WO2020011913A1

WO2020011913A1 - Sampling vessel and method of sampling

Info

Publication number: WO2020011913A1
Application number: PCT/EP2019/068661
Authority: WO
Inventors: Michael John Baker; Harry Alec BAXTER; Paul MERRIT; Linda Clare SCOTT; Darren Seymour; John Stephenson; Daniel Piers TALMAGE; Kevin Richard West
Original assignee: Castrol Limited
Priority date: 2018-07-13
Filing date: 2019-07-11
Publication date: 2020-01-16
Also published as: GB201811553D0; WO2020011914A1

Abstract

A combination sampling vessel adapted to receive a fluid is disclosed. The vessel comprises a first sampling container having a fluid receptacle provided with an aperture, and a second sampling container having a fluid receptacle provided with an aperture. A fluid conduit is associated with at least one of the first and second sampling containers and is adapted to direct the fluid into the aperture of each of the first and second sampling containers. A kit of parts, use of such sampling vessel and method of filling such a vessel are also disclosed.

Description

SAMPLING VESSEL AND METHOD OF SAMPLING

This invention relates to a combination sampling vessel adapted to receive a fluid, comprising a first sampling container having a fluid receptacle provided with an aperture and a second sampling container also having a fluid receptacle provided with an aperture.

Various analytical techniques to determine the physical and chemical characteristics of fluids are well known, and may involve the examination of fluids in-situ, such as on a production line, or remotely as a sample in a laboratory. These analytical techniques may be suitable for investigating free-flowing dynamic fluids during production or in use, or may be suitable for examining fluids at rest. In each situation the quality of the analytical result is linked directly to the quality of the fluid sampling techniques used to obtain or view samples of a fluid. Using a sampling technique that is open to contamination or one where the sample quality is variable as the technique is not rigorous can lead to inaccurate data and results tainted by artefacts. Whilst it is a relatively simple task to set up an acceptable sampling technique to obtain a single sample of a fluid, it is far more complex to attempt to sample a fluid for use in two or more analytical techniques simultaneously - otherwise known as co-sampling. A co-sampling technique must ensure that the two or more samples obtained are not only physically and chemically a good representation of the fluid in question, but that the samples are effectively identical regardless of the order in which they were sampled. For example, when sampling from a vessel containing a static fluid there may be a difference between the fluid lying at the bottom of the vessel and that at the surface of the vessel.

The homogeneity of samples of fluid becomes even more important when analysing a fluid containing particulate debris of some kind, for example, in the ferrographic analysis of a used lubricant to determine machinery wear by examining the particulates suspended in the sampled fluid. In this situation a co-sampling technique needs to be able to handle both liquids and suspensions appropriately. Typically the fluid samples collected contain wear particulates - fragments of the surfaces of the machinery components being lubricated by the lubricant of hydraulic fluid. Such wear particulates are therefore an indication of the mechanical wear of the machinery. An increase in wear particulates may indicate increased mechanical wear, either as a result of the lubricant or hydraulic fluid being used, or as a result of the condition of the machinery. Immediately after sampling the particulates are freely suspended within the lubricant. However, over time these particulates begin to settle out of the lubricant in storage, creating a heterogeneity within the sample that can subsequently affect the ferrographic analysis detrimentally. To avoid this, before analysis, the lubricant undergoes several processes to re-suspend the particulates otherwise a false picture of the amount of wear is obtained - it is vital in these situations to have a truly representative fluid sample with wear particulates suspended therein. However, if multiple analytical techniques are required to fully characterise the wear particulates then there is the risk that the separate samples taken do not contain similar representative numbers of particulates. In addition if the sampling containers used for the individual samples are of different sizes there is also a risk of a disproportionate number of particulates being held in the various containers. Furthermore, should the sampling technique used to co-sample be too complicated there is an additional risk of this not being suitable for use in some industrial situations, such as pipelines.

There is therefore a need for a simple, reliable, repeatable and accurate co-sampling method for fluids undergoing multiple analytical techniques.

Embodiments of the present invention aim to address or ameliorate these issues by providing, in a first aspect, a combination sampling vessel adapted to receive a fluid comprising: a first sampling container having a fluid receptacle provided with an aperture; a second sampling container having a fluid receptacle provided with an aperture; and a fluid conduit associated with at least one of the first and second sampling containers and adapted to direct the fluid into the aperture of each of the first and second sampling containers.

Preferably, the fluid conduit is adapted to receive a flow of fluid from a fluid outflow. Preferably, the association between the fluid conduit and the first and second sampling containers determines the order in which the first and second sampling containers are filled with fluid.

Preferably, the first sampling container is co-located with the second sampling container. Preferably, the aperture of the first sampling container is aligned with the aperture of the second sampling vessel. Preferably, first sampling container is positioned within the second sampling container. Yet more preferably, the fluid conduit is adapted to suspend the first sampling container within the second sampling container. Yet more preferably still, the first and second sampling containers each comprise an axis of rotation perpendicular to the plane of the aperture, and wherein the first sampling container is positioned co-axially with the second sampling container.

The fluid conduit may comprise a flange having at least one opening. In this situation, the fluid conduit may be integral with the first sampling container. Alternatively, the fluid conduit is integral with the second sampling container.

The fluid conduit may comprise a first aperture aligned with the first sampling container and a second aperture aligned with the second sampling container. The fluid conduit may comprise one of: a channel, a section of a conic or a section of a pyramidal frustum. The first sampling container may be held adjacent the second sampling container by the fluid conduit.

The combination sampling vessel may further comprise a fluid guide adapted to guide fluid from an outflow to the fluid conduit.

Preferably, the apertures of the first sampling container and the second sampling containers are configured to receive a lid. The lid may comprise a seal, or the receptacle of the first sampling container may comprise a seal position remote from the aperture.

Preferably, the seal is a burstable seal to allow the exit of any fluid held within the first fluid container. More preferably, when the first sampling container comprises a lid, the lid is adapted to form a bund in an analytical apparatus.

Preferably, the first sampling container further comprises a filter and/or a plunger. The first sampling container may comprise the filter and the plunger, wherein the filter is adapted to resist rotation of the plunger.

Alternatively, the fluid conduit is a pipe. In this situation, the first and second sampling containers may be separated from each other by the fluid conduit, and removable from the fluid conduit.

Where the fluid conduit is a flange, the flange may further comprise a vent hole.

The combination sampling vessel may further comprise a fluid guide adapted to fit with the aperture of the first sampling container; wherein the fluid guide is provided with an upstanding wall forming a baffle around the vent hole of the flange. The fluid guide may further comprise a splash guard.

In another aspect, embodiments of the present invention provide for the use of a combination sampling vessel as described to sample a lubricant. Preferably, the lubricant is a used lubricant, wherein the used lubricant comprises wear particulates. In another aspect, embodiments of the present invention provide a kit of parts for forming a combination sampling vessel, comprising: a first sampling container having a fluid receptacle provided with an aperture; a second sampling container having a fluid receptacle provided with an aperture; and a fluid conduit associated with at least one of the first and second sampling containers and adapted to direct the fluid into the aperture of each of the first and second sampling containers. Preferably, the kit of parts further comprises a lid for the first sampling container. The kit of parts may also comprise a fluid guide adapted to fit into the aperture of either the first or the second sampling container.

In another aspect, embodiments of the present invention provide a method of filling a combination sampling vessel as described with a fluid, comprising: directing the flow of a fluid from an outflow of a fluid source into the fluid conduit; filling at least one of the first and second sampling containers from the flow of fluid; either ceasing the flow of fluid to the first sampling container and continuing to fill the second sampling container, or allowing fluid to overflow the first sampling container into the second sampling container; and removing the combination sampling vessel from the outflow.

Preferably, the fluid entering the first and second sampling containers originates from the same fluid source. Preferably, the fluid is an analytical fluid. More preferably, the analytical fluid is one of: a lubricant, a hydraulic fluid, a used lubricant or a used hydraulic fluid. Yet more preferably, analytical fluid is a used lubricant comprising wear particulates of a hydraulic fluid comprising wear particulates.

