NZ767986A - Water meter and systems - Google Patents
Water meter and systemsInfo
- Publication number
- NZ767986A NZ767986A NZ767986A NZ76798617A NZ767986A NZ 767986 A NZ767986 A NZ 767986A NZ 767986 A NZ767986 A NZ 767986A NZ 76798617 A NZ76798617 A NZ 76798617A NZ 767986 A NZ767986 A NZ 767986A
- Authority
- NZ
- New Zealand
- Prior art keywords
- sensor
- processor
- meter
- vibration
- flow
- Prior art date
Links
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Landscapes
- Measuring Volume Flow (AREA)
Abstract
Some embodiments relate to a water meter sensor. The vibration sensor comprises: a flow tube defining a lumen to receive water through the lumen, wherein the flow tube is configured to be coupled to a water supply network; a housing coupled to the flow tube and containing a self-contained power source, at least one processor, a memory and a wireless transceiver; a flow sensor positioned to measure liquid flow through the lumen and coupled to the at least one processor to provide flow measurement signals to the at least one processor; and a vibration sensor arranged to sense vibration in a material of the flow tube and coupled to the at least one processor to provide vibration measurement signals to the at least one processor, the vibration sensor comprising a piezoelectric transducer and is arranged to abut the flow tube without extending into the lumen; wherein the at least one processor is configured to process the flow measurement signals and the vibration measurements signals and to determine an upstream liquid leakage status based on at least the vibration measurement signals; wherein the at least one processor is configured to transmit the upstream liquid leakage status and flow measurement signals to a remote server wherein the vibration sensor comprises a sensor base positioned proximal to the flow tube, at least one transducer or transducer substrate coupled to the sensor base, and a seismic weight coupled to the sensor base distal of the at least one transducer or transducer substrate, and wherein the at least one processor receives the vibration measurement signals based on electrical outputs from the at least one transducer or transducer substrate.
Description
"Water Meter and Systems"
This is a divisional of New Zealand Patent Application No. 752668, the originally filed
ication of which is incorporated herein by reference in its entirety.
Technical Field
Embodiments generally relate to vibration sensors. Particular embodiments
relate to vibration sensors for fluid leak detection, optionally in combination with a water
meter, and to systems and methods employing such ion sensors.
Background
Domestic and ss premises ly rely on a source of water for various
purposes. For water usage tracking purposes, such premises commonly have a water
meter positioned to meter the amount of water flowing in a supply line to the premises.
[0003] In nearby fluid conduits, leaks can occur. Some such leaks can be minor and
have minimal consequences, while other leaks can be significant and/or have icant
consequences if they are not identified early and ed.
Some prior techniques of fluid leakage detection in fluid conduits, such as water
mains, have needed maintenance personnel to periodically attend the site of suspected
leaks around a water supply network and be present at the site for significant periods
while using cumbersome and/or costly listening devices. Such techniques may
sometimes take years to effectively monitor and determine leaks with in a water supply
network. The engagement of such leak ion services can represent a significant cost
to water utilities.
[0005] It is desired to address or rate one or more shortcomings or disadvantages
of prior vibration sensors, leak detection devices or leak detection techniques, or to at
least e a useful alternative thereto.
Any discussion of documents, acts, materials, devices, articles or the like which
has been included in the present specification is not to be taken as an admission that any
or all of these matters form part of the prior art base or were common general knowledge
in the field relevant to the present disclosure as it existed before the priority date of each
claim of this application.
Throughout this specification the word "comprise", or ions such as
"comprises" or "comprising", will be tood to imply the inclusion of a stated
element, integer or step, or group of elements, integers or steps, but not the exclusion of
any other element, integer or step, or group of elements, integers or steps.
y
According to an aspect of the present invention, there is provided a water
meter, comprising:
a flow tube defining a lumen to receive water through the lumen, wherein the
flow tube is configured to be coupled to a water supply network;
a housing coupled to the flow tube and containing a self-contained power source,
at least one processor, memory and a ss transceiver;
a flow sensor positioned to measure liquid flow through the lumen and coupled
to the at least one processor to provide flow ement signals to the at least one
processor; and
a vibration sensor arranged to sense vibration in a material of the flow tube and
coupled to the at least one processor to provide vibration ement signals to the at
least one processor, the vibration sensor comprising a piezoelectric transducer and is
ed to abut the flow tube without extending into the lumen;
wherein the at least one processor is configured to s the flow measurement
signals and the ion measurements signals and to determine an upstream liquid
leakage status based on at least the vibration ement signals;
wherein the at least one processor is configured to transmit the upstream liquid
leakage status and flow ement signals to a remote server, wherein the vibration
sensor comprises a sensor base positioned proximal to the flow tube, at least one
transducer or transducer substrate coupled to the sensor base, and a seismic weight
coupled to the sensor base distal of the at least one transducer or ucer substrate,
and wherein the at least one processor receives the vibration measurement signals based
on electrical outputs from the at least one ucer or transducer substrate.
According to another aspect of the present ion, there is provided a water
supply system, comprising:
a network of water supply conduits;
a plurality of water meters of any one of the preceding claims coupled to the
network at spaced water supply endpoints; and
the remote server, wherein the remote server is configured to generate a leakage
notification when the upstream liquid leakage status of at least one of the meters indicates
detection of an upstream liquid leak.
According to a further aspect of the present invention, there is provided a
system configured to determine leakage in a water supply network, comprising:
a network of fluid supply conduits;
a plurality of water meters according to any one of claims 1 to 18 coupled to
the k at spaced water supply endpoints, each water meter configured to take
sensor readings of one or more local conditions at the respective water meter and to
communicate a data payload to an external , the data payload including
information based on the sensor readings; and
a remote server to receive the data payloads from the water meters, wherein
the remote server is configured to generate a e notification when the information
indicates a leakage in the water supply network.
[0011] According to a further aspect of the present invention, there is provided a
method of leakage detection in a fluid supply network, comprising,
ing at a water meter according to any one of claims 1 to 18, coupled at a
supply int of fluid supply network, ions propagated from fluid ts
that form part of the fluid supply network;
determining a leakage status based at least in part on the ions; and
notifying a remote server of the leakage status..
Brief Description of the Drawings
Figure 1 is a block diagram of a fluid ng system according to some
embodiments;
[0013] Figure 2 is a further block diagram of the fluid metering system;
Figure 3 is a schematic diagram in cross-section of a water meter according to
some embodiments;
Figure 4 is a flowchart of a method of operating a fluid meter according to some
embodiments;
[0016] Figure 5 is a schematic m of a vibration sensor according to some
embodiments;
Figure 6 is a flowchart of a method of leakage determination according to some
embodiments;
Figure 7 is an example frequency um of a signal output of a vibration
sensor according to some embodiments;
Figure 8 is a schematic cross-sectional representation of a vibration sensor
ing to some embodiments;
Figure 9 is a perspective partial cut-away view of a vibration sensor according
to some embodiments, where the sensor is positioned in relation to a fluid conduit
forming part of a fluid meter assembly;
Figure 10 is an exploded ctive view of the vibration sensor shown in
Figure 9;
Figure 11 is a perspective partial cut-away view of a vibration sensor
according to further embodiments, shown positioned in relation to a fluid conduit of a
fluid meter assembly;
Figure 12A is a top perspective view of a vibration sensor according to further
embodiments;
Figure 12B is a bottom perspective view of the vibration sensor of Figure 12A;
Figure 12C is a top view of the vibration sensor of Figure 12A;
Figure 12D is a side elevation view of the vibration sensor of Figure 12A,
shown in l cross-section taken along line A-A of Figure 12C;
[0027] Figure 13 is a tic diagram of electrical components of vibration sensors
according to various embodiments, shown in communication with a separate processing
device of a fluid meter assembly;
Figure 14 is a schematic circuit diagram of ue front-end circuitry for
ioning output signals received from a piezoelectric transducer of the vibration
sensor of some embodiments;
Figure 15A is a flowchart of part of a method leak detection according to some
embodiments;
Figure 15B is a flowchart of the rest of the method shown in Figure 15A;
Figure 16A is a art of part of a method leak detection according to some
embodiments;
Figure 16B is a flowchart of the rest of the method shown in Figure 16A;
Figure 17 is an exploded perspective view of a vibration sensor according to
further embodiments;
Figure 18 is a perspective view of a printed circuit board and piezoelectric
transducer positioned ve to a base plate of the ion sensor of Figure 17;
[0035] Figure 19 is a cross-sectional side view of parts of the vibration sensor of
Figure 17, showing flexible printed circuitry covering part of the piezoelectric
transducer within the seismic weight;
Figure 20A is a plan view of a flexible printed t component for use with
the vibration sensor embodiments of Figure 17, shown in an unfolded configuration;
[0037] Figure 20B is a side elevation view of the flexible printed circuit component of
Figure 20A, shown in a folded configuration, in which it would normally at least
partially surround a cylindrical piezoelectric transducer;
Figure 21A is a back view of a printed circuit comprising the flexible printed
circuit component of Figures 20A and 20B in combination with a printed circuit board
for use in the vibration sensor embodiments shown in Figure 17;
Figure 21B is a front view of the printed circuit of Figure 21A; and
Figure 22 is a schematic t diagram of an alternative printed circuit board
assembly.
Detailed Description
Some embodiments generally relate to fluid meters, such as water meters, and
to s and methods ing such fluid meters. Some embodiments generally
relate to vibration sensors. Particular ments relate to vibration sensors for fluid
leak detection, optionally in combination with a water meter, and to systems and methods
employing such vibration sensors.
Referring in particular to Figures 1 to 3, a fluid metering system 200 is described
in greater detail. The system 200 comprises at least one water meter 100 that is in
ication with a server 210 via a network, such as a public or partly public k
including wireless mmunications infrastructure. The server 210 has access to a data
store 215. In practice, many fluid meters 100 will form part of system 200, with each of
those meters 100 being in communication with the server 210 via network 225.
A housing 300 (Figure 3) houses a water meter 100 and a sensor installation 340
comprising a flow sensor 145 for sensing fluid flow 320 within the conduit, and one or
more sensors 155, 156 for sensing at least one condition of the fluid or fluid conduit.
In some embodiments, the water meter 100 is a static flow meter such as an
ultrasonic or magnetic flow meter. Other embodiments may comprise a mechanical flow
meter. This meter will be configured to measure fluid flow characteristics such as
maximum/minimum flow rate, reverse flow, and other characteristics within a fluid
conduit, referred to for convenience as lumen 325. The meter may comprise a flow tube
310 having a hollow internal space to receive and conduct fluid flow 320 from fluid
supply side 330 and le for g a fluid condition about a fluid flow 320, using
flow sensor 145, and embedded flow sensors 155, 156. The flow tube 310 may be made
of a suitable material to allow for fluid sensing by the flow sensor 145. Some
ments may comprise a brass flow tube.
Flow sensor 145 is communicatively and electrically coupled to first ller
120, having a processor 121 and memory 122. The first controller 120 receives power
from power supply 135 and its power through to the other system ents.
First controller 120 is communicatively and electrically coupled to a second controller
150, which itself is electrically and communicatively coupled to one or more sensors
155, 156. In some embodiments of the invention, the functions of the first controller 120
and second controller 150 may be consolidated into a single controller or processor. In
some embodiments, one or more functions of the first controller 120 and second
controller 150 may be ted by another number of controllers and/or processors. For
example, embodiments may include additional processor circuitry, such as a digital
signal processor (DSP), but such additional processor circuitry should be understood to
be included as part of the controller or processor described herein unless context indicates
otherwise.
The first controller 120 only turns on power to the second controller and the one
or more sensors when it is desired to take a sensor reading in relation to fluid conditions
in the conduit, and the first controller removes power from the one or more sensors at
other times. The desired sensing interval may coincide with a daily data payload, and be
conducted according to a configurable interval.
The one or more sensors 155, 156 are ically and communicatively coupled
to a second controller 150, having a processor 151 and memory 152, configured to
control tion of the one or more sensors according to a urable interval. The
one or more sensors may include sensors to detect fluid pressure, vibrations within the
lumen 325, temperature, and other fluid characteristics. Sensors to detect other conditions
may also be provided, and more than one type of sensor may be used to measure one type
of condition. ing on what information is desired to be gathered, a sub-set of those
sensors may be comprised in system 100. For example, it may be desired in some
ces to measure fluid flow rate, fluid pressure, and conduit vibration for leak
detection, and in other instances to measure fluid flow rate, conduit vibration for leak
ion, and water quality.
Commercially available sensors may be used as sensors under the l of the
second controller, modified as necessary to operate at low power, or modified to allow
for small measurement thresholds. The separation of second controller 150 and sensors
155, 156 from the first controller 120 and flow sensor 145 may allow for adaptation of
ng, commercially available flow meters to be used as water meter 100, with
additional cation through inclusion of a second controller 150 within the housing
In some embodiments, first controller 120 and second controller 150 may
comprise a single main controller, having at least one processor and memory, and
performing the same functions.
