Field of the Invention

The present invention relates to leak detection apparatuses, and in particular leak detection apparatuses for use in detecting leaks in utilities management systems.

Backqround to the Invention

In a utility environment, such as water and/or natural gas, sensors may be used to detect fluid flow and leakage. Such leak detection apparatuses are invariably installed within a container or above an open channel and facilitate the detection of a leak in said container. During installation, a sensing apparatus is acutely positioned such that a leak sensor on the apparatus is accurately aligned or positioned within or above a container.

Attachment of such sensors to or above pipes or containers can be challenging, particularly in dirty, wet, below ground and/or awkwardly confined areas. In most instances, skilled installation technicians may require special tools, multiple people and/or considerable time to make an installation. Even when installed, skilled technicians may have concerns about dirt between the sensor and pipe, possible damage to the sensor, and whether the sensor was attached too tightly or too loosely, etc. In some technologies, magnets are used to make the connection. However, magnets are inherently made of ferrous material, and are subject to oxidation, particularly in wet environments. Thus, the integrity and consistency of the connection can degrade over time. Degradation of such fixing means may result in the alignment or orientation of the sensor becoming changed over time, or the sensor becoming detached entirely.

Post installation it is also possible for one or more of a number of events to reposition, move, dislodge or realign the apparatus such that the sensor is no longer accurately aligned or located, such that a reading provided is either imprecise or inaccurate. Such events might include debris, flood events, ragging or human intervention such as during inspection, jetting, maintenance or repair of the container or apparatus. It may be the case that after such an event, the alignment or location of the sensor causes the sensor to provide leak detection data that is reported or displayed by said leak detection apparatus which is no longer accurate.

In or around fire hydrants are common places to position a leak detection apparatus due to ease of access. In a further example wherein human intervention can affect the alignment or positioning of a leak detection apparatus, emergency services will, in the event of a fire, activate the fire hydrant, which can result in the leak detection apparatus changing position or becoming detached.

Technological advancements have driven an increase in remote monitoring, particularly in pipeline and utilities monitoring industries. Remote leak detection data monitoring often causes leak detection apparatuses to be positioned in hard-to-reach locations requiring specialist skill and equipment, along with extensive man hours, to reach.

In instances where such remote apparatuses are located in difficult-to-reach areas, the cost of inspection, maintenance or repair of said remote apparatuses is compounded by the skill and effort required to reach the location, and the resultant need for additional labour time, equipment and skilled manpower.

In many cases where a leak detection apparatus has been moved, through one of any number of possible scenarios discussed above, information provided by the apparatus relating to the depth or leak is often plausible, but inherently incorrect. The plausibility of such data poses further disadvantages and is a major concern for utilities management providers, since misinterpreted readings and false negatives can result in undue load on a system, accelerating degeneration of such a system and therefore reducing its lifetime and increasing the cost of management, maintenance, repair and replacement. False positives can be a key cause for unnecessary labour in locating and inspecting an apparatus, particularly if positioned in a hard- to-reach area, resulting in a waste of skilled man hours.

One example of a solution provided to address these problems is to increase the density of leak detection apparatuses per unit area, or increasing the number of leak sensors. In-built redundancy often aims to identify unreliable results and potentially faulty apparatuses, potentially by taking into account the leak detection data and measurements performed by a plurality of apparatuses or sensors. An increased number of apparatuses, and necessary installations, and/or sensors-per-apparatus requires a greater level of financial commitment from a utilities management company and provides the disadvantage of increased complexity in a system, increasing maintenance and repair costs along with the likelihood of errors.

As such, cost and unreliability are examples of the many limitations faced by current technology, driving an effort to deskill installation processes and reduce the incidence of false negatives and false positives by sustaining the accuracy of such technology over a more prolonged period of time. It is therefore desirable to provide an apparatus which enables the deskilling of the installation process for leak detection apparatuses, and preferably to overcome current issues with diminishing accuracy over time.

Summary of the Invention

In accordance with a first aspect of the present invention, there is provided a leak detection apparatus comprising a leak sensor arranged to detect a leak in a container, wherein the leak detection apparatus further comprises an alignment detecting member, the alignment detecting member arranged to detect an alignment (and/or optionally orientation) of the leak sensor; and one or more output nodes arranged to output the leak detection data and/or the alignment to one or more output members.

