AU2020203828A1 - Water monitoring apparatus - Google Patents

Abstract

The present invention relates to a water quality monitoring. device hull configuration that houses sensors within waterflow but out of the path of debris. Current devices may have issues with sensors being reduced in sensing quality due to debris or 5 stagnant water. The current device utilises a channel to divert a flow of water around sensors. - 22 20 100 FIGURE 1 1 20 23r 100 10F5 20 9 C 202- FIGURE 2

Description

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FIGURE 1

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FIGURE 2

WATER MONITORING DEVICE

The present invention relates to a water quality monitoring. More particularly but not exclusively it relates to a hull configuration that houses sensors within waterflow but out of the path of debris.

BACKGROUND

In general, water quality monitoring devices are known. Such devices are used to record data about the quality or condition of the water that supports them. Such devices may be located in streams, creeks, oceans, swimming pools or spa pools. The devices may be driven by onboard means, be tethered to buoys or other features. Where there is relative movement between a device and a body of water, it is required that there is flow about the sensors of the device. With stagnant water about sensors, the change in conditions or quality of the water may not recorded by the sensors. False data may even be recorded. Prior art systems such as those disclosed in patent publication CN108045510 may be subject to this issue. CN108045510 discloses an unmanned trimaran with onboard driving means. This patent publication discloses a trimaran that has water inlets at leading surfaces, where the water is directed to flow about the sensors. These sensors are located in a closed off chamber, which may be susceptible to stagnant water. Furthermore, prior art systems may be vulnerable to debris from impacting the sensors and damaging the sensors. Furthermore, if there is not significant flow of water about the sensors or change of water about where the sensors are located, these sensors may become covered in a biofilm or be susceptible to fouling.

In this specification, where reference has been made to external sources of information, including patent specifications and other documents, this is generally for the purpose of providing a context for discussing the features of the present invention. Unless stated otherwise, reference to such sources of information is not to be construed, in any jurisdiction, as an admission that such sources of information are prior art or form part of the common general knowledge in the art.

It is an object of the present invention to provide a water quality monitoring which overcomes or at least partially ameliorates some of the abovementioned disadvantages or which at least provides the public with a useful choice.

STATEMENTSOFINVENTION

In a first aspect the present invention may be said to consist of a water monitoring device configured to float on a body of water, the device comprising an elongate hull comprising a; bow, flanks, stern, and keel, the keel comprising an elongate downwardly open channel extending intermediate the bow and stern and central of the flanks, at least one inlet located towards or at the bow on each flank, the inlet configured to allow water to flow through the flanks of the hull and into the channel, the inlets and channel defining at least a laterally restrained flow path for water, wherein the hull is configured to receive one or more sensors to be located within the channel and in the flow path.

In one embodiment, the channel comprises a ceiling.

In one embodiment, the ceiling or regions of the ceiling (ceiling regions) are above the nominal waterline of the device.

In one embodiment, the inlets are located at inlet regions at the flanks that are angled laterally from a vertical midplane running along a major axis of the hull.

In one embodiment, the inlet regions are angled acutely rearwards from the midplane.

In one embodiment, the inlet regions are angled between 30 and 45 degrees from the midplane.

In one embodiment, the angle of the inlet regions, and hence inlets, discourages waterborne debris from entering into the inlets in operation.

In one embodiment, the channel comprises an outlet for the water in operation to leave the channel.

In one embodiment, the inlets have a combined opening area between 200mm 2

and 500mm 2 , and preferably 314 mm 2 .

In one embodiment, the device comprises a mesh or similar covering the inlets to discourage waterborne debris from entering into the inlets in operation, yet configured to allow flow of water through in operation.

In one embodiment, the flanks form the channel.

In one embodiment, the features that form the channel are integral or affixed to the hull.

In one embodiment, the channel comprises channel sides.

In one embodiment, the channel sides are contiguous with the hull flanks.

In one embodiment, the channel sides are dis-contiguous with the hull flanks.

In one embodiment, the channel sides comprise the inlet regions.

In one embodiment, the channel has a length between 250 mm and 260 mm.

In one embodiment, the channel has a width between 35 mm and 45 mm.

In one embodiment, the channel has a depth between 50 mm and 70 mm.

In one embodiment, the channel sides aid in stability (lateral) of the device in use in relative water flow past the device.

In one embodiment, the channel length is between 20 to 70% of the waterline hull length.

In one embodiment, the channel length is between 60 to 90% of the overall hull length.

In one embodiment, the channel sides are thin walled.

In one embodiment, the one or more sensors project(s) through the ceiling or ceiling region to a dry region of hull, where the dry region of the hull is not submerged in water in operation.