A power supply 135 provides power to the housed system, including the one or
more sensors, through connection to the meter’s first controller 120, which in turn
supplies power to the second controller 150.
A ications module 140 is electrically and communicatively connected
to the first controller 120, for the e of communicating with and receiving
instructions from a client device 220 over a network 225,
[0052] Referring particularly to Figure 3, the housing 300 may be an IP68 (acc.
EN60529) rated enclosure that is manufactured from plastic that is highly ant to UV
damage, ature fluctuations, and other environmental factors. In some
embodiments the meter system 100 within housing 300 may be sufficiently watertight to
withstand full immersion in water for at least 48 hours t ning permanent
damage. The threaded or flanged coupling portions 335 of the meter may be brass, and
provide an upstream and/or downstream orientation with an upstream end coupled to the
supply network and a downstream end coupled to the customer premises. In some
embodiments, a suitable alternative metal or material may be substituted. Some
embodiments comprise a completely metallic flow tube 310. The threaded coupling
portions 335 may be joined by a conductive metal band. In embodiments comprising a
plastic flow tube or other material, safety or bonding wires may be used in order to allow
meters to be safely installed or ined without risk of electrocution. The meter
system 100 within housing 300 should meet m electro-magnetic immunity and
electro-static discharge (ESD) standards such as IEC 61000-4.
[0053] The meter system 100 may have environmental limits of at least -10 to +55
s Celsius, and 5% to 95% humidity while operating or in storage. The meter
system 100 may be capable of operating in direct sunlight at up to at least 45 degrees
Celsius (in some ments up to 50 degrees Celsius) ambient air temperature.
The meter system 100 may provide suitable electrical conductivity across the
housing and connectors to ensure uity of earth for installations which rely on water
pipes as a means of earthing the mains electricity supply.
In some embodiments, the meter system 100 construction materials will be
chosen to minimise the recycling value of the meter, using a minimum of materials with
high recycling value such as copper or brass to reduce risk of theft or vandalism of the
meter system 100.
The g 300 may also odate buttons, switches, lights, or manually
actuated systems which would allow for an or to ascertain an operational status of
the meters, or manipulate certain functions of the meter, such as manual power operation,
taking of readings, and forcing a data payload. These functions may be accommodated
in external display 125 or external interface 130. For example, an activation mechanism
that wakes the meter from its sleep/dead/low-power mode so that it turns on and connects
to the network. An embodiment of this mechanism may be a push button, magnet, or an
LED actuation featured on al interface 130.
The housing 300 may further allow for a local display 125 readable in direct
sunlight from a suitable distance, nominally 100cm. The local display 125 may be
capable of displaying ation about the meter or sensed conditions in the lumen 325,
such as total water ption in kL with a resolution of 0.1L or better, the t time
of day, the meter state or red alarms, instantaneous flow rate, communication
status, the last readings for pressure, water temperature, or other information.
Housing 300 may provide for access to external display 125, showing local
visible indications (for example using visible LEDs) of:
Power on/off – meter operating or not operating (hibernating)
Communications (unavailable/searching/connected)
Battery level (percentage or e)
Internal fault (such as memory corruption, software error, communications
hardware failure)
In some embodiments, the installation 100 and housing 300 may be oriented
horizontally or vertically, and may be installed directly in line with a lumen 325 or be
installed in a bypass tube connected to a lumen 325. The installation may be installed
with minimum upstream distance, on a lumen 325 connected to a fluid supply network
330. The meter system 100 may continue to meet all requirements in any installed
orientation.
[0060] In some ments, a high-gain antenna may be installed in electrical and
communicative connection with communications module 140, to improve signal strength
in areas of low coverage. An embodiment may encompass a low profile fixture, situated
on the lid of the meter or within the meter housing 300. ative embodiments may
ass at least one al antenna port suitable to receive a later installation of a
high-gain antenna, the antenna port being in electrical and communicative connection
with the communications module. In such ments the antenna and antenna port
may comprise a le material, meeting an IP68 rating, and be resistant to UV damage,
temperature fluctuations, and other nmental factors. In other embodiments any
required communications antenna would be mounted internally.
[0061] The power supply 135 to the meter 100 supplies power to all components. The
power supply 135 may be of a kind having a long life and low self-discharge, le to
be installed for long periods (ideally 10, 15, or more years) without requiring a
replacement. An ment of the power supply 135 may be in the form of a lithium
battery, with capacity to 3.0V (@0.5a @1% duty cycle) of 19 Ah, l voltage of
3.6V, maximum 1 second pulse to 3.0V of 3A, maximum pulse length @0.5A to 2.8V
of 1000 seconds, no delay time to 3.0V @0.5A, a weight of approximately 140g, a safe
operating range of -40°C to +85°C, and a 96% capacity retention after 10 years, for
example. However, other suitable power supplies may be used with different operational
and/or functional parameters to those listed immediately above. The housing 300 should
allow access to the power supply 135 for maintenance or replacement.
Referring to Figure 1, the system 100 es both a first 120 and second
controller 150.
[0063] The first controller comprises a processor 121 and a memory 122. The memory
122 may comprise a ation of volatile and non-volatile computer readable storage
and has sufficient capacity to store program code executable by processor 121 in order
to perform appropriate processing functions as described herein. For example, sor
121 executes program code stored in memory 122 to activate the second controller 150
or flow sensor 145, which in turn take readings as required. Processor 121 may activate
other system components within water meter 100, such as external display 125, external
ace 130, and the communications module 140.
The first controller 120 also es power through power supply 135, and
provides the power from power supply 135 through wired connections to the second
controller 120 and sensors 155, 156, as well as to the remainder of the system
components.
The first controller 120 interfaces with communications module 140, and is
capable of receiving instructions or firmware upgrades over a network 225, and sending
stored data through network 225. This data may relate to meter status, or sensed
conditions within the lumen 325.
The second controller 150 comprises a sor 151 and a memory 152. The
memory 152 may comprise a combination of volatile and non-volatile computer readable
storage and has sufficient capacity to store program code executable by sor 151 in
order to perform appropriate processing functions as described herein. For e,
processor 151 executes program code stored in memory 152 to provide power to sensors
155, 156 and to take and store data sensed from sensors 155, 156 about a fluid condition
within a lumen 320 of a flow tube 310. The flow tube 310 may form part of a meter
assembly comprising meter 100 and the metering functions of the meter 100 are carried
out in relation to fluid flowing in the flow tube 310.
Memory 152 may store sensed fluid data in a data register, to be sent through
communications network 225 upon request of a client device 220 connected to network
225, or as instructed by program code stored in memory 152, 122.
Processors 121,151 are referred to in Figure 1 as CPUs (central processing
units). This term is used in a non-limiting ty and any suitable sor or
microprocessor may be used. In embodiments where the first controller 120 and second
controller 150 comprise a single controller, the single controller may have at least one
memory and at least one processor according to the above.
The first controller 120 or second controller 150 may be optionally configured
to receive instructions and communicate directly with a client device 220, for example a
handheld device or laptop er, in order to locally configure or diagnose the meter
through a local data interface 131. Embodiments of local interface 131 may be in the
form of an optical, wired, or ss communication system, suitable for connection to
a laptop computer and/or handheld device. It is envisioned that this local data ace
131 may only be accessed in cases of meter fault or if other changes are required in the
field, as configuration of the meter is otherwise possible over a network 225 through
communications module 140.
[0070] Through this local data ace 131, all parameters such as alarms,
transmission intervals, and other related fields are may be configurable or programmable.
stic logs providing meter ation may be extracted through this interface. It
is desirable that connection to the local data interface 131 uses zero or minimal power
from the power supply 135, instead being powered by the client device itself.
[0071] In some embodiments, first or second ller memory 122, 152 may store a
ermined data storage capacity for storage of a minimum amount of measurement
data. For example, first or second controller memory 122, 152 may have sufficient
storage capacity to store a minimum of 10, 20, 30 or 40 days of tamped fluid data,
together with the corresponding interval data, meter re information, and other
pertinent information.
r requirements for the local data interface 131 of some ments
include the local data interface 131 providing a capability to retrieve all stored billing
data, events, and alarms. The local data interface 131 may also be required to provide a
capability to update firmware and to read or update configuration.
Access to the local data interface 131 may be secured through a standards
based mutual authentication scheme. Any keys or certificates used may be able to be
revoked and/or ed. In some embodiments, the local data interface supports role-
based access control. At a minimum “read-only”, “configure”, and “full access” roles
may be supported. All of the access to the local data interface may be logged for audit
purposes. At a minimum the audit log may include ime, actions, and identity of
user.
[0074] The first controller 120 or second controller 150 may have an internal clock.
Sensed fluid flow characteristics may be time-stamped where required by a time set on
the internal clock.
Referring now to Figure 2, the water metering system 100 further comprises one
or more servers or server systems, referred to herein for convenience as server 210, in
connection with at least one wired client device 220 and a data store 215. In some
embodiments, client device 220 ses a wired computing device, or portable
computing device such as a laptop or smartphone. Server 210 may comprise, or be
arranged as, a supervisory control and data acquisition ) server to receive data
from water meters 100 at various different locations.
[0076] This data is ed over a data network comprising suitable communications
infrastructure that is at least partially wireless, such as a cellular network.
For e, the communications modules 140 of flow meter s 100 may
be configured to it data to server 210 using the GSM or GPRS/3G standards for
mobile telephony or their technological sors.
Thus, communication module 140 in communication with server 210 by direct
mobile data ication using available mobile telephony infrastructure, rather than
using a series of hops and other infrastructure to transmit messages. Alternatively, lower
power, shorter distance wireless communication techniques may be employed, for
example where a local wireless data hub is in sufficient proximity to support wireless
communication with the ications module 140 within a nearby water meter
system 100. However more direct forms of communication from the communication
module 140 to the server 210 are preferred for simplicity, speed, and reliability.
Server 210 processes the data received from the communications module 140,
and stores it in data store 215 for subsequent retrieval as needed. Data store 215 may
comprise any suitable data store, such as a local, external, distributed, or discrete
database. If the data received at server 210 from meters 100 te an alarm condition
in any one or more of the meters 100, server 210 accesses data store 215 to determine a
pre-determined appropriate action to be taken in relation to the specific alarm ion
and then takes the appropriate action. The action to be taken may vary, depending on the
meter 100, for example where some meters 100 may be configured to sense different
conditions over others. Such actions may include, for example, sending one or more
notifications, for example in the form of text messages and/or emails, to one or more
client devices 220.
Regardless of whether an alarm condition is ted by the data received at
server 210 from meters 100, the received data is processed and stored in data store 215
for later retrieval by a server process and/or at request from a client device 220. For
example, server 210 may execute processes (based on program code stored in data store
215 for example), to perform ng and reporting functions to one or more client
devices 220.
The ications module 140 may be enabled for bidirectional
communication with server 210, so that firmware updates can be received and/or
diagnostic testing can be performed remotely, and that client devices may remotely
configure data d intervals, and/or request current (or real-time) data from the
meter.
Referring to Figure 1, communications module 140 is described in further detail.
The ications module may be electrically and icatively connected to a
first controller 120, receiving power from power supply 135 through this tion, or
directly in some embodiments.
[0083] The configuration of communications module 140 may include an antenna, and
subscriber ty module (SIM) card. The ications module 140 may comprise
additional components and/or circuitry (not shown) as judged by a person of ordinary
skill in the art to be necessary or desirable in order to carry out the functions as described
herein.
[0084] Some embodiments of the meter 100 have communication requirements
including the meter 100 being capable of measuring and reporting over a network 225
on request:
Instantaneous water flow rate (in litres per minute);
Current battery level (in volts and estimated percentage);
Total meter activity time (time spent awake, transmitting, receiving) and
communications packet counters; and
Current internal temperature.
In some ments, the meter 100 requires being capable of supplying
identification data to the communications network on request.
The meter 100 may require being capable of supplying all stored interval data,
register snapshots, , alarms and any other business data or status information to
the communications network on request and/or as scheduled.
In some embodiments, the meter 100 es being capable of accepting
firmware upgrades over the communications network. All firmware components may
be upgradeable. The firmware upgrade process may be tolerant of communications
outages, power interruptions, head end system outages, and errors in transmission.
Meter systems 100 may require being capable of ndently and
automatically detecting failures, and recovering or rolling back to previous known good
settings or parameters (images) when recovery is not possible. The meter 100 may be
e of accepting configuration changes and reporting current configuration over the
communications network 225.
In some embodiments, the meter 100 requires being e of having its time
synchronised over the communications k 225.
[0090] The meter 100 is required to have a urable communications retry and
back-off sequence that allows for resending of data payloads that were unsuccessfully
sent to server 210. For example, if the meter ts to send its data payload and is
unsuccessful, it may retry a configurable number of times, such as 3, 5, 10, or some other
amount of times. After this, it may return to deep sleep/low-power mode and attempt
communications a number of hours later.