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

Figure la shows a cross-sectional view of the components of a combination sampling vessel in accordance with a first embodiment of the present invention;

Figure lb shows a cut away perspective view of the combination sampling vessel in accordance with a first embodiment of the present invention;

Figure lc shows a cross-sectional view of the first sampling container 10 in accordance with the first embodiment of the present invention in greater detail;

Figure ld shows a cross-sectional view of the emptying of the first sampling container in accordance with a first embodiment of the present invention; Figure le shows a plan view of a component in an exemplary air management system for use with a combination sampling vessel in accordance with a first embodiment of the present invention;

Figure lf shows an underside plan view of a fluid guide for use with the first embodiment of the present invention;

Figure lg shows a cross-sectional view of a fluid guide and combination sampling vessel in accordance with the first embodiment of the present invention and having an air management system;

Figure 2a shows a perspective view of the components of a combination sampling vessel in accordance with a second embodiment of the present invention;

Figure 2b shows a cross-sectional view of the combination sampling vessel in accordance with the second embodiment of the present invention;

Figure 2c is a side view of a first sampling container in accordance with a second embodiment of the present invention;

Figure 2d is a perspective view of a first sampling container in accordance with a second embodiment of the present invention being emptied of its fluid content;

Figure 3a shows a perspective view of the components of a combination sampling vessel in accordance with a third embodiment of the present invention;

Figure 3b shows a perspective view of the combination sampling vessel in accordance with a first embodiment of the present invention;

Figure 3c shows a perspective view of the first sampling container in accordance with the first embodiment of the present invention in greater detail;

Figure 3d shows a cross-sectional view of the emptying of the first sampling container in accordance with a first embodiment of the present invention;

Figure 4a shows a perspective view of the components of a combination sampling vessel in accordance with a third embodiment of the present invention;

Figure 4b shows a perspective view of the combination sampling vessel in accordance with a fourth embodiment of the present invention;

Figure 4c shows a cross-sectional view of the first sampling container in accordance with the first embodiment of the present invention in greater detail;

Figure 4d shows a cut away perspective view of the emptying of the first sampling container in accordance with a first embodiment of the present invention; Figure 5a shows an exploded perspective view of the components of a combination sampling vessel in accordance with a fifth embodiment of the present invention;

Figure 5b shows a cross-sectional view of the combination sampling vessel in accordance with a fifth embodiment of the present invention; and

Figure 6 is a flow chart illustrating a method of filling a combination sampling vessel in accordance with embodiments of the present invention.

The creation of a simple, reliable, repeatable and accurate co-sampling method for fluids undergoing multiple analytical techniques relies on both simplicity and ease of the method steps and the sampling vessel used to collect the fluid. Embodiments of the present invention take the approach of using a combination sampling vessel, comprising a first sampling container and a second sampling container, having a fluid conduit associated with at least one of the first and second sampling containers in a simple method that requires only a single filling step. In embodiments of the present invention the first sampling container has a fluid receptacle provided with an aperture. The second sampling container also has a fluid receptacle provided with an aperture. The fluid conduit is adapted to direct fluid into the aperture of each container. This causes the filling of the two containers to take place either concurrently or consecutively. The use of a single filling step increases the simplicity of the co-sampling process, and is a direct result of using the combination sampling vessel of the embodiments of the present invention. By including a fluid conduit in combination sampling vessel there is no need to find a funnel to fill the vessel, ensuring reliable and repeatable sample collection since there is no risk of contamination from, or variation in, external filling aids. This also aids in the accuracy of the sample collection, which in turn contributes to the accuracy of the results of the analytical methods used to subsequently investigate the fluid samples. Preferably each of the first sampling container and the second sampling container are used to sample fluid for different analytical techniques. Such analytical techniques may be carried out at different times and different locations. Alternatively, the same analytical technique may be employed and the results compared. Yet still alternatively, only one of the first or second sampling containers may be used in an analytical technique, with the other going to waste. In particular, embodiments of the present invention offer the advantage that the first sampling container may be used in a local analytical technique and the second sampling container may be sent away to an industrial laboratory. Using a local analytical technique is typically done within a short time following the collection of the fluid sample, and therefore should the fluid in question contain particulates no re-suspension is required.

Figures la to ld illustrate a combination sampling vessel and components in accordance with a first embodiment of the present invention. Figure la shows a cross- sectional view of the components of a combination sampling vessel in accordance with a first embodiment of the present invention. The first sampling container 10 comprises a fluid receptacle 11 provided with an aperture 12, and is preferably in the form of an ampule. The receptacle 11 is essentially cylindrical in shape having a closed end 13 and an open end 14 opposite the closed end 13, with the open end 14 forming the aperture 12 into the receptacle 11. The open end 14 is also provided with a fluid conduit 15 that is adapted to direct fluid into the aperture of each of the first 11 and second 16 sampling containers, as described in more detail below. The fluid conduit 15 is also adapted to receive a flow of fluid from a fluid outflow. In this embodiment, the fluid conduit 15 is associated with the first sampling container 10 as described below.

The second sampling container 16 comprises a fluid receptacle 17 provided with an aperture 18. The second sampling container 16 is generally in the form of a cylindrical bottle, having a closed end 19 (base) and an open end 110 (top), opposite the closed end 19, forming the aperture 18 and a neck of the bottle 111. In this embodiment, the fluid conduit 15 is associated with both the first 10 and the second 16 sampling containers, such that the fluid conduit 15 holds the first sampling container 10 in a position relative to the second sampling container 16. The fluid conduit 15 also acts to suspend the first sampling container 10 within the second sampling container 16. The first sampling container 10 is dimensioned to sit within the second sampling container 16 at the neck 111 of the bottle such that it is co-located with the second sampling container 16. In this embodiment, the first 10 and second 16 sampling containers each comprise an axis of rotation perpendicular to the plane of the apertures 12, 18, with the first sampling container 10 positioned co- axially within the second sampling container 16. This also causes the aperture 12 of the first sampling container 10 to be aligned with the aperture 18 of the second sampling container 16. The first sampling container 10 is significantly smaller than the second sampling container 16 in this example, however, it is envisaged that the first sampling container 10 could be closer in size to the second sampling container 16 if desired, as long as the first sampling container 10 remains dimensioned to sit within the second sampling container 16. The fluid conduit 15 therefore enables the first sampling container 10 to be co-located with the second sampling container 16.

In this embodiment of the present invention, the fluid conduit 15 is integral with the first sampling container 10. Fluid entering the first sampling container 10 enters directly via the aperture 12 of the receptacle 11. However, given the co-located nature of the first 10 and second 16 sampling containers a means for enabling fluid to flow into the second sampling container 16 is required. This is achieved in this embodiment by providing at least two openings 113 within the fluid conduit 15, such that when fluid flows down the gradient of the fluid conduit 15 a portion is able to pass through these openings and into the second sampling container 16. A central opening 114 is also included to aid in the flow of fluid. The openings 113 may also be used to allow air to escape from inside the first 10 and second 16 sampling containers to improve their filling. In addition, given the relative sizes of the first 10 and second 16 sampling containers, the first sampling container 10 may take less time to fill than the second sampling container 16. This may also be influenced by the surface area and number of openings 113 provided within the fluid conduit 15. The result of this is that the openings 113 also act as an overflow between the first fluid sampling container 10 and the second fluid sampling container 16. Fluid that flows via an overflow from the first sampling container 15 into the second sampling container 16 may be agitated as a result of this overflow process when compared with fluid entering the first sampling container 15. Such agitation may be beneficial in increasing the homogeneity of the fluid within the second sampling container 16.

In order to ensure that the first sampling container 10 is co-located accurately within the second sampling container 16, the first sampling container 10 is designed to function as a lid to the second sampling container 16, closing off the aperture 18 in the receptacle 17. To this end the first sampling container 10 is provided the receptacle 11 and is provided with an internal thread 115. This internal thread 115 guides the first sampling container 10 into position in the second sampling container 16, and interfaces with an external thread 116 provided for this purpose on the second sampling container 16. The fluid conduit 15 is therefore associated with the first 10 and second 16 sampling containers, and is adapted to direct the fluid F into the apertures 12, 18 of the first 10 and second 16 sampling containers respectively. Whilst simply removing the first sampling container 10 from the second sampling container 16 would allow the second sampling container 16 to be emptied, the first sampling container 10 is provided with a plunger 117 to aid in ensuring the contents of the first sample container 10 can be expelled when the fluid is required for use in an analytical technique.

The fluid conduit 15 further comprises a fluid guide l5a in the form of a conic frustum having an external aperture 112 (having a radius n) and a second aperture forming the aperture 12 of the first sampling container 10 (having a radius r? where n>r?. A gradient exists between the two apertures, causing fluid to flow along the gradient from the external aperture 112 to the aperture 12 of the first sampling container 10. The external aperture 112 is adapted to interact with a filling interface (not shown) to enable fluid to flow into the combination sampling vessel. This external aperture 112 is linked to the aperture 12 of the receptacle 11 by the fluid conduit 15. The diameter of the external aperture 112 is greater than that of the aperture 12 of the receptacle 11, with a portion of the fluid conduit 15 being positioned between them forming a gradient down which fluid can flow. This fluid guide l5a portion of the fluid conduit 15 in this embodiment is essentially a conic- frustum. However, other forms of funnel forming a fluid guide may be used as desired.

Figure lb shows a cut away perspective view of the combination sampling vessel in accordance with a first embodiment of the present invention. The combination sampling vessel 1 is shown with the first sampling container 10 in situ within the second sampling container 16, during the filling process. Fluid F enters the first fluid container 10 from the direction indicated by arrow“A” (gravity aided) and both flows directly through and overflows through the openings 13 provided in the fluid conduit 15.