In one embodiment, the device comprises a seal located at the ceiling and/or ceiling region to create a seal about the sensor, between a wet side and the dry side of the hull in operation.

In one embodiment, the device comprises a water guard in the form of a wall that extends upwardly above the nominal waterline, about a periphery of one or more sensors. In one embodiment, the water guard is on the dry side of the hull.

In one embodiment, the seals are IP68 rated.

In one embodiment, the seals are gland seals

In one embodiment, the channel has a ceiling at a level below the nominal water line, and one or more ceiling regions above the nominal water line.

In one embodiment, the ceiling regions are formed in a well.

In one embodiment, a sensor or sensors are located in the well.

In one embodiment, there are multiple wells along the length of the channel.

In one embodiment, there are multiple sensors along the length of the channel.

In one embodiment, the well has a depth between 50 mm and 70 mm.

In one embodiment, there is a linear array of sensors along the length of the channel.

In one embodiment, the sensor is removable and/or interchangeable.

In an alternative embodiment, there is no seal between the sensor and the ceiling or ceiling region and prevention of water from a wet side of the hull in operation to a dry side of the hull in operation relies upon the ceiling or ceiling region being higher than the nominal waterline in operation.

In one embodiment, the hull is symmetric about a vertical mid-plane.

In one embodiment, the hull is asymmetric about a coronal plane.

In one embodiment, the hull is elongate.

In one embodiment, the device is configured to tethered at the bow.

In one embodiment, the device floats.

In one embodiment, the device has a weight between 1000 grams and 3000 grams, preferably between 1500 grams and 2000 grams

In one embodiment, the device has a volume between 2.2 litres and 3 litres.

In one embodiment, the hull is configured to displace water at lower relative supporting water flow speeds, and plane or partially plane at higher relative supporting water flow speeds.

In one embodiment, the hull acts in displacement (displacement mode) at relative supporting water flow speeds less than 0.8m/s.

In one embodiment, the hull acts in displacement (displacement mode) at relative supporting water flow speeds less than 0.6m/s

In one embodiment, the hull planes or partially planes (planing mode) on the supporting water at relative supporting water flow speeds greater than 0.6 m/s.

In one embodiment, the hull planes or partially planes (planing mode) on the supporting water at relative supporting water flow speeds greater than 0.8 m/s.

In one embodiment, the channel is configured to be at least partially submerged in both displacement mode and planing mode.

In one embodiment, the channel is configured to be at least partially submerged along its length in both displacement mode and planing mode.

In one embodiment, the hull comprises a hard chine.

In an alternative embodiment, the hull comprises an S-bottom hull.

In one embodiment, the device waterline length is between 350 mm and 500 mm.

In one embodiment, the device overall length between 350 mm and 550 mm.

In one embodiment, the hull and/or keel comprises a leading edge with an angle of between 30 degrees and 60 degrees to the vertical, preferably 40 degrees.

In one embodiment, the device comprises a lid to cover the hull.

In one embodiment, the lid is composed of a radio frequency transparent material.

In one embodiment, the device comprises a seal to create a watertight seal between the lid and the hull.

In one embodiment, the seal is located at about the gunwale of the hull.

In one embodiment, the lid is hinged to the hull.

In one embodiment, the hull is composed of a plastics material.

In one embodiment, the device comprises a metal member at its bow configured to be engaged to a tether.

In one embodiment, the device comprises one or more selected from; a GPS and/or aerial, a radio transmitter, a radio receiver, an aerial, a power supply, a memory, a status indicator, a display screen, a processor, and a circuit board.

In one embodiment, the sensor may be one or more selected from a turbidity sensor, a pH sensor, a dissolved oxygen sensor, a conductivity sensor, and a temperature sensor.

In one embodiment, the device comprises mounts for the sensors and electronics.

In one embodiment, the mounts for the sensors (sensor mounts) allow the sensors to be interchangeable, modular, and/or removable.

In one embodiment, the mounts allow the electronics (excluding the required submergible sensor parts) to be located above the nominal waterline.

In a further aspect the present invention may be said to consist of a buoyant water monitoring device with multiple sensors emergent from the buoyant envelope of a buoyant body assembly of the device; wherein the device is of tetherable or positionable displacement floating on still water with the sensors below the waterline of the buoyant body assembly; wherein, when tethered or being tether dragged, the buoyant body assembly can plane on a planing axis should the water move, or move relatively, above a speed threshold for the tethered, or tether pulled, device; and wherein the buoyant body assembly defines a. a downwardly open laterally protected zone or downwardly open cavity ("zone") of the buoyant body assembly into which the sensors present, and b. at least one water inlet to provide water for sensor monitoring to said protected zone through at least one part of the buoyant body assembly on a locus or loci not aligned to the planing axis of the device.

