embodiment) from thesensor17 to pressure. Other I/P or E/P converters could be employed. In some embodiments, thesensor17 provides a signal that can be directly used by thevalve positioner14 and theconverter16 is omitted. In alternative embodiments,converter16 can receive electrical signals from thevalve position controller39, from thesensor17, or from both thevalve position controller39 and theprocess sensor17. Thevalve position controller39 is a remote controller, in some embodiments. Thevalve position controller39 is a manually operable controller in some embodiments.
• In the illustrated embodiment, theconverter16 is coupled to thevalve positioner14 which supplies an operating pneumatic pressure to theactuator12. Thediaphragm actuator12 includes adiaphragm21, and aspring23 operating on the diaphragm. Thediaphragm actuator12 can be of a type that is opened by pneumatic fluid and closed by the spring, or can be of a type that is closed by a pneumatic fluid and opened by the spring. Theactuator12 is coupled to a slidingvalve stem24 and to thecontrol valve11. Thespring23 is biased between thevalve stem24 and thediaphragm21. Feedback is provided by the actuator-valve stem coupler13 which has one end connected to thevalve stem24 and another end coupled to thepositioner14 so as to track movement of thevalve stem24. As thevalve11 approaches the closed position, feedback is used to seat thevalve11 without slamming. Theregulator valve18 merely reduces pressure frompneumatic supply line19 andbooster15 merely increases pressure to a level required to operate thepneumatic actuator12.
• Alternative arrangements are possible. For example, while thepneumatic actuator12 shown inFIG. 1 is a direct-acting pneumatically operated diaphragm actuation, in which increasing pneumatic pressure pushes down on thediaphragm21 extending theactuator stem24, alternative actuator types could be employed. For example, in one alternative embodiment (not shown), a reverse-acting pneumatically operated diaphragm actuator type is employed in which increasing pneumatic pressure pushes up on the diaphragm and retracts the actuator stem. In another alternative embodiment (not shown), a reversible type pneumatic actuator is employed that can be assembled and installed as either a direct-acting or reverse-acting type pneumatic actuator.
• Similarly, while an electro-pneumatictype valve positioner47 is shown inFIG. 1, includingpneumatic positioner14 and I/P converter16, alternative embodiments are possible. For example, while an analog type electro-pneumatic positioner14 is shown inFIG. 1, a digital electro-pneumatic positioner is used in alternative embodiments. Further, in some applications a pneumatic type positioner will be used. In these embodiments, thepneumatic positioner14 receives a pressure input signal directly from theprocess sensor17 or valve position controller166.
• In some embodiments, a plurality of RFID sensor assemblies is provided to establish on-line self-diagnostic, prognostic, and calibration capabilities for the pneumatically operated valve. To instrument a component such as the pneumatically operatedvalve10, individual RFID sensor assemblies are attached to monitor various parameters. Various RFID sensor assemblies may have unique sensor interfaces. More particularly, the RFID sensor assemblies include mounting structure such that the mounting and sensing is noninvasive to normal valve operation. Some such mounting structures are described below in connection withFIGS. 3 and 4.
• The RFID sensor assemblies are used, in the embodiment ofFIG. 1, to provide on-line or in-use self-diagnostic, prognostic, and calibration capabilities for pneumatically operated process control valves and control system components. For example, RFID sensor assemblies can be coupled to or proximate (e.g., upstream or downstream of) components such as, for example, the I/P or E/P converter16, thevalve positioner14, the pressure orvolume booster15, theactuator spring23, the packing of thecontrol valve11, and the fluidsupply regulator valve18. InFIG. 1, anRFID sensor assembly31 is coupled to anelectrical conductor41 between theconverter16 and thevalve positioner14, anRFID sensor assembly32 is coupled to the actuator-valve stem coupler13, anRFID sensor assembly33 is coupled to aconduit22 between thebooster15 and thepneumatic actuator21, anRFID sensor assembly34 is coupled to aconduit43 between thevalve positioner14 and thebooster15, anRFID sensor assembly35 is coupled to aconduit45 between thevalve positioner14 andregulator valve18, anRFID sensor assembly36 is coupled topneumatic supply line19 between feeds to theregulator valve18 and to thebooster15, andRFID sensor assemblies37 are coupled to the process line orconduit20 on either side of thecontrol valve11.