Preferably the leak detection apparatus comprises said one or more output members. Embodiments will be appreciated wherein the apparatus is arranged to communicate with an output member. Additional embodiments will be appreciated comprising said output members.

The present invention proposes the incorporation of an alignment detecting member within a leak detection apparatus, preferably to facilitate a determination of sensor alignment and/or orientation during installation and/or sensor movement post-installation, and preferably facilitating the alerting of a user to said sensor alignment and/or orientation and/or sensor movement. The “alignment” or“orientation” of the leak sensor may, for example, be an alignment or orientation of the leak sensor relative to one or more of: a current point in space or a previous point in space; a surface or level of a material or fluid; a geophysical property such as, for example, geomagnetism; an internal property of the alignment detecting member; a current or previous alignment, orientation or positioning of the leak sensor, among others which will be appreciated by the skilled addressee.

Due to the required accuracy of leak detection apparatuses of the available technology, and the need for correct alignment and/or positioning of the apparatus within a container, skilled manpower and surplus equipment, such as levelling kits for example, are often required for installation of leak detection apparatuses. Preferably, by providing an on-board detection and reporting of an alignment and/or orientation of a leak detection apparatus, a reduced level of skill and/or a reduction in auxiliary installation equipment is required to install the apparatus of the present invention. A large number of possible events may result in the repositioning or misalignment of a leak detection apparatus, potentially resulting in the provision of plausible but fundamentally incorrect leak detections and measurements. The present invention preferably enables a user to cross-reference leak detection data and measurements with alignment and/or orientation data, preferably in order to determine the reliability of the leak detection and/or measurement. Such cross-referencing can also preferably act to inform a user of the requirement for maintenance and/or repair of a leak detection apparatus, and whether a realignment or repositioning of the apparatus is required. For instance, if a non-plausible leak detection and/or measurement is provided and the alignment appears normal, the leak detection apparatus may need repair or replacement. On the other hand, if a plausible leak detection and/or measurement is provided and the alignment appears atypical, a realignment of the apparatus may be required. Such decisions can preferably be made with more confidence using the present invention.

Preferably the leak sensor is an acoustic leak sensor. Preferably the acoustic leak sensor is an acoustic leak sensing transducer.

Acoustic leak sensing transducers are often preferably advantageous due to having no moving parts, therefore preferably reducing the likelihood of failure through repetitive motion, friction and wear and tear. Such transducers can preferably detect or measure a leak from a distance. This preferably makes acoustic leak sensing transducers optimal for measuring leak detection data in containers housing hazardous contents such as sewage or waste water. Accuracy of leak sensing using acoustic transducers is maintained during changes to the composition of a content, which can be variable in the case of sewage or waste water.

Embodiments will be appreciated wherein the leak sensor is not an acoustic leak sensor. In such embodiments, the leak sensor may comprise an optical leak sensor; an infra-red leak sensor; a laser; an audio probe; a pressure sensor; a magnetic field sensor; a Hall effect sensor; and/or a radar. Embodiments will be appreciated wherein the leak sensor comprises any suitable means for detecting a leak using a leak measurand.

Preferably the one or more output members comprise a display member arranged to display the leak detection data and/or the alignment to a user.

On-board reporting of leak detection data and/or alignment and/or orientation to a user is preferably advantageous in providing an easier installation and inspection of an apparatus according to the present invention. Preferably the one or more output members comprise a transceiver arranged to transmit the leak detection data and the alignment to a receiver. Preferably the transceiver is arranged to transmit the leak detection data and alignment and/or orientation to the receiver using a communication technology selected from the group: wired communication; wireless communication; short-range wireless communication; long-range wireless communication; radio signal; mobile communication technology; optical fibre communication.

The term“transceiver” in the context of the paragraph immediately above will be understood to mean“signal transceiver” used for transmission of the leak detection data and/or alignment and/or orientation, and will be understood by the skilled addressee to be different to any acoustic transceiver which may be comprised within a leak sensor and used for leak measurement.