In one embodiment, the buoyant body assembly is a lidded hull form.

In one embodiment, the device has its centre of gravity below its centre of buoyancy.

In one embodiment, a tether point or zone of the buoyant body assembly will maintain stability of the device when planing.

In a further aspect the present invention may be said to consist of a water monitoring floating device comprising a plurality of water monitoring sensors emergent of an underside of the device but still within a zone in the form of a cavity, channel or the like of the float to provide a protective, at least partial, surround of the sensors, the device having provision whereby water can duct into the channel of the device from at least one inlet of the device remote from the channel.

In a further aspect the present invention may be said to consist of a floatable water monitor device comprising sensors and associated water protected powerable electronics, the device being characterised that its bottom defines a protected zone for the emergent sensors and that protected zone has ducted infeed provision(s) for water to be monitored, the intake(s) of which infeed provision(s) is/are spaced or remote from the protected zone.

In one embodiment, the protected zone is occluded horizontally in that part of the bottom that might be tethered or tether pulled upstream relative to any supporting water flow (whether that water be static or flowing).

In one embodiment, the intake(s) is/are in a flank or to the flanks of a hull-like form.

In a further aspect the present invention may be said to consist of A water monitoring device configured to float on a body of water, the device comprising an elongate hull comprising a; bow, flanks, stern, and keel, the keel comprising an elongate downwardly open channel extending intermediate the bow and stern and central of the flanks, wherein the hull is configured to receive one or more sensors to be located within the channel and in the flow path.

In one embodiment, the at least one inlet is located towards or at the bow on each flank of the keel, the inlet configured to allow water to flow through the flanks of the keel and into the channel, the inlets and channel defining at least a laterally restrained flow path for water.

In one embodiment, internal to the hull, the sensor regions are separated from the main volume in the hull by one or more walls that extend to above the normal water line of the device, to prevent flooding of the hull in case of a seal leak around the sensors.

Other aspects of the invention may become apparent from the following description which is given by way of example only and with reference to the accompanying drawings.

As used herein the term "and/or" means "and" or "or", or both.

As used herein "(s)" following a noun means the plural and/or singular forms of the noun.

The term "comprising" as used in this specification and claims means "consisting at least in part of". When interpreting statements in this specification and claims which include that term, the features, prefaced by that term in each statement, all need to be present but other features can also be present. Related terms such as "comprise" and "comprised" are to be interpreted in the same manner.

The term "ducted" or "duct" as used in this specification and claims means broadly to include any passageway etc that will feed the channel.

The term "water flow" as used in this specification and claims means any relative water movement between the device and a supporting body of water, and includes wind induced surface movement.

The entire disclosures of all applications, patents and publications, cited above and below, if any, are hereby incorporated by reference.

This invention may also be said broadly to consist in the parts, elements and features referred to or indicated in the specification of the application, individually or collectively, and any or all combinations of any two or more of said parts, elements or features, and where specific integers are mentioned herein which have known equivalents in the art to which this invention relates, such known equivalents are deemed to be incorporated herein as if individually set forth.)

BRIEF DESCRIPTION OF FIGURES

The invention will now be described by way of example only and with reference to the drawings in which:

Figure 1: shows a top front perspective view of the device. Figure 2: shows a front view of the device. Figure 3: shows a top stern perspective view of the device and schematic flow paths. Figure 4: shows a bottom view of the device. Figure 5: shows a side view of the device. Figure 6A: shows a side view of a device in operation in a water flow at 1.1m/s relative speed. Figure 6B: shows a top bow perspective view of figure 6a. Figure 7A: shows a side view of a device in operation in a water flow at 0.8m/s relative speed. Figure 7B: shows a top bow perspective view of figure 7a. Figure 8A: shows a side view of a device in operation in a water flow at 0.6m/s relative speed.

Figure 8B: shows a top bow perspective view of figure 8A Figure 9A: shows a stern bottom perspective of the relative water speed travelling through the channel and about the hull at 1.1 m/s. Figure 9B: shows a stern bottom perspective of the relative water speed travelling through the channel and about the hull at 0.6 m/s. Figure 9C: shows a stern bottom perspective of the relative water speed travelling through the channel and about the hull at 0.1 m/s. Figure 10: shows a bow top perspective view of the device showing the transparent lid. Figure 11: shows a cross sectional schematic view through the mid plane of the device. Figure 12: shows a cross sectional schematic view through the mid plane of the device, highlighting a well and associated sensor.