• The use of RFID sensor assemblies31-37 allows for condition monitoring (e.g., periodic monitoring and data logging) of important valve performance parameters such as valve seating force,spring23 preload and spring constant, bench set, spring packing drag or bearing friction loads, linearity of thespring23, condition of thediaphragm21, andvalve11 position, stroke times, and calibration. Bench set comprises compression on the spring.
• In the illustrated embodiment, thesystem9 further includes anRFID control tag38, and each of the RFID sensor assemblies31-37 communicates to thecontrol tag38. This is, in some embodiments, a bi-directional link so that thecontrol tag38 can request data from the RFID sensor assemblies31-37 and also communicate with a reader. Thesystem9 further includes areader40 defined by, for example, aportable computer42 such as a laptop or personal digital assistant plus an RF receiver ormodule44 coupled to the laptop or personal digital assistant for communication with the laptop or personal digital assistant. Communication can be via an RS-232 link, PCMCIA connection, serial port, or other communication link. In the illustrated embodiment, thecomputer42 includes software that allows for data transfer from thecontrol tag38 and/or the RFID sensor assemblies31-37. The software (or separate software) permits setting up the tags.
• In other embodiments, the RFID sensor assemblies31-37 communicate directly with the reader, instead of through thecontrol tag38.
• In the illustrated embodiment, the RF link between thereader40 and the control tag38 (and/or the sensor assemblies31-37) is a low power link. For example, low power is used for transmissions. This allows the read/write range to be restricted to a predetermined range. The restricted read/write range allows for multiple networks to be placed in zones or grids, much like cell phone grids, without crossover RF interference.
• The tags have individual IDs, only tags with requested IDs will respond. In the illustrated embodiment, the tags and reader operate in a frequency band that does not require government licensing such as the ISM (industrial scientific measurement) band in the U.S. or frequency bands that similarly do not require government licensing in other countries.
• The RFID sensor assemblies31-37 could be or include, in some embodiments, RFID tags that are the same as or substantially similar to the RFID tags described in the following patent applications, which are incorporated herein by reference: U.S. patent application Attorney Ser. No. 10/263,826, filed Oct. 2, 2002, entitled “Radio Frequency Identification Device Communications Systems, Wireless Communication Devices, Wireless Communication Systems, Backscatter Communication Methods, Radio Frequency Identification Device Communication Methods and a Radio Frequency Identification Device” by inventors Michael A. Hughes and Richard M. Pratt; U.S. patent application Ser. No. 10/263,809, filed Oct. 2, 2002, entitled “Method of Simultaneously Reading Multiple Radio Frequency Tags, RF Tag, and RF Reader”, by inventors Emre Ertin, Richard M. Pratt, Michael A. Hughes, Kevin L. Priddy, and Wayne M. Lechelt; U.S. patent application Ser. No. 10/263,873, filed Oct. 2, 2002, entitled “RFID System and Method Including Tag ID Compression”, by inventors Michael A. Hughes and Richard M. Pratt; U.S. patent application Ser. No. 10/264,078, filed Oct. 2, 2002, entitled “System and Method to Identify Multiple RFID Tags”, by inventors Michael A. Hughes and Richard M. Pratt; U.S. patent application Ser. No. 10/263,940, filed Oct. 2, 2002, entitled “Radio Frequency Identification Devices, Backscatter Communication Device Wake-Up Methods, Communication Device Wake-Up Methods and A Radio Frequency Identification Device Wake-Up Method”, by inventors Richard Pratt and Michael Hughes; U.S. patent application Ser. No. 10/263,997, filed Oct. 2, 2002, entitled “Wireless Communication Systems, Radio Frequency Identification Devices, Methods of Enhancing a Communications Range of a Radio Frequency Identification Device, and Wireless Communication Methods”, by inventors Richard Pratt and Steven B. Thompson; U.S. patent application Ser. No. 10/263,670, filed Oct. 2, 2002, entitled “Wireless Communications Devices, Methods of Processing a Wireless Communication Signal, Wireless Communication Synchronization Methods and a Radio Frequency Identification Device Communication Method”, by inventors Richard M. Pratt and Steven B. Thompson; U.S. patent application Ser. No. 10/263,656, filed Oct. 2, 2002, entitled “Wireless Communications Systems, Radio Frequency Identification Devices, Wireless Communications Methods, and Radio Frequency Identification Device Communications Methods”, by inventors Richard Pratt and Steven B. Thompson; U.S. patent application Ser. No. 10/263,635, filed Oct. 4, 2002, entitled “A Challenged-Based Tag Authentication Model”, by inventors Michael A. Hughes and Richard M. Pratt; U.S. patent application Ser. No. 