Leak detection device

Abstract

A leak detection device 100 comprising a substantially watertight housing 102 configured to be coupled to a pipe network; and a sensor assembly disposed within the housing. The sensor assembly compris

Description

Field of the Invention The present invention relates to leak detection devices. In particular, the present invention relates to leak detection devices configured to detect fluid leaks in pipe networks. Background of the Invention The UK’s water security is being impacted by population increase, urbanisation and climate change. In particular, global temperature rises are contributing to hot, dry summers, less predictable rainfall and an overall decrease in rainfall with a reduction of 10% predicted by 2050. As such, a risk of drought is currently increasing and is expected to rise further. At the same time, 3 billion litres of water are lost every day in the UK through leaks in mains pipe networks. The economic and environmental cost of water leaks is substantial. Leaks can form in pipework that is corroded and weakened through extended use, as well as pipework that is under strain due to ground movement, such as shifting building foundations. Accordingly, there is a need to tackle the excessive loss of water through leakage to promote water security. Summary of the Invention At its most general, the present invention provides a device for monitoring a pipe network for leaks. The device comprises a substantially watertight housing and a sensor assembly disposed within the housing. The sensor assembly comprises a sensor, such as a micro-electromechanical system, MEMS, microphone, in acoustic communication with an air pocket. The air pocket is configured to transmit vibrations originating in the pipe network to the sensor to enable detection of leaks in the pipe network. The sensor assembly further comprises a board, which may be a printed circuit board assembly, PCBA, on which the sensor is mounted. The board may comprise electrical circuitry to support, e.g., supply power to, the sensor. The board comprises a through-hole cavity disposed proximate the sensor, the cavity forming part of the acoustic air pocket. A second gasket encloses a further part of the acoustic air pocket adjacent the board. According to a first aspect of the invention, there is provided a leak detection device configured to detect a fluid leak in a pipe network, the device comprising: a housing comprising: a base configured to be coupled to the pipe network; a lid configured to be coupled to the base; and a first gasket configured to be disposed between the base and the lid to provide a substantially watertight seal between the base and the lid; and a sensor assembly configured to be disposed within the housing, the sensor assembly comprising: a board configured to be coupled to the base, the board comprising a cavity extending through the board from a first aperture on a first surface of the board to a second aperture on a second surface of the board; a sensor configured to be mounted on the first surface of the board and configured to substantially cover the first aperture; and a second gasket configured to be disposed between the second surface of the board and the base to enclose a space comprising the second aperture and provide a seal between the board and the base; wherein the cavity and the space together define an acoustic air pocket configured to receive vibrations originating in the pipe network via the base; and wherein the acoustic air pocket is configured to transmit the vibrations to the sensor to enable detection of leaks in the pipe network based on the vibrations. The leak detection device may be configured to monitor a pipe network to enable detection of leaks in the pipe network. The device may be configured to detect a liquid leak, e.g., a water leak. Alternatively, the device may be configured to detect a gaseous leak, e.g., a natural gas leak. In many cases, a fluid leak in a pipe network generates vibrations in the pipe network. The vibrations may travel through the components of the pipe network, e.g., pipes and valves. Accordingly, the leak detection device of the present invention enables detection of leaks by being sensitive to vibrations in a pipe network. The device comprises a structure, i.e., the base, configured to receive vibrations from a pipe network and a sensor configured to measure the vibrations to enable detection of leaks in the pipe network. The device comprises a substantially water-tight enclosure, i.e., the housing, through which vibrations are transferred to the sensor. Accordingly, the device is capable of detecting vibrations through a substantially completely sealed enclosure. The device comprises an acoustic air pocket disposed adjacent the sensor. The acoustic air pocket receives vibrations from the structure of the device. In the air pocket the vibrations may be considered as sound waves. The sound waves propagate through the acoustic air pocket and are received by the sensor. The sensor may measure an amplitude and frequency of the sound waves to estimate an amplitude and frequency of the vibrations. In this way, the sensor may measure the vibrations to enable detection of leaks in the pipe network. The device may be substantially cylindrical. That is, the device may have two substantially circular, flat faces connected by a substantially curved face arranged substantially perpendicular to each circular face. The device may comprise a substantially cylindrical shape or a plurality of substantially cylindrical shapes. For example, the device may, in all planes parallel to a flat face, have a substantially circular cross