In other ments, the meter may retry sending unsuccessful payloads, and
then return to deep sleep/low-power mode until the next scheduled transit time (for
example, the following day). In such an embodiment, the meter and communications
module may require the ability to handle larger than normal data payloads. For e,
if the meter has not been able to communicate for 10 days, this would result in a payload
times the size of a regular payload that would cause the communications module 140
to be activated for a prolonged period.
In some embodiments, sensors 155, 156 are physically and/or electrically
connected to second controller 150 and sense fluid ions within the lumen 320. In
other embodiments, the sensors 155, 156 may be electrically and/or physically connected
to the first controller 120 or, where the functions of the first and second controller are
provided by one controller, the sensors 155, 156 may be so connected to that controller.
These sensors 155, 156 may comprise more than two sensors or sensor functions, at least
one sensor including a vibration sensor, a pressure sensor, and stray current sensor.
Sensors 155, 156 may include other sensors or sensor functions to sense electrical
tivity, fluid temperature, pH level and free chlorine levels. In some embodiments,
multiple fluid conditions may be sensed by individual sensors.
Figure 3 shows an ment where the meter system 100 is installed in-line
with a fluid supply conduit 325, to communicate fluid from the supply conduit 325
through a fluid flow tube 310 via which conditions of fluid flow in the lumen 320 are
detected. In this embodiment, a vibration sensor 500, a sensor installation 340 and other
sensors 155, 156 are positioned on/in or in relation to the flow tube 310.
Sensors 155, 156 may be installed tely, or as one unit, depending on the
uration of sensors used. Sensor 155, 156 sense at least one condition within the
lumen 320. Described sensors may be ultra-low powered, with low start-up currents and
small stabilization times in order to ze power consumption.
[0095] In some embodiments, sensor 155 comprises a vibration sensor 500, interfaced
with the lumen 320 in order to detect vibrations in the upstream fluid supply conduit
. In some embodiments, a part of the vibration sensor 500 is in direct contact, for
example by abutment, with a portion of the meter flow conduit coupling 335, positioned
on the (upstream) supply side 330. The sensor 500 can be physically interfaced with the
t coupling 335 using a suitable e technique. For example, an ve fixture
or mechanical method of fixture such as a gasket fixture or screws can be used, provided
that the fixture would not otherwise provide mechanical action in the form of further
vibration.
Figure 5 depicts an embodiment of the vibration sensor 500, comprising a
piezoelectric sensor system. The sensor 500 comprises at least one thin stacked
electrically conductive plate 515 (made from a suitable material such as copper) and two
or more piezoelectric elements or plates 535. The stack of piezoelectric plates 535 and
tive plates 515 are disposed between a seismic mass 510 and a base unit 520,
which are connected to each other. Affixing shaft 530 clamps or connects the seismic
mass 510 to or onto base unit 520, which may exert a compression force in rest state, but
still allowing for small movement and compression of piezoelectric sensor plates 535
n copper plates 515. The base unit 520 comprises one or more masses configured
to convey ional movement from the material of the flow conduit to the piezoelectric
plates 535. The base unit 520 can also be an integral part of the meter flow conduit
coupling 335 or flow tube 310 in the form of a cast mounting plate with provisions for
fastening. The number of copper plate and piezoelectric layers may vary between
embodiments. The example shown in Figure 5 shows two copper plates 515 and three
piezoelectric elements 535. Conductive plates 515 may be substantially thinner than
piezoelectric plates 535, for example by a factor of around 5 to 20. In some embodiments,
the copper plate may be between 0.1-0.2mm in thickness, s the piezoelectric
plates may be 1-2mm in thickness, for example. It should be understood that Figure 5
does not y a scale embodiment of vibration sensor 500.
[0097] ions transmitted along fluid conduits of an upstream fluid supply network
may couple into the al of the flow tube of the meter 100 and thereby be transmitted
to the base unit 520 that is connected to flow tube 310, or in some embodiments the meter
ng portions 335. When vibrations travel through base unit 520, piezoelectric plates
535 are compressed between against seismic mass 510 and base unit 520. One or more
electrical conductors 525 may be connected to the copper plates 515 to carry t (or
convey voltage differences) generated by the piezoelectric plates 535 to processing
circuitry in the meter 100. In some embodiments a plurality of piezoelectric plates 535
are used to provide an amplifying effect on the ion signal.
Sensor 500 may be configured to provide sensed fluid condition data along
conductors 525 to a second processor 152, through process 400 or 600.
The material of the flow tube 310 that the sensor 500 is affixed to should be
constructed from a material suitable to conduct detectable vibrations along its e. It
is oned that upstream supply ts and/or the flow tube 310 may be formed of
or comprise vibration-conducting metals, such as brass, or copper, r in some
embodiments may comprise suitable alternative ion-conducting materials.
An embodiment of a leak detection method 600 using vibration sensor 500 is
described in Figure 6. At 610 the vibration sensor 500 awaits activation from a second
controller. Once a predetermined measurement interval (stored in memory 122) has
expired, the first controller 120 causes power supply 135 to provide power to the second
controller 150 to listen to output signals from vibration sensor 500. At stage 620, the
controller may await diagnostic information from vibration sensor 500, and may await
confirmation that sensor 500 is operational.
At 620, vibration sensor 500 captures vibration data in the form of an analogue
signal. A number of readings may be taken in order at stage 620. The sensed data will be
transmitted to the second controller 150 along conductors 525 and in some embodiments,
stored in memory 152.
At 625 a first or second controller 120, 150 performs a Fast Fourier Transform
(FFT) to the analogue time domain data. At 630 the FFT data may be t to filtering,
such as band pass filtering, to identify frequency ranges consistent with one or more
predetermined leak conditions. An example of such an embodiment is rendered in Figure
7 as a ve plot of the FFT output, with amplitude on the Y-axis and frequency on
the x-axis.
At 635, after any filtering is d to the FFT data, the data may be subject to
a comparison t predetermined thresholds, further indicating leak conditions. In
some embodiments, the threshold 710 may se an integral threshold, where leak
conditions may be assessed based on the integral of the range of frequencies within a
band pass filtered range. In such embodiments, the total area in a frequency range may
be the condition assessed by threshold 710. Figure 7 indicates one such example where
the al of a filtered frequency range 716 does not meet threshold 710, despite the
presence of frequencies in a predetermined range 715. In such an embodiment, the
integral 721 of frequency range 720 does surpass threshold 710 and as such, would be
detected as a type of leak or leaks.
[0104] In some embodiments, threshold 710 may be an amplitude threshold, where
both 715 and 720 contain frequencies 717, 722 within the filtered range that exceed the
amplitude threshold 710. In such an embodiment, frequency range 725 would not surpass
threshold 710 as although frequencies 726 within the filtered range are detected, their
amplitude does not exceed the threshold.
[0105] In some ments, old 710 may be configured with a suitably low
value, such that ce of a frequency with an amplitude r than zero in a filtered
range may indicate a type of leak or leaks. In such embodiments, frequency ranges 715,
720, 725 may all indicate the presence of a type of leak or leaks.
Various vibration frequency characteristics may be used to determine and
entiate different types or combinations of leaks. In some embodiments, at least one
additional sensed characteristic of the fluid flow 320 may be used to identify at least one
leak condition in conjunction with vibration data. For example, detection of a frequency
in ranges 715, 720, 725 may not trigger an alarm condition unless it is detected in
conjunction with a predetermined condition sensed by sensors 155, 156 or by flow sensor
145, for example, a detection of low flow rate, and/or ion of a low pressure. Where
this additional condition is met, a frequency in the range of any of ranges 715, 720, 725
may indicate presence of a leak. Threshold 710 may be configured as per any of the
above described embodiments, but also conditional upon the detection of at least one
sensed fluid condition. In such embodiments, at least one sensed condition may be used
in conjunction with the vibration such as ature, pressure, flow rate, ical
conductivity, pH level, free chlorine levels, or other conditions sensed by s
155,156 or flow sensor 145.
After this stage is completed in 635, the first or second controller 120, 150
updates an alarm condition in 640 indicating the presence of a leak or leaks, or ting
that no leak or leaks are detected. This alarm may be a binary flag, comprising at least
one bit. In such embodiments, a d bit may indicate presence of any leak.
[0108] In some embodiments, at least one bit may be used to flag the presence of a
particular type of leak, for example a tion leak, or the presence of multiple leak
conditions.
At stage 645, the alarm condition is stored within a first or second controller
memory 152, 122 to be sent with normal data ds.
[0110] In some embodiments, sensor 155 or 156 comprises a gauge pressure sensor that
may operate in the 0-15 bar (0-150mH20, i.e. in ‘meters head of water’) range. The data
from the pressure sensor may be ed to accommodate the elevation of the meter and
configuration of the meter 100 installation.
Some embodiments may comprise a commercially available pressure sensor
having on-board analogue to digital conversion and incorporated temperature sensing
capabilities. Such sensors should be le within the specified re range, and be
ultra-low powered.
In some embodiments, the pressure sensor or other sensors 155, 156 may be
installed within the internal cavity (lumen 320) of the flow tube 310, in a sensor
installation 340 having a housing that may be in direct contact with fluid flow 330. In
such an embodiment, the pressure sensor, sensor lation 340 and connections may
be suitably waterproofed and resistant to wear from conditions of fluid flow 330. In other
embodiments, sensor installation 340 comprises sensors 155, 156 in direct contact with
fluid flow 330. In other embodiments, sensor installation 340 may be installed on the
external body of flow tube 310. In such embodiments, sensors 155, 156 may not require
direct contact with fluid flow 320 in order to take readings.
In some embodiments, sensor 155, 156 comprises a stray current detection
sensor, optionally a magnetometer. The magnetometer may be located proximally close
to the lumen 320 and configured to detect a magnetic field due to an electric leakage
current present in or near the lumen 320.
[0114] Embodiments allow for detection of a ic field due to a leakage current
above a certain Ampere level that can be harmful to humans or other animals, for
example such as a current of 1A. ative embodiments may allow for lower, or
different current detection thresholds.
The stray current detection sensor may be configured to receive instructions
from the at least one controller 120, 150. In some embodiments a second controller 120
may periodically poll the sensor to retrieve readings to be included in daily data payloads.
Optionally to be polled at different times to the vibration sensor.
Detection of a stray current during a polling period may trigger an alarm
ion, to be stored in a memory 152, 122 and sent in a regular (e.g. daily) data
payload to external server 210 in accordance with process 400.
In some embodiments, the flow sensor/water meter system 100, herein ed
to as water meter 100 for convenience comprises a ic flow meter or an onic
flow sensor 145 in electrical and icative connection with a second controller
[0118] The flow meter controller 120 may be suitable for retaining measured flow data
in memory 122 to be transferred with daily d data over a network 225.
Commercially ble flow meter systems may be used, modified in some
embodiments to suitably interface with a second controller 150 and sensors 155, 156.
The water meter 100 may comprise at least a means for detecting and/or
measuring fluid flow 320 within a lumen 325, a means for detecting and/or measuring a
minimum or maximum flow rate in a time period, means for detecting and/or measuring
reverse fluid flow (that is, flow s the fluid supply network 330). Temperature,
electrical conductivity, free chlorine , or other fluid flow characteristics may be
sensed, measured, and stored by a first ller 120 or second controller 150 depending
on the flow meter capabilities.
[0120] Some embodiments of the water meter 100 have further requirements, such as
having a minimum flow rate, being in the range of 10, 20, 40 litres per hour or higher
as necessitated by the meter size. The meter sizes may vary, and may be in the range of
29, 25, 32, or 40 mm. Embodiments may comprise higher or lower sizes.
The meter 100 may require being configured with a maximum or minimum
permissible error of measurement (MPE). In some embodiments this may comprise a
range of 2-5%. The configuration of the MPE may be consistent with NMI R49 and
class II meters.
The meter 100 may require being capable of detecting and measuring reverse
flow.
[0123] In some ments, the meter 100 requires being fitted with either a single
check valve, or a dual check valve.
The meter 100 may require being capable of recording (with timestamp) peak
daily instantaneous flow in litres per second with a resolution of about 0.01 litres. The
meter 100 may require being capable of measuring and recording water pressure in
m.H20 (i.e. “Meters head of water”). This pressure value may be gauge pressure.
In some embodiments, the meter 100 requires being able to measure and store
water consumption al reads (the interval data), total water consumption
accumulation (the accumulation register), and time aligned snapshots of the
accumulation register (the er snapshots) (collectively known as billing data). The
al length for interval data may be configurable supporting at minimum the
following values: 1 minute, 5 minutes, 15 minutes, 30 minutes, and 60 minutes. In
some embodiments, other values may be used. An accumulation register may be
measured and stored in kilolitres with resolution and significant digits based on meter
size, with resolutions ially in the range of about 100,000 to about 000 kL.
