Pressure sensor embedded in a metering device

Abstract

An exemplary pressure sensing device includes a pipe or conduit having an upstream connector and a downstream connector for respective upstream and downstream transducers to measure the flow of a fluid (e.g., water). The conduit can be at least partially made from an elastically deformable material. The deformable electrode of the capacitor can be attached in contact with the dry side surface of an area of the elastically deformable material. The wet side surface of the area can define a portion of the path for the flow of the fluid. During operation, the area of the elastically deformable material changes the location and / or shape of the deformable electrode in response to a change in the pressure of the fluid. The fixed electrode of the capacitor is separated from the deformable electrode by a dielectric material (e.g., air or an insulator), and the circuit determines the pressure of the fluid based at least in part on the capacitance between the deformable electrode and the fixed electrode.

Description

Technical Field

[0001] Related Applications This application claims priority to U.S. Patent Application No. 17 / 829,162, filed May 31, 2022, entitled "PRESSURE SENSOR EMBEDDED IN A METERING DEVICE," the entire disclosure of which is incorporated herein by reference.

Background Art

[0002] Pressure sensors for measuring water pressure in public utilities are known. However, known pressure sensors have problems that arise when integrated into water meters, including water leakage, excessive cost, and / or excessive power consumption. Accordingly, an improved pressure sensor for metering devices should be welcomed by the industry.

Summary of the Invention

[0003] For a detailed description, reference will be made to the accompanying drawings. In the figures, the leftmost digit of the reference number identifies the figure in which the reference number first appears. The same numbers are used throughout the drawings to refer to similar features and components. Further, the figures are illustrative of general concepts and do not show required and / or necessary elements.

Brief Description of the Drawings

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[0005] Overview The present disclosure describes components and operating techniques for fluid pressure sensing, such as for use in water meters, gas meters, steam meters, or other pressure measurement and / or fluid handling devices. In one example of a static water meter, the measurement device includes a pipe or conduit having upstream and downstream connectors for respective upstream and downstream transducers to measure water flow. A static (i.e., no moving parts) meter measures water flow rate based on the difference in velocity between upstream and downstream acoustic signals in the water flow. The present disclosure is also adapted for use with mechanical water meters or other devices (e.g., pump devices or valves) in a fluid (water, gas, steam, etc.) network and / or supply system. Further, the present disclosure describes the use of an elastically deformable material for attaching the electrodes of a capacitor, although in an alternative, a hole in the pipe or conduit can be used to communicate with a capacitor within the fluid flow. This alternative configuration of components can result in different costs and / or design advantages and disadvantages.

[0006] The conduit can include an area made of an elastically deformable material. The elastically deformable and / or movable electrode of the capacitor can be attached in contact with the dry side surface of the area of the elastically deformable material. The wet side surface of the area of the elastically deformable material can define a portion of the path within the conduit for the fluid flow. During operation, a change in the pressure of the fluid (e.g., water) on the area of the elastically deformable material changes the location and / or shape of the deformable electrode. In one example, a higher fluid pressure will push the deformable and / or movable electrode (i.e., capacitor plate) closer to the electrode at a fixed location, thereby increasing the capacitance between the electrodes. Thus, the capacitor is a variable capacitor having variability based at least in part on the pressure of the fluid (e.g., the pressure of water passing through the conduit of a water meter). In one example, the fixed electrode of the capacitor is separated from the deformable electrode by a dielectric. In this example, the thickness of the electrically insulating dielectric material (dry air, electrical insulator, vacuum, etc.) changes in response to the water pressure.

[0007] A circuit to which a variable capacitor is attached can be configured to determine the pressure of a fluid based at least in part on the capacitance between a deformable electrode and a fixed electrode. In one example, a unipolar astable multivibrator circuit can be attached to the variable capacitor. The circuit can create an output signal, which can be sent to a processor (e.g., a microcontroller, a microprocessor, an application specific integrated circuit, etc.). The processor can be configured to count the pulses of the output signal over time and obtain a value of the frequency of the output signal. The frequency can be mapped to a value of the fluid pressure. The mapping can be performed by accessing a look-up table, evaluating a polynomial or formula, or other techniques indicated by the design requirements.