DETAILED DESCRIPTION

With reference to the above drawings, in which similar features are generally indicated by similar numerals, a device according to a first aspect of the invention is generally indicated by the numeral 1.

In one embodiment now described, there is provided a buoyant device (1) that is boat shaped and configured to float on a body of supporting water. The device is preferably able to float in a river, creek, stream or ocean or other supporting fluid. There may be relative movement between the device and the supporting water, providing 'flow'. Preferably the device (1) is tethered to a fixed object. The tether (not shown) is tethered to the device (1) at a tether mount (16).

The device comprises an assembly or body (23). The body (23) is comprised of a hull (100) and a lid (20). Preferably the device (1) is able to support one or more sensors (6) that are configured to record or monitor one or more characteristics of said water.

The invention generally relates to the hull (100) and formations appended or integral with the hull (100). In particular, the invention relates to a channel or protected zone (201), that is generally a downwardly open cavity. The channel (201) defines a flow path (2) to direct flow of the supporting fluid along the channel (201). The one or more sensors (6) are located in, or present in, the channel (201) and the flow path (2). The flow enters the channel (201) through an inlet or intake (202) located at an inlet region (203) on the hull (100).

In an alternative embodiment (not shown), the channel is not downwardly open, but has a floor opposite the ceiling. This embodiment may be used where the device (1) is to be used in a heavy debris laden water. This embodiment will provide another layer of protection for the sensors. In this embodiment there will be an outlet at the stern end of the channel. The floor may have further inlets so water is still flushed through the channel.

Preferably the sensors are aligned linearly along a length of the channel (201). Preferably there is a linear array (22) of the sensors (6). The channel (201) is defined to keep or entrain a flow of water about the sensors (6) / array (22).

The hull (100) is defined by a keel (101) that comprises the channel (201). The channel (201) may be affixed to the hull (100), or may be integral. Where the 'channel' is mentioned, it generally means the formations that form the 'channel', i.e. the ceiling and walls, were relevant. The hull (100) has a bow (102), opposite a stern (103). Intermediate the bow (102) and stern (103) are sides or flanks (104) of the hull (100). In the preferred embodiment the flanks (104) of the hull (100) comprise a hard chine (105). In other embodiments, the chine may be a soft or S shaped chine. The hard chine has the effect in some embodiments of straightening or making more stable the device (1) when planing, with respect to the direction of flow.

In one embodiment the channel (201) is defined by channel sides (207) - which are formed of walls. The channel sides (207) have an internal side facing the channel, and an external side. The external side may form part of the flank (104).

In one embodiment, the external sides that form the channel (201) are contiguous with the sides of the hull. In alternative embodiments the channel sides are discontiguous with the hull sides. Where contiguous means a constant, preferably smooth, surface. A discontiguous side is as shown in the figures where there is a delineation in the surface between the flanks (104) and the channel sides (207).

Preferably the channel (201) is located at the lowermost region of the hull (100). Preferably the channel (201) or channel sides (207) form a keel or at least part of a keel (101). The keel (101) may be partly, or wholly, formed by the flanks (104). As such, the flanks of the hull, may also be described as the flanks of the keel. Preferably the keel (101) aids in the stability of the device (1) in the flow.

Preferably at or towards the bow end of the channel (201) are the inlet regions (203). The inlet regions (203) may be formed as part of the flanks (104) / channel sides (207). The inlet regions (203) are so located, angled and shaped so as to encourage the flow of water into the inlet (202), yet discourage the intake or inlet of debris or detritus (not shown). Preferably the angle of the inlet regions (203) and hence the inlets (202) are shaped so that the debris or detritus is trapped in the external water flow. The external water flow being defined as water flow that does not enter the inlet (202). I.e. the external water flow that flows about the hull (100) and not into the channel (201).

Preferably the inlet regions (203) are angled acutely rearwards from the midplane of the hull (100). Where the midplane is a vertical plane running through the middle of the device (1) from bow (102) to stern (103). Preferably the inlet regions (203) are angled between 30 and 45 degrees from said midplane.

Debris larger than the dimension of the inlets is discouraged from being caught on the keel by an angled leading edge of the keel, preferably the angle of this leading edge is between 60 and 30 degrees, preferably 40 degrees from the vertical. The channel leading-edge aids in deflecting debris in the main flow away from the sensor section and inlet regions (203).Small debris that can enter the inlets is small enough to pass through the sensor channel without getting caught between the sensors, or the sensors and side walls of the channel. The channel leading-edge may be separate from the leading-edge of bow of the hull (100). The channel leading-edge (209) is immediately forward of the inlet regions (202).