09/589,001, filed Jun. 6, 2000, entitled “Remote Communication System and Method”, by inventors R. W. Gilbert, G. A. Anderson, K. D. Steele, and C. L. Carrender; U.S. patent application Ser. No. 09/802,408; filed Mar. 9, 2001, entitled “Multi-Level RF Identification System”; by inventors R. W. Gilbert, G. A. Anderson, and K. D. Steele; U.S. patent application Ser. No. 09/833,465, filed Apr. 11, 2001, entitled “System and Method for Controlling Remote Device”, by inventors C. L. Carrender, R. W. Gilbert, J. W. Scott, and D. Clark; U.S. patent application Ser. No. 09/588,997, filed Jun. 6, 2000, entitled “Phase Modulation in RF Tag”, by inventors R. W. Gilbert and C. L. Carrender; U.S. patent application Ser. No. 09/589,000, filed Jun. 6, 2000; entitled “Multi-Frequency Communication System and Method”, by inventors R. W. Gilbert and C. L. Carrender; U.S. patent application Ser. No. 09/588,998; filed Jun. 6, 2000, entitled “Distance/Ranging by Determination of RF Phase Delta”, by inventor C. L. Carrender; U.S. patent application Ser. No. 09/797,539, filed Feb. 28, 2001, entitled “Antenna Matching Circuit”, by inventor C. L. Carrender; U.S. patent application Ser. No. 09/833,391, filed Apr. 11, 2001, entitled “Frequency Hopping RFID Reader”, by inventor C. L. Carrender.
• The RF tags offer significant features at the sensors. The tags include microprocessors. In the illustrated embodiments, the microprocessors allow for calibration, compensation, preprocessing, and onboard diagnostics and prognostics. Each tag includes a large amount of nonvolatile memory. In some embodiments, the RFID tags are used as data loggers. The tags use the memory to periodically or at various times store data that is measured by the sensors. The nonvolatile memory is also used to store setup information that is particular to the type of sensor and the tag application requirements. For example, the time period for acquiring data is user settable (e.g., times when data is to be taken and frequency of data logging within specified time ranges). Each control tag and RFID tag included in the assemblies31-37 has its own unique identification code or ID which is a main element in the RF protocol for communications. In some embodiments, the RF link between thereader40 and the control tag or RFID assembly31-37 is two way (RF reader40 request tag to transmit). In other embodiments, the RF link between thereader40 and the control tag or RFID assembly31-37 is one way (tag periodically transmits to an RF reader). In some embodiments, thereader40 is coupled to (or selectively coupled to) the Internet and defines a web server so that process reporting is performed via web pages and so that users can monitor process parameters using web browsers. Alternatively, data from thereader40 is transferred at times to aweb server46 separate from the reader.
• The system ofFIG. 1 can be adapted for use with either sliding stem or rotary stem control valves and actuator assemblies with either pneumatic or electromagnetic controllers.
• Another RFID sensor assembly design is shown inFIG. 2A. The RFID sensor assemblies are relatively small. TheRFID sensor assembly50 that is shown inFIG. 2A is configured to sense temperature and impact (acceleration). Other parameters are sensed in alternative embodiments. TheRFID sensor assembly50 includes aprocessor54 that can accommodate both analog and digital sensors. In the illustrated embodiment, theprocessor54 is a Texas Instruments 430×325 integrated circuit microprocessor. Other embodiments are possible. Athermocouple53 and atemperature sensor55 are coupled to the microprocessor. In the illustrated embodiment, thethermocouple53 is a high temperature thermocouple. Other temperature sensors are possible. Thesystem50 further includes an impact sensor oraccelerometer57 coupled to theprocessor50; e.g., via a buffer op-amp.
• Theassembly50 further includes anRF transceiver56 coupled to theprocessor54 and to anantenna58. Theassembly50 further includes a lowpower RF detector60 configured to provide a wakeup signal to theprocessor54.
• Theassembly50 further includes abattery62 coupled to theintegrated circuit54 to supply power to various components of theassembly50 that require electrical power. In the illustrated embodiment, theassembly50 includes apower supervisor64 coupled to a reset input of theintegrated circuit54 and a power on/offswitch66 coupled between thepower supervisor64 and thebattery62. Theassembly50 further includes abattery monitor68 coupled to theintegrated circuit54 and configured to monitor the condition of the battery. In the illustrated embodiment, theassembly50 further includes a super capacitor orultracapacitor70 and anLDO regulator72 having an input coupled to a positive terminal of theultracapacitor70. The input of theLDO regulator72 and the positive terminal of thesuper capacitor70 are also coupled to the on/offswitch66. TheLDO regulator72 has an output that provides a regulated voltage to the various electronic components of theassembly50. Theultracapacitor70 provides supplemental power for RF communications and allows continued operation when thebattery62 is replaced. The components of theassembly50 other than thebattery62 andthermocouple53 are enclosed in acommon housing74 and thebattery62 is enclosed in ahousing76 that is removable from thehousing74. The components enclosed in thehousing74 and in thehousing76, and thehousings74 and76 together can be referred to as anRFID tag51.