section where a diameter of cross sections varies throughout the device. The base is configured to be coupled to the pipe network. In this way, the leak detection device may be coupled to a component of the pipe network via the base of the housing. Accordingly, the base may be in acoustic communication with the pipe network. The base may be coupled to a pipe, valve, access point, hydrant, stop-tap, reservoir, accumulator or any other suitable part or component of a pipe network. The base may be coupled to the pipe network in any suitable manner. For example, the base may be coupled to the pipe network by a threaded connection, a bayonet connection, a clamped connection, a magnetic connection or a bonded connection. The lid of the housing is configured to be coupled to the base. The lid may be coupled to the base by any suitable connection, such as a threaded connection. The first gasket is configured to be disposed between the base and the lid to provide a substantially watertight seal between the base and the lid. The lid and base may be coupled to compress the first gasket to form an effective seal between the lid and the base. The first gasket may be substantially ring-shaped. That is, the first gasket may be annular. The first gasket may comprise an elastomeric O-ring seal. The first gasket may seal the housing to meet at least ingress protection code 68, IP68, as defined by the International Electrotechnical Commission (I EC) under international standard I EC 60529. The first gasket may even seal the housing to a greater extent. In other words, the device may be dust-tight and protected against immersion at depths of greater than 1 m. Preferably, the first gasket may seal the housing to withstand immersion in water at a depth of 10 m for 48 hours. During such an immersion, the device should preferably suffer no water ingress that would affect a functioning of the device. Following an immersion test, the device may be tested to ensure that its function is unchanged by the immersion. Accordingly, the present invention provides a sealed device capable of detecting leaks from vibrations in a pipe network. The sensor assembly is configured to be disposed within the housing. Accordingly, the housing protects the sensor assembly from the environment of the device. In this way, the sensor assembly is protected from dust and water ingress into the housing and may be rugged and reliable. As such, the sensor may be suitable for use in harsh environments. The device may be configured for use on water pipelines disposed below ground level. As it is protected by the housing, the sensor assembly may have a long operational life span before failure. The sensor assembly comprises a board. The board may be a printed circuit board, PCB, or printed circuit board assembly, PCBA. That is, the board may comprise a PCB with additional electrical components assembled onto the board to form a PCBA. Alternatively, the board may comprise a platform configured to receive circuitry of the device. Alternatively, the board may comprise a platform and circuitry of the device may be disposed elsewhere, for example, in the lid of the housing. The board is configured to be coupled to the base. In this way, the board is supported on the base. The board may be coupled to the base directly or indirectly, e.g., via an intermediate component. By being coupled to the base, the board may be secure within the housing. In this way, motion of the board within the housing is inhibited so that the sensor may accurately measure vibration. In some cases, the board may be acoustically coupled to the base. Alternatively, the board may be acoustically insulated from the base, e.g., by a sound attenuating, damping or deadening intermediate component. The board comprises a cavity extending through the board from a first aperture on a first surface of the board to a second aperture on a second surface of the board. That is, the board comprises a through-hole cavity. The cavity is bounded by the board. The first surface may be opposite the second surface so that the cavity may be substantially straight and cylindrical. In other embodiments, the cavity may have an alternative shape. The cavity may comprise any suitable shape. For example, the cavity may form a curve through the board. The sensor is configured to be mounted on the first surface of the board. The first surface of the board may be an upper surface of the board. Alternatively, the first surface may be an underside of the board. The sensor is configured to substantially cover the first aperture. In other words, the sensor may be disposed so that at least half of the first aperture is covered by the sensor. That is, when viewing the first surface of the board in a direction perpendicular to the first surface, at least half of the first aperture may be obscured from view by the sensor. Preferably, a majority of the first aperture is covered by the sensor and more preferably, the entire first aperture is covered by the sensor. The second gasket is configured to be disposed between the second surface of the board and the base to enclose a space comprising the second aperture and provide a seal between the board and the base. The space may be bounded by the board, base and second gasket. The second gasket may be configured to be disposed on an opposite side of the board to the sensor. In other words, the second gasket may be disposed so that the entire second aperture is inside an area defined by the gasket. The second gasket, the board and the base may together enclose the second aperture. The board and the base may be configured to compress the second gasket to form an effective seal