The interval data may be measured and stored in litres with tion and
significant digits based on meter size, with resolutions potentially ranging between 100
to 10,000 L.
It is envisioned that data payloads may be transmitted from a first controller 120
across a network 225 once per predetermined time period (i.e. a day). This transmission
frequency may be a configurable ter, allowing for more or less frequent d
transmission. Data collection intervals for all sensed data may be configurable.
An embodiment of the data payload content is described below. The contents of
the data payload may vary depending on the capabilities of the sensors used.
Volumetric fluid flow within the lumen 325 may be recorded and time-stamped
every 30 minutes. In some embodiments, a shorter interval (such as 10 seconds) may be
recorded and time-stamped for a first or second controller 120, 150 to summarize through
algorithms, and to be transmitted with a daily payload.
As some embodiments of the flow meter may record data every few seconds,
only the value and timestamp of the maximum flow rate each day may be transmitted.
This data is valuable to determine taneous flow spikes at each meter 100.
[0131] In some embodiments of the meter 100, temperature and/or electrical
conductivity may be sensed. These may be sensed either with embodiments of sensors
155, 156 or the flow sensor 145. In embodiments where these conditions are , time
stamped values of the sensed fluid data may be recorded at configurable intervals, for
example, every 4 hours. This dataset is to be itted daily along with the main flow
data payload.
In monitoring power consumption, voltage level of the power supply 135 may
be transmitted along with daily ds to monitor life. Additionally, daily meter
communication ty time may be recorded and transmitted with the daily d as
an indicator of meter power consumption based on its attempts (successful or
unsuccessful) to connect to the network 225. Daily activity time may indicate the time in
seconds that the meter was activating the communications module 140.
In some embodiments, alarms to come with a daily payload may be customer
leakage alarms, potentially a binary flag indicating ual usage (for example, a
recorded flow rate of greater than 5L/h for 24 hours. This value may be configurable,
and have a default value prescribed.
A reverse flow alarm may be recorded in a binary flag. Reverse flow volume
may be ed in litres of fluid flowing in the reverse direction, for example, toward
the water supply network.
An empty pipe alarm may be indicated through a binary flag, and detectable
through operation of the flow sensor 145.
A Tamper alarm will indicate presence of strong magnetic fields or other
ical sources that effect a ic flow meter embodiment. This may optionally
indicate tampering through vandalism or opening the water meter housing 300.
Some embodiments of the flow sensor 145 uration would allow for a
high/low pressure alarm. The threshold for this alarm may be configurable per meter,
having an initial default value. This alarm may be able to be enabled or disabled by user
choice.
High/low temperature alarms may be user configurable, having default high and
low temperature threshold values stored in the first or second controller memory.
A high flow alarm may indicate r fluid flow 320 within the lumen 325 is
abnormally high for a defined period of time. This alarm may be triggered based on a
default alarm old triggering value and may be configurable. Triggering of this
alarm may indicate the presence of a broken pipe, for example.
[0140] A network leak alarm may be a binary flag and may be based on frequency
output of the vibration . When an identified frequency is ed that has
amplitude over a defined threshold, and that is characteristic of a fluid supply network
leak, this alarm will be triggered.
These alarms may require acknowledgement from server 210, and may transmit
again upon change of state. If not acknowledged by server 210, after a suitable interval,
the meter 100 may continue to report the alarm binary value in the data payload until
acknowledgement from the server 210 is received.
Through the server 210, multicast end-point firmware in the form of binary files,
and configuration data may be able to be sent to some or all of the end-points meters 100.
The mechanism for this may be efficient such that it has minimum impact on battery life.
The at least one controller 120, 150 may store sent re/configuration binary files,
and only apply them once fully downloaded and certified. If the data received by the
meter 100 is incomplete or corrupted, some embodiments of the at least one controller
120, 150 may instead rely on existing configurations until such time as the new
configuration data is acquired, rather than overwriting existing files.
A typical daily data payload is estimated to be approximately 100 bytes,
including all mandatory and optional parameter data sets listed in the below table. In
some embodiments, the d will use the ained application protocol (CoAP)
and JavaScript Object Notation (JSON) or binary messages. An embodiment of a data
payload, provided by way of example only, may comprise the following fields and data
size distribution:
Date and timestamp data, 7 bytes
Flow data (48 readings of 0-999.9 litres each, with number of records in the
dataset) ~62 bytes
Billing er, ~8 bytes
Meter identification data, ~ 8 bytes
Meter firmware version ~0.5 bytes
Battery voltage, ~9 bits
Meter daily activity time, ~ 17 bits
Pressure, 6 readings per day + read interval, ~7 bytes
Vibration, 3 readings per day+ read interval, ~7 bytes
Daily maximum flow + timestamp offset, ~4 bytes
Other data may be itted with daily payloads depending on meter and
sensor configuration.
Through access to the local data interface 131, a user may directly access or
trigger the sending of payload data, or locally request measurements from the meter 100.
[0146] Payload data requirements according to some embodiments include the meter
100 being capable of locally storing (including in the absence of oning
communications) at least:
100 days of al data (with 30 minute interval uration) and
register snapshots (with daily register snapshots);
The last 50 events. Where in some embodiments an event may be an
alarm condition being triggered. In other embodiments an event may be a timestamped
instance of payload data transmittal; and
Alarm state ted / not asserted) for each alarm.
[0147] In some embodiments, the meter 100 also requires being capable of locally
storing information recorded as an event which may be user configurable. The meter
100 may require being e of recording as an event or alarm on a configurable
basis:
Continuous low flow (leak detection) (not dropping below a provided
value of litres per minute for a period of time);
Continuous high flow (burst detect) (more than a provided value of litres
per minute for a period of time);
Detection of tampering;
Low battery (in some ments this may be in days remaining or in
a percentage of capacity);
High internal ature (greater than a value of degrees Celsius).
In some embodiments, the meter 100 may require being capable of recording
as an event or alarm on a configurable basis the following features (where a le
sensor is fitted):
Reverse flow (more than a provided value of litres per minute for a
period of time).
High and low pressure (more or less than a provided value in
meters.H2O).
High and low temperature (more or less than a provided value degrees).
[0149] It should be understood that provided values may optionally be configurable
values in some embodiments.
In some embodiments, users may define alternative events or conditions as an
alarm. Alarms may be able to be configured as be self-clearing (the alarm is cleared
automatically when the alarm condition ends) or operator cleared (the alarm remains
triggered until an or clears it). A triggered alarm may generate one message when
set and another when d (it does not continue to generate messages for the entire
time the alarm condition is present). The current state of an alarm should be able to be
read.
In some embodiments, the meter 100 may require suitable hysteresis to be
implemented on alarm thresholds to prevent repeated triggering and clearing of alarms
or repeated logging of events.
In some embodiments, the meter 100 may require being capable of
maintaining an alarm state (triggered or not triggered) for each alarm and may provide
a mechanism to clear the state.
ing now to Figure 4, a method 400 of fluid monitoring is shown and
bed in further detail. Method 400 is ed by the at least one controller 120, 150
to control operation of the one or more sensors 155, 156, or flow sensor 145 to sense a
condition of a fluid in a lumen 320.
In some embodiments of method 400, at 410 the first controller 120 waits for a
preconfigured time interval to expire before switching power to the at least one sensor
155, 156, 145. The time interval of 410 may be user configured or a default value. After
a time interval has d in 410, the first controller 120 switches power to the sensors
415 and waits for a “warm up” period for the at least one sensor 155, 156, 145. This may
comprise the at least one sensor powering up their own internal electronics, running their
own operational diagnostics (if riate), and ly indicating their operational
state (e.g. properly ional or partially or fully non-operational). The interval timing
may be aligned to hourly times based on the meter internal clock, or a timing defined
from server 200. Other time alignments may be used as required.
Once the one or more sensors 155, 156, 145 have warmed up, and ng
they are operational, the sensors 155, 156, 145 measure the relevant conditions and
indicate at 425 a value of the condition they are ured to sense by providing a digital
or analogue output signal to their configured controller 120, 150 via cable 157. The
output signals from sensors 155, 156, 145 are converted from analogue to digital signals,
if appropriate, and then reted and stored in a memory 122, 152 for subsequent
ission to the . During this time at 425, any additional computation of the
sensed data using algorithms may be applied, if appropriate.
At 430, once the sensor measurements (i.e. output signals) have been received
from sensors 155, 156, 145, the first ller 120 discontinues supply of power from
power supply 135 to sensors 155, 156, 145. The first controller 120 processes the data
derived from the output signals to compare measured values to figured alarm
condition levels. In some embodiments this process may be completed by the second
controller 150. At 435 the at least one controller 120, 150 may set a binary flag indicating
an alarm condition, for example.
If an alarm condition is detected, for example, because the sensed measurement
exceeds or is equal to the alarm threshold for a particular sensor type, then the second
controller 120 raises flag bits within the binary flag to indicate which alarm/s have been
triggered. At 440, data is stored in the at least one controller memory 122, 152 to be
stored upon expiration of the notification interval. This data may include typical payload
data and/or alarm conditions.
At 445, if the notification interval has expired, the first controller 120 causes the
communications module 140 to be turned on (for example, by causing power supply 135
to supply power to communications module 140) and an appropriate e to be
transmitted to server 210 at 455. If the notification interval has not expired, the first
ller may wait until the notification has expired before proceeding to 450. In some
embodiments, the measurement interval in 410 may expire again before the notification
interval in 445 expires. In such embodiments, data may be continually stored in 440 as
discrete time-stamped entries without being overwritten.
Steps 440 and 445 may also be performed to send a notification message where
lid sensor (not shown) on the water meter 100 detects the lid being opened or where some
kind of fault in a sensor or telemetry unit 120 is detected.
The message sent to server 210 may include an identifier of the telemetry unit,
a time stamp, an indication of one or more sensed values (if appropriate) and an alarm or
notification type, for example. Meanwhile, until the notification interval expires at 445,
steps 410 to 440 may again be executed a number of times.
The notification interval may be a period of hours, for example such as four,
six, twelve, twenty four, or another number of hours, while the measurement interval
may be in the order of a few minutes, for example such as one, two, three, four, five, ten,
twenty, thirty, forty, fifty, sixty or more minutes.
In some embodiments, the cation interval may be ured to expire on
the detection of an alarm in 435. In such embodiments, the detection of an alarm
ion may trigger the transmittal of the alarm and/or the data payload. In one
ment, users may configure the notification internal to expire, and for an alarm or
data payload to be sent, upon detection of at least one alarm event. Such events may be
the detection of one alarm condition, or a combination of alarm conditions.
Some embodiments of meter configurations, including suggested default sample
intervals are detailed in the below table.
Parameter Model Model Alar User t Default Value Units
1 2 m / configurab sample send range
Event le interval interval
Meter NO No N/A Daily (with N/A
fication scheduled
payload)
Meter Firmware NO No, N/A Daily (with N/A
version scheduled
Flow NO No. daily daily kL
register/accumul
Flow interval data NO Yes. 30 min daily 0-999.9 L
Customer leakage YES Yes 24 hrs daily 0- L
alarm 99999
Reverse flow YES Yes, only to 6 hrs daily
alarm turn on or
Reverse flow NO Yes, only to 6 hrs daily 0- L
value turn on or 99999
Empty pipe alarm YES On/off 1 minute Immediate
(‘realtime
Tamper Alarm YES On/off immediate immediate
High/Low X YES Yes 4 hrs daily 0-150 mH2O
Pressure alarm
High/Low YES Yes 4 hrs daily -20 - 60 Deg C
Temperature
alarm
High Flow Alarm YES Yes 1 hr Real-time 0- L
n pipe) 99999
Network Leak YES Yes 1 hr daily
Alarm
Daily max flow NO No 10 sec daily 0-999 L
Temperature NO Yes 4 hrs daily -20 - 60 Deg C
interval data
Pressure interval X NO Yes 4 hrs daily 0-150 mH2O
Vibration interval NO Yes 1hr daily
Battery e NO No Daily daily 0-3.3 Volts
Low Battery YES No - daily 0-3.3 Volts
Alarm
Meter activity NO No Daily daily 0- secon
time 86400 ds
Referring now to Figure 8, a schematic cross-sectional representation of a
vibration sensor 800 is shown and described in further detail. The vibration sensor 800
operates on a r basis to sensor 500, in that vibration sensor 800 has a sensor base
820 configured to abut or otherwise be positioned close to the flow tube 310 for receiving
vibrations propagated from upstream (or downstream) conduits into the material of flow
tube 310. The sensor base 820 is arranged to propagate vibrational movement of a
piezoelectric transducer 835 in response to the received vibrations. A seismic weight
810 is positioned on an opposite side of the piezoelectric transducer 835 from the sensor
base 820. Since the seismic weight 810 tends to remain relatively still due to its inertia,
the lectric transducer 835 is squeezed (between the seismic weight 810 and the
sensor base 820) by small compressions and bending moments arising from ions
transmitted through the sensor base 820. Such small ssions and bending moments
result in a detectable current h (or voltage across) the lectric transducer 835.