• In some embodiments, sensors such as strain gauges and/or LVDTs are used. In such embodiments, interface circuitry is provided between the sensor and themicroprocessor54.
• The reader52 (FIG. 2B) includes atransceiver78 configured to communicate with the transceiver56 (FIG. 2A). The reader52 further includes aprocessor80 coupled to thetransceiver78. In the illustrated embodiment, theprocessor80 is a Texas Instruments 430×325 integrated circuit microprocessor. The reader52 further includes abattery82. The reader52 further includes anLDO regulator84 configured to provide a regulated voltage to electrical components of the reader52. The reader52 further includes an on/offswitch86 coupled between thebattery82 and theLDO regulator84. The reader52 also includes an interrogateswitch88 which, when actuated, causes the reader52 to interrogate the tag assembly50 (FIG. 2A). The reader52 further includes input/output interfaces such adisplay90.
• In the illustrated embodiment, the reader52 further includes a low battery indicator, a power onindicator92, and aspeaker96. Other embodiments are possible.
• In the illustrated embodiment, the reader52 is configured to be coupled to a PDA or portable computer. In alternative embodiments, the reader52 is coupled to or incorporated in a PDA or portable computer and uses the display and/or speaker, and/or keyboard or input interface of the PDA or computer.
• Some aspects of the invention provide a suite of RFID sensor assemblies for sensor use in industrial process control. The suite can include, for example, sensors configured to sense one or more of temperature, pressure, strain, or other process control parameters. In some aspects of the invention, a tailored mechanical package or mounting structure is provided to allow the RFID tag to be readily adapted to a particular process component or parameter.
• For example,FIG. 3 is a perspective view of asensor assembly150, which can be substantially similar to theRF tag assembly50 shown inFIG. 2A. Thesensor assembly50 includes anRFID tag151, which can be identical to or substantially identical to theRFID tag51 shown inFIG. 2A. Theassembly151 is configured to be used to measure temperature and may be placed in a high temperature environment. Theassembly151 includes a probe orwaveguide152 having first and second ends153 and154. Thefirst end153 defines a tip, and athermocouple155 is supported on the tip. TheRFID tag151 is supported on thesecond end154.
• An RFID sensor assembly for use with a fluid conduit such as one used in a nuclear reactor includes a band that encircles thefluid conduit156, and an RFID tag supported by the band. The sensor assembly can be for sensing temperature, such as thesensor assembly150 shown inFIG. 3. TheRFID sensor assembly150 is for use with afluid conduit156 and includes aband157 that encircles thefluid conduit156, and anRFID tag151 supported by theband157.
• AnRFID sensor assembly200 for use in sensing pressure is shown inFIG. 4 and includes agas inlet port202 configured to be coupled to a port on aconduit206. For example, the gas inlet port, in some embodiments, is configured to be coupled (mechanically mated) to an ancillary port or threaded stub on a flow pipe.
• A variety of additional RFID sensor assembly designs is contemplated, the above specific designs being provided by way of example. Each RFID sensor assembly includes a mating adaptor that allows for ease of installation and minimization of modification to existing process control components. Some RFID sensor assemblies just sense switch closures such as for limit switches or relay contacts.
• The ability to locally add desired sensing to an industrial process provides tremendous flexibility for continually adding to, modifying, or enhancing a sensor network.
• In compliance with the statute, the invention has been described in language more or less specific as to structural and methodical features. It is to be understood, however, that the invention is not limited to the specific features shown and described, since the means herein disclosed comprise preferred forms of putting the invention into effect. The invention is, therefore, claimed in any of its forms or modifications within the proper scope of the appended claims appropriately interpreted in accordance with the doctrine of equivalents.