Figure lc shows a cross-sectional view of the first sampling container 10 in accordance with the first embodiment of the present invention in greater detail. In addition to the features described above, in order to close the external aperture 112 and prevent the egress of any of the fluid F a lid 118 is inserted into the external aperture 113 as a push fit. Preferably this push fit is tamper-proof to the extent that once inserted into the external aperture 112 the lid 118 cannot be removed without damaging the first sampling container 10. The lid contains both a fine filter 119 ( 1 OOmhi mesh in this example) and a seal 120 to further prevent any fluid F egress before the first sampling container reaches an analytical device. Furthermore, although the first sampling container 10 is removable from the second sampling container 16, the fluid conduit 15 is integral with the first sampling container 10 and cannot be removed. When used in conjunction with an analytical apparatus the lid 118 remains positioned on the first sampling container 10, since in this manner it may form a bund preventing the unwanted escape of analytical fluid container within the first sampling container 10.

Figure ld shows a cross-sectional view of the emptying of the first sampling container in accordance with a first embodiment of the present invention. In this embodiment the fluid F exits the first sampling container 10 via the aperture 12 of the receptacle 11. To accomplish this the plunger 117 located at the base of the first sampling container 10 is pushed inwards, creating an increase in pressure within the first sampling container 10 and causing the seal 120 to burst. The fluid F is then forced out past the burst seal 120 and through the filter 119. When the fluid F is a suspension, the filter 119 prevents large particulates that may damage analytical apparatus from passing through, whilst allowing either desired or no particulates through. The fluid F thus exits the first sampling container 10 in the same direction as indicated by arrow“A” as the first sampling container 10 was filled.

By using the plunger 117 and filter 119 together a unidirectional system is created, where fluid can only be emptied once allowing only a single analysis pass through the analysis apparatus. This may obviate any issues regarding double-counting of samples when in use. The first sampling container may comprise both the filter 117 and the plunger 119, wherein the filter 117 may be adapted to resist rotation of the plunger 119. Alternatively, the plunger 117 may be used without the filter 119, allowing the fluid to be emptied from the combination sampling vessel and then the combination sampling vessel refilled with the same fluid. This may be to enable disposal of the fluid, or to enable multiple analytical passes through the analysis apparatus such that results from each pass may be averaged or otherwise compared to increase accuracy or to study degradation of the fluid over time, for example.

The filter 119 may also play a role in deaerating the fluid. For example, if during fluid collection a number of bubbles are present in the fluid once stored in the second fluid container 16 then depending on the mesh size of the filter 119 and the diameter of the bubbles a number of these bubbles may be removed at the point the plunger 117 forces the fluid through the filter 119. Alternatively or additionally it may be desirable to agitate the fluid ultrasonically to achieve this bubble reduction, for example, by causing either the second fluid container 16 or the plunger 117 to vibrate.

A further consideration is the ability to use the combination of the filter 119 and the plunger 117 to give an initial measurement of viscosity of the fluid. For example, it is possible to measure kinematic viscosity v as follows:

v = t*[(nR⁴gh_m)l(%LV)\

where t is time, R is the radius of the pores in the filter, g is gravity, h_m is the mean hydrostatic pressure height, L is the length of the pores in the filter and V is the flow volume. Therefore by knowing the rate fluid flow (for example, from the pressure applied to the plunger 117 and the time taken for a volume of fluid to pass through the filter 119) it is possible to make an initial viscosity assessment, which may be confirmed by later analysis or used to determine the type of analysis to be undertaken.

Figures le to lg show an exemplary air management system for use with a combination sampling vessel in accordance with a first embodiment of the present invention. The use of an air management system may be desirable in situations where the viscosity of the fluid being sampled causes the fluid conduit and/or an additional fluid guide, such as a funnel, to fill rapidly with the fluid. This causes the central 114 and other openings 113 to become effectively sealed by the fluid, preventing air from escaping from the combination sampling vessel 1. Without air escape, the fluid cannot enter the combination sampling vessel. Typically in time large bubbles of air are able to break through the fluid covering the openings 114, 113, enabling a portion of the fluid to enter the combination sampling vessel. Consequently, for very viscous fluids there is a risk that a substantially large air bubble could form, which on bursting, causes a shower of hot oil to splash around the combination sampling vessel and person operating the filling mechanism (such as a tap, valve or pump). The time taken for fluid to enter the combination sampling vessel also increases with the viscosity of the fluid, and it may become impractical for increasingly large fluid conduits or fluid guides to be employed to enable filling of the combination sampling vessel. One solution to this issue is to tilt the combination sampling vessel such that at least a portion of one of the openings 113 in the fluid conduit remains free from fluid and in air throughout the filling operation. This ensures that air is able to escape the combination sampling vessel at a constant rate. The greater the angle the combination sampling vessel is tilted at, the fasting the filling rate, until a maximum is reached when an entire opening 113 is held in air.

Another solution, one that avoids the need to tilt the combination sampling vessel when collecting a sample of a hot fluid, is to use an air management system such as that illustrated in Figures le to lg. The air management system 121 comprises a fluid guide 122 in the form of a funnel dimensioned to fit within the aperture 12 of the first sampling container 10 and provided with an upstanding wall feature 123 adapted to form a baffle around one of the openings 113 in the fluid conduit 15. Turning to Figure le, this shows a plan view of a component in an exemplary air management system for use with a combination sampling vessel in accordance with a first embodiment of the present invention. In the combination sampling vessel 1 a central opening 114 is provided to locate the first sampling container 10 and to enable fluid to enter the receptacle 11, and two further openings 113 are provided for fluid to flow via the fluid conduit 15 into the second sampling container 16. These two openings 113 extend along an arc of a circle concentric with the central opening 114. A vent hole 124 is provided between the openings 113 such that the openings 113 are spaced further apart at one end. In the embodiment illustrated, the vent hole 124 is circular, but it could be any appropriate shape provided it is able to act as a vent. The precise dimensions of the central opening 114, the openings 113 and the vent hole 124 are chosen based upon the volume of the first 10 and second 16 sampling containers and the viscosity range of the fluid F being sampled. Although in this embodiment of the present invention a specific vent hole 124 has been provided it may be desirable to repurpose one of the openings 113 as a vent hole.

Figure lf shows an underside plan view of a fluid guide for use with the first embodiment of the present invention. This view of the base of the fluid guide 122, illustrates the upstanding wall feature 123 forming a baffle around the vent hole 124.

Since in this embodiment of the present invention the vent 124 is circular, the upstanding wall feature 123 is substantially conic in shape, and may be described as a parabolic section. The upstanding wall feature comprises three sections: a first linear section 123 a extending between the vent hole 124 and a first opening 113; a second linear section l23b extending between the vent hole 124 and a second opening 113; and curved section l23c, sharing the radius of curvature of the vent hold 124. In terms of a parabolic curve, the centre of the circle of a circular vent hole 124 corresponds to the focus of the parabola. In addition the sections of the upstanding wall feature 123 vary in height to accommodate the slope of the surface of the funnel fluid guide 122 and to maintain contact with the fluid conduit 15. This prevents any fluid F from flowing into the vent hole 124 during filling of the combination sampling vessel 1. As an additional measure a seal may be provided at the top of the upstanding wall feature 123 remote from the funnel 122 in order to reduce the likelihood of any fluid leaking between the upstanding wall feature 123 and into the vent hole 124. Such a seal may be a Viton seal formed from a fluorinated elastomer.

In addition to the upstanding wall feature 123 the air management system 121 also comprises a recessed portion 125 cut into the underside of the funnel 122 (as illustrated in Figure lf). This recessed portion 125 is designed to aid in air flow out of the combination sampling vessel 1 during filling. Figure lg shows a cross-sectional view of a fluid guide and combination sampling vessel in accordance with the first embodiment of the present invention and having an air management system. As shown in Figure lg, in this embodiment of the present invention the fluid guide 122 is screwed onto the combination filling vessel 1 by means of a screw thread. An external screw thread 126 is provided on the outside of the first sampling container 10, which is designed to mate with a matching internal screw thread 127 provided on the funnel 122. In order to provide an improved air escape route from the combination sampling vessel 1 the thread 126 on the first sampling container 10 is cut away at the point corresponding to the recessed portion 125 in the underside of the funnel 122, creating an air flow channel 128, enabling an air flow as indicated by arrow E. It may be desirable to use other mechanisms to attach the funnel 122 to the combination sampling vessel 1. Any mechanism where a firm, mating fit is obtained between the funnel 122 and combination sampling vessel 1 are suitable, for example: screw fit; push fit (where the funnel contacts the outer surface of the first sampling container or where the funnel contacts the inner surface of the first sampling container); bayonet fit (where the funnel contacts the inner surface of the first sampling container); a locking fit (where the funnel is rotated into a locked position or pushed into a locked position where a locking means such as a protrusion and corresponding indent hold the funnel in position); or a combination of any of these means (for example where the funnel is pushed onto the first sampling container and then rotated into a locked position). In each of these alternative mating fit mechanisms it is necessary to provide an indent or other air path that corresponds to the recess 125 in the funnel 122 to ensure that the escape of air during filling of the combination sampling vessel is not impeded. Furthermore, if the combination sampling vessel 1 is to be used with a pump for filling there is no need for a funnel 122, therefore the alterations to the combination sampling vessel 1 itself to promote air flow should not interfere with the ability of the combination sampling vessel 1 to interface with a pump correctly.