This current is detected as time varying electrical signals that can be sensed as an
electrical output via conductors 825 that are coupled to electrodes 815 positioned on the
piezoelectric transducer 835.
The difference of vibration sensor 800 ve to vibration sensor 500 is that a
variable compression element is employed in vibration sensor 800, whereas an affixing
shaft 530 is used in sensor 500, which applies a static compression. This compression
element may be in the form of a spring 830, for example, that is arranged to exert a force
on the seismic weight 810, in order to place the piezoelectric transducer 835 in
compression, as a rest state (i.e. when movement due to vibrations does not occur). The
effect of having the piezoelectric transducer 835 in compression in a rest state es
for improved signal output quality detected on conductors 825 (as the ical output
of the piezoelectric transducer 835) when vibration does occur.
[0166] The compression element may take various forms, but can include the spring
830 in the form of a coil spring, or may take other forms of spring, such as one or more
leaf springs or a wave type spring (930, Figure 9 and 10), provided that the compression
element acts to bias the c weight onto the piezoelectric transducer 835. In some
embodiments, the compression element may include one or more clamps or g
devices arranged to provide a spring-like resilient biasing force on the seismic weight
810 (or other seismic weight embodiments described herein) in the direction of the
piezoelectric transducer 835.
In the ement shown in Figure 8, the vibration sensor 800 has a sensor
housing 840 that is sized and arranged to fit over the spring 830, seismic weight 810 and
piezoelectric ucer 835 and to substantially enclose and/or retain those elements in
place against the sensor base 820. Although not shown in Figure 8, the housing 840 is
removeably attachable to the sensor base 820 by attachment means, such as fasteners
and/or clips or latches.
A top portion 841 of the housing 840 may have a ration formation 842
formed therein in order to assist in positioning tering) the spring 830 against the
top n 841 of the housing 840. The registration formation 842 may be in the form
of a recessed area (or, in other embodiments, may comprise one or more projecting
portions or flanges) in order to assist in ly positioning the spring 830 to be
concentric and coaxial with the seismic weight 810 and the piezoelectric transducer 835.
The top portion 841 of the housing 840 also assists in providing a top bearing surface
against which the spring can be braced in order to exert force against the seismic weight
The seismic weight 810 may be formed to be generally cylindrical, for example,
with a lower portion 810 extending over and around a ntial portion of the
piezoelectric transducer 835, while leaving clearance space between a bottom surface
811 of the seismic weight 810 and the sensor base 820 against which the piezoelectric
transducer 835 is biased. The clearance space allows for some degree of angular tilting
of the seismic weight 810 relative to the sensor base 820 in response to certain kinds of
vibrations. The seismic weight 810 has an upper portion 810b with a top face 814 being
located toward to the top portion 841 of the housing 840. The seismic weight 810 is
shaped to define a g surface 813 at a shoulder position where the seismic weight
transitions between the lower portion 810a and the upper portion 810b. The bearing
surface 813 is arranged to be in contact with the lower end of the spring 830 in order to
allow force from the spring to be transmitted through the seismic weight 810 and onto
the piezoelectric transducer 835. The cylindrical face of upper portion 810b of seismic
weight 810 is arranged to be in contact with the inside helical face of spring 830 in order
to assist in ly positioning the spring 830 to be concentric and coaxial with the
c weight 810 and the piezoelectric transducer 835.
Piezoelectric transducer 835 is preferably formed as a er type transducer
and may be formed of a PZT (lead zirconate te) or PVDF (polyvinylidene fluoride)
piezoelectric material. The piezoelectric transducer 835 rests on the sensor base 820, with
a disc-shaped printed circuit electrode 815 positioned between the bottom of the
piezoelectric transducer 835 and an upper surface of the sensor base 820. The
lectric transducer 835 has a flat bottom and a flat top with a rical shape in
between and is held in place on a flat central area of the sensor base 820 by force applied
to the upper flat end of the piezoelectric transducer 835 by the spring 830 pressing
through the seismic weight 810. A second haped printed circuit style electrode 815
is located at the top of the piezoelectric transducer 835 and may be the only thing
separating the flat top surface of the piezoelectric transducer 835 and the corresponding
flat recessed inner surface of the seismic weight 810 that bears down upon the
piezoelectric transducer 835.
A cavity is formed in the lower part 810a of the seismic weight 810 and defined
by an inner cylindrical wall 812 of the seismic weight 810. The cavity is coaxial and
concentric with cylindrical parts of the seismic weight 180. The cavity is sized to receive
most (more than half, for example between about 50-95%, optionally about ) of
the length of the piezoelectric transducer 835 but less than all of its length, while allowing
a slight gap between the cylindrical wall 812 and the cylindrical outer e of the
piezoelectric transducer 835. This slight gap 816 may have a radial width of about 0.2mm
to about 0.9mm, for example, in order to allow room for a conductor to pass down one
side of the piezoelectric transducer 835 from the top electrode 815. In some
embodiments, the gap 816 may be around 0.7mm in regions where the conductor 825 is
not t. The gap 816 does also allow for an insulating layer between the cylindrical
outer surface of piezoelectric transducer 835 and the cylindrical wall 812 of the seismic
weight 810.
The dimensions of the electrodes 815 at the top and bottom of the piezoelectric
transducer 835 are selected to be thin, and at the top electrode not radially larger than the
piezoelectric transducer 835 (other than by a small margin of say 0.5 mm). The carrier
material (i.e. a flexible substrate for carrying printed circuits or a thin fibre board
commonly used for PCBs) of the electrodes 815 is selected to have electrical insulating
properties, in order to avoid current passing between the piezoelectric transducer 835 and
the sensor base 820. In alternative ments, different kinds of electrodes can be
ed as electrodes 815 and insulating properties can be provided by a separate thin
insulating layer, rather than by the insulating material that s the conducting parts of
the electrodes 815.
s 9 and 10 illustrate embodiments of a vibration sensor 900 that is suited
to be led within a water meter assembly g 980 so as to be able to sense
vibrations propagating in the fluid t 310 of the water meter assembly 100. The
vibration sensor 900 operates in a substantially similar way to vibration sensor 800 in
that it uses a biasing element to press the seismic weight 910 downwardly on to the
piezoelectric transducer 935, so that the piezoelectric transducer 935 is compressed
between the seismic weight 910 and a sensor base 920. However, vibration sensor 900 is
ent from ion sensor 800 in that it uses a wave spring 930 as the biasing
element, and in that the vibration sensor 900 comprises a dedicated local processing unit,
for e in the form of a PCB (printed circuit board) 970 located within the housing
940, in order to provide the ons of the sing unit 150. In other words, the PCB
970 is configured to receive the output signals from conductor 925 that are coupled to
receive ical outputs from the piezoelectric transducer 935, and to amplify, filter and
process such output in order to determine whether the sensor vibrations indicate the
presence of a fluid leak am of the position of the vibration senor 900. Such a local
processing unit arrangement may also be ed with embodiments of vibration
sensor 800.
The positioning of the PCB 970 within the housing 940 allows the vibration
sensor 900 to be provided as a standalone unit for ready assembly into the meter assembly
housing 980. The sensor is configured to be mounted onto a ng plate 982 of the
fluid conduit 310 so that the sensor base 920 can receive vibrations propagated through
the mounting plate 982. The mounting plate 982 is formed as a flattened section
extending generally tangentially to the diameter of the fluid conduit 310 and providing a
flat mounting surface through which vibrations propagating into fluid conduit 310 can
be readily transmitted into sensor base 920 when the sensor base 920 is mounted thereto
in a el and abutting arrangement.
[0175] In various embodiments, the vibration sensor according to embodiments
described herein can be coupled as a alone device to another device that is not a
water meter. For example, the vibration sensors described herein may be coupled with a
data-logger and put into service independently of a meter or flow cell.
Figure 9 additionally shows mounting fasteners 928 to couple the sensor base
920 to the mounting plate 982, as well as further fasteners 929 (coupling fasteners) to
couple the vibration sensor housing 940 onto the sensor base 920.
The piezoelectric transducer 935 is similar to piezoelectric transducer 835 (i.e.
cylinder-type PZT or PVDF), except that an insulating material 936 has been wrapped
around the main portion of the cylindrical body of the piezoelectric transducer 935. The
insulating material 936 serves to reduce the potential for electric charge transmitting from
the piezoelectric transducer 935 to the seismic weight inside the cavity defined by the
inner wall 912 of the seismic weight 910. The insulating material 936 is arranged to cover
the conductor 925 that extends from the top ode 915a rd along the
cylindrical side of the piezoelectric transducer 935.
A further ence of vibration sensor 900 over vibration sensor 800 is that a
sealing ring 943 is positioned between the housing 940 and base plate 920 in order to
seal the chamber defined between the housing 940 and the sensor base 920 against
ingress of ulates or moisture.
An output wire bundle and/or connector 967 is coupled to the PCB 970 in order
to e data to an external device and receive power and control signals therefrom.
The output wire bundle/connector 967 comprises 5 wires (though in different
ments this number can be different) that are bundled together in an outer jacket
of insulating material, that can also be used to act as a sealing cable gland to exit housing
940. The output wire bundle may be terminated in the connector to facilitate connection
to a board or a compatible connector in the water meter, without requiring soldering or
the like. As shown in Figure 10, conductors 925 are d directly to an ue front
end 1310 (Figure 13) on the PCB 970, and the output wire bundle/connector 967 is
coupled to a micro-controller 1320 (Figure 13) carried by the PCB 970 and arranged to
allow communication n the vibration sensor 900 and an external device.
Figure 11 illustrates embodiments of a vibration sensor 1100 that is suited to be
installed within a water meter assembly housing 980 so as to be able to sense vibrations
ating in the fluid conduit 310 of the water meter assembly 100. The vibration
sensor 1100 operates in a substantially similar way to vibration sensor 900 in that it uses
a biasing element to press the seismic weight 1110 downwardly on to the piezoelectric
transducer 1135 (which may be the same as the piezoelectric transducer 935), so that the
piezoelectric transducer 1135 is compressed between the seismic weight 1110 and a
sensor base 1120. However, vibration sensor 1100 is different from vibration sensor 900
in that it uses a coil spring 1130 as the biasing element. Although not shown in Figure
11, the vibration sensor 1100 may se a PCB 970 (as shown and described in
relation to Figures 9 and 10) located within a part of a bracket 1140 (that functions as a
partial housing) and configured to provide the functions of the sing unit 150.
Sensor 1100 may se a similar conductor and output wire bundle/connector
arrangement as is described and shown in relation to vibration sensor 900.
Additionally, vibration sensor 1100 differs from vibration sensor 900 in that it
has a seismic weight 1110 of a different configuration and a top portion 1141 of the
bracket 1140 has a downwardly projecting boss as the registration formation 1142 for
positioning the biasing element (spring 1130). A further difference lies in the sensor base
1120 having a central recessed area that is ed from a flat upper surface of the sensor
base 1120. The central recessed area is sized to receive an electrode 915b and a lower
part (e.g. a lower 10-30%) of the lectric ucer 1135.
The c weight 1110 has a generally similar configuration to seismic weight
910, with an upper face 1114 spaced from the bracket top portion 1141, a lower face
1111 spaced from the sensor base 1120, a lower portion 1110a having an inner wall 1112
defining a cavity to receive the piezoelectric transducer 1135, and an upper portion
1110b. The upper portion 1110b s an annularly recessed area with a bearing surface
1113 that defines a surface against which a lower end of the spring 1130 can exert a
downward force. The inner cylindrical face of the annular recessed area of upper portion
1110b is ed to be in contact with the inside helical face of spring 1130 in order to
assist in properly positioning the spring 1130 to be concentric and coaxial with the
seismic weight 1110 and the piezoelectric transducer 1135.
The sensor 1100 is configured to be mounted onto a mounting plate 982 of the
fluid conduit 310 so that the sensor base 1120 can receive vibrations propagated through
the ng plate 982. The mounting plate 982 is formed as a flattened section
extending lly tangentially to the diameter of the fluid conduit 310 and providing a
flat mounting surface through which vibrations propagating into fluid conduit 310 can
be readily transmitted into sensor base 1120 when the sensor base 1120 is mounted
thereto in a parallel and abutting arrangement.
Figure 11 additionally shows mounting fasteners 1128 to couple the sensor base
1120 to the ng plate 982, as well as further fasteners 1129 (coupling fasteners) to
couple the vibration sensor housing 1140 onto the sensor base 1120.
Vibration sensor 1100 differs from vibration sensor 900 in that bracket 1140
does not define an ed space and functions mainly as a means of securing and
positioning the spring 1130 to bias rdly on the seismic weight 1110.