An acoustic transceiver may be comprised within a leak sensor such as an acoustic leak sensor or an acoustic leak sensing transducer, which use an acoustic transmitter for transmitting an acoustic wave and an acoustic receiver for receiver a returned (echo) wave before computing the leak detection data using the time taken for the“echo” to be received along with the speed of sound in the medium used.

In some applications it may be required for leak detection data and measurements to be provided in remote and hard-to-reach locations. As such, remote telemetry of the leak detection data and/or alignment and/or orientation is preferably provided by some embodiments of the present invention comprising a transceiver. Communication of the alignment and/or leak detection data can preferably be provided by a long-distance wireless communication transceiver, such as a radio or mobile communication technology signal transceiver. Alternatively, communication of the leak detection data and/or alignment and/or orientation can preferably be provided by short-distance wireless communication technology such as, for example, Bluetooth™ transceiver. Embodiments will be appreciated wherein any suitable wireless communication technology can be used for communication of the leak detection data and/or alignment and/or orientation by a transceiver to a receiver.

Embodiments will be appreciated wherein the one or more output members comprise a display screen in communication with the transceiver. Preferably, the display screen depicts an image of a real alignment of the leak sensor, the real alignment being the alignment of the leak sensor within the container. Preferably, the real image is overlaid on to an image of a“perfect” alignment of the leak detection apparatus, perfect alignment being the alignment of the leak detection apparatus had it not been moved and/or altered. Advantageously, such an embodiment allows for a user to judge how urgently the leak detection apparatus may need readjustment. Preferably, thresholds are set wherein an angle of misalignment corresponds to the urgency of the misalignment, a higher angle corresponding to a higher degree of urgency.

Embodiments will be appreciated wherein one or more output members comprise both a display member and a transceiver.

Preferably the container comprises one selected from the group: open channel; sewer overflow; storm drain; storage tank; a pipeline; a weir; a grain silo. Preferably the container is a utilities management pipeline.

The term“container” in the context of the present invention will be understood by the skilled addressee to mean any enclosed, open, sealed and/or openable container arranged to accommodate a content.

In embodiments wherein the container comprises a weir, the content is preferably a fluid. Measurement of the leak of said fluid in such embodiments is preferably arranged to inform of other corresponding measurands. Preferably, for example, said leak detection data is proportional to flow rate and/or volume of fluid over the weir.

Applications of the apparatus of the present invention preferably include utilities management and monitoring, but embodiments will be appreciated that are suitable for any appropriate application requiring leak sensing. Additional example applications may include agriculture; fuel storage; recycling; and/or waste management.

Preferably the alignment detecting member comprises an accelerometer. Preferably the accelerometer is a 6-axis accelerometer.

Accelerometers preferably provide a cheap and reliable means of providing accurate alignment and/or orientation information. Their suitable miniaturisation of modern accelerometers preferably enables their easy incorporation into a leak detection apparatus without requiring significant modification or alternation to the architecture of the apparatus. Embodiments will be appreciated wherein the alignment detecting member is not an accelerometer. In such embodiments, the alignment detecting member may comprise, for example, a gyro sensor; a compass sensor; a magnetometer; a magnet; a microelectromechanical system (MEMS); a nanoelectromechanical system (NEMS); a laser; a Hall effect sensor; a Hall effect switch; a motion sensor; and/or a proximity sensor. Embodiments will be appreciated wherein the alignment detecting member comprises any suitable means for detecting a change in an alignment and/or orientation of the leak sensor.

Preferably the leak detection apparatus further comprises an alerting member arranged to provide an alert to a user, said alert being arranged to alert said user to a change in the alignment and/or the leak detection data.

Preferably the alerting member is arranged to provide an alarm. Preferably the alert and/or alarm comprises one selected from the group: a visible alert and/or alarm; an audible alert and/or alarm; a haptic alert and/or alarm; a vibratory alert and/or alarm; a digital alert and/or alarm. Preferably the alerting member is arranged to provide an alert and/or alarm to the transceiver for communication to a receiver. In such embodiments, the transceiver is arranged to transmit the alert and/or alarm. Preferably the alert and/or alarm is arranged to alert a user to an atypical alignment and/or orientation, and/or an atypical leak detection data.

