Gravimetric dilution device for a sample with a predetermined quantity of liquid and corresponding method

Abstract

A gravimetric dilution device (10) is proposed for a sample in a container (S) with a predetermined quantity of liquid. The device comprises container reception means (30; 35) defining a volume suitable for receiving the container in an open position, and injection means (40) configured to inject the liquid into the container when the container is received by the reception means. The injection means have an injection axis. The injection means and the reception means are configured such that, during injection of the liquid into the container, the injection axis is directed towards a chosen lateral edge (S1; S2) of the container, so that the liquid is substantially poured onto the lateral edge of the container. Figure 2

Description

Title of the invention: Device for gravimetric dilution of a sample with a predetermined quantity of liquid and corresponding method Technical field

[0001] The invention relates to the field of instrumentation for biology or microbiology laboratories. More particularly, the invention relates to a device for gravimetric dilution of a sample with an appropriate quantity of liquid. This type of device, commonly called a "gravimetric dilutor" or "gravimetric dilutor" is used in particular, but not exclusively, in biological analysis laboratories in certain agri-food, cosmetic, medical, chemical or pharmaceutical industries. Prior art

[0002] In recent years, the agri-food sector has experienced a number of health crises. Professionals in the sector are now aware of the risks associated with pathogenic microorganisms on human and animal health. In order to anticipate any health problems, food industry laboratories have equipped themselves with devices to carry out microbiological analyses to control the quality of agri-food products before they are placed on the market.

[0003] To carry out a microbiological analysis of a sample, it is necessary to prepare this sample beforehand. This preparation phase consists first of all in collecting various samples from the product concerned, then for each sample collected, in diluting it in a sterile bag with a suitable liquid. Once the dilution has been carried out, the solution obtained is ground, incubated and filtered before being subjected to the microbiological analysis itself. For the dilution step, laboratories generally use gravimetric dilutors, which are sometimes housed under a microbiological safety cabinet (typically an “ESB” or “PSM” cabinet).

[0004] As illustrated in [Fig.l], a gravimetric dilutor 1 traditionally comprises a base 2 housing weighing means (also called “balances”), an injection member 4 for injecting a dilution liquid into a suitable bag 5 and a bag support 3 connected to the weighing means. The bag support or rack 3 is generally U-shaped having two side walls 3a, 3b and a bottom wall 3c connecting the two side walls. The bottom and side walls define a volume capable of receiving the bag 5. The free ends of the side walls 3a and 3b (located on the side opposite the bottom wall) are shaped to be brought closer to each other by elastic deformation (carried out by manual pinching) and hold the bag in the open position (after releasing the side walls). To facilitate placing and holding the bag 5 in the open position, the free ends of the rack 3 are coated with an adhesive material intended to make the edges of the bag 5 adhere at its filling opening. The sampling bags used in the laboratory are generally made from a flexible and sterile polymeric material, capable of containing a liquid and / or solid solution of variable mass.

[0005] The gravimetric dilution operation is typically carried out as follows. The operator places the bag 5 vertically in the vertical median plane of the rack 3, with the filling opening in the upper position. After pinching the free ends of the rack 3 to make the walls of the bag adhere to the adhesive material, the operator releases the free ends of the rack 3 so that they return to their rest position, thus keeping the bag 5 open. A solid sample is then poured into the bag 5 through the filling opening. The dilutor carries out a weighing and dispenses a precise quantity of liquid which is calculated as a function of the mass of the sample introduced into the bag. The balance automatically carries out a continuous weighing of the mass of the solution contained in the bag and controls the stopping of the dispensing when the desired mass of solution is reached.The bag is then closed, crushed and left to stand for a certain period of time at a temperature that encourages the development of bacteria.

[0006] The surface area of ​​the side walls of the rack defines the dimensions of the bag that can be received in the dilutor rack. To increase the volume of a bag that can be received in the rack, it is common to increase the surface area of ​​the side walls of the rack. However, increasing the surface area of ​​the side walls of the rack makes manipulations carried out by the operator difficult, in particular when these are carried out under a controlled atmosphere. Indeed, in this case, the rack is placed on the base of the dilutor which itself is housed under a standardized biological safety enclosure. This enclosure is provided with a central opening allowing the passage of the operator's arms to access the device. However, to avoid the escape of contaminating products, such an opening has a limited height which is standardized, sometimes causing the operator to have to contort himself to carry out his manipulations.Increasing the dimensions of the rack can therefore make dilution operations very tedious.

[0007] Furthermore, some studies show that sample preparation generally represents about 60% of a laboratory technician's working time in the analysis process. Also, in order to increase productivity, one solution would be to reduce the diluent distribution time, in other words to increase the diluent distribution speed. However, due to the particular configuration of the traditional dilutors, this solution is limited by the risk of splashing. Indeed, it turns out that the greater the speed of the incident liquid coming into contact with the wall of the bag (which is pressed against one of the side walls of the carrier), the greater the amount of splashing outside the bag. In other words, increasing the dispensing speed would increase the risk of accidental liquid spilling outside the bag, which would cause a lack of hygiene and more cleaning, and therefore a waste of time in the end.