Claims (45)

1. A system comprising:

a valve;

a plurality of RFID sensor assemblies coupled to the valve to monitor a plurality of parameters associated with the valve;

a control tag configured to wirelessly communicate with the respective tags that are coupled to the valve, the control tag being further configured to communicate with an RF reader; and

an RF reader configured to selectively communicate with the control tag, the reader including an RF receiver:

2. A system in accordance withclaim 1 wherein the valve is a fluid-operated valve.

3. A system in accordance withclaim 2 wherein the valve includes a valve positioner, an electrical conductor, and an I/P transducer coupled to the valve positioner by the electrical conductor, and wherein at least one of the plurality of RFID sensor assemblies is coupled to the electrical conductor.

4. A system in accordance withclaim 2 wherein the valve includes a pneumatic actuator, a valve stem coupled to the pneumatic actuator, and an actuator-valve stem coupler, and wherein at least one of the plurality of RFID sensor assemblies is coupled to the actuator-valve stem coupler.

5. A system in accordance withclaim 2 wherein the valve includes a pneumatic actuator, a valve positioner, and a fluid conduit in fluid communication between the pneumatic actuator and the valve positioner, and wherein at least one of the plurality of RFID sensor assemblies is coupled to the fluid conduit between the pneumatic actuator and the valve positioner.

6. A system in accordance withclaim 2 wherein the valve includes a pneumatic actuator, a valve positioner, a booster, a first fluid conduit in fluid communication between the pneumatic actuator and the booster, a second fluid conduit in fluid communication between the booster and the valve positioner, and wherein at least one of the plurality of RFID sensor assemblies is coupled to the first fluid conduit and at least another one of the plurality of RFID sensor assemblies is coupled to the second fluild conduit.

7. A system in accordance withclaim 6 and further comprising a fluid supply line in fluid communication with the booster, and wherein at least one of the plurality of RFID sensor assemblies is coupled to the fluid supply line.