Preferably the leak detection apparatus further comprises a locating member arranged to detect a location of the leak detection apparatus, and wherein the one or more output nodes are further arranged to output the location. In embodiments comprising an alerting member, preferably the alerting member is further arranged to alert a user to a change to the location.

There are a number of events, such as flooding, seismic events or human intervention such as ragging, which may cause a leak detection apparatus to dislodge and/or move location within a container. It is therefore preferable that embodiments of the present invention are arranged to provide a location of the leak detection apparatus. The detecting of the location of the leak detection apparatus by the locating member preferably also enables easier inspection, maintenance and repair of a leak detection apparatus, even in instances wherein there is no change to the location. Preferably the location enables easier interpretation of the leak detection data and/or the alignment, in order to determine reliability of the leak detection data and/or the alignment provided by the apparatus.

Preferably the content is one selected from the group: waste water; fresh water; treated water; agricultural material; agricultural waste; grain; feed; fuel; slurry; sewage. Embodiments will be appreciated wherein the content comprises a fluid. Embodiments will be appreciated wherein the content comprises any material suitable to be contained within and/or transported along a container.

Preferably the leak detection apparatus further comprises a clock arranged to provide a time stamp and wherein the one or more output nodes arranged to output the time stamp to the one or more output members.

In accordance with a second aspect of the present application, there is provided a leak detection system comprising a leak detection apparatus of the first aspect of the present invention, wherein the system further comprises a receiver arranged to receiver the leak detection data, the alignment and/or the location, the receiver further comprising a storage member arranged to store the leak detection data, the alignment and/or the location.

The ability for the apparatus of the first aspect of the present invention, and system of the second aspect of the present invention, to allow a user to remotely cross reference the apparatus or sensor alignment and/or orientation and/or location with potentially suspect leak detection data provided by the apparatus would preferably have real-world benefits, such as improving confidence in the technology, and reducing the requirements for skilled labour and cost. The ability of said apparatus or system to record the apparatus- or sensor-alignment and/or orientation and/or location, and then correlate it with information provided by on-site visits performed by technicians would also preferably help during maintenance contracts.

Detailed Description

Specific embodiments will now be described by way of example only, and with reference to the accompanying drawings, in which:

FIG. 1 shows a sectional view of a pipe having a leak detection apparatus affixed thereto, the leak detection apparatus being in accordance with a first aspect of the present invention;

FIG. 2 shows a view of a utilities management pipe having a leak detection apparatus affixed thereupon, the leak detection apparatus being in accordance with a first aspect of the present invention; FIG. 3 shows a schematic view of a leak detection system in accordance with the second aspect of the present invention;

FIG. 4a shows a sectional view of the pipe having the leak detection apparatus affixed thereto, the leak detection apparatus being in accordance with the third aspect of the present invention; and

FIG. 4b shows a perspective view of a display screen depicting a real view of the leak detection apparatus as depicted the embodiment shown in FIG. 4a overlaid on to a perfect view of the leak detection apparatus.

Referring to FIG.1 , there is provided a leak detection apparatus 10 comprising a housing 12 affixed to an interior surface of a metal pipe 20 by a magnetic portion 14 affixed to the housing 12. The leak detection apparatus 10 is suspended in an affixed position within the interior of the pipe 20 above a fluid 18 located within said pipe 20. The leak detection apparatus 10 comprises a leak sensor 16 taking the form of an acoustic probe 16 extending from the housing 12 of the leak detection apparatus 10. The leak detection apparatus 10 further comprises an alignment detecting member 21 located inside the housing 12 of the leak detection apparatus 10, and a display member 22 taking the form of display screen 22 positioned on an exterior surface of the housing 12 of the leak detection apparatus 10. The leak detection apparatus 10 further comprises a transceiver 23 located inside the housing 12.