[0008] Exemplary Systems and Techniques FIG. 1 shows an exemplary water supply system 100. The water supply system generally represents a fluid transfer system that further includes gas, steam, and others. In the exemplary system 100, a central office 102 communicates with a plurality of water meters 106-110 via a network 104. The central office 102 can include one or more computers, servers, memory devices, etc. The network 104 can utilize one or more technologies or standards including those related to common carriers, private systems, commercial cellular systems, radio frequency (RF) systems, or other technologies. In one example, the network 104 can include the Internet. The network 104 can be used to transmit consumption data from the plurality of water meters to the central office 102. Other data such as software updates can request consumption data, and other data can be sent via the network 104. Further, requests for and / or responses including water pressure information can be sent via the network. In one example, the water pressure information can be obtained by one or more of the water meters 106-110 and sent to the central office 102 via the network 104.

[0009] Water meters 106 - 110 represent water meters in the water system 100, which may include thousands of water meters. In one example, the meters may each include a pressure sensor for measuring water pressure at the location of each meter. Water meter 106 represents a meter having a pressure sensor. Processor 112 may be a microprocessor, a microcontroller, an application specific integrated circuit (ASIC), or other processing device. Processor 112 may communicate with memory device 114 via bus 116, wiring, a printed circuit card, or other connectivity device. Memory device 114 may include an operating system 118 that includes appropriate drivers, low-level programs, and other routines, objects, data, and software in known ways.

[0010] The pressure sensing application 120 may perform functions such as determining the frequency of an output signal that is the output from the pressure sensing circuit 124 (e.g., the astable multivibrator circuit of FIG. 4) and associated variable capacitor 126, and mapping the frequency of the signal to a fluid pressure value (e.g., by accessing a look-up table 122 as described in one or more of FIGS. 5 - 8).

[0011] The measurement unit 128 may measure the consumption of fluid for payment billing, for identification of fluid leaks, for use in a fluid conservation program, etc. Exemplary static measurement devices are described with respect to FIGS. 2 and 3. A battery and / or power supply 130 may be used to power the water meter 106. The communication device 132 may include one or more of wireless, an antenna, a power line communication modem, a data port, or a user interface (e.g., for manual meter reading).

[0012] Figure 2 shows an exemplary measurement unit 128 of a water meter configured to measure flow rate and fluid pressure. The measurement unit 128 includes a conduit 200 of a certain length having an upstream connector 202 and a downstream connector 204 for fixing an upstream transducer 206 and a downstream transducer 208, respectively. The transducers measure the flow rate of the water flow 210 (moving from left to right in this example). In this example, the upstream transducer 206 reflects off an upstream mirror 214, travels a known fixed distance, then reflects off a downstream mirror 216 and sends a signal 212 detected by the downstream transducer 208. Similarly, the downstream transducer 208 reflects off the downstream mirror 216, travels a known fixed distance, then reflects off the upstream mirror 214 and sends a signal 218 detected by the upstream transducer 206. Calculations are performed using the flight time of the signal 212 moving downstream and the flight time of the upstream signal 218, thereby determining the flow rate of the fluid flow 210.

[0013] The variable capacitor 126 is connected to or located adjacent to the conduit 200. In one example, the variable capacitor 126 includes a deformable electrode 220 and a fixed electrode 222. The two electrodes are separated by a dielectric 226 which, in some examples and / or implementations, has a variable thickness. In a typical example, the "fixed" electrode has a fixed location and / or shape. The fixed electrode 222 is fixed in a planar form and can be supported by a rigid backing material 224 such as rigid plastic, resin, or metal or other suitable material.

[0014] In one example, a change in the location and / or shape of the deformable electrode 220 changes the thickness of the dielectric 226 and / or the distance between the two electrodes. In an example, the dielectric 226 can be dry air, compressible foam, some conventional dielectric materials, a vacuum, or other electrical insulators and / or other materials. Due to the deformable nature of the deformable electrode 220, the distance between the two electrodes 220, 222 changes in response to a change in water pressure. Also, since the distance changes, the capacitance of the variable capacitor 126 changes.

[0015] In one example where the water pressure is increased, the higher water pressure can push the deformable electrode 220 closer to the fixed electrode 222, thereby increasing the capacitance of the variable capacitor 126. (This can be seen by comparing FIGS. 2 and 3.) In one example where the water pressure is decreased, the lower water pressure can cause an increase in the distance of the deformable electrode 220 from the fixed electrode 222, thereby decreasing the capacitance of the variable capacitor 126.

[0016] During operation, the pressure of the fluid (e.g., water) moving through the conduit presses against the area 228 of the conduit formed from an elastically deformable material. The pressure changes the location of the deformable electrode 220 and / or its shape. By changing the spatial relationship between the deformable electrode 220 and the fixed electrode 222, the capacitance of the variable capacitor 126 is changed. Different values of capacitance can be mapped to different water pressure values.