One risk that needs to be minimised once an air management system 121 is provided is that the user of the combination sampling vessel 1 does not inadvertently close off the air escape route by placing a thumb or finger over the region of the recess 126.

This risk can be mitigated by providing ridges or other corrugated or raised features to prevent the formation of an airtight seal by a user. An alternative air management system 121 may comprise a membrane seal provided over the vent hole 124. The membrane itself has a sufficient porosity that the surface tension of the fluid being poured into the funnel prevents the fluid from passing through the membrane. However, the porosity of the membrane is also such that air is able to pass out through the membrane, thus preventing a build-up of air/fluid impeding the filling of the combination sampling vessel 1.

It may be desirable to provide a funnel 122 with each combination sampling vessel 1, for example, this may be pre-fitted during manufacture, or it may be fitted by a user. Such a funnel is optional, but may be advantageous for certain fluids and removes the need to use an intermediate sampling vessel (such as a jug), reducing the likelihood of contamination of the fluid being sampled. Having a single funnel 122 per combination sampling vessel 1 reduces the risk of cross-contamination from different fluid sources. Alternatively, it may be desirable to have a funnel 122 that is reusable with a number of combination sampling vessels, given suitable cleaning by a user to reduce cross- contamination. In this situation it is necessary to provide a locating feature on both the combination sampling vessel 1 and the funnel 122 to ensure that the funnel 122 sits in the correct orientation for the recessed portion 125 of the funnel 122 and the air flow channel of the combination sampling vessel 1 to align. Suitable location mechanisms include a protrusion and corresponding detent and a protrusion and corresponding aperture, where the mating fit of the funnel 122 and the combination sampling vessel 1 is achieved when the location mechanism is positioned correctly, for example, with an audible click or abrupt cessation of rotation or translation. Preferably a screw thread having a double-start thread is used to attach the funnel 122 to the combination sampling vessel 1, and may also be used to affix a cap subsequent to the removal of the funnel 122 and/or the first sampling container 10. The advantage of providing such a screw thread is that assembly of the component parts of the combination sampling vessel 1 and funnel 122 is both simplified and made quicker for the user. A double-start thread results in two vent holes 124 being provided diametrically opposite one another, one per thread, and requires a 180° rotation to lock and align the components in place. Whilst it may be desirable to use a triple-start thread, since this requires only a 120° rotation to lock and align components in place, three vent holes 124 would need to be provided at 120° intervals, one per thread, requiring a more complex moulding arrangement to produce the funnel 122 and combination sampling vessel 1. As an alternative to a screw thread, it may be desirable to utilise a clip or other mechanical abutment mechanism to hold the funnel 122 onto the combination sampling vessel 1.

As illustrated in Figure lg it may also be desirable to provide an anti-splash or splash guard feature 129 as part of the funnel 122. This is particularly useful when the combination sampling vessel 1 is being used to sample either a hot fluid or one with a low viscosity. The splash guard 129 may be formed of a wall extending around the periphery of the funnel 122 to act as a retainer to fluid within the funnel 122. The wall may be vertical (parallel with the walls of the first sampling container 10) or, as illustrated in Figure lg, or curved back in towards the inside of the funnel 122. This latter design is particularly preferred. However, such a splash guard feature is optional, dependent upon the fluid being sampled and may be provided as a clip-on or press on ancillary component

In order to determine the effect that an appropriate air management system may have on the ability to fill the first 15 and second 16 sampling containers at an increased speed or without overflow, a series of experiments was undertaken. These measured the time taken for lOOml of fluid to flow into a combination sampling vessel provided with an air management system substantially as shown in Figures le to lg. The opening of the neck of the funnel 122 was approximately 75mm in diameter and the aperture at the exit of the funnel 122 and the aperture 12 of the first fluid container 10 were both approximately l2mm in diameter. The depth of the funnel 122 was approximate 43mm, leading to the length of fluid flow between the opening of the funnel 122 and the exit of the funnel 122 approximately 50 - 60mm. The fluid used was an API (American Petroleum Institute) Group I base oil having a viscosity of 31.6 cSt at l00°C. The diameter of the vent hole 124 was varied as show in Table 1 below:

Table 1

Increasing the size of the vent hole 124 clearly decreases the time taken for lOOml of fluid to be collected. However providing a large (8mm) vent hole does not result in a corresponding incremental improvement in filling time compared with a smaller vent hole (3mm). Therefore it was determined that an acceptable practical air management system required a vent hole diameter of 3mm. Although this testing was carried out using a funnel 122, similar air management system considerations regarding the diameter of the vent hole

124 still apply.

Figures 2a to 2d show a combination sampling vessel and components in accordance with a second embodiment of the present invention. Figure 2a shows a perspective view of the components of a combination sampling vessel in accordance with a second embodiment of the present invention. The first sampling container 20 comprises a fluid receptacle 21 provided with an aperture 22, and is preferably in the form of a pouch. The receptacle 21 is essentially rectangular in shape and sealed around its perimeter, and has a closed end 23 and an open end 24 opposite the closed end 23, with the open end 24 forming the aperture 22 into the receptacle 21. The open end 24 is also adapted to correspond with a fluid conduit 25 that is adapted to direct fluid into the aperture of each of the first 21 and second 26 sampling containers, as described in more detail below. The fluid conduit 25 is also adapted to receive a flow of fluid from a fluid outflow. The fluid conduit 25 is associated with the first 20 and second 26 sampling containers, and serves to hold the first 20 and second 26 sampling containers in a relative position to one another.

The second sampling container 26 comprises a fluid receptacle 27 provided with an aperture 28. The second sampling container 26 is generally in the form of a cylindrical bottle, having a closed end 29 (base) and an open end 210 (top), opposite the closed end 29, forming the aperture 28 and a neck of the bottle 211. The first sampling container 20 is positioned to sit adjacent to and outside of the second sampling container 26. This is achieved by the fluid conduit 25 being arranged to hold the first sampling container 20 outside and adjacent to the second sampling container 26. The first sampling container 20 sits approximately level with the neck 211 of the bottle forming the second sampling container. The first sampling container 20 is significantly smaller than the second sampling container 26 in this example, however it is envisaged that the first sampling container 20 could be closer in size to the second sampling container 26 if desired, as long as the first sampling container 20 is suitable to be positioned adjacent to and outside of the second sampling container 26.

In this embodiment the fluid conduit 25 is removable to separate the first 20 and second 26 sampling containers. The fluid conduit 25 is formed from a section of a conic frustum, having a broad open end 212 adapted to receive a fluid from a fluid source (not shown) and a narrow end 213 adapted to dispense fluid into the second sampling container 26. An aperture 214 is located adjacent to the narrow end 213, the aperture 214 being adapted to dispense fluid into the first sampling container 20. The fluid conduit 25 is used to link the first 20 and second 26 sampling containers as well as being adapted to direct fluid into the aperture 22, 28 of each of the first 20 and second 26 sampling containers.

Figure 2b shows a cross-sectional view of the combination sampling vessel in accordance with the second embodiment of the present invention. The combination sampling vessel 2 is shown with the first sampling container 20 in situ adjacent the second sampling container 26, during the filling process. Fluid F enters the first fluid container 20 from the direction indicated by arrow“A” (gravity aided) through the aperture 214 in the fluid conduit 25 and flows directly into the second sampling container 26 over the narrow end 213 of the fluid conduit 25. Fluid F may also overflow from the first sampling container 20 back through the aperture provided in the fluid conduit 15. In order to link the first 20 and second 26 sampling containers together using the fluid conduit 15, since the first sampling container 20 is formed from a flexible pouch it can be inserted though the aperture 214 to hang below the fluid conduit 25. Given the position of the aperture 214 this results in the first sampling container 20 being positioned adjacent to the second sampling container 26. The first sampling container 20 is upstream of the second sampling container 26. The fluid conduit 25 also comprises connector 215 in the form of an incomplete ring adapted to clip on to the outer surface of the second sampling container 26 at the aperture 28. This keeps the fluid connector 25 in position to enable fluid to flow over the narrow end 213 of the fluid connector 25 and into the aperture 28 of the second sampling container 26. The second sampling container 26 is further provided with a flange 216 located within the container adjacent to the aperture 37 of the receptacle 36. The flange 216 comprises at least two openings 217 through which a portion of the fluid entering the fluid conduit 25 is able to flow into the receptacle 17. During filling, air may escape from the first sampling container 20 due to the angle of the fluid conduit 25, consequently forming an air management system enabling air to flow out of the first sampling container 20 as fluid enters, and preventing splashing or overflow of fluid from the combination sampling vessel 2 or fluid conduit 25.