The piezoelectric transducer 1135 may be substantially similar to piezoelectric
transducer 935 (i.e. cylinder-type PZT or PVDF), with an ting material 936
wrapped around the main portion of the cylindrical body of the piezoelectric transducer
1135. The insulating al 936 is arranged to cover the conductors (not shown in
Figure 11) that extend from the top electrode 915a downward along the cylindrical side
of the piezoelectric transducer 1135.
[0187] Other than the differences noted above, the vibration sensor 1100 is
substantially similarly configured and operates substantially similarly to vibration sensor
500, 800, and 900 as described herein.
Figures 12A, 12B, 12C and 12D illustrate further embodiments of a vibration
sensor 1200 that is suited to be installed within a water meter assembly housing 980 so
as to be able to sense vibrations propagating in the fluid conduit 310 of the water meter
assembly 100. The ion sensor 1200 operates in a substantially r way to
vibration sensors 800, 900 and 1100 in that it uses a biasing element to bias the seismic
weight 1210 rdly on to a piezoelectric transducer 1235 (which may be the same
as the piezoelectric transducer 835 or 935), so that the piezoelectric transducer 1235 is
compressed between the seismic weight 1210 and a sensor base 1220. However,
ion sensor 1200 is different from vibration sensor 900 in that it uses a coil spring
1230 as the biasing element and because the coil spring 1230 is arranged to pull the
c weight 1210 toward the sensor base 1220 and onto the piezoelectric transducer
1235.
Although not shown in Figures 12A-12D, the vibration sensor 1200 may
comprise a PCB 970 (as shown and described in relation to Figures 9 and 10) located
within a part of a housing (not shown but functionally similar to housing 840, 940 or
1140) and configured to provide the functions of the processing unit 150. Sensor 1200
may comprise a similar conductor and output connector ement as is described and
shown in relation to vibration sensor 900, for example including conductors 925 coupled
at one end to top and bottom printed t electrodes 1215a, 1215b and coupled at an
opposite end to an electrical connector 967 that can couple to a PCB 970 or another
external processing device.
Vibration sensor 1200 may anchor the spring 1230 to the sensor base 1220 and
the seismic weight 1210 by fasteners, such as screws 1231, or other ing means.
An adjustable set screw 1232 is positioned in an axial bore through the seismic weight
1210. The set screw 1232 can be manually adjusted to push (or not push) the seismic
weight axially away from the piezoelectric transducer 1235, via a free movable spacer
1233 that is disposed within the axial bore in between the set screw 1232 and the
piezoelectric transducer 1235, to allow the spring 1230 to be placed under more (or less)
tension and thereby apply more (or less) force to push the seismic weight 1210 onto the
piezoelectric transducer 1235 ng compression thereto. The set screw 1232 may be
substantially fixed in position.
The seismic weight 1210 is different from seismic weight 835, 935 and 1135 in
that it does not receive the lectric ucer 1235 within an internal cavity.
d, that cavity is defined by a part of the sensor base 1220. The seismic weight 1210
needs to be axially aligned and generally axisymmetric and l/concentric with the
piezoelectric transducer 1235 and give provision for the seismic weight 1210 to be
coupled to a suitable biasing element, such as spring 1230. The sensor base 1220 needs
to be axisymmetric with the piezoelectric transducer 1235 and the seismic weight 1210
so it can efficiently it to the piezoelectric transducer 1235 ions from a
e it is coupled to.
Vibration sensors 800, 900, 1100 and 1200 operate according to similar
ples to vibration sensor 500 in that all such sensors rely on the combination of a
piezoelectric transducer positioned in between a sensor base and a seismic weight, with
all of those three key elements being axially aligned. There is at least one conductor
coupled to the lectric transducer. Embodiments may use two such conductors. The
sensor base, the piezoelectric transducer and the seismic weight are arranged so that
relative movement between the sensor base and the seismic weight arising from a
vibration source through the sensor base causes a current to be generated in the
lectric transducer and an output signal corresponding to the generated current is
then detectable on the at least one conductor. In vibration sensor embodiments 500, 800,
900, 1100 and 1200, the seismic weight 510, 810, 910, 1110, 1210 is preferably generally
axisymmetric and is coaxial and concentric with the piezoelectric transducer 535, 835,
935, 1135, 1235 about the same central (longitudinal) axis defined h the centre of
the piezoelectric sensor. Thus, the seismic weight 510, 810, 910, 1110, 1210 preferably
has a round profile in plan view (e.g. as seen in Figure 12C).
In the embodiment of vibration sensor 1200, the seismic weight 1210 is
ted to the sensor base 1220, in this case by the spring 1230. On the other hand,
other embodiments, such as vibration sensors 800, 900, 1100, do not have the seismic
weight and the sensor base connected to each other; rather, they are held in position
relative to each other by the housing. The variable compression using a le biasing
element in sensors 800, 900, 1100 and 1200, versus the static compression using the preload
of the affixing shaft 530 in sensor 500 assists in achieving increased sensitivity in
ing vibrations.
Other than the differences noted above, the vibration sensor 1200 is
substantially similarly configured and operates substantially similarly to vibration
sensors 800, 900 and 1100 as described herein.
Referring now to Figures 13 and 14, the electrical arrangement employed in the
vibration sensors 800, 900, 1100 and 1200 are described in further detail. Current and/or
e signals detected via electrodes 815, 915, 1115, 1215 on the piezoelectric
transducer are received at analogue front end circuitry 1310 by conductors 925. The
analogue front end circuitry 1310 provides a half rail offset and amplifies s in the
frequency region of st (i.e. up to 1 kHz, and ly up to 4 kHz in some
embodiments), while only using a single side supply. To achieve this, the signals received
via conductors 925 are first biased with large value pull-up and own resistors
1412a, 1412b and are then fed into the positive terminal 1415a of an operational amplifier
1415. The negative al 1415b of the operational amplifier 1415 is driven by the
output of the operational amplifier 1415 that has been first fed through a ss filter
1417. Because of the inverse nature of the ck-gain onship, the analogue front
end circuitry (AFE) 1310 achieves an overall response of 1 for all DC signals (consisting
only of the DC off-set introduced by the biasing resistors) and a gain that rapidly
approaches a configurable amount for frequencies above DC.
Output signals 1312 from the analogue front end circuitry 1310 are received at
an analogue-to-digital converter (ADC) 1325 that may form part of microcontroller 1320
forming part of the PCB 970 or may be separate from and connected to the
microcontroller 1320. Thus, the amplified and filtered signals received on conductors
925 are converted by the ADC 1325 into digital signals that are stored in a memory 1335
of the microcontroller 1320. The memory 1335 may comprise flash memory and random
access memory (RAM), for example. An example microcontroller that can be used as
microcontroller 1320 is the STM32F091RB microcontroller from
oelectronicsTM, for example.
[0197] The ADC 1325 samples the analogue output of the AFE 1310 at a sampling rate
that is twice the maximum frequency of interest during a ermined sampling time
period (set as a configuration parameter of the microcontroller 1320). The predetermined
sampling time period may be set as the number of FFT sample frequencies divided by
the sampling rate. Timer functions of the microprocessor 1330 can be used for controlling
the ADC sampling interval. The predetermined sampling time period may be in the range
of between around 0.05 s to about 1.0 second, optionally about 0.05 seconds to
about 0.2 seconds, for example. In some embodiments, the predetermined sampling time
period may be about 0.1 seconds, for example.
The sampled signals from the AFE 1310 are output from the ADC 1325 to a
sor 1330 in the microcontroller 1330 and are stored as digitised s in
memory 1335. The digitised samples are sed by the processor 1330 executing a
frequency analysis algorithm stored in a non-transitory part (i.e. flash) of the memory
1335 of the microcontroller 1320. This algorithm involves the processor 1330 performing
a calculation of a fast Fourier orm (FFT) on the stored digitized samples. Using the
complex values of the results from the FFT calculations performed by the processor
1330, the magnitude of each one of the complex amplitudes at each sampled frequency
is then stored by the sor 1330 in an array in the memory 1335. The processor 1330
then scans the array of amplitude values to e the amplitude values for specific
frequency bands with predefined ude thresholds (stored in memory 1335) for those
bands. If the magnitude in one or more specific frequency bands is above the predefined
thresholds for the respective band and the amplitude thresholds of any other bands
matching a certain frequency profile of a particular kind of fluid leak, then the
microcontroller 1320 sets an alarm flag or indication to indicate that the sensed vibrations
indicate the presence of a fluid leak in the vicinity of the vibration sensor 900.
[0199] In some ments, the processor 1330 performs a single set (one or more)
of comparisons to look for a specific frequency pattern associated with a known
(previously experimentally determined, machine learned or otherwise determined)
frequency signature for a particular leak. This set of comparisons may involve comparing
the detected amplitude in a single frequency band against a single threshold amplitude
value or it may involve ing the detected amplitude in multiple frequency bands
against le respective threshold amplitude values. In some ments, the
processor 1330 performs a series of comparisons in order to compare the sample data
against a series of different frequency profiles associated with a series of distinct kinds
of fluid leaks. In some embodiments, multiple threshold amplitude values may be applied
to the same frequency band, for example where an amplitude above a lower threshold
may te the likely presence of a leak and an amplitude above a higher amplitude in
the same frequency band may indicate a leak of a certain magnitude (e.g. above a 3mm
diameter hole in a t within 10 metres from the location of the vibration sensor).
Once the processor 1330 determines that an alarm flag is to be set, then the
processor 1330 stores an appropriate indication of this in memory 1335 and then es
an output data d for storage and/or ate transmission to the external device
120 via output connector 967. The output data payload includes timing information, such
as a timestamp of when the vibration sensor s were received, any ional status
indicators as to the functioning of the PCB 970 and optionally an indication of the type
of leak detected (if the vibration sensor is configured to detect more than one leak type).
In some embodiments, the data payload may include the stored array of amplitude values
of the received signals at each ncy within the range of interest. The processor 1330
is configured to receive power (e.g. 3.3 V DC) via the tor 967 and to receive
commands, such as an operation (e.g. wake-up) command. Serial communications
between the PCB 970 and the external unit 120 may also be provided by connector 967.
In some embodiments, the processor 1330 may effectively perform a rough
analysis of the received s to flag a possible leak or other condition, and the data
payload may be provided to an external processing , such as a server 210, so that
a final (or possible more accurate) determination can be made about the possible presence
of a leak in the vicinity of the vibration sensor. For example, the server 210 may use data
payloads received from multiple vibration sensors to ine the likely presence or
absence of a leak. If the server 210 receives multiple alarm flags from meters or other
devices coupled to neighbouring or closely spaced vibration sensors, then the server 210
may make a final determination that a leak exists in the vicinity of such vibration sensors.
[0202] Referring to Figures 15A and 15B, some embodiments relate to a leak detection
method 1500 using vibration sensor 500, 800, 900, 1100, 1200 and 1700 (described
below). The method 1500 comprises providing power to the vibration sensor 500, 800,
900, 1100, 1200 and 1700 to enable measurements to be taken, at 1501. The method 1500
further comprises initialising an iteration counter value and a leak counter value, at 1502.
For example, the iteration counter value and the leak counter value may be set by
processor 151, 1330 to an initial value of 0.
At 1504, the iteration counter value is compared to a predetermined iteration
limit. If the iteration counter value is less than or equal to the predetermined iteration
limit, the iteration counter value is incrementally increased, at 1506. The iteration r
value may, for example, be increased by adding a value of 1 to the ion counter value.
If the ion counter value is greater than the predetermined iteration limit, then method
1500 stops. Method 1500 may therefore be repeated a plurality of times equal to the
iteration limit. The iteration limit may be set at a value between 7 and 10 iterations, for
example, but can be configured to have a ent value.
Vibrations propagated through fluid conduit als from upstream locations
are sensed by a piezoelectric transducer and corresponding electrical signals are received
at analogue front end circuitry 1310 by conductors 925. An analogue voltage signal 1312
from the ue front end circuitry 1310 is received and vibration data is recorded, at
1508. As discussed above, the signals may be d and converted into digitised data
and vibration data may be stored in memory 1335. The vibration data may, for example,
comprise voltage amplitude and frequency data.
In some embodiments, at least one of the iteration counter value, the leak
counter value and vibration data may be stored in any one or more of memory 152, 1335,
volatile memory or non-volatile memory.
The analogue voltage signal 1312 is passed through a low-pass filter to reduce
or remove high-frequency signals. For example, frequencies above 1.2 kHz may be
filtered out.
In some embodiments, the ue voltage signal 1312 may be passed through
a ass filter to reduce or remove low-frequency signals, at 1509. For e,
frequencies below about 360 Hz may be filtered out.
A Fast Fourier Transform (FFT) is then applied to the recorded data to separate
a set of frequency bands approximating the frequency um of the low-pass filtered
signals, at 1510.
In some embodiments, the FFT transformed data is filtered to remove low
frequency data, at 1511. For example, frequencies below about 360 Hz may be deleted.