[0017] The enlarged view of FIG. 2A shows an exemplary configuration of the variable capacitor 126 embedded in a metering device in a low-pressure state, where the water pressure is not acting on the inner surface of the conduit 200 with sufficient force to push the deformable electrode 220 closer to the fixed electrode 222. That is, the area 228 of the deformable material does not deform, and the variable capacitor 126 is configured to have a minimum level of capacitance. Thus, FIG. 2A shows a configuration related to the minimum value of the pressure that can be measured.

[0018] In FIG. 2A, the deformable electrode 220 is attached to the dry side surface 234 of the elastically deformable material area 228 of the conduit 200. The elastically deformable material area 228 is characterized by its flexibility in response to changes in water pressure. In response to water pressure, the elastically deformable material is stretched, pushed, or relocated, thereby allowing a change in water pressure and resulting in a change in the shape and / or location of the deformable electrode 220 relative to the fixed electrode 222. Advantageously, the elastically deformable material area 228 does not have any holes, paths, gaskets, seals, and / or any other structures that can cause leakage over time.

[0019] Wire 230 (or a similar conductor) is connected to the deformable electrode 220, and wire 232 (or a similar conductor) is connected to the fixed electrode 222. The wires 230, 232 of the capacitor 126 can be connected to a circuit that generates an output signal based at least in part on the capacitance of the variable capacitor 126.

[0020] In one example, the elastically deformable material area 228 may be non-conductive (e.g., if it is made from a polymer, etc.). However, the deformable electrode 220 can be applied to the elastically deformable material area 228 by any suitable technique such as metal deposition, painting process, inkjet, etc. If the deformable electrode 220 is a sheet material, it can be applied and / or fixed to the elastically deformable material area 228 by the use of an adhesive.

[0021] Figure 3 shows an exemplary measurement unit 128 of a water meter configured to measure flow rate and fluid pressure in a situation where the pressure of water is higher than the water pressure seen in Figure 2. Thus, a comparison between Figure 2 and Figure 3 shows that the area 228 of the elastically deformable material is flexed, arched, and / or deformed in a manner that the deformable electrode 220 moves to a position closer to the fixed electrode 222 than it was in the view of Figure 2. As the electrodes move closer to each other, the capacitance of the variable capacitor becomes larger, resulting in an increased frequency of the output signal from a circuit that generates an output signal based at least in part on the variable capacitor, such as the unipolar astable multivibrator circuit 400 of Figure 4.

[0022] Figure 3A shows an enlarged view of the area 228 of the elastically deformable material that is pushed upward, thereby moving the deformable electrode 220 to a position closer to the fixed electrode 222. The area of the dielectric 226 is reduced in response to the movement of the deformable electrode 220. Thus, the value of the capacitance of the variable capacitor 126 increases.

[0023] Figure 3B shows a variable capacitor 300 configured to decrease capacitance as the fluid pressure increases and increase capacitance as the fluid pressure decreases. Different from the versions of the variable capacitor in Figures 3 and 3A, the capacitance of the variable capacitor 300 varies inversely with the fluid pressure. The variable capacitor 300 may include an area 302 of a conductor formed from an elastically deformable material that supports a deformable electrode 304. A second area 306 of the conductor is formed from a rigid material and supports a fixed electrode 308. A passage 310 allows fluid within an area 312 between the deformable electrode 304 and the fixed electrode 308.

[0024] FIG. 4 shows an exemplary circuit 400 in which an output signal can be created, and the characteristics of the output signal are at least partially based on the capacitance of variable capacitor 126. The exemplary circuit 400 is a unipolar astable multivibrator circuit. Other circuits can be used as alternatives to generate the output signal based on the capacitance of variable capacitor 126. In a second example, the capacitor can be connected to an astable multivibrator circuit. In a third example, the capacitor can be connected to an oscillator circuit having a frequency that is at least partially based on the capacitance of the capacitor. In a fourth example, the capacitor can be connected to an oscillator circuit having one or more characteristics that are at least partially based on the capacitance of the capacitor. Such characteristics can include aspect ratio, frequency, or others. In a fifth example, the capacitor can be connected to any circuit configured to create an output signal having one or more characteristics that are at least partially based on the capacitance of the circuit.