Figure 2c is a side view of a first sampling container in accordance with a second embodiment of the present invention. The first sampling container 20 comprises a flexible pouch, designed to contain a fluid F, which may be formed from a plastics material or a metallic foiFplastic-foil laminate. The pouch is essentially rectangular in shape, narrowing towards a base portion 23 and openable via the aperture 22 at top portion 24 via a lid 218. The lid 218 is a simple flip-top lid, although other options are possible. The narrow base portion 23 serves as the support for an integrated filter 219. In addition the base portion 23 is sealed at its narrowest point by a seal 220 designed to burst following an increase in pressure within the pouch, for example, where the second sampling container is squeezed by a set of rollers, in order to expel its fluid content.

This is illustrated further in Figure 2d. Figure 2d is a perspective view of a first sampling container in accordance with a second embodiment of the present invention being emptied of its fluid content. The first sampling container 20 undergoes an increase in internal pressure, illustrated in this Figure by a force (arrows“P”) being applied to each side of the first sampling container. This causes the seal 220 to burst, expelling the fluid F through the base 23 of the first sampling container in a direction indicated by arrow“B”.

In this second embodiment of the present invention, the first 20 and second 26 sampling containers are intended to provide samples for two different analytical methods. Alternatively the first 20 and second 26 sampling containers may provide samples to be used in the same analytical method. One example of the use of the second embodiment of the present invention in different analytical methods is in the field of ferrography. As described above in relation to the first embodiment of the present invention, the second sampling container 26 is suitable for use with traditional ferrographic methods, and the first sampling container 20 is particularly suitable for use in local small-scale analysis.

Figure 3a to 3d show a combination sampling vessel in accordance with a third embodiment of the present invention. Figure 3a shows a perspective view of the components of a combination sampling vessel in accordance with a third embodiment of the present invention. The first sampling container 30 comprises a fluid receptacle 31 provided with an aperture 32, and is preferably in the form of an ampule. The receptacle 31 is essentially cylindrical in shape having a closed end 33 and an open end 34 opposite the closed end 33, with the open end 34 forming the aperture 32 into the receptacle 31.

The second sampling container 35 comprises a fluid receptacle 36 provided with an aperture 37. The second sampling container 35 is generally in the form of a cylindrical bottle, having a closed end 38 (base) and an open end 39 (top), opposite the closed end 38, forming the aperture 37 and a neck of the bottle 310. The first sampling container 30 is dimensioned to sit within the second sampling container 35 at the neck 310 of the bottle such that it is co-located with the second sampling container 35. In this embodiment, the first 30 and second 35 sampling containers each comprise an axis of rotation perpendicular to the plane of the apertures 32, 37, with the first sampling container 30 positioned co- axially within the second sampling container 35. This also causes the aperture 32 of the first sampling container 30 to be aligned with the aperture 37 of the second sampling container 35. The first sampling container 30 is significantly smaller than the second sampling container 35 in this example, however, it is envisaged that the first sampling container 30 could be closer in size to the second sampling container 35 if desired, as long as the first sampling container 30 remains dimensioned to sit within the second sampling container 35.

A fluid conduit 311 is associated with the second sampling container 35.

Preferably, the fluid conduit 311 is integral with the second sampling container. In addition, the fluid conduit 311 acts to suspend the first sampling container 30 within the second sampling container 35. The fluid conduit 311 is in the form of a flange 312 located within the container adjacent to the aperture 37 of the receptacle 36. The flange 312 comprises at least two openings 313 through which a portion of the fluid entering the fluid conduit 311 is able to flow into the receptacle 36. These openings serve as an overflow system once the first sampling container 30 is in place. The first sampling container 30 is dimensioned to sit within the second sampling container 35 by contacting the flange 312 such that it is co-located with the second sampling container 35. In this embodiment, the first 30 and second 35 sampling containers each comprise an axis of rotation perpendicular to the plane of the apertures 32, 37, with the first sampling container 30 positioned co-axially within the second sampling container 35. This also causes the aperture 32 of the first sampling container 30 to be aligned with the aperture 37 of the second sampling container 35. The first sampling container 30 is significantly smaller than the second sampling container 35 in this example, however, it is envisaged that the first sampling container 30 could be closer in size to the second sampling container 35 if desired, as long as the first sampling container 30 remains dimensioned to sit within the second sampling container 35.

Fluid entering the first sampling container 30 enters directly via the aperture 32 of the receptacle 31. However, given the co-located nature of the first 30 and second 35 sampling containers a means for enabling fluid to flow into the second sampling container 35 is required. This is achieved in this embodiment by the at least two openings 313 within the flange 312, such that when fluid flows down the gradient of the fluid conduit 311 a portion is able to pass through these openings and into the second sampling container 35. In addition, given the relative sizes of the first 30 and second 35 sampling containers, the first sampling container 30 takes less time to fill than the second sampling container 35. This may also be influenced by the surface area and number of openings 313 provided within the flange 312. The result of this is that the openings 313 also act as an overflow between the first fluid sampling container 30 and the second fluid sampling container 35. The openings 313 also enable air to escape from the first 30 and/or second 35 sampling vessels during filling. An air management system, similar to that shown in Figure le may also be used with this embodiment of the present invention.

In addition, a fluid guide 314 in the form of a conic frustum having a first aperture 315 and a second aperture 316 (aperture 1 with radius n, aperture 2 with radius r? where ri>ri), such that a gradient exists between the two apertures 315, 316, causing fluid to flow along the gradient from one aperture 315 to the other aperture 316. The first aperture 315 with the largest radius is adapted to receive a flow of a fluid F from a fluid source. The second aperture 316 is adapted to receive the first sampling container 30, as described below. The second aperture 315 is also dimensioned to fit within the aperture 37 of the second sampling container 35. The fluid guide 314 further comprises a wall 317 standing proud from the second aperture 316 and directed outwards from the fluid guide 314. This wall 317 forms the connection between the fluid guide 314 and second sampling container 35, and is provided with an external thread adapted to mate with an internal thread provided at the aperture 37 of the second sampling container 35. In order to collect a sample of fluid F the fluid guide 314 is therefore simply screwed onto the second sampling container 35.

Figure 3b shows a perspective view of the combination sampling vessel in accordance with a first embodiment of the present invention. The combination sampling vessel 3 is shown with the first sampling container 30 in situ within the second sampling container 35, during the filling process. Fluid F enters the first fluid container 30 from the direction indicated by arrow“A” (gravity aided) and both flows directly through and overflows through the openings 313 provided in the fluid conduit 311.

Figure 3c shows a cross-sectional view of the first sampling container 30 in accordance with the first embodiment of the present invention in greater detail. In addition to the features described above, in order to close the aperture 32 and prevent the egress of any of the fluid F a lid 317 is pushed onto the aperture 32 of the first sampling container 30. Preferably this push fit is tamper-proof to the extent that once pressed onto the aperture 32 the lid 317 cannot be removed without damaging the first sampling container 30. The lid 317 contains a plunger 318 to aid in emptying the first sampling container 30 in use in an analytical method. The lid contains both a fine filter 319 ( 1 OOmhi mesh in this example) and a seal 320 to further prevent any fluid F egress before the first sampling container 30 reaches an analytical device. A seal 321 is also provided at the base 33 of the first sampling container 30 for use in emptying the container.

Figure 3d shows a cross-sectional view of the emptying of the first sampling container in accordance with a first embodiment of the present invention. In this embodiment the fluid F exits the first sampling container 30 via the seal 321 at the base 33 of the container. To accomplish this the plunger 318 located at the aperture 32 of the first sampling container 30 is pushed inwards, creating an increase in pressure within the first sampling container 30 and causing the seal 321 to burst. The fluid F is then forced out past the burst seal 321. The fluid F thus exits the first sampling container 30 in the opposite direction as indicated by arrow“B” as the first sampling container 30 was filled. In this third embodiment of the present invention, the first 30 and second 36 sampling containers are intended to provide samples for two different analytical methods. Alternatively the first 30 and second 35 sampling containers may provide samples to be used in the same analytical method. One example of the use of the third embodiment of the present invention in different analytical methods is in the field of ferrography. As described above in relation to the first and second embodiments of the present invention, the second sampling container 35 is suitable for use with traditional ferrographic methods, and the first sampling container 30 is particularly suitable for use in local small-scale analysis.

Figures 4a to 4d show a combination sampling vessel in accordance with a fourth embodiment of the present invention. Figure 4a shows a perspective view of the components of a combination sampling vessel in accordance with a third embodiment of the present invention. The first sampling container 40 comprises a fluid receptacle 31 provided with an aperture 42, and is preferably in the form of an ampule. The receptacle 41 is essentially cylindrical in shape having a closed end 43 and an open end 44 opposite the closed end 43, with the open end 44 forming the aperture 42 into the receptacle 41.