In other embodiments, low frequency data (e.g. data relating to frequencies less than 360
Hz) may be stored but ignored when FFT is applied. In some embodiments, the FFT is
d to recorded data over a frequency range of interest. For example, the ncy
range of interest may be between about 360 Hz to 1.2 kHz.
[0210] The amplitude of the FFT data at each frequency is compared to an amplitude
old, at 1513. If a threshold number of the amplitudes in the FFT data is greater than
or equal to the amplitude threshold, then the leak counter value is entally
increased, at 1514. The leak counter value may, for example, be increased by adding a
value of 1 to the leak counter value. In some embodiments, the threshold number of
amplitudes required to increment the leak counter may be one amplitude, i.e. if the
amplitude at any frequency is greater than or equal to the amplitude threshold, then this
indicates a potential upstream (or possibly downstream) leak and the leak counter value
is incremented.
The amplitude threshold may, for example, be in the range of about 200 micro-
Volt seconds to about 500 micro-Volt seconds, optionally about 200 µV.s to about 400
µV.s, and optionally about 250 µV.s to about 350 µV.s. In some embodiments, the
amplitude old is about 300 micro-Volts seconds.
In some embodiments, only the FFT data over a frequency range of interest is
compared to the amplitude threshold. For example, the frequency range of st may
be between about 360 Hz to 1.2 kHz. The frequency range of interest may be divided
into frequency bands of equal range, for example, 10 Hz or 20 Hz bands.
At 1520, the leak counter value is compared to an alarm level. If the leak counter
value is greater than or equal to the alarm level, then a detection flag is set to a ‘yes’ state
to indicate that a leak has been ed, at 1522. The ‘yes’ state may, for example,
correspond to a binary flag value of 1. Method 1500 is then stopped. The requirement of
a leak counter being greater than the alarm level may advantageously reduce the
occurrence of false alarms being raised as the amplitude must be greater than or equal to
the amplitude threshold a number of instances before an alarm is . In some
embodiments, the alarm level may be between 3 and 10 counts, optionally between 4 and
6 counts. In some embodiments, the alarm level may be 5 counts. The alarm level is less
than the ion limit.
In some embodiments, an alarm signal may be sent to a server 210 if the
detection flag is set (but before the method 1500 is stopped) to indicate that the detection
flag is set. In other embodiments, the state of the ion flag is stored for later retrieval
in a data payload by the server 210. The alarm signal may be sent before, after or while
the detection flag is set.
If the leak counter value is less than the alarm level, then an iteration period is
waited, at 1524, before returning to step 1504. The iteration period may be between about
and about 20 minutes, for example. In some embodiments, the iteration period is about
minutes.
[0216] Referring to Figures 16A and 16B, some embodiments relate to a leak detection
method 1600 using vibration sensor 500, 800, 900, 1100, 1200 and 1700 (described
below). The method 1600 comprises providing power to the ion sensor 500, 800,
900, 1100, 1200 and 1700 to enable measurements to be taken, at 1601. The method 1600
r comprises initialising an iteration counter value, a leak counter value and in some
embodiments, a burst counter value, at 1602. For e, the iteration counter value,
the leak counter value and the burst counter value may be set by processor 151, 1330 to
an initial value of 0.
At 1604, the iteration counter value is compared to a predetermined iteration
limit. If the iteration counter value is less than or equal to the predetermined iteration
limit, the iteration counter value is incrementally increased, at 1606. The iteration r
value may, for example, be sed by adding a value of 1 to the iteration counter value.
If the iteration counter value is greater than the predetermined iteration limit, then method
1600 stops. Method 1600 may therefore be repeated a ity of times equal to the
iteration limit. The iteration limit may be set n 7 and 10 iterations, for example,
but can be configured to have a different value.
Vibrations propagated through fluid conduit als from upstream locations
are sensed by a piezoelectric transducer and corresponding electrical signals are received
at analogue front end circuitry 1310 by conductors 925. An analogue voltage signal 1312
from the analogue front end circuitry 1310 is received and vibration data is recorded, at
1608. As discussed above, the s may be sampled and converted into digitised data
and vibration data may be stored in memory 1335. The vibration data may, for example,
comprise voltage amplitude and frequency data.
In some embodiments, at least one of the iteration r value, the leak
counter value, the burst counter value and ion data may be stored in any one or
more of memory 152, 1335, volatile memory or non-volatile memory.
The analogue e signal 1312 is passed through a low-pass filter to reduce
or remove high-frequency signals. For example, frequencies above 1.2 kHz may be
filtered out.
In some embodiments, the analogue voltage signal 1312 may be passed through
a high-pass filter to reduce or remove low-frequency signals, at 1609. For example,
frequencies below about 360 Hz may be filtered out.
[0222] A Fast Fourier Transform (FFT) is then applied to the recorded data to separate
a set of frequency bands approximating the frequency spectrum of the low-pass filtered
signals, at 1610.
In some embodiments, the FFT ormed data is filtered to remove low
frequency data, at 1611. For example, frequencies below about 360 Hz may be deleted.
In other embodiments, low frequency data (e.g. data relating to frequencies less than 360
Hz) may be stored but ignored when FFT is applied. In some embodiments, the FFT is
applied to recorded data over a frequency range of interest. For example, the frequency
range of interest may be between about 360 Hz to 1.2 kHz.
The FFT data may be analysed to calculate an amplitude metric at 1612. The
amplitude metric may be calculated over a frequency range of interest. For example, the
frequency range of interest may be between about 360 Hz and 1 kHz or 360Hz and 1.2
kHz. The ude metric represents the power or strength of the sensed signal.
In some embodiments, the amplitude metric may be, for example, an integration
of the FFT data (integrating under the ‘curve’).
In some embodiments, the amplitude metric may be a root mean square (RMS)
value for the FFT data over the frequency range of interest.
[0227] A detection ratio x is ated by dividing the amplitude metric by a noise
value, at 1613. The noise value is indicative of a background value for the metric where
a leak would not be considered to be occurring. The noise value may be calibrated for
each location where a ion sensor is placed or may be generalised for a water supply
network or a sub-network. For example, the noise value for the amplitude metric that is
an RMS value may be 40 micro-Volt seconds.
The detection ratio x is then compared to a first detection threshold, at 1614. If
the detection ratio x is greater than or equal to the first detection threshold, then the leak
counter value is incrementally sed, at 1618. The leak counter value may, for
e, be increased by adding a value of 1 to the leak counter value. In some
embodiments, the first detection threshold may be in the range of about 2 to 5, for
example. In some ments, the first detection threshold may be about 3.5.
The sensed vibration signal strength may be correlated with the severity of a
leak. As the detection ratio x is indicative of the signal strength, it may be advantageously
used to determine if the vibrations are indicative of a burst or very severe leak. In some
embodiments, if the detection ratio x is greater than or equal to the first detection
threshold, then the ion ratio x is further compared to a second detection threshold,
at 1615. The second detection threshold is greater than the first detection threshold. If the
detection ratio x is greater than or equal to the second detection old, then the burst
counter value is incrementally increased, at 1616. The burst r value may, for
example, be increased by adding a value of 1 to the burst counter value. In some
ments, the second detection threshold may be in the range of about 5 to about 30,
optionally about 15 to about 25, for example. In some ments, the first detection
threshold may be about 20.
At 1619, the leak counter value is compared to a leak alarm level. If the leak
counter value is greater than or equal to the leak alarm level, then a leak detection flag is
set to a ‘yes’ state to indicate that a leak has been detected, at 1621. For e, setting
the leak detection flag to ‘yes’ may pond to setting a binaryflag value to 1. The
method 1600 is stopped after a leak detection flag is set. Requiring a leak counter value
may advantageously reduce the occurrence of false alarms being raised as the ion
ratio must be r than or equal to the first detection threshold a number of instances
before the alarm is raised. In some embodiments, the leak alarm level may be between 3
and 10 counts, optionally between 4 and 6 counts. In some embodiments, the leak alarm
level may be 5 counts. The leak alarm level is less than the iteration limit.
In some embodiments, if the leak counter value is greater than or equal to the
leak alarm level, then the burst counter value is compared to a burst alarm level (before
stopping the method), at 1620. If the burst counter value is greater than or equal to the
burst alarm level, a burst detection flag is set to a ‘yes’ state indicate that a burst has been
ed, at 1622. For example, setting the burst detection flag to ‘yes’ may correspond
to setting a binary flag value to 1.The method 1600 is stopped after a burst detection flag
is set to ‘yes’. In some situations, the leak detection flag and the burst detection flag may
both be set to ‘yes’. In some embodiments, the burst alarm level may be between 3 and
counts, optionally between 4 and 6 counts. In some embodiments, the burst alarm
level may be 5 counts. The burst alarm level is less than the ion limit.
In some embodiments, a leak alarm signal may be sent to a server 210 if the leak
detection flag is set e the method 1600 is stopped) to indicate that the leak ion
flag is set. A burst alarm signal may be sent to a server 210 if the burst detection flag is
set (but before the method 1600 is stopped) to indicate that the burst detection flag is set.
The leak and burst alarm signals may be sent before, after or while the leak detection flag
is set.
In other embodiments, the state of the leak and/or burst detection flags are stored
for later retrieval in a data payload by the server 210. In some ments, only a burst
alarm signal is sent to the server 210 while the leak detection flag is stored for later
retrieval.
If the leak counter value is less than the alarm level, then an iteration period is
waited, at 1624, before returning to step 1604. The iteration period may be between about
10 and about 20 minutes, for example. In some embodiments, the iteration period is about
minutes.
As method 1500, 1600 is limited to a set number of iterations, sensing and leak
detection is also limited to a certain time period. This ts sensing and leak detection
from occurring over the entire predetermined time period. This is advantageous as it
reduces energy consumption and timing can be selected to avoid noisy periods of time
that correspond to peak water usage. By limiting the time over which method 1500, 1600
occurs, us alarms may be reduced and alarms for slow and intermittent leaks may
be reduced or avoided.
In some embodiments, the vibrations are sensed and vibration data is ed
for a predetermined length of time in method 1500, 1600. The predetermined length of
time may be in the range of 0.05 seconds to 0.2 seconds, optionally about 0.1 seconds,
for example.
In some embodiments, the vibrations are sensed and vibration data is recorded
between a predetermined time . The predetermined time period may, for example,
be between midnight and 6 am. The predetermined time period may pond with
times that there is low background (ambient) acoustic and/or vibrational noise. Sensing
and recording during the predetermined time period may therefore ageously result
in better signal-to-noise ratios for recorded vibration ements.
In some embodiments, methods 1500, 1600 are applied to leak detection at
different locations using multiple separate vibration sensors, whether integrated into or
connected with a water meter 100. Different vibration sensors may sense and record data
obtained from different ons. Signals from each of the different vibration sensors
may be sent to a server 210 and an alarm may be raised only if an alarm signal, leak
alarm signal or burst alarm signal is received from multiple vibration s.
The sensor housing of various embodiments of vibration sensors described
above (e.g., sensors 800, 900, 1100) may be formed of a plastic material or suitable metal
material. It is generally preferred that the sensor housing be sealed, for e using a
roof seal such as a sealing ring 943. For the biasing element applied in vibration
sensors 800, 900, 1100 and 1200, a stainless steel or spring steel spring (or multiple such
springs) is considered suitable. The biasing element may have a spring nt in the
range from 1 to 15 N/mm, optionally from 2 to 15 N/mm or 3 to 12 N/mm, for example.
A suitable force on the seismic weight may be in the range of about 45 to about 60
newtons, for e.
The c weight can comprise or consist of a brass alloy or manganese
bronze or other suitable density material. The mass of the seismic weight may be in the
range of 50 grams to about 200 grams, for example. Optionally, the mass of the seismic
weight may be in the range of 100 grams to 175 grams, for example.
The electrodes positioned at each opposite end of the piezoelectric transducer in
sensors, 800, 900, 1100 and 1200 can be formed of either a rigid or flexible material,
with a thickness ranging from about 0.2mm to about 1.6mm, for example. The
conductive tracks may be printed on one side (the side facing the piezoelectric
transducer) of the flexible material, with the other side comprising substantially
insulating material, for example.
While the piezoelectric transducer of various embodiments can se a
PVDF material, a PZT material may perform better under certain circumstances. For
example, PZT columnar shaped piezo-ceramic material used for the piezoelectric
transducer may have an example column diameter of about 6.35mm. The piezoelectric
material may have a piezoelectric voltage constant (g33) in the range of about 0.02 to
about 0.03Vm/N, for e.
[0243] The sensor base may comprise a brass alloy or other metal that can be suitably
flat and smooth, with a surface finish suited for optimal transfer of vibrations between
the flow conduit 310 and the bottom or the piezoelectric ucer. In some
embodiments, ers 929 used to couple the housing on to the sensor base may
include, for example break-stem blind pop rivets, self-tapping screws for thermoplastics
or machine screws and nuts. The fasteners 929 need to be able to clamp the sensor
housing and base together against the spring force (e.g., 45 to 60 newtons) and the sealing
force combined, and to be resistant to loosening due to vibrations.