[0025] FIG. 4 shows an exemplary circuit 400 that receives as input the capacitance from variable capacitor 126 and creates an output signal 402. In one example, the value of the capacitance of variable capacitor 126 of FIGS. 1 - 3 is at least partially based on (e.g., correlated with) the pressure of the fluid (e.g., water) in conduit 200 of water meter 106. Thus, since the capacitance of variable capacitor 126 is correlated with the water pressure, the frequency of output signal 402 is also correlated with the pressure of the water in fluid flow 210 through conduit 200 of water meter 106. By counting the signal pulses 404 of the output signal per unit of time (e.g., per second), a processor (e.g., processor 112 of FIG. 1) can acquire the frequency of output signal 402. The frequency can be used to determine the pressure of water flow 210. In one example, the processor can access a look-up table and / or evaluate a function to obtain the pressure value.

[0026] The exemplary circuit 400 represents a circuit that generates an output signal having a characteristic that is at least partially based on the capacitance of the variable capacitor 126. The output signal characteristic need not represent the microfarad (uF) or picofarad (pF) value of the variable capacitor at a given point in time. Instead, the output characteristic (e.g., frequency) is used by a mapping function that inputs the value of the characteristic and maps that value to a water pressure value. Thus, the mapping is used to determine the water pressure associated with each output frequency value (or range of frequencies) of the circuit 400. Depending on the particular design characteristics of the circuit used, an appropriate look-up table is designed to map the frequency (or other characteristic) of the output signal to a water pressure value (or range of values).

[0027] In the exemplary circuit 400, an operational amplifier 406, several resistors 408 - 414, and ground connections 416, 418 are used. The exemplary circuit 400 using the operational amplifier 406 provides a particular design, component placement, and electrical connection to enable full use of the systems, methods, and techniques described herein. However, in a second, more generalized example, a voltage comparator may be used in a circuit having appropriate connections, components, and design for a particular system. In either implementation, an output signal 402 is created that correlates to the pressure of the fluid flow 210 passing through the conduit 200 of the water meter 106. An appropriate look-up table is designed depending on the nature of the capacitor, circuit, and resulting output signal, and / or other factors.

[0028] Exemplary method In some examples of the techniques described herein, the method of operation can be implemented by one or more application specific integrated circuits (ASICs) or by a general purpose processor utilizing software defined in a computer readable medium. In the examples and techniques described herein, memory 114 can comprise a computer readable medium and can take the form of volatile memory such as random access memory (RAM) and / or non-volatile memory such as read only memory (ROM) or flash RAM. A computer readable medium device includes volatile and non-volatile media, removable media, and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules, or other data for execution by one or more processors of a computing device. Examples of computer readable media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read only memory (ROM), electrically erasable programmable read only memory (EEPROM), flash memory or other memory technologies, compact disc read only memory (CD-ROM), digital versatile disc (DVD) or other optical storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other non-transitory media that can be used to store information accessible by a computing device.

[0029] As defined herein, a computer readable medium does not include transitory media such as modulated data signals and carrier waves, and / or signals.

[0030] In one example, a processor 112 that uses instructions (e.g., pressure sensing application 120) obtained from a memory device 114 is configured to perform the operations illustrated by FIGS. 5 through 8. The processor 112 can include a microprocessor and memory, an FPGA, and / or one or more integrated circuits, and the instructions can be stored in memory or implemented in a hardware circuit.

[0031] Computer-readable instructions stored on one or more non-transitory computer-readable storage media can, when executed by one or more processors, perform the operations described above with respect to FIGS. 5 through 8 described below. Generally, computer-readable instructions include routines, programs, objects, components, data structures, etc. that perform a particular function or implement a particular abstract data type. The order in which the operations are described should not be construed as limiting, and any number of the described operations can be combined in any order and / or in parallel to implement the process.

[0032] FIG. 5 shows an exemplary method 500 for operating a pressure sensing device of a metering device such as metering device 106 of FIG. 1. In one example, the operations can be performed by a processor 112 that uses the instructions of the pressure sensing application 120 of FIG. 1. In other examples, other devices and / or software objects can be used. Accordingly, FIGS. 5 through 8 show exemplary methods for operating devices such as those shown in FIGS. 1 through 3A, but are not limited to the operation of such devices.

[0033] In block 502, the flow of water is received through the path of the metering device. In the example of block 504, the path is partially defined by an area of an elastically deformable material. In the example of block 506, the water pressure against the wet side surface of the area of the elastically deformable material moves the deformable electrode of the capacitor relative to a fixed second electrode. In the example of FIG. 2, water presses against area 228 of the condit which is elastically deformable. This adjusts the location of the deformable electrode 220 relative to the fixed electrode 222, thereby adjusting the capacitance of the variable capacitor.

[0034] In block 508, an output signal is generated, and the output signal is at least partially based on the capacitance of the capacitor. In the example of block 510, the frequency of the output signal is determined. In the example, the output signal is at least partially based on the capacitance between the deformable electrode and the fixed electrode. Referring to the example of FIG. 4, the unipolar astable multivibrator circuit 400 generates such an output signal.