The second sampling container 45 comprises a fluid receptacle 46 provided with an aperture 47. The second sampling container 45 is generally in the form of a cylindrical bottle, having a closed end 48 (base) and an open end 49 (top), opposite the closed end 48, forming the aperture 47 and a neck of the bottle 410. The first sampling container 40 is dimensioned to sit within the second sampling container 46 at the neck 410 of the bottle such that it is co-located with the second sampling container 45. In this embodiment, the first 40 and second 45 sampling containers each comprise an axis of rotation perpendicular to the plane of the apertures 42, 47, with the first sampling container 40 positioned co- axially within the second sampling container 45 This also causes the aperture 42 of the first sampling container 40 to be aligned with the aperture 47 of the second sampling container 45. The first sampling container 10 is significantly smaller than the second sampling container 16 in this example, however, it is envisaged that the first sampling container 40 could be closer in size to the second sampling container 45 if desired, as long as the first sampling container 40 remains dimensioned to sit within the second sampling container 45.

A fluid conduit 411 is associated with the second sampling container 45.

Preferably, the fluid conduit 411 is integral with the second sampling container. In addition, the fluid conduit 411 acts to suspend the first sampling container 40 within the second sampling container 45. The fluid conduit 411 is in the form of a flange 412 located within the container adjacent to the aperture 47 of the receptacle 46. The flange 412 comprises at least two openings 413 through which a portion of the fluid entering the fluid conduit 411 is able to flow into the receptacle 46. These openings serve as an overflow system once the first sampling container 40 is in place.

The first sampling container 40 is dimensioned to sit within the second sampling container 45 by contacting the flange 412 such that it is co-located with the second sampling container 45. In this embodiment, the first 40 and second 45 sampling containers each comprise an axis of rotation perpendicular to the plane of the apertures 42, 47, with the first sampling container 40 positioned co-axially within the second sampling container 45. This also causes the aperture 42 of the first sampling container 40 to be aligned with the aperture 47 of the second sampling container 45. The first sampling container 40 is significantly smaller than the second sampling container 45 in this example, however, it is envisaged that the first sampling container 40 could be closer in size to the second sampling container 45 if desired, as long as the first sampling container 40 remains dimensioned to sit within the second sampling container 45.

Fluid entering the first sampling container 40 enters directly via the aperture 42 of the receptacle 41. However, given the co-located nature of the first 40 and second 45 sampling containers a means for enabling fluid to flow into the second sampling container 45 is required. This is achieved in this embodiment by the at least two openings 413 within the flange 412, such that when fluid flows down the gradient of the fluid conduit 411 a portion is able to pass through these openings and into the second sampling container 45. In addition, given the relative sizes of the first 40 and second 45 sampling containers, the first sampling container 40 takes less time to fill than the second sampling container 45. This may also be influenced by the surface area and number of openings 413 provided within the flange 412. The result of this is that the openings 413 also act as an overflow between the first fluid sampling container 40 and the second fluid sampling container 45. The openings 413 also enable air to escape from the first 40 and/or second 45 sampling vessels during filling. An air management system, similar to that shown in Figure le may also be used with this embodiment of the present invention. In addition, a fluid guide 414 in the form of a conic frustum having a first aperture 415 and a second aperture 416 (aperture 1 with radius n, aperture 2 with radius r? where ri>ri), such that a gradient exists between the two apertures 415, 416, causing fluid to flow along the gradient from one aperture 415 to the other aperture 416. The first aperture 415 with the largest radius is adapted to receive a flow of a fluid F from a fluid source. The second aperture 416 is adapted to receive the first sampling container 40, as described below. The second aperture 415 is also dimensioned to fit within the aperture 47 of the second sampling container 45. The fluid guide 414 further comprises a wall 417 standing proud from the second aperture 416 and directed outwards from the fluid guide 414. This wall 417 forms the connection between the fluid guide 414 and second sampling container 35, and is provided with an external thread adapted to mate with an internal thread provided at the aperture 47 of the second sampling container 45. In order to collect a sample of fluid F the fluid guide 414 is therefore simply screwed onto the second sampling container 45.

Figure 4b shows a cross-sectional view of the combination sampling vessel in accordance with a fourth embodiment of the present invention. The combination sampling vessel 4 is shown with the first sampling container 40 in situ within the second sampling container 45, during the filling process. Fluid F enters the first fluid container 40 from the direction indicated by arrow“A” (gravity aided). In this embodiment a filter 417 (lOOpm) is located partway along the length of the first sampling container. When filling the combination sampling vessel 4 it is important to ensure that the level of fluid F within the first sampling container 40 reaches no further than the filter 417. In this embodiment the filter 417 prevents large particulates from entering the volume of sample fluid on filling, rather than preventing the outflow of such larger particulates on emptying, as with some the other embodiments described herein. The openings 413 in the flange 412 are sized to enable the flow of fluid F into the second (larger) sampling container 45 at an appropriate rate to reach a desired level of fluid f in the second sampling container 45 at the same time as ensuring that the level of fluid F in the first sampling container 40 does not exceed that of the filter 417. This may be achieved by minimising the opening available for fluid F to flow into the first sampling container 40 and maximising the opening(s) available for fluid F to flow into the second sampling container 45. Figure 4c shows a cross-sectional view of the first sampling container 40 in accordance with the first embodiment of the present invention in greater detail. In addition to the features described above, in order to close the aperture 42 and prevent the egress of any of the fluid F a lid 418 is pushed onto the aperture 42 of the first sampling container 40, for example, a flip lid may be used. The first sampling container further contains a seal 419 to further prevent any fluid F egress before the first sampling container 40 reaches an analytical device. This seal 419 is provided at the base 43 of the first sampling container 40 for use in emptying the container.

Figure 4d shows a cut away perspective view of the emptying of the first sampling container in accordance with a first embodiment of the present invention. In this embodiment the fluid F exits the first sampling container 40 via the seal 419 at the base 43 of the container 40. To accomplish this, a needle or fine tube 420 pierces the lid 418 to allow air to be injected into the first sampling container 40. The amount of air injected into the first sampling container 40 is gradually increased until the pressure within the first sampling container is great enough to burst the seal 419 located at the base 43 of the container 40. The fluid F is then forced out past the burst seal 419. The fluid F thus exits the first sampling container 40 in the opposite direction as indicated by arrow“B” as the first sampling container 40 was filled.

In this fourth embodiment of the present invention, the first 40 and second 45 sampling containers are intended to provide samples for two different analytical methods. Alternatively the first 40 and second 45 sampling containers may provide samples to be used in the same analytical method. One example of the use of the fourth embodiment of the present invention in different analytical methods is in the field of ferrography. As described above in relation to the first and second embodiments of the present invention, the second sampling container 45 is suitable for use with traditional ferrographic methods, and the first sampling container 40 is particularly suitable for use in local small-scale analysis.

Figures 5a and 5b show a combination sampling vessel in accordance with a fifth embodiment of the present invention. This embodiment differs from those described above in that there is no need to remove the fluid from the first sampling container 50 when used in a suitable analytical technique, for example, an optical analysis of wear particles within the fluid F. This simplifies the structure of the embodiment, as well as the manner in which fluid F is collected in both the first sampling container 50 and the second sampling container 51. Figure 5a shows an exploded perspective view of the components of a combination sampling vessel in accordance with a fifth embodiment of the present invention. In this example the first sampling container 50 is generally cylindrical in shape, but unlike those containers in the embodiments described above, in this embodiment the diameter d of the cylinder is greater than its height h. Preferably the ratio between d and h is in the range of 2:1 to 10:1. The first sampling container 50 comprises a receptacle 52 provided with an aperture 53. The second sampling container 51 is generally in the form of a cylindrical bottle, having a closed end 54 (base) and an open end 55 (top), opposite the closed end 54, forming the aperture 56 and a neck of the bottle 57.

The fluid conduit 58 is in the form of a cylindrical pipe to which both the first 50 and second 51 sampling containers are connected in order to sample the fluid within the fluid conduit 58. The fluid conduit 58 is provided with a first aperture 59 in a side wall of the cylindrical pipe, and with a second aperture 510 forming an open end of the fluid conduit 58 remote from the fluid source. The second sampling container 51 is provided with an internal screw thread 511 adjacent the aperture 56, which fits with an external screw thread provided on the fluid conduit 48 adjacent the second aperture 510. A small attachment 512 is provided on the side wall of the fluid conduit 58 and adapted to fit into the aperture 53 of the first sampling container 50 to enable the container to be filled with fluid F.

Figure 5b shows a cross-sectional view of the combination sampling vessel in accordance with a fifth embodiment of the present invention. The combination sampling vessel 5 is shown with the first sampling container 50 in situ an attached to the fluid conduit 58, and the second sampling container 55 also attached to the fluid conduit 58, during the filling process. Fluid F enters the first fluid container 50 from the direction indicated by arrow“A” (gravity aided) through the first aperture 59 first, although a significant amount of fluid F will flow past the first aperture 59 and continue on to the second aperture 510 to fill the second sampling container 51. In addition, once the first sampling container 50 is full, fluid will overflow from the first aperture 59 during filling. Consequently, the fluid conduit links the first 50 and second 51 sampling containers and is adapted to direct the fluid into the aperture 53, 56 of each of the first 50 and second 51 sampling containers. Once the first 50 and second 51 sampling containers are filled they are removed from the fluid conduit 58 a cap 513 is used to seal each sampling container. Given the angle of the fluid conduit 58 fluid should be able to flow into the first sampling container 50 and air exit the first sampling container 50 during the filling operation. This therefore forms an air management system, preventing splashing or overflow of fluid from the first sampling vessel.