[0008] There is therefore a real need to propose a gravimetric dilution device which is more ergonomic and faster in terms of liquid distribution, in order to make the sample preparation phase more productive. Summary of the invention

[0009] In a particular embodiment of the invention, there is provided a device for gravimetric dilution of a sample in a container with a predetermined quantity of liquid, the container comprising two walls joined by opposite lateral edges, a bottom and a filling opening, said device comprising:

[0010] - means for receiving the container defining a volume capable of receiving the container in an open position;

[0011] - injection means configured to inject the liquid into the container when the container is received by the receiving means, the injection means having an injection axis directed towards the filling opening.

[0012] Such a device is characterized in that the injection means are arranged relative to the receiving means so that during an injection of the liquid into the container, said injection axis is directed towards one of the lateral edges of the container so that the liquid pours substantially onto said lateral edge of the container.

[0013] Thus, the present invention is based on a new approach making it possible to optimize gravimetric distribution operations. Indeed, thanks to this particular arrangement of the injection means relative to the receiving means, when a quantity of liquid is poured into the container, splashing outside the container is reduced. Thus, unlike traditional dilutors, the injection axis is always directed towards a lateral edge of the container, which makes it possible to increase the liquid distribution speed, regardless of the orientation of the container, without losing weighing accuracy. Furthermore, such a device is more convenient to use due to the reduced risk of accidental splashing of liquid outside the container.

[0014] According to a particular aspect of the invention, the injection means are configured to be mobile in rotation relative to a support member.

[0015] Thus the liquid injected by the injection means can be directed onto the desired part of the container. Such a characteristic is particularly interesting on two points. On the one hand, making the injection means mobile allows flexibility in the choice of the direction of orientation of the container placed on the receiving means: the receiving means of the device can in fact be configured so that the container is positioned either parallel to the operator or perpendicular to the latter while respecting the general principle above (injection axis is directed towards one of the two lateral fold zones of the container). On the other hand, this gives the operator the possibility, for any manipulation not requiring liquid distribution (preparation of the samples, introduction and / or removal of the container typically), to direct the injection axis in a direction other than those aimed at the receiving means (and therefore the container when it is present). It is thus possible to gain work space and therefore make manipulations easier.In addition, keeping the injection means away from the container opening provides some protection for the injection means against manual contamination and reduces the risk of inter-sample contamination.

[0016] According to a particular implementation, the device being intended to be housed under a protective enclosure provided with an access window defining a window plane, then the reception means define a reception plane, in which the lateral edges of the container are intended to be substantially located, so that the reception plane is perpendicular to the window plane.

[0017] Thus, once the container is placed in the receiving plane, the container is positioned perpendicular to the operator, which greatly facilitates access to the device as well as to the container. The weighing and dilution manipulations are thus easier because the working space offered on either side of the container provides greater freedom of movement for handling and / or placing tools under a protective enclosure, and in particular under a standardized protective enclosure. This configuration is all the more interesting because it also offers the possibility of using containers of different sizes without reducing the working space useful for preparing the sample.

[0018] According to a particular configuration, the access window is a front access window.

[0019] Thus, the invention makes it possible to use a standard enclosure provided with a front window, the latter being substantially perpendicular to the side walls of the container. Alternatively, rather than a front access window, the enclosure is provided with a side access window, allowing lateral access to the device. In this particular configuration, the reception means are then configured so that the reception plane is perpendicular to the window plane.

[0020] According to a particular implementation of the invention, the receiving means comprise a receptacle capable of supporting the container and an opening clamp capable of keep the container in the open position.

[0021] Such a receptacle may take the form of a tray whose dimensions allow it to at least partially cover the base of the device. In this way, when liquid (or part of the sample) is poured out of the container, it can be collected by the receptacle, avoiding soiling the device, thus protecting the base. For example, it may be shaped so as to completely cover the upper face of the base of the device. The receptacle may be configured to be removable so as to facilitate cleaning of the device.

[0022] According to a particular aspect, the opening clamp being integral with the receptacle, for example with one of the side walls thereof, thus forming one-piece receiving means. Thus, making the receiving means removable not only makes it easier to clean the device, but also to position the container when this is done outside the enclosure.

[0023] Alternatively, the opening clamp is not integral with the receptacle but is integral with the base of the device.

[0024] According to an alternative embodiment, the receiving means comprise a rack capable of receiving the container and a receptacle capable of receiving said rack, said rack being formed of two side walls and a bottom wall connecting the two side walls, said vertical walls being shaped to hold the container in the open position.

[0025] Thus, the device according to the invention offers the possibility of using traditional racks.

[0026] According to a particularly interesting characteristic from a practical point of view, the device comprises a removable transport basket shaped to transport the container, said basket being intended to be placed on a bottom wall of the receptacle. The carrier can be removable and separable from the basket.

[0027] This makes it easier to transport the container and place it on the receptacle of the device. In the case where a rack is used, the basket is shaped to transport the rack, which accommodates the container.