Referring to Figures 17 to 22, further embodiments of a ion sensor 1700
are shown and described. The vibration sensor 1700 is substantially the same in
operation, structure and function as vibration sensor 900, with the y difference
being that a different electrical conductor uration is used to sense the ical
output of the piezoelectric transducer 935. Like reference numerals are used among the
drawings to te the same physical features or functions as between the vibration
sensor 1700 and the vibration sensor 900.
[0245] The vibration sensor 1700 uses a printed circuit board 1765 that has a rigid
component 1770 and a flexible component 1780. The flexible component 1780
comprises a le coupling portion 1775 that acts as a bridge n the rigid printed
circuit component 1770 (that houses the main electrical circuits as shown in Figure 22)
and a foldable portion of the flexible printed circuit 1780. The foldable portion is
arranged to partially surround and contact the top and bottom surfaces of the piezoelectric
transducer 935 in order to sense the electrical output thereof. In addition to the
entioned differences from vibration sensor 900, vibration sensor 1700 may
employ a gasket 1743 (instead of the sealing ring 943) for g the internal chamber
of the vibration sensor 1700 against the ingress of water or gas. Additionally, the top
housing part 1740 is slightly different from housing part 940, with an electrical tor
e defined at one end to extend close to the base plate 920. Different fasteners,
such as bolts or screws 1729 may also be employed.
[0246] Figures 20A, 20B, 21A and 21B illustrate the d circuit component 1765
in further detail. Figure 20B shows the le printed circuit portion 1780 in a folded
configuration and Figure 18 shows how the piezoelectric transducer 935 is situated to be
lly wrapped by the flexible printed circuit component 1780. The flexible printed
circuit portion 1780 comprises a lower portion 1781 and an upper portion 1791 joined
by a second coupling portion 1785 that extends between the lower portion 1781 and
upper portion 1791.
The lower flexible printed circuit portion 1781 has a base 1784 with an upper
side 1784A that has exposed conductive material (that may be gold , for example)
thereon for receiving electrical potential variations (in the form of current and voltage)
arising from ical contact with the bottom of the piezoelectric transducers 935. The
base 1784 also has a rigid bottom disc or plate portion 1784b (for example, formed of
fibreglass “FR-4”) that is an electrical insulator but which is rigid enough to transmit
vibrations propagated through the sensor base 920 without substantial attenuation. The
lower flexible printed circuit portion 1781 also has folding fingers or wings 1783 that are
deformable from a flat configuration (see Figure 20A) to a folded configuration (see
Figure 20B) in order to shield a lower part of the piezoelectric ucer 935 from
contact with an inner surface of the seismic weight 910.
The upper flexible printed t part 1791 has a generally flat top portion 1794,
which has a lower (inner) surface 1794A with exposed electrically conductive material
(e.g., gold plated) and has a rigid insulating disc or plate portion 1794b on the upper
(outer) face thereof. Similar to the lower portion 1781, the upper portion 1791 has a
plurality of fingers or wings 1793 that can fold by bending or deforming to at least
partially cover an upper part of the outside cylindrical wall of the piezoelectric transducer
935 to shield it from electrical contact with an inner wall of the c weight 910.
As seen best in s 21A and 21B, the flexible printed circuit 1780 has
conductors d thereon and extending from the top portion 1791 and the bottom
portion 1781 to the rigid printed circuit board component 1770. In order to avoid the
conductors for the top portion 1791 interfering with or crossing the conductors of the
bottom portion 1781, a first conductor (or set of conductors) 1796a is coupled to the
conductive area of the conductive lower surface 1794a of the top portion 1794. The first
conductor 1796a extends along an inner wall of coupling portions 1785 without
extending all the way to the lower portion 1781. Instead, to ue to conduct electrical
signals, the first conductor 1796a couples to further first conductors 1796b on an opposite
side of the second coupling portion 1785 by conductive h holes (not shown). The
first tors 1796B then pass between the plate or disc 1784b and the upper
conductive surface 1784a of the bottom portion 1784, with the first conductor 1796b
continuing on the underside of first coupling portion 1775 to finally couple (via through
holes) to electrodes 1797 carried on the vely rigid ate 1772 of the rigid PCV
portion 1770. The second conductors 1776 extend on a side of coupling portion 1175
opposite from conductors 1796 directly from the upper conductive surface 1784a of the
bottom portion 1784 to electrodes or other circuit components on the vely rigid
substrate 1772.
As shown in the drawings, the upper set of s 1793 are ed in a spaced
array which, together with the second coupling portion 1785 that extends like a strip
n the top portion 1791 and the bottom portion 1781, serves to generally avoid
contact between the material of the piezoelectric transducer 935 and the inside wall of
the seismic weight 910 (or other seismic weights described herein). A different
arrangement of protective fingers or wings 1783 is provided extending from the lower
portion 1781 which, together with the strip material of the coupling portion 1785, also
serves to shield the piezoelectric transducers 935 from contact with the seismic weight
Use of a single printed circuit board 1765 that has a flexible component 1780
and a rigid component 1770 allows for improved ease and efficiency of assembly of the
piezoelectric transducer and electronic interface circuitry with the seismic weight 910
and the housing 1740 and sensor base 920. Both the bottom and top insulating discs or
plates 1784B and 1794B are selected to be of sufficiently rigid material to substantially
avoid dampening vibrations transmitted through the base plate 920 and thereby
substantially avoid dampening relative movement n the piezoelectric transducer
and the seismic weight 910.
Figure 22 shows a further schematic circuit diagram to illustrate an alternative
circuit layout for the printed t board assembly 970, shown in the embodiment of
Figure 22 as printed circuit board assembly 2270. Analogue front end 2210 shown in
Figure 22 is lly analogous to the analogue front end 1310 shown in s 13 and
14, but for a slight difference in arrangement (and values) of the output resistors and
capacitors. The electrical conductors 1776 and 1796 shown in Figures 21A and 21B
provide the input to the analogue front end 2210. A ontroller unit 2220 is provided
in the printed t board assembly 2270 and is similar in function to the
microcontroller 1320 as bed above. Power l circuitry 2267 is further
comprised in the printed t board assembly 2270 and allows for receipt of a wakeup
signal from an al controller, such as the water meter controller 120. S eparate
circuitry (not shown) may be provided for enabling communication between the
microcontroller 2220 and an external controller.
It will be appreciated by s skilled in the art that numerous variations
and/or modifications may be made to the above-described embodiments, without
departing from the broad general scope of the present disclosure. The present
embodiments are, therefore, to be considered in all respects as illustrative and not
restrictive.
THE
Claims (22)
1. A water meter, sing: a flow tube defining a lumen to receive water through the lumen, wherein the flow tube is configured to be coupled to a water supply network; 5 a housing coupled to the flow tube and containing a self-contained power source, at least one processor, a memory and a wireless transceiver; a flow sensor positioned to measure liquid flow through the lumen and coupled to the at least one sor to provide flow measurement signals to the at least one sor; and 10 a vibration sensor arranged to sense vibration in a material of the flow tube and coupled to the at least one processor to provide vibration measurement signals to the at least one processor, the vibration sensor sing a piezoelectric ucer and is arranged to abut the flow tube without extending into the lumen; wherein the at least one processor is configured to process the flow measurement 15 s and the vibration measurements signals and to determine an upstream liquid leakage status based on at least the vibration measurement signals; wherein the at least one processor is ured to transmit the upstream liquid leakage status and flow measurement signals to a remote server wherein the vibration sensor comprises a sensor base positioned proximal to the 20 flow tube, at least one transducer or transducer substrate coupled to the sensor base, and a seismic weight coupled to the sensor base distal of the at least one transducer or transducer substrate, and wherein the at least one processor receives the vibration ement signals based on electrical outputs from the at least one transducer or transducer substrate.
2. The meter of claim 1, wherein the at least one processor is configured to determine the upstream liquid leakage status by determining a frequency spectrum of the vibration measurement signals and determining whether an amplitude of the frequency spectrum in at least one frequency band is at or above a predetermined 30 old amplitude.
3. The meter of claim 2, n the at least one processor is further ured so that, when the amplitude in the at least one frequency band is determined to be at or above the predetermined old amplitude, the at least one processor records a leakage detection indication of a possible upstream liquid leak in the water supply network. 5
4. The meter of claim 3, wherein the at least one processor sets the upstream liquid leakage status to indicate a detected liquid leak once a ermined number of leakage detection tions have been ed.
5. The meter of any one of the preceding claims, further comprising a spring 10 arranged to bias the seismic weight against the at least one transducer or transducer substrate.
6. The meter of claim 3 or claim 4, wherein the at least one processor is further configured to apply a further threshold to the frequency spectrum to determine the 15 likely presence of an upstream fluid conduit burst in the water supply network.
7. The meter of any one of the preceding claims, wherein the at least one processor is configured to selectively enable receipt of the vibration measurement signals at predetermined times in a ing cycle.
8. The meter of claim 7, wherein the predetermined times are during at least one off-peak water usage period.
9. The meter of claim 7 or claim 8, wherein the ermined times are 25 ted by one to ten time intervals.
10. The meter of any one of the preceding claims, further comprising a magnetometer positioned in the housing to sense a magnetic field of the flow tube and configured to provide a ic field sensor output to the at least one processor, 30 wherein the at least one processor is configured to determine an electrical current in the flow tube based on the magnetic field sensor output.
11. The meter of claim 10, wherein the at least one processor is configured to set a leakage current alarm if the electrical current is determined to meet or exceed a humansafe current threshold.
12. The meter of any one of the preceding claims, wherein the flow sensor is an ultrasonic flow sensor.
13. The meter of any one of the ing claims, n the at least one 10 processor is configured to transmit the upstream liquid leakage status to the remote server from one to five times in a two day period.
14. The meter of any one of the preceding claims, wherein the at least one processor comprises a first processor to receive and s the vibration ement 15 signals and a second processor to receive and process the flow ement signals.
15. The meter of claim 14, wherein the first sor provides the upstream liquid leakage status to the second processor for transmission to the remote server. 20
16. The meter of claim 14 or claim 15, wherein the memory comprises: a first memory accessible to the first processor but not the second processor; a second memory accessible to the second processor but not the first processor.
17. The meter of any one of the preceding claims, further comprising at least one sensor selected from: a pressure sensor to sense water pressure in the flow tube; a stray current sensor to sense current in the flow tube; 30 an electrical conductivity sensor to sense ical conductivity of fluid in the flow tube; a fluid temperature sensor to sense temperature of fluid in the flow tube; a pH sensor to sense pH of fluid in the flow tube; a turbidity sensor to sense turbidity of fluid in the flow tube; or a free chlorine sensor to sense free chlorine in fluid in the flow tube.
18. A water supply system, comprising: 5 a network of water supply conduits; a plurality of water meters of any one of the preceding claims coupled to the network of water supply conduits at spaced water supply endpoints; and the remote server, wherein the remote server is configured to generate a leakage notification when the upstream liquid e status of at least one of the plurality of 10 water meters indicates detection of an upstream liquid leak.
19. A server system configured to communicate with a ity of water meters according to any one of claims 1 to 18 to receive upstream leakage status information from the water meters and to generate a leakage notification when the upstream liquid 15 leakage status of at least one of the meters indicates ion of an upstream liquid leak.
20. The server system of claim 19, n the upstream leakage status information is based on vibrations sensed at the water meters in relation to vibrations transmitted along fluid conduits of an upstream water supply network.
21. A system configured to ine leakage in a water supply network, comprising: a k of fluid supply conduits; a ity of water meters according to any one of claims 1 to 17 coupled to the network at spaced water supply nts, each water meter configured to take sensor 25 readings of one or more local conditions at the respective water meter and to communicate a data payload to an external system, the data payload including information based on the sensor readings; and a remote server to receive the data payloads from the water meters, n the remote server is configured to generate a leakage notification when the information 30 indicates a leakage in the water supply k.
22. A method of leakage detection in a fluid supply network, comprising, receiving at a water meter according to any one of claims 1 to 17, coupled at a supply end-point of fluid supply network, vibrations propagated from fluid conduits that 35 form part of the fluid supply network; determining a leakage status based at least in part on the vibrations; and ing a remote server of the leakage status.
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
AU2016904153A AU2016904153A0 (en) | 2016-10-13 | Water meter | |
AU2017902012A AU2017902012A0 (en) | 2017-05-26 | Vibration sensor for fluid leak detection | |
NZ752668A NZ752668A (en) | 2016-10-13 | 2017-10-13 | Vibration sensor for fluid leak detection |
Publications (1)
Publication Number | Publication Date |
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NZ767986A true NZ767986A (en) | 2022-07-29 |
Family
ID=83229129
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
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NZ767986A NZ767986A (en) | 2016-10-13 | 2017-10-13 | Water meter and systems |
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NZ (1) | NZ767986A (en) |
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2017
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