The acoustic leak sensor 16 and the alignment detecting member 23 are in digital communication with the display member 22 and the transceiver 23. The leak sensor 16 in the embodiment shown is an acoustic probe 16 arranged to detect an acoustic wave signal. The acoustic wave produced by a leak 24 is detected by the acoustic probe 16 which outputs leak detection data corresponding to the acoustic wave to a memory module (not shown). In the embodiment shown, a processor (not shown) is arranged to process the stored leak detection data and provide an output to the display screen 22 and/or the transceiver 23 accordingly. The processor determines from the leak detection data that a leak 24 has occurred and transmits an alert to a remote monitoring system (not shown) using the transceiver 23. In the embodiment shown, the transceiver 23 is a GSM transceiver. Embodiments will be appreciated wherein the transceiver 23 is a radio transceiver, or a transceiver arranged to send and receiver data by any suitable means of electronic communication.

The leak detection apparatus 10 of the embodiment shown further comprises a clock (not shown) arranged to provide a time stamp of the leak detection data. Said time stamp may be used in combination with the leak detection data to determine a location of the leak 24. In use, multiple leak detection apparatuses may be used to compare time stamp data and leak detection data in order to triangulate a leak position.

The ability of the leak detection apparatus 10 to provide accurate and reliable leak detection data depends on the leak detection apparatus remaining in position. Any relocation or misalignment of the leak detection apparatus 10 over time could result in the apparatus 10 providing unreliable or misleading leak detection data to, for example, a remote monitoring system. Such misalignment or relocation could result in the inability of the remote monitoring system to accurate detect the presence and/or location of a leak.

In the leak detection apparatus 10 of the embodiment shown, the alignment detecting member 23 is an accelerometer. In order to provide a continued accurate and comparable calculation of a leak of the fluid 18 using the leak sensor 16 over time, the alignment of the leak detection apparatus 10 must remain substantially the same. The accelerometer 23 is used to detect a change in alignment of the leak detection apparatus 10. Upon a detection of a change to the alignment of the leak detection apparatus 10 by the processor in digital communication with the accelerometer 23, the processor provides an alert to the display member 22 and the transceiver 23. During installation of the leak detection apparatus 10, an engineer may use the display member 22 as a direct feedback mechanism to alert the engineer to the optimum orientation/alignment. As such, the installation of the leak detection apparatus 10 of the embodiment shown according to the first aspect of the present invention is made easier, and does not require skilled use of equipment or installation tools unlike comparable existing technology.

In use, the transceiver 23 is arranged to transmit the leak detection data and the alignment data to a remote receiver (not shown).

In the embodiment 10 shown in FIG. 1 , the alignment detection member 21 is arranged to provide alignment data to the memory module for processing by the processor. The display member 22 is arranged to display that the alignment has changed since installation. Said change in alignment may be brought about by any event causing a movement of the leak detection apparatus 10, for example, debris within a pipe, flood events, ragging or human intervention such as during inspection, jetting, maintenance or during repair of the pipe or apparatus. It may be the case that after such an event, the leak (indicating the depth or leak said fluid) that is reported or displayed by said leak detection apparatus 10 is no longer accurate. In some cases, the orientation or alignment may be altered in use such that the leak that is reported or displayed by the leak detection apparatus 10 is plausible, and therefore, in leak detection apparatus not in accordance with the present invention, would otherwise misinform leak detection data monitoring personnel of the fluid leak detection data. The alignment member of the embodiment shown, in accordance with the present invention, ensures that leak detection data monitoring personnel are informed of any change to the alignment and therefore reliability of any leak detection data sensing. The monitoring personnel are therefore provided with the option to ignore said leak detection data or reduce the impact of said leak detection data on any conclusions drawn from an array of said leak detection apparatuses.

In the embodiment shown, the alignment and the leak detection data are stored and processed on-board the leak detection apparatus 10 by a memory module and a processor respectively. Embodiments will be appreciated wherein the leak detection data and the alignment are transmitted to a remote location by the transceiver 23 prior to storage and/or processing.