[0035] In block 512, the operation of the processor determines the frequency of the output signal. In the example of FIG. 1, the processor 112 receives the output signal as an input from the astable multivibrator circuit during the listening period. The processor 112 determines the frequency of the signal by counting the signal pulses over the listening period. In a further example for power saving, two listening periods can be separated by a quiescent period.

[0036] In block 514, the value of the water pressure is determined. The value can be at least partially based on the frequency. In the example of block 516, the frequency is mapped to the associated pressure of the water, such as by use of a look-up table, an evaluated formula, and / or a polynomial. That is, each frequency and / or range of frequencies is mapped to a water pressure and / or range of water pressures. In the example of FIG. 1, the processor 112 that determined the frequency of the output signal examines the look-up table 122 to determine the pressure associated with the frequency.

[0037] FIG. 6 is a flow diagram showing an exemplary detail of block 508 of FIG. 5. Thus, FIG. 6 shows two examples where an appropriate output signal may be generated, and the output signal is at least partially based on the capacitance of the capacitor. In the example of block 600, the output signal may be generated by the operation of a unipolar astable multivibrator circuit. In one example, the unipolar astable multivibrator circuit may be constructed in a manner similar to circuit 400 of FIG. 4. In the example of block 602, the unipolar astable multivibrator circuit receives a first lead wire from the deformable electrode of the capacitor and a second lead wire from the fixed location electrode of the capacitor. In this example, neither the first lead wire nor the second lead wire passes through an elastically deformable material. This is advantageous because the possibility of leakage in the area of the conductor and / or the elastically deformable material of the conductor is significantly reduced. In the example of FIG. 2, the area 228 of the elastically deformable material allows the water pressure to push against the deformable electrode 220 without allowing water to contact the variable capacitor 126.

[0038] FIG. 7 shows an exemplary detail of block 512 of FIG. 5. Thus, FIG. 7 shows two examples where the operation of the processor determines the frequency of an output signal generated by a circuit such as an astable multivibrator circuit that receives an input from a variable capacitor. In the example of block 700, the processor counts the pulses of the output signal during a first time period. In the example, the processor may count the pulses of the output signal for fractions of a second, one second, or multiple seconds. In the example of block 702, a pause period may be timed and then the pulses are counted. In this example, the water pressure may be measured periodically, intermittently, at intervals, etc. The periods during which the measurements are made may be interleaved with periods during which power is conserved.

[0039] FIG. 8 shows an exemplary detail of block 514 of FIG. 5. Thus, FIG. 8 shows an example where the value of the water pressure is determined at least in part based on the frequency of the output signal. In the example of block 800, a look-up table that maps the frequency of the output signal to the water pressure value can be accessed by a processor. In the example of FIG. 1, processor 112 uses look-up table 122 to map the frequency of the output signal to the water pressure value.

[0040] Exemplary Systems and Devices The following examples of pressure sensors embedded in metering devices are presented as numbered clauses. While the examples illustrate some possible configurations and techniques, they are not meant to be an exhaustive list of the systems, methods, and / or techniques described herein.

[0041] 1. A metering device comprising a conduit defining an upstream connector for an upstream transducer and a downstream connector for a downstream transducer, the conduit being at least partially made of an elastically deformable material, the conduit, a deformable electrode of a capacitor, the deformable electrode being attached in contact with a dry-side surface of an area of the elastically deformable material of the conduit, a wet-side surface of the area of the elastically deformable material defining a portion of a path for the flow of water, the area of the elastically deformable material being configured to change the location and shape of the deformable electrode in response to a change in water pressure, the deformable electrode of the capacitor, a fixed electrode of the capacitor, the fixed electrode being separated from the deformable electrode by a dielectric material, the fixed electrode of the capacitor, and a circuit for determining the water pressure based at least in part on the capacitance between the deformable electrode and the fixed electrode. In one example, a water meter has a variable capacitor located on the dry side of a conduit made of an elastically deformable material. No perforations, gaskets, and / or O-rings are required. Instead, the area of the conduit "flexes" or "deforms" slightly in response to water pressure. The change in water pressure causes a change in capacitance due to the movement of the area of the elastically deformable material of the conduit to which the electrodes (e.g., "plates") of the capacitor are attached.

[0042] 2. The elastically deformable material is the metering device according to clause 1 that forms a waterproof barrier without a port between the water flow path and the capacitor. In one example, the elastically deformable material of the conduit forms a waterproof barrier between the water flow path and the capacitor. Thus, holes, gaskets, fasteners, etc. that may leak (between the wet side and the dry side) are not required.