In the embodiments of the present invention, the first and second sampling containers are intended to provide samples for two different analytical methods.

Alternatively the first and second sampling containers may provide samples to be used in the same analytical method. As a further alternative, it may be desirable to fill both the first and second sampling containers to ensure that a fully representable sample of the fluid is held in the first sampling container, and for the second sampling container to be disposed of as waste. However, one example of the use of the first embodiment of the present invention in different analytical methods is in the field of ferrography.

Ferrography may be used to predict and diagnose potential faults and errors occurring or about to occur on machinery, and the second sampling container and its contents are particularly suitable for use in this analytical method. The particulates and contaminants present in a sample fluid (for example a lubricant or hydraulic fluid) associated with the machinery are identified and analysed. Information regarding the lifespan, environment, and usage of the machinery may be inferred from characteristics associated with the identified particulates. Traditional ferrography techniques comprise obtaining a sample of lubricating oil from machinery and separating out the particulates present in the oil sample for analysis. The sample may first be chemically diluted to improve particulate precipitation and adhesion, and then arranged to travel down a glass slide to deposit particulates on the slide. A magnet may be used such that ferromagnetic particulates present in the oil are attracted and separated at distances along the slide corresponding to their magnetic properties. Non-magnetic particulates are randomly deposited along the length of the slide. Once this process is complete, the slide is washed clear of lubricant or hydraulic fluid and analysed under a microscope. By studying the parameters of the particulates obtained from the sample, information relating to the wear of the machinery from which the sample was taken may be inferred. This analytical technique forms a key component of sample analysis in the oil and gas industry, and is an ideal use for the fluid F captured in the second sampling vessel. However, it may be desirable to investigate such physical and chemical properties of a lubricant or hydraulic fluid locally, for example, on a wind farm or a ship, or to look at dynamic images of the fluid F and the particulates contained therein. The first sampling container and its contents are particularly suited to use in this analytical technique. This may be done using an analytical apparatus comprising at least a flow cell (also known as a microfluidic cell) for handling the flow of the fluid F, a first light source to provide backlit illumination to the fluid F, a second light source to provide frontlit illumination to the fluid F, and an image capture means such as a CCD camera. The analytical apparatus is connected to an analysis means and data storage means for analysing and processing data from the apparatus. The image capture means is configured to capture images of the particulates within the fluid F in the flow cell. The flow cell is arranged to receive the fluid whilst the fluid is in motion such that dynamic images of a moving particulate may be seen. The first sampling container may be emptied directly into the flow cell of the analytical apparatus, or into a fluid flow system designed to pass the fluid F though the flow cell via other components such as a pump.

In another aspect, embodiments of the present invention provide for the use of a combination sampling vessel as described above for sampling a lubricant or a hydraulic fluid. Preferably the lubricant is used lubricant comprising wear particulates or the hydraulic fluid is a used hydraulic fluid comprising wear particulates. Sampling of such used lubricants and hydraulic fluids and their subsequent analysis provides vital information for wear monitoring of mechanical or hydraulic machinery that requires a lubricating fluid for use. The above embodiments of the present invention were tested with a lubricant having a viscosity of 1600 cSt at ambient temperature. However, the combination sampling vessel is intended for use with fluids having a temperature in the range -50°C to l50°C, and a viscosity range of 0.1 to 10,000 cSt. Other fluids that may be sampled include, but are not limited to: coolants, metalworking fluids, aqueous fluids, emulsions, colloidal suspensions, hydrocarbons (crude oil), foodstuffs, aggregate assay systems, industrial chemicals, medical and biologicaFbiochemical fluids.

In another aspect, embodiments of the present invention provide a kit of parts for forming a combination sampling vessel, such as those described in the above embodiments of the present invention. Such a kit of parts preferably contains: a first sampling container having a fluid receptacle provided with an aperture and a second sampling container having a fluid receptacle provided with an aperture. A fluid conduit associated with at least one of the first and second sampling containers and adapted to direct the fluid into the aperture of each of the first and second sampling containers is also included. A lid for the first sampling container, at least, is also included.

In another aspect, embodiments of the present invention provide a method of filling a combination sampling vessel, preferably a combination sampling vessel in accordance with an above described embodiment of the present invention. Figure 6 is a flow chart illustrating a method of filling a combination sampling vessel in accordance with embodiments of the present invention. Such a method is suitable for use with any of the embodiments of combination sampling vessels described above, but for simplicity is described with respect to a combination sampling vessel in accordance with the first embodiment, as illustrated in Figure 1.

In the embodiment described above, the external aperture is adapted to receive a flow of fluid from a fluid outflow, such as a tap, valve, stopcock, spout or pipe. In order to fill the combination sampling vessel, at step 600, the flow of a fluid from an outflow of a fluid source is directed into the fluid conduit. At step 602, at least one of the first and second sampling containers is filled from the flow of fluid. At step 604, either the flow of fluid to the first sampling container is ceased and filling the second sampling container is continued, or, at step 606, fluid is allowed to overflow the first sampling container into the second sampling container. At step 608, the second sampling container is filled until the desired fill level is reached. And at step 610, the first and second sampling containers are removed from the fluid conduit and consequently also removed from the outflow.

Preferably, the fluid entering the first and second sampling containers originates from the same fluid source. The method may further comprise the fitting of a fluid guide to either the first or second sampling container as an initial step if this is not provided in a pre- assembled manner.

Depending on the construction of the fluid conduit and/or the presence of a flange within the second sampling container, the fluid may flow first into the first sampling container, which is therefore located upstream of the second sampling container.

Alternatively, the fluid may flow first into the second sampling container, which is therefore located upstream of the first sampling container. Alternatively, the fluid may flow into the first and second sampling containers at the same time. There may also be an overflow of fluid from the first sampling container into the second sampling container.

One further advantage of using the co-located sampling vessels of certain embodiments of the combination sampling vessels described above is the ability to use such combination sampling vessels within existing standard operating procedures for sampling fluids intended for ferrographic examination. For example, the second sampling container 16 may be suitable for use in existing ferrographic analysis, such that sampling systems are already set up to allow fluids to be dispensed into such containers. Providing a combination sampling vessel that is of a similar volume, appearance and use as existing sampling containers enables these to be used with no additional user training other than in assembly of parts. As an extension of this, once the first sampling container 10 is removed from the combination sampling vessel, a cap identical to that used in existing sampling containers may be affixed to the second sampling container 16. The capped container may then be placed into an existing analytical analysis procedure.

In the above embodiments, the second sampling container may be a bottle formed from a plastics material such as polypropylene (PP), high density polyethylene (HDPE or acetyl, which may be a virgin material, or may be formed from a mix of recycled and virgin materials, or may be formed entirely from recycled materials. Other similar materials may also be used, with the proviso that they must be able to withstand the fluid to be contained without degradation affecting sample quality, such as by the fluid leaching into the material or causing a structural failure. Preferably the second sampling container has a volume in the range of 5 to 500ml. The first sampling container may also be a bottle formed from a plastics material such as polypropylene (PP), high density polyethylene (HDPE) or acetyl, which may be a virgin material, or may be formed from a mix of recycled and virgin materials, or may be formed entirely from recycled materials. Other similar materials may also be used, with the proviso that they must be able to withstand the fluid to be contained without degradation affecting sample quality, such as by the fluid leaching into the material or causing a structural failure. Polypropylene is the preferred material for both the first and the second sampling containers. This functions well when a Viton seal is used in conjunction with an air management system. Preferably both the first and second sampling containers are also free from carbon black to avoid this causing any contamination issues with the fluids being sampled. Preferably the first sampling container has a much smaller volume than the second sampling container, in the range of 0.5 to 500ml. In the above embodiments, a first sampling container volume of 3ml was used. When a pouch is used, as in the second embodiment of the invention described above, such a pouch may be formed from a flexible plastics material, a foil material or a plastic-foil laminated material. Whilst in the embodiments described above generally cylindrical bottles are employed as the first and second sampling containers, other shapes of container may be suitable, such as

square/rectangular cross-section bottles or pouches. The relative size and/or volume of the first and second sampling containers are determined by the configuration chosen to form the combination sampling vessel. The lids applied to the first sampling containers may be of the same material as the first sampling containers, or of a different material, for example, an elastomeric material.