between the board and the base. The second gasket may be substantially ring shaped, or annular. The second gasket may comprise an elastomeric O-ring seal. The cavity in the board and the space enclosed by, or bounded by, the second gasket together define an acoustic air pocket configured to receive vibrations originating in the pipe network via the base. That is, vibrations caused by a leak in the pipe network travel through the pipe network and are received by the base of the device. The acoustic air pocket receives the vibrations from the base. In the acoustic air pocket, the vibrations may be considered as sound waves. The acoustic air pocket is further configured to transmit the vibrations to the sensor to enable detection of leaks in the pipe network. That is, the sound waves in the acoustic air pocket travel through the acoustic air pocket to the sensor and are measured by the sensor. The sensor may measure an amplitude and / or a frequency of the sound waves to estimate an amplitude and / or a frequency of the vibration. From the measured characteristics of the sound waves, presence of a leak in the pipe network may be detected. Any suitable sensor may be used in the device. For example, a piezoelectric sensor may be used. In some embodiments, the sensor is a microphone. Accordingly, the sensor may be configured to collect sound data. In preferred embodiments, the sensor is a microelectromechanical system, MEMS, microphone. Such a sensor may be suitable to detect vibrations in air (i.e., sound) in the acoustic air pocket. Such a sensor may also be lightweight, durable and cost-effective compared to other vibration sensors, e.g., piezoelectric sensors. In other embodiments, other bottom port microphones may be used in the device. In some embodiments, the MEMS microphone comprises a membrane configured to be arranged proximate the first aperture. The membrane may be provided to avoid contamination of the MEMS microphone. The membrane may affect a performance of the MEMS microphone. In particular, a sensitivity, frequency response and / or signal to noise ratio may be affected by the membrane. The membrane may provide an advantageous effect on frequency response as the membrane may dampen resonances and thus extend a usable frequency range of the MEMS microphone. In some embodiments, the board is acoustically coupled to the base such that the acoustic air pocket is configured to receive vibrations originating in the pipe network via the base and the board. The board may be acoustically coupled to the base by being securely clamped to the base. The board may be directly coupled to the base. By being acoustically coupled to the base, the board may also act to provide vibrations to the acoustic air pocket. In this way, the acoustic air pocket may be configured to receive vibrations originating in the pipe network via the base and / or the board. As such, low amplitude vibrations may be received by the acoustic air pocket and transmitted to the sensor. In this way, smaller or more distant leaks in the pipe network may be detected by the device. In some embodiments, the sensor is acoustically coupled to the board such that the acoustic air pocket is configured to receive vibrations originating in the pipe network via the base, the board and the sensor. The sensor may be acoustically coupled to the board by being securely connected to the board. The sensor may be directly coupled to the board, e.g., by a solder joint. By being acoustically coupled to the board, the sensor may also act to provide vibrations to the acoustic air pocket. In this way, the acoustic air pocket may be configured to receive vibrations originating in the pipe network via the base, board and / or sensor. As such, low amplitude vibrations may be received by the acoustic air pocket and transmitted to the sensor. In this way, smaller or more distant leaks in the pipe network may be detected by the device. When the base is excited by vibrations originating in the pipe network, the vibrations may travel through the base and into the board and through the board and into the sensor. The sensor may be configured to measure sound, i.e., vibrating air, rather than vibration of itself. The vibrations may excite the sensor and thereby the acoustic air pocket. By exciting the acoustic air pocket, sound, i.e., vibrating air, is generated and measured by the sensor. In this way, a unique operating principle is employed; vibrations excite the sensor to generate sound in the acoustic air pocket for measurement by the sensor to facilitate the detection of leaks. In some embodiments, the base comprises a mounting element configured to couple the base to a coupling element. The coupling element may be provided by a component of a pipe network. For example, the coupling element may be provided on a hydrant, or a stop tap. The device may be coupled to the coupling element by the mounting element of the base. In other embodiments, the coupling element may be part of the device. In some embodiments, the mounting element comprises a blind hole configured to receive a threaded stud. In other words, the coupling element may comprise a threaded stud. In this way, the mounting element may comprise a tapped, blind hole. The device may be configured to be coupled to a pipe network by any suitable method. As discussed, a tapped hole in the base of the device may be configured to receive a threaded stud provided on a component of the pipe network. Alternatively, the device may be clamped to a component of a pipe network. In some embodiments, the base comprises a pillar configured to be disposed within the housing, the pillar being disposed substantially