[0043] 3. The capacitance between the deformable electrode and the fixed electrode is a variable and is the metering device according to one or more of the preceding clauses that is at least partially based on the properties of the elastically deformable material of the conduit. In one example, the capacitance is a variable capacitance that is at least partially based on the water pressure and at least partially based on the shape and location of the deformable electrode. In other examples, the look-up table will link or map the variable capacitance to the water pressure.

[0044] 4. The metering device according to one or more of the preceding clauses further comprising a fixed backing material for supporting the fixed electrode. In an exemplary feature, the fixed electrode is held in a fixed location while the deformable electrode moves in response to a change in water pressure.

[0045] 5. The elastically deformable material is configured to move the deformable electrode closer to the fixed electrode as the water pressure increases and to move the deformable electrode farther from the fixed electrode as the water pressure decreases, which is the metering device according to one or more of the preceding clauses. In one example, the elastically deformable material is configured to assume a'relaxed' state at a lower water pressure that separates the electrodes and results in less capacitance. Higher water pressure applies stress to the deformable material and increases the capacitance as the electrodes (or plates) of the capacitor move closer together. Such a configuration can be reversed with appropriate changes to the mapping function or look-up table.

[0046] 6. The circuit is a metering device according to one or more of the preceding clauses, comprising an astable multivibrator circuit for outputting an output signal based at least in part on a capacitance, and a processor for receiving the output signal and determining the water pressure. In one example, the deformable electrode and the fixed electrode are connected to the circuit, which creates an output having a frequency (or other information transmission means) related to the water pressure.

[0047] 7. The circuit is a metering device according to one or more of the preceding clauses, comprising a comparator or operational amplifier connected to at least one electrode of a capacitor for creating an output signal, the output signal being based at least in part on the capacitance between the deformable electrode and the fixed electrode, and a processor for receiving the output signal and determining the water pressure based at least in part on the frequency of the output signal. In one example, such alternative implementations regarding the details of the circuit are possible and consistent with the concepts set forth herein.

[0048] 8. The circuit is a metering device according to one or more of the preceding clauses, comprising a memory device including a look-up table, and a processor for receiving the output signal, determining the frequency of the output signal based at least in part on the capacitance between the deformable electrode and the fixed electrode, and using the frequency and the look-up table to determine the water pressure. In one possible version, the look-up table is used to map or link the capacitance between the deformable electrode and the fixed electrode to the water pressure.

[0049] 9. The circuit includes a processor and a memory device. When the instructions on the memory device are executed by the processor, the metering device is caused to determine the frequency of an output signal, where the output signal is at least partially based on the capacitance between a deformable electrode and a fixed electrode, and to perform an action including mapping the frequency to the water pressure, as described in one or more of the preceding clauses. In one example, the processor receives a signal, determines the frequency of the signal, and then "maps" the frequency to the pressure (e.g., using a look-up table or polynomial evaluation).

[0050] 10. The circuit includes a processor and a memory device. When the instructions on the memory device are executed by the processor, the metering device is caused to input a signal from an unstable multivibrator circuit during a listening period, where two listening periods are separated by a quiescent period, to determine the frequency of the signal, and to determine the water pressure from a look-up table based at least in part on the frequency of the signal, as described in one or more of the preceding clauses. In one example, the processor inputs signals at intervals (e.g., using a 100 ms listening period), determines the frequency, and then "maps" the frequency to the pressure.

[0051] 11. A method of operating a metering device, the method including receiving a flow of water through a path of the metering device, where the path is partially defined by an area of an elastically deformable material and the water pressure against the wet side surface of the area of the elastically deformable material moves a deformable electrode of a capacitor, generating an output signal, where the output signal is at least partially based on the capacitance of the capacitor, determining the frequency of the output signal by operation of a processor, and determining a value of the water pressure based at least in part on the frequency. In one example, the circuit and / or processor performs an action enabling measurement of the water pressure.

[0052] 12. Determining the value of the water pressure includes accessing a look-up table that maps the frequency of the output signal to the water pressure value, the method according to claim 11. In one example, the processor determines the water pressure using a look-up table that maps pressure to frequency.

[0053] 13. Determining the frequency of the output signal includes counting the pulses of the output signal during a first time period and, following the counting of the pulses, timing a pause period, the method according to one or more of the preceding clauses. In one example, counting the pulses by the processor can be alternated with a pause period to save power.