The above embodiments find particular use in analytical methods where it is desirable to study particulates held in a liquid phase. Therefore the fluid F may preferably be an analytical fluid, such as lubricant, in particular, a used lubricant, or a hydraulic fluid, in particular, a used hydraulic fluid. Such used lubricants and hydraulic fluids contain wear particulates, thus indicating the mechanical wear of an item of machinery. Many analysis techniques rely on the ability to obtain homogeneous samples of analytical fluids, and these may or not need to obtain particulates. The filters used in the above

embodiments were chosen to have a pore size of 1 OOmhi, since this is useful in the field of ferrography. The filter may be a mesh or a porous filter medium, depending on the application of the fluid F for analysis, and may be sized to exclude either all particulates within a fluid phase or particulates of a desired size.

Each of the first to fourth embodiments above employs a seal that is somehow broken for the fluid F to exit the first sampling container. Preferably the seal is one that breaks under an increase in pressure, such as a burstable seal, for example, a foil seal, such as an aluminium foil seal. However it may be preferable for the seal to break via a different method, such as puncturing, tearing or removal (complete or partial). Each of these mechanisms is again dependent on the analytical method being used and the fluid being studied. As an alternative to a seal it may be desirable to use a stopper, such as a rubber or elastomer stopper, an elastomer seal, or a valve, such as a duckbill valve or a slit valve, or use a wax material or other material that is able to withstand the chemical nature of the fluid yet is dissolvable under heat and is easily identifiable rather than becoming a contaminant. As a further alternative, dependent upon the material used to form the filter, the surface tension and capillary action of the fluid within the first sampling container may be sufficient to create a robust and reliable seal.

The optional fluid guide and fluid conduit of the second embodiment above are preferably formed from a rigid plastics material, such as polypropylene, (PP). As with the first and second sampling containers preferably the fluid guide does not contain any carbon black. It may be preferable for the material to exhibit a small amount of flexibility to enable fitting on the second sampling container, but sufficient rigidity that the fluid may flow over the surface of the fluid guide without the material showing any deformation that may affect the ability of the fluid conduit to direct fluid into both the first and second sampling containers. The fluid guide may be any form of channel capable of holding, retaining and directing a volume or flow of fluid. The fluid guide should also be adapted to receive fluid from a fluid outflow. A channel (“V”-,“U”-shaped or square-sided shape), folded design (fluid bearing when unfolded), conical, ffusto conical, ffusto pyramidal or similar shape may be used as the fluid guide. Folded designs are particularly advantageous for ease of storage. It should be noted that a fluid guide may be reused for many combination fluid vessels.

Each of the embodiments above illustrates the combination of a first and a second sampling vessel and a fluid conduit. However, it may be desirable to link at least two of the first sampling containers with one or more second sampling containers. This may be done, for example, by using a fluid conduit with multiple apertures, or linking sampling containers together using a series of fluid conduits.

Although the present invention has been described in connection with some embodiments, it is not intended to be limited to the specific form set forth herein. Rather, the scope of the present invention is limited only by the accompanying claims.

Additionally, although a feature may appear to be described in connection with particular embodiments, one skilled in the art would recognize that various features of the described embodiments may be combined in accordance with the invention. In the claims, the term‘comprising’ does not exclude the presence of other elements or steps.

Furthermore, the order of features in the claims does not imply any specific order in which the features must be performed and in particular, the order of individual steps in a method claim does not imply that the steps must be performed in this order. Rather, the steps may be performed in any suitable order. In addition, singular references do not exclude a plurality. Thus, references to‘a’,‘an’,‘first’,‘second’, etc. do not preclude a plurality. In the claims, the term‘comprising’ or“including” does not exclude the presence of other elements.

Claims

1. Combination sampling vessel adapted to receive an analytical fluid, the analytical fluid being one of a lubricant, hydraulic fluid, used lubricant or used hydraulic fluid, the vessel comprising:

A first sampling container having a fluid receptacle provided with an aperture;

A second sampling container having a fluid receptacle provided with an aperture; and

A fluid conduit associated with at least one of the first and second sampling containers and adapted to direct the fluid into the aperture of each of the first and second sampling containers.

2. Combination sampling vessel of claim 1, wherein the fluid conduit is adapted to receive a flow of fluid from a fluid outflow.

3. Combination sampling vessel of claim 1 or 2, wherein the association between the fluid conduit and the first and second sampling containers determines the order in which the first and second sampling containers are filled with fluid.

4. Combination sampling vessel of any of claims 1 to 3, wherein the first sampling container is co-located with the second sampling container

5. Combination sampling vessel of claim 5, wherein the aperture of the first sampling container is aligned with the aperture of the second sampling vessel.

6. Combination sampling vessel of claim 4 or 5, wherein the first sampling container is positioned within the second sampling container.

7. Combination sampling vessel of claim 6, wherein the fluid conduit is adapted to suspend the first sampling container within the second sampling container.

8. Combination sampling vessel of claim 6 or 7, wherein the first and second sampling containers each comprise an axis of rotation perpendicular to the plane of the aperture, and wherein the first sampling container is positioned co-axially with the second sampling container.

9. Combination sampling vessel of any of claims 4 to 8, wherein the fluid conduit comprises a flange having at least one opening.

10. Combination sampling vessel of claim 9, wherein the fluid conduit is integral with the first sampling container.

11. Combination sampling vessel of claim 9, wherein the fluid conduit is integral with the second sampling container.

12. Combination sampling vessel of claim 11, wherein the fluid conduit is adapted to receive the first sampling container.

13. Combination sampling vessel of claim 1 or 2, wherein the fluid conduit comprises a first aperture aligned with the first sampling container and a second aperture aligned with the second sampling container.

14. Combination sampling vessel of claim 13, wherein the first sampling container is held adjacent the second sampling container by the fluid conduit.

15. Combination sampling vessel of claim 2, further comprising a fluid guide adapted to guide fluid from an outflow to the fluid conduit.

16. Combination sampling vessel of any preceding claim, wherein the apertures of the first sampling container and the second sampling containers are configured to receive a lid.

17. Combination sampling vessel of claim 16, wherein the lid comprises a seal.

18. Combination sampling vessel of claim 16, wherein the receptacle of the first sampling container comprises a seal position remote from the aperture.

19. Combination sampling vessel of claim 17 or 18, wherein the seal is a burstable seal to allow the exit of any fluid held within the first fluid container.

20. Combination sampling vessel of claim 16, wherein when the first sampling container comprises a lid, the lid is adapted to form a bund in an analytical apparatus.

21. Combination sampling vessel of claim 1 or 2, wherein the first sampling container further comprises a filter and/or a plunger.

22. Combination sampling vessel of claim 21, wherein the first sampling container comprises the filter and the plunger, and wherein the filter is adapted to resist rotation of the plunger.

23. Combination sampling vessel of claim 1 or 2, wherein the fluid conduit is a pipe.

24. Combination sampling vessel of claim 23, wherein the first and second sampling containers are separated from each other by the fluid conduit, and removable from the fluid conduit.

25. Combination sampling vessel of claim 9, wherein the flange further comprises a vent hole.

26. Combination sampling vessel of claim 25 further comprising:

A fluid guide adapted to fit with the aperture of the first sampling container;

wherein the fluid guide is provided with an upstanding wall forming a baffle around the vent hole of the flange.

27. Combination sampling vessel of claim 26, wherein the fluid guide further comprises a splash guard.

28. Use of a combination sampling vessel according to any of claims 1 to 27 to sample a lubricant or a hydraulic fluid.

29. Use as claimed in claim 28, wherein the lubricant is a used lubricant, and wherein the used lubricant comprises wear particulates, or wherein the hydraulic fluid is a used hydraulic fluid and the used hydraulic fluid comprises wear particulates.

30. A kit of parts for forming a combination sampling vessel adapted to sample an analytical fluid, the analytical fluid being one of a lubricant, hydraulic fluid, used lubricant or used hydraulic fluid, the kit of parts comprising:

A first sampling container having a fluid receptacle provided with an aperture;

31. Kit of parts as claimed in claim 30, further comprising a lid for the first sampling container.

32. Kit of parts as claimed in claim 30 or 31, further comprising a fluid guide adapted to fit with either the first or the second sampling container.

33. Method of filling a combination sampling vessel in accordance with any of claims 1 to 27 with an analytical fluid, the analytical fluid being one of a lubricant, hydraulic fluid, used lubricant or used hydraulic fluid, comprising:

Directing the flow of a fluid from an outflow of a fluid source into the fluid conduit;

Filling at least one of the first and second sampling containers from the flow of fluid; Either ceasing the flow of fluid to the first sampling container and continuing to fill the second sampling container, or allowing fluid to overflow the first sampling container into the second sampling container;

Continuing to fill the second fluid container until the desired fill level is reached; and

Removing the combination sampling vessel from the outflow.

34. Method of claim 33, wherein the fluid entering the first and second sampling containers originates from the same fluid source.

35. Combination sampling vessel of any of claims 1 to 27 or method of any one of claims 33 or 34, wherein the analytical fluid is a used lubricant comprising wear particulates or a used hydraulic fluid comprising wear particulates.