coaxially with the mounting element; and the second gasket is configured to be disposed between the second surface of the board and the pillar to enclose a space comprising the second aperture and provide a seal between the board and the pillar of the base. In other words, the base may comprise a pillar configured to extend into an internal cavity of the housing. The base may further comprise a mounting element, such as a tapped blind hole. An axis of the mounting element may be arranged collinear with an axis of the pillar. In this way, the mounting element may be arranged substantially opposite the pillar. Where the mounting element is a blind hole, the mounting element may be arranged substantially inside the pillar. In this way, the base may be compact to provide a mounting element and a pillar configured to cooperate with the second gasket to enclose the space. In some embodiments, the pillar may be arranged substantially coaxially with the sensor. Further, the mounting element and / or coupling element may be arranged substantially coaxially with the sensor. By disposing the mounting element substantially coaxially, substantially opposite and / or substantially inside the pillar, the coupling element configured to be coupled to the base by the mounting element may be disposed proximate the space, in use. That is, when the device is installed on a pipe network, the coupling element may be received by the mounting element which may be arranged at least coaxially with the pillar which co-operates with the second gasket to define the space, which forms part of the acoustic air pocket configured to transmit vibrations to the sensor. As such, the sensor of the device may be effectively acoustically coupled to the pipe network for effective monitoring of the pipe network for leaks. The second gasket may be configured to be disposed between the second surface of the board and the pillar to enclose a space comprising the second aperture and provide a seal between the board and the pillar of the base. In this way, a volume of the space may be tuned by adjusting a height of the pillar. Accordingly, the device may be configured to operate in a variety of circumstances to detect a variety of leaks, e.g., liquid or gaseous leaks, by adjusting the height of the pillar. In some embodiments, the leak detection device further comprises a coupling element comprising a magnet configured to couple the base to the pipe network. That is, in some embodiments, the coupling element is part of the device and the device is configured to be coupled to a component of a pipe network by the coupling element. The coupling element may comprise a magnet configured to magnetically connect the base to a component of the pipe network. Advantageously, magnetic coupling may be fast and simple to couple and decouple. In addition, a magnetic coupling may be fatigue resistant. In some embodiments, the coupling is interchangeable with another coupling. For example, the base of the device may be compatible with a magnetic coupling for coupling the device to magnetic components of a pipe network, and a threaded coupling provided by a component of the pipe network. The coupling element may be any suitable element configured to couple the device to a pipe network in any suitable way. In some embodiments, the coupling element comprises a probe configured to couple the base to the pipe network. That is, the device may be coupled to a probe, and the probe may be coupled to the pipe network. The probe may be a listening stick comprising a pole. Alternatively, the probe may comprise a tripod. The probe may be threadedly coupled to the pipe network, for example via a threaded insert. In this way, the device may be substantially mobile in that the probe and device may be moved between locations on the pipe network for mobile detection of leaks. In this way, the device may be versatile. Further, one device may be used to detect leaks throughout a large pipe network. In some embodiments, the base comprises a first clamping surface and the lid comprises a second clamping surface; and the board is configured to be clamped between the first clamping surface and the second clamping surface. In this way, the board may be clamped between the base and the lid. By clamping the board between the base and the lid, the board may be acoustically coupled to the base and / or the lid. In addition, the board may be secured within the housing when the lid is fitted to the base such that the board may not move, e.g., rattle, within the housing. The first clamping surface may be provided at or proximate an edge, or circumference, of the base. The second clamping surface may be provided at or proximate an edge, or circumference, of the lid. In some embodiments, when the board is clamped between the first clamping surface and the second clamping surface, the second gasket is compressed to provide the seal between the board and the base. That is, when the lid is fitted to the base to clamp the board between the lid and base, the board may be urged by the second clamping surface of the lid towards the first clamping surface of the base and, simultaneously, towards the second gasket such that the second gasket is squashed between the board and the base by the lid. In this way, fitting the lid to the base secures the board in place and compresses the gasket to seal the space. Accordingly, the device may be operational only when the lid is securely fitted. As such, unauthorised use of the device with the lid removed may be inhibited. In this way, the sensor may be protected from water and dust by requiring a secure fitting of the lid to operate correctly. In