[0054] 14. Generating the output signal includes generating the output signal by the operation of a unipolar astable multivibrator circuit, the method according to one or more of the preceding clauses. In one example, generating the output signal can be generated by the operation of a unipolar astable multivibrator circuit. In other examples, other circuits can be used.

[0055] 15. Generating the output signal includes receiving, in a unipolar astable multivibrator circuit, a first lead wire from a deformable electrode of a capacitor and a second lead wire from a fixed location electrode of the capacitor, wherein neither the first lead wire nor the second lead wire passes through an area of an elastically deformable material, the method according to one or more of the preceding clauses. In one example, the capacitor is on the dry side and there are no holes, gaskets, paths, fasteners, etc. on the wet side.

[0056] 16. A pressure sensing device for a metering device, comprising a deformable electrode of a capacitor, the deformable electrode being attached in contact with a dry side surface of an area of an elastically deformable material, the elastically deformable material defining at least a portion of a path that includes a flow of water to be measured by the metering device, the area of the elastically deformable material being configured to change the location and shape of the deformable electrode in response to a change in water pressure, a deformable electrode of the capacitor; a fixed electrode of the capacitor, the fixed electrode being held in a fixed location, the fixed electrode being separated from the deformable electrode by a dielectric material, a fixed electrode of the capacitor; and a circuit that determines the water pressure based at least in part on the capacitance between the deformable electrode and the fixed electrode. In one example, the pressure sensing device includes two electrodes and a circuit.

[0057] 17. The pressure sensing device according to one or more of the preceding clauses, wherein the elastically deformable material is configured to move the deformable electrode closer to the fixed electrode as the water pressure increases and to move the deformable electrode farther from the fixed electrode as the water pressure decreases. In one example, the capacitance changes as the pressure changes.

[0058] 18. The pressure sensing device according to one or more of the preceding clauses, wherein the dielectric material is configured to allow a change in the distance between the deformable electrode and the fixed electrode while still electrically insulating the deformable electrode from the fixed electrode. In one example, the dielectric material (e.g., air or some elastically deformable electrical insulating material) allows the deformable electrode to move relative to the fixed electrode in response to a change in water pressure.

[0059] 19. The pressure sensing device according to one or more of the preceding clauses configured to change the location and shape of the deformable electrode in response to a change in water pressure from 30 to 80 psi (206.8 to 551.6 kPa). In one example, the elastically deformable material is configured to change the location and / or shape of the deformable electrode in response to a change in pressure from 30 to 80 psi (206.8 to 551.6 kPa) (or other ranges of water pressure) associated with the water supply system. That is, pressure measurement is possible over at least the pressure range used by the utility company.

[0060] 20. The area of the elastically deformable material is the pressure sensing device according to one or more of the preceding clauses comprising a wet side surface in contact with the water flow and a fixed adhesive connecting the deformable electrode to the elastically deformable material. In one example, the area of the elastic deformability of the material includes a wet side surface in contact with the water flow and a dry side surface in contact with the deformable electrode. The elastically deformable material can prevent leakage between the wet side and the dry side.

[0061] Conclusion Although the subject matter has been described in terms of words specific to structural features and / or methodological acts, it should be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described. Rather, the specific features and acts are disclosed as exemplary forms for implementing the claims.

[0062] The terms "comprise", "comprises", and / or "comprising" when used in this specification and / or the claims specify the presence of the stated features, devices, techniques, and / or components. The terms do not preclude the presence or addition of one or more other features, devices, techniques, and / or components and / or groups thereof.

Claims

1. A metering device comprising: a conduit defining an upstream connector for an upstream transducer and a downstream connector for a downstream transducer, the conduit being at least partially made of an elastically deformable material; a deformable electrode of a capacitor, the deformable electrode being attached in contact with a dry-side surface of the area of the elastically deformable material of the conduit, the wet-side surface of the area of the elastically deformable material defining a portion of a path for the flow of water, the area of the elastically deformable material being configured to change the location and shape of the deformable electrode in response to a change in water pressure; a fixed electrode of the capacitor, the fixed electrode being separated from the deformable electrode by a dielectric material; and a circuit for determining the water pressure based at least in part on the capacitance between the deformable electrode and the fixed electrode. A metering device.

2. The elastically deformable material forms a waterproof barrier between the path of the water flow and the capacitor without a port therebetween. The metering device according to claim 1.

3. The capacitance between the deformable electrode and the fixed electrode is variable and is based at least in part on the properties of the elastically deformable material of the conduit. The metering device according to claim 1.

4. The metering device according to claim 1, further comprising a fixed backing material for supporting the fixed electrode. The metering device according to claim 1.