The inlets (202), also known as intakes or infeed provisions, may be a variety of shapes, such as circular, elliptical, and/or polygonal etc. The device (1) may comprise one or many inlets. For example, the device shown in the figures comprises two inlets on either side of the channel. However in other embodiments the device (1) may comprise twenty inlets on either side of the channel (201). In one embodiment not shown, the device may comprise a series of inlets down the length of the channel. The location of the inlets may not be symmetrical about the midplane plane of the device, for example, there may be more or less inlets on either side of the keel/channel.

In one embodiment, the device (1) comprises a mesh (not shown) or similar covering the inlets (202) to discourage waterborne debris or detritus from entering into the inlets (202) in operation. Preferably this mesh or similar covering is configured to allow, and not substantially hinder, the flow of water through the inlets in operation.

Further defining the channel (201) is a ceiling (204). The ceiling (204) faces an opening that is downwardly open. The ceiling (204) may be on a single horizontal plane or at least one plane. The ceiling (204) comprises multiple apertures or regions for receiving the one or more sensors (6). In one embodiment the ceiling (204) is above a nominal waterline (18) - Figure 12. In other embodiments the ceiling (204) is below the nominal waterline (18) - Figure 11. In other, embodiments, the ceiling (204) may be partially above and least partially below the nominal waterline (18).

In one embodiment the ceiling (204) comprises ceiling regions (205) that are at a different height to the ceiling (204). In one embodiment the ceiling region (205) is above the nominal waterline (18) and the ceiling (204) is below the nominal waterline. In the preferred embodiment, the channel (201) comprises wells (206) that comprise the ceiling regions (205) at their upper regions. The wells (206) are configured to receive or locate the sensors (6).

Preferably there are one or more wells (206) that relate to the one or more sensors (6). For example there may be a linear array of wells (206) to complement the linear array of sensors (22). Preferably the wells (206) have their ceiling region (205) above their nominal waterline (18). The ceiling (204) and ceiling region (205) separate the wet side of the device (1) from the dry side of the device (1). Where the wet side is below the hull (100) in operation and the dry side is above the hull (100) in operation. In the preferred embodiment the hull (100) is a shell type hull.

Preferably at an upper region of the well (206) or at the region where the sensors (6) are located in the hull (100), there is a sensor seal (12) to seal the sensors (6) to the hull (100) to delineate between the wet side and the dry side. Preferably sensor seal (12) is located at the relevant ceiling (204) or ceiling region (205). Preferably there is a ceiling (204) that is below the ceiling region (205) of the well (206). The wells are located so that the, or at least part of the, sensor seals (12) are above the nominal waterline (18). This is a backup to prevent water from seeping through the sensor seal (12). The wells (206) may be present to adequately locate the seals (12).

In one embodiment the sensor seal is an IP rated seal. In a further embodiment, the sensor seal is an IP68 rated seal. Preferably the seal is a gland seal. A person skilled in the art will envisage that there are a range of adequate seals that are applicable to be used in this situation to seal between a wet side and a dry side.

In one embodiment there is no seal between the sensor (6) and the ceiling (204) or ceiling region (205). In this embodiment the prevention of water from a wet side of the hull in operation to a dry side of the hull in operation relies upon a ceiling or ceiling region being higher than a nominal waterline in operation.

Figure 12 shows a well with a ceiling region (205) above the nominal waterline (18). Figure 11 shows a ceiling (204) that is below the nominal waterline so that the sensor seals (12) are also below the nominal waterline (18). Figure 11 also shows a sensor or water guard (14) that extends around periphery of the sensor array (22) or sensors (6) and their complementary sensor seals (12), where the water guard (14) extends from below to above the nominal waterline. The water guard prevents any water from coming in contact with electronics of the device (1) should a leak occur between the wet side and the dry side through the sensor seals (12) / sensor and ceiling/ceiling region boundary.

The water guard (14) is an optional alternative to having a well (206) that has a ceiling region (205) above the nominal waterline (18). Alternatively a device (1) may comprise both a well (206) and a water guard (14)

The sensors (6) may be selected from a variety of sensors for water quality or condition monitoring or data recordal. For example a sensor or sensors may be one or more selected from a turbidity sensor, a pH sensor, a dissolved oxygen sensor, a conductivity sensor, and a temperature sensor. A person skilled in the art will envisage that there are other sensors that may be applicable for particular uses.

The data from the sensors (6) is recorded or processed by a processor/circuit board (11) and stored on a hard drive (not shown) and/or sent wirelessly to another source. The data may be transmitted via one or more aerials. For example a GPX aerial (8) or an X-Bee aerial (9). Preferably the aerials are mounted by mounts (10) to the hull (100).