some embodiments the device further comprises a frame configured to be disposed inside the housing and comprising a third clamping surface and, where the base comprises a first clamping surface, the board is configured to be clamped between the first clamping surface and the third clamping surface. In this way, the board may be clamped between the base and the frame. By clamping the board between the base and the frame, the board may be acoustically coupled to the base and / or the frame. In addition, the board may be secured within the housing such that the board may not move, e.g., rattle, within the housing. The first clamping surface may be provided at or proximate an edge, or circumference, of the base. The third clamping surface may be provided at or proximate an edge, or circumference, of the frame. In some embodiments, when the board is clamped between the first clamping surface and the third clamping surface, the second gasket is compressed to provide the seal between the board and the base. That is, when the frame is fitted to the base to clamp the board between the frame and base, the board may be urged by the third clamping surface of the frame towards the first clamping surface of the base and, simultaneously, towards the second gasket such that the second gasket is squashed between the board and the base by the frame. In this way, fitting the frame to the base secures the board in place and compresses the gasket to seal the space. In some embodiments, the frame is configured to be threadably engaged with an interior surface of the base when the board is clamped between the first clamping surface and the third clamping surface. In other words, the frame may be screwed into the base to clamp the board in place. In some embodiments, the frame may support other components of the device, such as a battery or a wireless charging circuitry. In this way, the frame may securely hold the other components, inhibiting noise-generating movement, e.g., rattling, which may interfere with the operation of the sensor. In particular, the frame may extend towards a lid of the device to clamp a wireless charging board between the frame and lid. Accordingly, the device may be effectively wirelessly charged via the lid. In some embodiments, the acoustic air pocket is disposed substantially centrally within the device. In other words, a longitudinal axis of the acoustic air pocket may be collinear with a longitudinal axis of the device. When the acoustic air pocket is disposed centrally in the device, an orientation of the device about its longitudinal axis may have no effect on a performance of the device to detect leaks. For example, interior features of the device may be arranged substantially symmetrically around the acoustic air pocket such that vibrations received by the acoustic air pocket from a first direction and from a second, different, direction may be transmitted to the sensor by substantially identical paths. In other embodiments, the acoustic air pocket is disposed proximate an edge of the device. In this way, the device may be particularly sensitive to vibrations originating from a particular direction relative to the acoustic air pocket. The acoustic air pocket may be disposed in any suitable location within the device. In some embodiments, the device is substantially rotationally balanced about a longitudinal axis of the device. That is, the device may be substantially rotationally symmetrical, a centre of gravity may be disposed on the longitudinal axis and / or the device may be mass symmetrical. In this way, the device may have no distinguishable front or back. As such, the device may detect vibrations originating from any direction within the pipe network to which the device is coupled. In some embodiments, the cavity comprises a substantially cylindrical shape, a height of the cavity being greater than a diameter of the cavity; and the space comprises a substantially cylindrical shape, a diameter of the space being greater than a height of the space. In some embodiments, the height of the cavity is less than twice the diameter of the cavity. Such a shape may provide an optimal acoustic channel for the sensor. In some embodiments, the leak detection device further comprises a battery disposed inside the housing and the sensor is configured to receive electrical power from the battery. In other words, the battery may power the sensor. The battery may also power other electrical components of the device, e.g., an LED, a Bluetooth transmitter. Other wireless communication protocols may be used, for example, other radio frequency communication protocols such as Wi-Fi. Such components may be provided on the board. The battery may be disposed in any suitable location within the housing, may be fastened to the housing by any suitable means and may be connected to the sensor in any suitable way. In preferred embodiments, the battery may be connected to the board by a wired connection. Alternatively, the battery may be connected to the board via a busbar. The battery may be arranged inside a lid of the housing. That is, the battery may be connected to an inside surface of the lid of the housing. In this way, the board may not be required to support the battery. Further, the battery may have a minimal acoustic effect. That is, the battery may not be acoustically coupled to the board such that vibration of the board may be damped by the battery, as this may reduce a sensitivity of the device. The battery may be permanently connected to the lid, e.g., by a bonded connection. Alternatively, the battery may be removably retained in the lid, e.g., by a fastened connection such as a hook