8. A system in accordance withclaim 7 and further comprising a regulator valve in fluid communication between the fluid supply line and the valve positioner, a conduit between the regulator valve and the valve positioner, and wherein at least one of the plurality of RFID sensor assemblies is coupled to the conduit between the regulator valve and the valve positioner.

9. A system in accordance withclaim 1 and further comprising a conduit upstream of the valve and a conduit downstream of the valve, wherein at least one of the plurality of RFID sensor assemblies is coupled to the conduit upstream of the valve and at least another one of the plurality of the RFID assemblies is coupled to the conduit downstream of the valve.

10. A system in accordance withclaim 1 wherein the valve includes a seat and wherein the RFID sensor assemblies are used to determine valve seating force.

11. A system in accordance withclaim 1 wherein the valve includes a spring and wherein the RFID sensor assemblies are used to determine a spring preload of the spring.

12. A system in accordance withclaim 1 wherein the valve includes a spring and wherein the RFID sensor assemblies are used to determine a spring constant of the spring.

13. A system in accordance withclaim 1 wherein the valve includes a spring and wherein the RFID sensor assemblies are used to determine spring compression.

14. A system in accordance withclaim 1 wherein the RFID sensor assemblies are used to determine a friction load on the valve.

15. A system in accordance withclaim 1 wherein the RFID sensor assemblies are used to determine valve position.

16. A system in accordance withclaim 1 wherein the RFID sensor assemblies are used to determine valve stroke times.

17. A sensor assembly comprising:

an RFID tag;

a thermocouple; and

a probe having first and second ends, the first end defining a tip, the thermocouple being supported on the tip, and the RFID tag being supported on the second end and electrically coupled to the thermocouple.

18. A sensor assembly in accordance withclaim 17 wherein the probe defines an electrical conductor electrically coupling the RFID tag to the thermocouple.

19. A sensor assembly in accordance withclaim 17 wherein the RFID tag includes memory and is configured to log measurements from the thermocouple, at different times, in the memory.

20. A plurality of RFID sensor assemblies for sensor use in industrial process control, the plurality comprising:

sensors configured to sense at least two of temperature, pressure, and strain;

at least one of the sensor assemblies including a band configured to encircle a fluid conduit; and

an RFID tag supported by the band and in electrical communication with at least one of the sensors.

21. A sensor assembly in accordance withclaim 20 wherein the RFID tag includes memory and is configured to log data in the memory from the at least one sensor in electrical communication with the RFID tag, at different times.

22. A sensor assembly comprising:

an RFID tag;

a pressure sensor; and

a band configured to encircle a fluid conduit, the RFID tag being supported by the band and in electrical communication with the pressure sensor.

23. A sensor assembly in accordance withclaim 22 wherein the RFID tag includes memory and is configured to log data from the pressure sensor in the memory at different times.

24. A method of monitoring an industrial process which makes use of a valve, the method comprising:

coupling a plurality of RFID sensor assemblies to the valve to monitor a plurality of parameters associated with the valve;

providing a control tag to wirelessly communicate with the respective tags that are coupled to the valve, the control tag being configured to communicate with an RF reader; and

selectively communicating with the control tag using an RF reader, the reader including an RF receiver.

25. A method in accordance withclaim 24 wherein the valve is a fluid-operated valve, wherein the valve includes a valve positioner, an electrical conductor, and an I/P transducer coupled to the valve positioner by the electrical conductor, and wherein the method comprises coupling at least one of the plurality of RFID sensor assemblies to the electrical conductor.

26. A method in accordance withclaim 24 wherein the valve is a fluid-operated valve, wherein the valve includes a pneumatic actuator, a valve stem coupled to the pneumatic actuator, and an actuator-valve stem coupler, and wherein the method comprises coupling at least one of the plurality of RFID sensor assemblies to the actuator-valve stem coupler.