Referring to FIG. 2, a further example embodiment of a leak detection apparatus 26 of the present invention is shown, the apparatus 26 comprising an out-of-pipe alternative to the embodiment 10 shown in FIG. 1. In the second example embodiment 26 shown, the leak detection apparatus comprises a central processing unit 28 comprising a processor and a memory module and is arranged to receive, store and process leak detection data, alignment data and location data. The apparatus 26 further comprises a leak noise sensor 30, in digital communication with the central processing unit 28 by a wire 32. The leak noise sensor 30 is supported above a utilities management pipe 38 on a platform 34. The leak noise sensor 30 houses an acoustic leak sensor (not shown), an alignment detection member (not shown) and a location sensor (not shown). In use the leak noise sensor 30 is arranged to output leak detection data from the leak sensor, alignment data from the alignment detection member and location data from the location detection member to the central processing unit 28. The central processing unit 28 is arranged to store, process and/or output the leak detection data, alignment data and/or the location data to an antenna 35 connected thereto by a wire 36. In the embodiment 26 shown in FIG. 2, the leak detection apparatus 26 is positioned on a pipe 38 within a well 42 in the ground 40, the well lined with a metal casing 44 providing a housing for the apparatus 26. The antenna 35 is affixed to the metal casing 44 by a magnet located in a base of the antenna 35.

As with the embodiment 10 described and shown in FIG. 1 , the leak sensor located within the leak noise sensor 30 of the embodiment 26 of FIG. 2 is arranged to detect an acoustic wave emitted from a leak in the pipe 38. Said leak detection, as described for FIG. 1 , is dependent upon accurate positioning and alignment of the leak noise sensor 30. Any change in alignment or location of the leak noise sensor 30 over time, which may be brought about by human intervention or flooding of the well 42, among other things, would result in inaccurate and unreliable leak detection data being provided to a user or a remote receiver. The alignment detection member, which in the embodiment 26 shown is a 6-axis accelerometer, contained within the leak noise sensor 30 is arranged to provide alignment data to permit the detection of such a change.

In the embodiment shown, the leak detection apparatus 26 of FIG. 2 is arranged to be compatible with leak detection data received from embodiments of the apparatus shown in FIG. 1.

FIG. 3 shows a remote utilities pipeline monitoring system 45 in accordance with the second aspect, comprising a plurality of leak detection apparatuses 10 in accordance with the first aspect of the present invention and as described in relation to FIG. 1. Said leak detection apparatuses 10 are distributed about a utilities management pipeline network 46 and are arranged to communicate leak detection data and/or an alignment to a remote receiver 48 using a wireless transceiver, and by way of a cell tower 50. In the embodiment, the remote receiver 48 is a server 48 within a control room wherein leak detection data monitoring personnel monitor the leak detection data and alignment detected and communicated by said apparatuses 10. The server 48 comprises a processor arranged to process said leak detection data and alignment and is arranged to calculate and use said leak detection data and alignment to calculate a change in said leak detection data and/or said alignment over time.

In the embodiments shown, the leak detection apparatus 10 does not comprise a location detecting member. Embodiments will be appreciated wherein the leak detection apparatus is substantially as described in relation to FIG. 2, and may further comprise a location detecting member arranged to detect a location of the leak detection apparatus and communicate the location to the transceiver for remote transmission of said location to a remote receiver. In such embodiments, should said leak detection apparatus become detached from the interior of a container and/or change location, a remote receiver receiving said location may be arranged to detect said change in location and provide an alert. Said detachment may be due to, for example, debris within a pipe, flood events, ragging or human intervention such as during inspection, jetting, maintenance or during repair of the pipe or apparatus. In such circumstances, the location detecting member preferably improves the ease of locating said leak detection apparatus. In the embodiment shown, the primary communication technology is GSM mobile communication technology, and further in use, the server 48 is arranged to communicate with the leak detection apparatuses 10 using GSM mobile communication technology via a GSM mobile communication tower 50, or via the internet.

Embodiments of a system according to the second aspect of the present invention may use two or more of the acoustic leak detection apparatuses 10 to identify the location of a leak 52. Said locating of a leak 52 may be performed by determining the relative distance of the leak 52 from each of two or more leak detection apparatuses 10 through analysis of the leak detection data, which may include an acoustic profile.

Referring to FIG. 4a; there is shown a sectional view of the metal pipe 20 having the leak detection apparatus 10 affixed thereto, the leak detection apparatus 10 being in accordance with the fourth aspect of the present invention. In the illustrated embodiment, the fluid 18 has raised, impacting the leak detection apparatus 10 such that the leak detection apparatus 10 is offset 52 from its original alignment. Upon a detection of the offset 52, the alignment detecting member 23 communicates information regarding the leak detection apparatus 10 alignment to the utilities management pipeline network 46.