and loop fastener. The battery may be rechargeable. In this way, the battery may be reused, promoting a sustainability of the device. In some embodiments, the leak detection device further comprises a wireless charging coil, and the battery is configured to receive charge from the wireless charging coil. In some embodiments, the wireless charging coil is disposed in a lid of the device. For example, the wireless charging coil may be disposed between a battery and a lid of the device. Accordingly, the battery of the device may be recharged by the wireless charging coil when the wireless charging coil is placed in proximity to a wireless charger device. In this way, the battery may be recharged without being removed from the device. Further, the battery may be recharged without any wires being plugged into the device. As such, the device may comprise no electrical port configured to receive a connector for charging. In this way, the device may be sealed to a high standard of ingress protection. The device may be sealed to meet the requirements of IP68 under international standard I EC 60529. In some embodiments, the device is further configured to collect data indicative of a location of a leak. Data indicative of a location of a leak may include an amplitude of vibrations, frequency of vibrations, frequency range of vibrations and / or signal to noise ratio. Where more than one device is operating on a pipe network and the devices are substantially time synchronised, a time difference in the signals measured by each device may also be data indicative of a location of a leak. In some embodiments, a plurality of devices may be used in conjunction to collect data indicative of a location of a leak. A location of a leak may be indicated by an estimation of a distance of the leak from each sensor. Each device of the plurality of devices may be synchronised so as to provide time synchronised data. The distance of the leak from each sensor may be estimated by performing time-of-flight calculations based on data from each synchronised sensor. Properties of the pipe network may be taken into account during estimation of the distance of the leak from each sensor. In some embodiments, the sensor assembly comprises a plurality of sensors. In this way, a device may comprise a plurality of sensors. By providing a plurality of sensors, the device may have improved redundancy. Alternatively, each sensor may be calibrated to detect leaks in different applications of the device, e.g., one sensor may be calibrated to detect gaseous leaks, while another is calibrated to detect liquid leaks. In some embodiments, the sensor may record measurements at predetermined intervals. In other embodiments, the sensor may record measurements substantially constantly. In some embodiments, the leak detection device comprises a local storage medium configured to record sound data collected by the sensor. In this way, the device may store data locally. As such, the device may operate without any external data connection. Periodically, data may be transferred, or exported, from the device. For example, the device may be configured to export data after a predetermined period of time, or once a predetermined volume of data is collected. The device may export data wirelessly via a wireless communication method such short-range radio, e.g., using a technology standard such as Bluetooth® or Wi-Fi®. In some embodiments, the device is configured to communicate with a server. For example, data may be periodically transferred to a server via a wireless connection. Alternatively, the device may be configured to be in continual communication with a server for data transfer. The device may also communicate with other devices, such as mobile phones, tablets, computers, e.g., via a software application, app, or a web interface. Brief Description of the Drawings Embodiments of the present invention will now be described by way of example only and with reference to the accompanying drawings, in which: Figure 1 shows a schematic cross section view of a leak detection device according to an embodiment of the first aspect of the invention; and Figure 2 shows a schematic side view of the leak detection device of Fig. 1. Detailed Description With reference to Figure 1, there is illustrated a leak detection device 100 configured to detect a fluid leak in a pipe network. The device 100 comprises a housing 102. The housing 102 comprises a base 104 configured to be coupled to the pipe network. The housing 102 further comprises a lid 106 configured to be coupled to the base 104. The housing 102 further comprises a first gasket 108. The first gasket 108 is configured to be disposed between the base 104 and the lid 106 to provide a substantially watertight seal between the base 104 and the lid 106. The device 100 further comprises a sensor assembly 110. The sensor assembly 110 is configured to be disposed within the housing 102. The sensor assembly 110 comprises a board 112 configured to be coupled to the base 104. The board 112 comprises a cavity 114 extending through the board 112 from a first aperture on a first surface 118 of the board 112 to a second aperture on a second surface 122 of the board 112. The sensor assembly 110 further comprises a sensor 124 configured to be mounted on the first surface 118 of the board 112. The sensor 124 is configured to substantially cover the first aperture. The sensor assembly 110 further comprises a second gasket 126. The second gasket 126 is configured to be disposed between the second surface 122 of the board 112 and the base 104 to enclose a space 128 comprising the second aperture and provide a seal between