5. The elastically deformable material is configured to: move the deformable electrode closer to the fixed electrode as the water pressure increases; and move the deformable electrode farther from the fixed electrode as the water pressure decreases. The metering device according to claim 1.

6. The circuit comprises: an astable multivibrator circuit for outputting an output signal based at least in part on the capacitance; and a processor for receiving the output signal and determining the water pressure. The metering device according to claim 1.

7. The circuit comprises: ​ ​ A comparator or operational amplifier connected to at least one electrode of the capacitor to create an output signal, wherein the output signal is at least partially based on the capacitance between the deformable electrode and the fixed electrode, the comparator or operational amplifier, A processor that receives the output signal and determines the pressure of the water based at least in part on the frequency of the output signal Comprising The metering device according to claim 1.

8. The circuit is A memory device including a look-up table, A processor that receives an output signal, determines the frequency of the output signal based at least in part on the capacitance between the deformable electrode and the fixed electrode, and uses the frequency and the look-up table to determine the pressure of the water Comprising The metering device according to claim 1.

9. The circuit includes a processor and a memory device, and the instructions on the memory device, when executed by the processor, cause the metering device to Determine the frequency of an output signal, wherein the output signal is at least partially based on the capacitance between the deformable electrode and the fixed electrode, Map the frequency to the pressure of the water Perform actions including The metering device according to claim 1.

10. The circuit includes a processor and a memory device, and the instructions on the memory device, when executed by the processor, cause the metering device to Input a signal from an unstable multivibrator circuit during a listening period, wherein two listening periods are separated by a quiescent period, Determine the frequency of the signal, Determine the pressure of the water from a look-up table based at least in part on the frequency of the signal Perform actions including The metering device according to claim 1.

11. A method of operating a metering device, comprising: Receiving a flow of water through a path of the metering device, the path being partially defined by an area of an elastically deformable material, and the water pressure on the wet side surface of the area of the elastically deformable material moving the deformable electrode of the capacitor; Generating an output signal, the output signal being at least partially based on the capacitance of the capacitor; Determining the frequency of the output signal by operation of a processor; Determining the value of the water pressure based at least in part on the frequency; A method comprising the above steps.

12. The step of determining the value of the water pressure includes accessing a look-up table that maps the frequency of the output signal to a water pressure value. The method according to claim 11. The method according to claim 11.

13. The step of determining the frequency of the output signal includes counting the pulses of the output signal during a first time period, and timing a pause period following the step of counting the pulses. The method according to claim 11. The method according to claim 11. The method according to claim 11.

14. The step of generating the output signal includes generating the output signal by operation of a unipolar astable multivibrator circuit. The method according to claim 11. The method according to claim 11.

15. The step of generating the output signal includes, in a unipolar astable multivibrator circuit, receiving a first lead wire from a deformable electrode of the capacitor and a second lead wire from a fixed location electrode of the capacitor, wherein neither the first lead wire nor the second lead wire passes through the area of the elastically deformable material. The method according to claim 11. The method according to claim 11.

16. A pressure sensing device for a metering device, comprising a deformable electrode of a capacitor, wherein the deformable electrode is attached in contact with a dry side surface of an area of elastically deformable material, the elastically deformable material defining at least a portion of a path that includes a flow of water to be measured by the metering device, and the area of the elastically deformable material is configured to change the location and shape of the deformable electrode in response to a change in water pressure; a deformable electrode of the capacitor; a fixed electrode of the capacitor, wherein the fixed electrode is held in a fixed location and is separated from the deformable electrode by a dielectric material; a fixed electrode of the capacitor; and a circuit for determining the pressure of the water based at least in part on the capacitance between the deformable electrode and the fixed electrode. A pressure sensing device. A pressure sensing device.

17. The elastically deformable material moves the deformable electrode closer to the fixed electrode as the water pressure increases. Moving the deformable electrode away from the fixed electrode as the water pressure decreases configured to perform The pressure sensing device according to claim 16.

18. The dielectric material is configured to allow a change in the distance between the deformable electrode and the fixed electrode while still electrically insulating the deformable electrode from the fixed electrode. The pressure sensing device according to claim 16.

19. The elastically deformable material is configured to change the location and shape of the deformable electrode in response to a change in water pressure from 30 to 80 psi (206.8 to 551.6 kPa). The pressure sensing device according to claim 16.

20. The area of the elastically deformable material a wet side surface in contact with the flow of water, a fixed adhesive connecting the deformable electrode to the elastically deformable material comprising The pressure sensing device according to claim 16.

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