Preferably the electronic componentry of the device (1) such as the GPX system X-Bee system, circuitry, hard drives, batteries etc. are located all above the nominal waterline (18). Figure 11 shows mounts (10) that locates some of the aforementioned electronic hardware above the waterline (18).

The electronic componentry typically will have a greater weight than the hull and lid combined, or at least has a more moveable weight. As such, the electronic componentry may be located in the hull so a adequate centre of gravity is achieved for the conditions. For example, the battery may be moved forward or aft depending on the conditions of the flow. Preferably the device has a centre of gravity below its centre of buoyancy.

Preferably the hull (100), and/or the channel (201), as well as the sensor seals (12) are configured to allow easy access to the sensors, as well as allowing removable and/or interchangeable sensors. The sensor seals (12) and channel (201) allow the sensors to be removable and/or interchangeable. There is a somewhat modular nature to the device (1) for allowing sensors to be easily interchanged. The array of sensors (22) may be changed in one, or single sensors (6) may be removed or interchanged. The channel aids in the easy access to the sensors.

Preferably the device (1) comprises generally a hull (100) being the bottom portion of the device (1) and a lid being the top portion of the device (1). Generally, the lid (20) is above the nominal waterline. However, in other embodiments, the lid may be below the nominal waterline. Preferably there is a lid seal (13) intermediate the hull (100) and the lid (20). A space or volume is defined by the closure of the hull (100) with the lid (20). The electronics, as previously described, are located within this internal volume. In one embodiment, lid seal (13) is silicon tubing.

Preferably the lid seal (13) is hermetic or at least waterproof to prevent water from seeping into the internal volume. In one embodiment, the lid (20) is hinged to the hull (100) via a hinge (21). The hinge (21) is preferably located at a stern or bow region; however, the hinge (21) can be located at other reasons. Figure 1 shows the hinge located at the stern (103). Figure 1 shows at the bow multiple fastening features, e.g. bolts and associated nuts to fasten the lid (20) to the hull (100). Preferably this fastening has a compression effect of the lid (20) onto the hull (100). This compression effect compresses the lid seal (13). This compression of the lid seal (13) increases the inherent water and hermetic prevention characteristics. Preferably the lid seal (13) is located at or about the gunwale of the hull (100).

Un-fastening of the fastening features allows the lid (20) to be hinged about the hinge (21) so that a user can access the internal volume of the device (1).

Portions of the lid (20) may be formed from a radio frequency transparent material (15). The radio frequency transparent material (15) allows or increases the ability of radio frequencies to transmit through the lid (20), or portions of the lid (20) where there is a radio frequency transparent material (15). For example, the GPX aerial and X-Bee aerial can transmit and receive signals more easily through the radio frequency transparent material.

In one embodiment, the device (1) comprises a mounting member (16) at its bow (102) configured to be engaged to a tether (not shown). Preferably the mounting member is composed of a metal material to prevent fatigue in general or wear from the tether.

Preferably the hull is generally the shape of a long keel displacement hull. The hull is ideally symmetric about a mid-sagittal vertical (mid-plane) plane. As well as being asymmetric about a coronal plane. Preferably the hull is elongate and has a major axis running from its bow (102) to its stern 103). As previously described, the device is configured to be tethered at the bow (102). However in other embodiments hull (100) and/or associated lid (20) may be asymmetric about the coronal plane. The length or location of the keel can be adjusted for the different centre of gravity and dimensions of the device (1). For example if the device (1) was oscillating or weaving in use, the keel could be moved further aft to move the centre of pressure behind the centre of gravity, thus causing a greater straightening effect.

An example: The maximum displacement hull speed calculation predicts the transition to planing at 0.74 m/s for the 0.35m hull. The CFD model confirms this with the device pitching sternward significantly between 0.6 and 0.8 m/s. The 1.1 m/s model is clearly on the plane as shown in Figure 6. During modelling, it was found that moving the centre of gravity forwards would make the high-speed runs sit flatter on the water, but the low speed runs would then be significantly bow-down which was not desirable. The best compromise was with the centre of gravity 190-200 mm from the bow.

The device (1) is configured to float on water. As such the example device has a weight between 1500 grams and 2000 grams. Furthermore, the device has a volume of 2.4 litres. As such, the device (1) is always preferably buoyant. Other weights and volumes and clearly able to be used, as long the device can float.

The hull is configured to displace water when in operation. At lower speeds, the device (1) may plow or partially plane. In one embodiment at relatively higher flow speeds the device (1) shifts from a displacement mode to a plowing mode. Where in plowing mode the bow (102) rises upwards above the stern (103). At higher speeds, the device (1) may be fully planing, or in a 'planing mode'.