the board 112 and the base 104. The cavity 114 and the space 128 together define an acoustic air pocket. The acoustic air pocket is configured to receive vibrations originating in the pipe network via the base 104. The acoustic air pocket is configured to transmit the vibrations to the sensor 124 to enable detection of leaks in the pipe network. In Fig. 1, the sensor 124 is a micro-electromechanical system, MEMS, microphone configured to collect sound data. In this embodiment, the board 112 is acoustically coupled to the base 104 such that the acoustic air pocket, i.e., the cavity 114 and the space 128, is configured to receive vibrations originating in the pipe network via the base 104 and the board 112. Further, in this embodiment, the sensor 124 is acoustically coupled to the board 112 such that the acoustic air pocket is configured to receive vibrations originating in the pipe network via the base 104, the board 112 and the sensor 124. In Fig. 1, the base 104 comprises a mounting element 130 configured to couple the base 104 to a coupling element 132. As shown, the mounting element 130 comprises a tapped blind hole configured to receive a threaded stud 134 of the coupling element 132. The mounting element 1300 may comprise a threaded insert. The threaded insert may be heat staked into the base 104. In this embodiment, the coupling element 132 comprises a magnet configured to couple the base 104 to the pipe network. In other embodiments, the coupling element 132 comprises a probe configured to couple the base 104 to the pipe network. In this embodiment, the base 104 comprises a pillar 136 inside the housing 102. The pillar 136 is disposed substantially coaxially with the mounting element 130. The second gasket 126 is disposed between the second surface of the board 112 and the pillar 136 to enclose the space 128. In Fig. 1, the device 100 further comprises a frame 120 inside the housing 102. In this embodiment, the base 104 comprises a first clamping surface 138 and the frame 120 comprises a third clamping surface 140. The board 112 is clamped between the first clamping surface 138 and the third clamping surface 140. In this way, the second gasket 126 is compressed to provide the seal between the board 112 and the base 104. The frame 120 is threadably engaged with an interior surface of the base 104 such that the board 112 is clamped between the first clamping surface 138 and the third clamping surface 140. In this embodiment, the acoustic air pocket is disposed substantially centrally within the device 100. The cavity 114 is substantially cylindrical and a height of the cavity 114 is greater than a diameter of the cavity 114. The space 128 is substantially cylindrical and a diameter of the space 128 is greater than a height of the space 128. In Fig. 1, the device 100 comprises a battery 142 disposed inside the housing 102 and supported by the frame 120. The sensor 124 is configured to receive electrical power from the battery 142. In some embodiments, the device 100 comprises a wireless charging coil 144. The battery 142 may be configured to receive charge from the wireless charging coil 144. With reference to Fig. 2, there is illustrated the leak detection device of Fig. 1. The device 100 is substantially rotationally symmetrical about a longitudinal axis of the device 100. The device 100 is substantially cylindrical. That is, the device 100 has two substantially circular, flat faces 202 connected by a substantially curved face 204 arranged substantially perpendicular to each circular face 202. The device 100 comprises a plurality of substantially cylindrical shapes, for example cylinders 206, 208, 210. The invention is not limited to the specific examples or structures illustrated. Further embodiments within the scope of the present invention may be envisaged that have not been described above, for example, the device may be used to monitor any suitable pipe network. The device may be coupled to any suitable part of a pipe network in any suitable manner. The device may comprise any suitable type and number of sensors. The acoustic air pocket may have any suitable configuration. The device may be formed of any suitable materials and manufactured using any suitable methods. A greater number of components than are illustrated in the figures could be used, for example. To provide a leak detection device suitable for use in harsh environments, a substantially watertight device is required. To provide an effective and compact leak detection device that is substantially watertight, an innovative device is required. The present invention provides a unique arrangement of components providing an acoustic air pocket proximate the sensor for effective monitoring of a pipe network and detection of leaks. Accordingly, there is herein described a leak detection device comprising: a substantially 5 watertight housing; and a sensor assembly disposed within the housing and comprising: a board coupled to the base and comprising a cavity extending through the board from a first aperture on a first surface of the board to a second aperture on a second surface of the board; a sensor mounted on the first surface of the board to substantially cover the first aperture; and a second gasket disposed between the second surface of the board and the base to enclose a space 10 comprising the second aperture and provide a seal between the board and the base; wherein the cavity and the space together define an acoustic air pocket configured to receive vibrations via the base; and wherein the acoustic air pocket is configured to transmit the vibrations to the sensor to enable detection of leaks in the pipe network.