27. A method in accordance withclaim 24 wherein the valve is a fluid-operated valve, wherein the valve includes a pneumatic actuator, a valve positioner, and a fluid conduit in fluid communication between the pneumatic actuator and the valve positioner, and wherein the method comprises coupling at least one of the plurality of RFID sensor assemblies to the fluid conduit between the pneumatic actuator and the valve positioner.

28. A method in accordance withclaim 24 wherein the valve is a fluid-operated valve, wherein the valve includes a pneumatic actuator, a valve positioner, a booster, a first fluid conduit in fluid communication between the pneumatic actuator and the booster, a second fluid conduit in fluid communication between the booster and the valve positioner, and wherein the method comprises coupling at least one of the plurality of RFID sensor assemblies to the first fluid conduit and coupling at least another one of the plurality of RFID sensor assemblies to the second fluild conduit.

29. A method in accordance withclaim 28 wherein a fluid supply line is in fluid communication with the booster, and wherein at least one of the plurality of RFID sensor assemblies is coupled to the fluid supply line.

30. A method in accordance withclaim 29 wherein a regulator valve is in fluid communication between the fluid supply line and the valve positioner, a conduit is between the regulator valve and the valve positioner, and wherein at least one of the plurality of RFID sensor assemblies is coupled to the conduit between the regulator valve and the valve positioner.

31. A method in accordance withclaim 24 wherein a conduit is upstream of the valve and a conduit is downstream of the valve, wherein at least one of the plurality of RFID sensor assemblies is coupled to the conduit upstream of the valve and at least another one of the plurality of the RFID assemblies is coupled to the conduit downstream of the valve.

32. A method in accordance withclaim 24 wherein the valve includes a seat and wherein the method comprises using the RFID sensor assemblies to determine valve seating force.

33. A method in accordance withclaim 24 wherein the valve includes a spring and wherein the method comprises using the RFID sensor assemblies to determine a spring preload of the spring.

34. A method in accordance withclaim 24 wherein the valve includes a spring and wherein the method comprises using the RFID sensor assemblies to determine a spring constant of the spring.

35. A method in accordance withclaim 24 wherein the valve includes a spring and wherein the method comprises using the RFID sensor assemblies to determine spring compression.

36. A method in accordance withclaim 24 and comprising using the RFID sensor assemblies to determine a friction load on the valve.

37. A method in accordance withclaim 24 and comprising using the RFID sensor assemblies to determine valve position.

38. A method in accordance withclaim 24 and comprising using the RFID sensor assemblies to determine valve stroke times.

39. A method of manufacturing a sensor assembly, the method comprising:

providing an RFID tag;

providing a thermocouple;

providing a probe having first and second ends, the first end defining a tip;

supporting the thermocouple on the tip, and

supporting the RFID tag on the second end and electrically coupling the RFID tag to the thermocouple.

40. A method in accordance withclaim 39 and comprising using the probe to define an electrical conductor electrically coupling the RFID tag to the thermocouple.

41. A method in accordance withclaim 39 wherein the RFID tag includes memory, the method comprising logging measurements from the thermocouple, at different times, in the memory.

42. A method of using a plurality of RFID sensor assemblies for sensor use in industrial process control, the method comprising:

providing a plurality of sensors configured to sense at least two of temperature, pressure, and strain;

providing a mechanical package to support at least one of the sensors and define a sensor assembly, the package including a band configured to encircle a fluid conduit; and

supporting an RFID tag by the band, in electrical communication with at least one of the sensors.

43. A method in accordance withclaim 42 wherein the RFID tag includes memory, the method comprising configuring the RFID tag supported by the band to log data, at different times, in the memory from the at least one sensor supported by the band.

44. A sensor method comprising:

providing an RFID tag;

providing a pressure sensor;

providing a band configured to encircle a fluid conduit;

supporting the RFID tag by the band and placing the RFID tag in electrical communication with the pressure sensor.

45. A method in accordance withclaim 44 wherein the RFID tag includes memory and is configured to log data from the pressure sensor in the memory at different times.

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