The hull (100) will preferably act in displacement at relative supporting water flow speeds less than 0.8m/s. Preferably the hull acts in displacement mode at relative supporting water flow speeds less than 0.6m/s In one embodiment, the hull planes or partially planes, or acts in a planing mode on the supporting water at relative supporting water flow speeds greater than 0.6 m/s. Preferably, the hull planes or partially planes on the supporting water at relative supporting water flow speeds greater than 0.8 m/s.

The above speeds can be determined by a maximum hull speed calculation. For a displacement hull the maximum hull speed is defined as: vhull=1.25VLWL . Where vhull is the maximum hull velocity in m/s and LWL is the waterline length. For example, the hull speed for a 0.45 m long boat the max hull speed is 0.83 m/s. For a length of 0.35 m this drops to 0.74 m/s. To maintain displacement mode at 1.1 m/s the boat should be at least 0.77 m long. Above the displacement mode speed, a speed threshold is reached and the device (1) transitions to a plowing mode or planing mode.

Preferably the channel is configured to be at least partially submerged in both displacement mode and planing mode to allow the sensors 6 to take accurate readings. In one embodiment, the channel is configured to be at least partially submerged along its length in both displacement mode and planing mode, so at least the required wetted regions of the sensors are always in the water flow.

In one embodiment, the waterline length is between 350 mm and 500 mm. However in other embodiments the waterline length can be lesser or greater.

It is important that at the range of operational flow speeds that there is good flow around the sensors (6). A CFD model was developed, and the flow around the sensors was determined. The flow rate about the bottom of the hull and sensors as shown in figures 9 a-9C. Figure 9A shows a flow of 1.1 m/s, figure 9B shows a flow of 0.6 m/s, and figure 9C shows a flow of what 0.1 m/s. The CFD model ensured that there is sufficient flow entering through the inlets, along the channel, and around the sensors at at least these flow speeds.

At high and medium speeds, Figure 9A and Figure 9B, the majority of the flow in the channel is about half the external flow speeds. This should allow good flushing of water across the sensors. The inlets perform their intended function of providing water the bow forward sensors, while the stern rear sensors get entrained flow from the channel formed between the channel sides. At low speeds, Figure 9C, the flow is more laminar and there is not a lot of flow to drive mixing inside the channel. However, the flow direction is maintained and all the sensors within the channel should still receive fresh (upstream, not stagnant) water.

Preferably the body 23, or at least the hull 100 is a low drag design. This aids in stability, and pulling force on the tether. For example, the device shown in the figures has the following drag forces:

RIVER VELOCITY (M/S) DRAG FORCE (N) 0.1 0.08 0.4 0.18 0.6 0.33 0.8 0.84 1.0 1.80 1.1 2.46

Some advantages of the present invention are described below. The sensor arrangement according to water flow direction is important because of the influence of flow on sensor readings. To obtain accurate readings the water flow needs to be constant. The arrangement of sensors inline will allow for a more streamlined direction of water flow over the sensors. Conversely, bundled or circular arrangements of sensors as seen in most other units, disturb the water flow and cause eddying and diversion of water in a manner which is not desirable for accurate sampling. The downwardly open sensor cavity allows for unobstructed water flow over the sensors. Most other units lack the hydrodynamics to protect sensors from debris whilst keeping constant flow over the sensors and thus cannot have open sensor cavities such as the channel (201). The open sensor channel (201) provides unrestricted water flow for accurate sampling.

In some embodiments, A small hole is made in the lid (20) a Breather Membrane (not shown) is fitted over the hole for the purpose of allowing moisture to escape from the internal volume. This is to ensure electrical components are kept dry in high moisture environments and exposure to sun and humidity. The breather membrane maybe one of many types of breathable (air permeable) vents. Preferably the breathable membrane is rated IP 67 or 68. The membrane may be composed at least partially of polytetrafluoroethylene.

Although the invention has been described by way of example and with reference to particular embodiments, it is to be understood that modifications and/or improvements may be made without departing from the scope or spirit of the invention.

Where in the foregoing description reference has been made to elements or integers having known equivalents, then such equivalents are included as if they were individually set forth.

Claims (30)

1. A water monitoring device configured to float on a body of water, the device comprising an elongate hull comprising a; bow, flanks, stern, and keel, the keel comprising an elongate downwardly open channel extending intermediate the bow and stern and central of the flanks, at least one inlet located towards or at the bow on each flank, the inlet configured to allow water to flow through the flanks of the hull and into the channel, the inlets and channel defining at least a laterally restrained flow path for water, wherein the hull is configured to receive one or more sensors to be located within the channel and in the flow path.