Claims

1. A leak detection device configured to detect a fluid leak in a pipe network, the device comprising:a housing comprising: a base configured to be coupled to the pipe network; a lid configured to be coupled to the base; and a first gasket configured to be disposed between the base and the lid to provide a substantially watertight seal between the base and the lid; anda sensor assembly configured to be disposed within the housing, the sensor assembly comprising:a board configured to be coupled to the base, the board comprising a cavity extending through the board from a first aperture on a first surface of the board to a second aperture on a second surface of the board;a sensor configured to be mounted on the first surface of the board and configuredto substantially cover the first aperture; anda second gasket configured to be disposed between the second surface of the board and the base to enclose a space comprising the second aperture and provide a seal between the board and the base;wherein the cavity and the space together define an acoustic air pocket configured to receive vibrations originating in the pipe network via the base; andwherein the acoustic air pocket is configured to transmit the vibrations to the sensor to enable detection of leaks in the pipe network based on the vibrations.

2. The leak detection device of claim 1, wherein the sensor is a micro-electromechanical system, MEMS, microphone configured to collect sound data.

3. The leak detection device of claim 2, wherein the MEMS microphone comprises a membrane configured to be arranged proximate the first aperture.

4. The leak detection device of any preceding claim, wherein the board is acoustically coupled to the base such that the acoustic air pocket is configured to receive vibrations originating in the pipe network via the base and the board.

5. The leak detection device of claim 4, wherein the sensor is acoustically coupled to the board such that the acoustic air pocket is configured to receive vibrations originating in the pipe network via the base, the board and the sensor.

6. The leak detection device of any preceding claim, wherein the base comprises a mounting element configured to couple the base to a coupling element.

7. The leak detection device of claim 6, wherein the mounting element comprises a blind hole configured to receive a threaded stud.

8. The leak detection device of claim 6 or claim 7, wherein the base comprises a pillar configured to be disposed within the housing, the pillar being disposed substantially coaxially with the mounting element; andwherein the second gasket is configured to be disposed between the second surface of the board and the pillar to enclose a space comprising the second aperture and provide a seal between the board and the pillar of the base.

9. The leak detection device of any preceding claim, further comprising a coupling element, wherein the coupling element comprises a magnet configured to couple the base to the pipe network.

10. The leak detection device of claim 9, wherein the coupling element comprises a probe configured to couple the base to the pipe network.

11. The leak detection device of any preceding claim, wherein the base comprises a first clamping surface and the lid comprises a second clamping surface; andwherein the board is configured to be clamped between the first clamping surface and the second clamping surface.

12. The leak detection device of claim 11, wherein, when the board is clamped between the first clamping surface and the second clamping surface, the second gasket is compressed to provide the seal between the board and the base.

13. The leak detection device of any one of claims 1 to 10, wherein the device further comprises a frame configured to be disposed inside the housing and comprising a third clamping surface, and the base comprises a first clamping surface; andwherein the board is configured to be clamped between the first clamping surface and the third clamping surface.

14. The leak detection device of claim 13, wherein the frame is configured to be threadably engaged with an interior surface of the base when the board is clamped between the first clamping surface and the third clamping surface.

15. The leak detection device of any preceding claim, wherein the acoustic air pocket is disposed substantially centrally within the device.

16. The leak detection device of any preceding claim, wherein the cavity comprises a substantially cylindrical shape wherein a height of the cavity is greater than a diameter of the cavity; and wherein the space comprises a substantially cylindrical shape wherein a diameter of the space is greater than a height of the space.

17. The leak detection device of any preceding claim, further comprising a battery disposed inside the housing and wherein the sensor is configured to receive electrical power from the battery.

18. The leak detection device of claim 17, further comprising a wireless charging coil, wherein the battery is configured to receive charge from the wireless charging coil.

19. The leak detection device of any preceding claim, wherein the device is further configuredto collect data indicative of a location of a leak.

20. The leak detection device of any preceding claim, wherein the sensor assembly comprises a plurality of sensors.

21. The leak detection device of any preceding claim, comprising a local storage medium configured to record sound data collected by the sensor.

22. The leak detection device of any preceding claim, wherein the device is configured to communicate with a server.

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