Referring to FIG. 4b, there is shown an alignment display 62 in accordance with the third aspect of the present invention as described in relation to FIG. 3a. The alignment display 62 comprises a true image 64 and a perfect image 66. The utilities management pipeline network 66 transmits the information regarding the leak detection apparatus 10 alignment to a central server (not shown) via cloud communications. The central server causes the alignment display 62 to display the true position 64 of the leak detection apparatus 10, as well as the perfect position 66 of the leak detection apparatus 10 such that the alignment display 62 shows a comparison of the true position 64 and the perfect position 66. In the example shown the true position 64 is superimposed over the perfect position 66 such that deviation of the true position 64 from the perfect position 66 can be readily observed by a maintenance engineer.

Using the information provided by the alignment display 62, the maintenance engineer can observe the degree of misalignment for the leak detection apparatus 10 and therefore make an informed decision about how urgently the rise of the fluid 18 should be dealt with. The urgency is therefore correlated to the degree of misalignment with a high urgency corresponding to a high degree of misalignment. It should be appreciated that whilst the offset 52 of the leak detection apparatus 10 has been caused by a raise in the fluid 18 level in the illustrated embodiment, there could be additional events that cause the fluid level to rise. Such events might include debris, flood events, ragging or human intervention such as during inspection, jetting, maintenance or repair of the container or apparatus.

Common methods of analysing data signals from two or more leak detection apparatuses include subtractive comparison and cross-correlation, which can help to identify the positioning of an anomaly detected by the data signals. Such analysis can include receiving time-dependent data from each of the leak detection apparatuses, the data being obtained by each leak detection apparatus at a predetermined time according to a clock on said leak detection apparatuses. Analysis of the data signals can include comparing similarities of the signals from each leak detection apparatus at differing comparative timings, determining the comparative timing at which the similarity is greatest and generating a clock time difference signal corresponding to the greatest similarity comparative timing, this signal indicating the time interval by which these recordings are out of synchronism due to difference in clock times of the leak detection apparatuses; comparing similarities of the data signals from the leak detection apparatuses at differing comparative timings, determining the comparative timing at which the similarity is greatest and generating an anomaly time difference signal indicative of anomaly position between the known positions of the leak detection apparatuses; performing a correlation on the data signals from the leak detection apparatuses, generating an anomaly time difference signal indicative of anomaly position between the known positions of the leak detection apparatuses; and adjusting the anomaly time difference signal and/or an anomaly position signal generated therefrom to take account of the clock time difference signal and estimate the anomaly position as the leak detection apparatus clocks were in synchronism.

Whilst it can be appreciated that simpler forms of comparison may be able to be employed, such as subtractive comparison, it is preferred to use cross-correlation for data signal comparisons, in like manner to conventional correlation of data from pairs of leak detection apparatuses.

It will be appreciated that the above described embodiments are given by way of example only and that various modifications thereto may be made without departing from the scope of the invention as defined in the appended claims. For example, the embodiments described relate to a fluid within a container taking the form of a pipeline. Additional embodiments will be appreciated wherein the container is an open channel. The fluid may be liquid or gas. The embodiments are discussed in relation to a utilities management system. Additional further embodiments will be appreciated wherein the content is fuel, which may be located in a fuel tank. Additional further embodiments will be appreciated wherein the content is not a fluid, and is, for example, grain in a grain silo. Further embodiments will be appreciated wherein the leak sensor is positioned within or below the surface of said contents. In the example embodiments described, the leak sensor is an acoustic leak sensor. Additional embodiments will be appreciated wherein the leak sensor is not an acoustic leak sensor, and may for example comprise a Hall effect sensor, a ground penetrating radar and/or any suitable means for detecting a leak using a leak measurand. In the example embodiments described, the alignment detecting member is an accelerometer. Additional embodiments will be appreciated wherein the alignment detecting member is not an accelerometer, and may for example comprise a gyro, a compass and/or any suitable means for detecting a change to an alignment of the apparatus.