2. The device as claimed in claim 1, wherein the channel comprises a ceiling and/or ceiling regions.

3. The device as claimed in claim 2, wherein the ceiling and/or regions of the ceiling are above a nominal waterline of the device.

4. The device as claimed in any one claims 1 to 3, wherein the inlets are located on inlet regions at the flanks that are angled laterally from a vertical midplane running along a major axis of the hull.

5. The device as claimed in claim 4, wherein the angle of the inlet regions, and hence inlets, discourages waterborne debris from entering into the inlets in operation.

6. The device as claimed in any one claims 1 to 5, wherein the flanks form the channel.

7. The device as claimed in any one claims 1 to 6, wherein the channel is integral or affixed to the hull.

8. The device as claimed in any one claims 1 to 7, wherein the channel comprises channel sides.

9. The device as claimed in claim 8, wherein the channel sides are contiguous with the hull sides.

10. The device as claimed in claim 8 or 9, wherein the channel sides comprise the inlet regions

11. The device as claimed in any one claims 1 to 10, wherein the device comprises a water guard in the form of a wall that extends upwardly above the nominal waterline, about a periphery of one or more sensors.

12. The device as claimed in any one claims 1 to 11, wherein the channel has a ceiling at a level below a nominal water line, and one or more ceiling regions above the nominal water line.

13. The device as claimed in claim 12, wherein the ceiling regions are formed in a well.

14. The device as claimed in claim 13, wherein a sensor or sensors are located in the well.

15. The device as claimed in claim 14, wherein there are multiple wells along the length ofthe channel.

16. The device as claimed in any one claims 1 to 15, wherein there is a linear array of sensors along the length of the channel.

17. The device as claimed in any one claims 1 to 16, wherein the hull is configured to displace water at lower relative supporting water flow speeds (displacement mode), and plane or partially plane at higher relative supporting water flow speeds (planing mode).

18. The device as claimed in claim 18, wherein the channel is configured to be at least partially submerged in both displacement mode and planing mode.

19. The device as claimed in any one claims 1 to 18, wherein the device comprises a lid to cover the hull.

20. The device as claimed in any one claims 1 to 19, wherein the lid is composed of a radio frequency transparent material.

21. The device as claimed in any one claims 1 to 20, wherein the device comprises one or more selected from; a GPS and/or aerial, a radio transmitter, a radio receiver, an aerial, a power supply, a memory, a status indicator, a display screen, a processor, and a circuit board.

22. The device as claimed in any one claims 1 to 21, wherein the sensor may be one or more selected from a turbidity sensor, a pH sensor, a dissolved oxygen sensor, a conductivity sensor, and a temperature sensor.

23. A buoyant water monitoring device with multiple sensors emergent from the buoyant envelope of a buoyant body assembly of the device; wherein the device is of tetherable or positionable displacement floating on still water with the sensors below the waterline of the buoyant body assembly; wherein, when tethered or being tether dragged, the buoyant body assembly can plane on a planing axis should the water move, or move relatively, above a speed threshold for the tethered, or tether pulled, device; and wherein the buoyant body assembly defines a. a downwardly open laterally protected zone or downwardly open cavity ("zone") of the buoyant body assembly into which the sensors present, and b. at least one water inlet to provide water for sensor monitoring to said protected zone through at least one part of the buoyant body assembly on a locus or loci not aligned to the planing axis of the device.

24. The device as claimed in claim 23, wherein the buoyant body assembly is a lidded hull form.

25. The device as claimed in claim 23 or 24, wherein the device has its centre of gravity below its centre of buoyancy.

26. The device as claimed in any one of claims 23 to 25, wherein a tether point or zone of the buoyant body assembly will maintain stability of the device when planing.

27. A water monitoring floating device comprising a plurality of water monitoring sensors emergent of an underside of the device but still within a zone in the form of a cavity, channel or the like of the float to provide a protective, at least partial, surround of the sensors, the device having provision whereby water can duct into the channel of the device from at least one inlet of the device remote from the channel.

28. A floatable water monitor device comprising sensors and associated water protected powerable electronics, the device being characterised that its bottom defines a protected zone for the emergent sensors and that protected zone has ducted infeed provision(s) for water to be monitored, the intake(s) of which infeed provision(s) is/are spaced or remote from the protected zone.

29. The device as claimed in claim 28, wherein the protected zone is occluded horizontally in that part of the bottom that might be tethered or tether pulled upstream relative to any supporting water flow (whether that water be static or flowing).

30. The device as claimed in claim 28 or 29, wherein the intake(s) is/are in a flank or to the flanks of a hull-like form.

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