[0028] According to a particular characteristic, the device comprises a telescopic mast at the end of which is fixed a head-up display and means for controlling said telescopic mast configured to modify the position of the head-up display along a vertical axis, said head-up display being mechanically connected to the injection means via the support member.

[0029] This offers the possibility of adjusting the head-up display, and therefore the injection means, according to the height of the bag used, and thus gaining in ergonomics. According to another particular aspect of the invention, the device comprises a removable injection pump, which is connected to the injection means and can be placed outside the enclosure. Thus, unlike the prior art, the volume usually used by the injection pump within the enclosure is freed up to gain working space. In other words, the system becomes more compact within the enclosure.

[0030] In another particular embodiment of the invention, there is provided a method for gravimetric dilution of a sample in a container with a predetermined quantity of liquid using a dilution device, the container comprising two walls joined by opposite side edges, a bottom and a filling opening, the method comprising the following steps:

[0031] - placing the container in an open position via receiving means;

[0032] - pouring said sample into the container through the filling opening;

[0033] - injecting the liquid into the container via injection means, said means injection having an injection axis directed towards the filling opening.

[0034] The method is characterized in that it comprises a step, carried out prior to the injection step, consisting of directing the injection axis of said injection means towards one of the lateral edges of the container so that the injection means inject the liquid substantially onto said lateral edge of the container.

[0035] It is thus possible to increase the speed of distribution of the liquid in the container. Figures

[0036] Other characteristics and advantages of the invention will appear more clearly on reading the following description of a preferred embodiment, given as a simple illustrative and non-limiting example, and the appended drawings, among which:

[0037] [Fig.l], already discussed above, schematically represents a state-of-the-art gravimetric dilution device;

[0038] [Fig.2] is a perspective view of a gravimetric dilution device according to a first particular embodiment of the invention;

[0039] [Fig.3] is a perspective view of the device illustrated in [Fig.2], when the latter is housed under a protective enclosure;

[0040] [Fig.4] is a front view of the device illustrated in [Fig.3];

[0041] [Fig.5] is a perspective view of a gravimetric dilution device according to a second particular embodiment of the invention;

[0042] [Fig.6] is a side view of the device illustrated in [Fig.5];

[0043] [Fig.7] illustrates a variant of the reception means equipping the device conforming to the first embodiment;

[0044] [Fig.8] is a top view of the device in its first embodiment of the invention;

[0045] [Fig.9] is a top view of the device in its second embodiment of the invention;

[0046] [Fig. 10] illustrates a particular embodiment of the method according to the invention

[0047] [Fig. 11] illustrates an example of the use of a carrying basket in the first embodiment of the invention. Detailed description of the invention

[0048] In the figures of this document, identical elements are designated by the same numerical reference.

[0049] The general principle of the invention is based on a particular arrangement of the liquid injection means and the sampling bag support means of the device to allow, on the one hand, an optimized distribution of the liquid in the bag, and on the other hand ease of use, in order to gain in productivity during the sample preparation phase in the laboratory.

[0050] In the remainder of this document, the invention is more particularly described in the context of microbiological quality control of a solid sample from an agri-food product. Indeed, it turns out that food safety, of which the microbiological quality of food is an essential component, represents a considerable challenge for agri-food manufacturers. The invention is of course not limited to this particular field of application, but is applicable to any sector or application requiring preparation of a sample by gravimetric dilution.

[0051] Two particular configurations of the device are proposed: a so-called “portrait mode” configuration allowing the bag to be arranged substantially perpendicular to the operator and a so-called “landscape mode” configuration allowing the bag to be arranged substantially parallel to the operator. The second configuration is described further below in relation to Figures 5, 6 and 9.

[0052] In order to better understand the concept of the present invention, the device of the invention (in any of its embodiments) is represented in an X, Y, Z reference system. For better readability of the figures, the different planes and axes are represented in dotted lines.

[0053] A gravimetric dilution device 10 according to a first embodiment of the invention is now presented in relation to Figures 2, 3 and 4. For simplicity, the device according to the invention is hereinafter referred to as a “diluter”.

[0054] The dilutor 10 according to the invention comprises:

[0055] - a base 20 housing weighing means and various electronic components and / or mechanical (not shown);

[0056] - reception means 30 and 35 intended to receive the container S in position opening;

[0057] - injection means 40 configured to inject a dilution liquid into the containing S along an injection axis Xi for sample dilution purposes.

[0058] In the example illustrated here, the container S is a sterile sampling bag, made from a flexible and waterproof material, for example a plastic film such as polyethylene. The bag S typically comprises two walls - a front wall and a rear wall - joined by opposite side edges S1 and S2, a bottom F and a filling opening O.

[0059] The weighing means form the scale of the dilutor: they are configured to allow the container poured into the bag S (sample, dilution liquid) to be weighed continuously and automatically.

[0060] The receiving means of the dilutor 10 are configured to define a volume capable of receiving the bag S in an open position allowing the liquid to be received. The receiving means comprise, in this first embodiment, a support 30 capable of supporting the bag S and an opening clamp 35 capable of opening the bag S and holding it in an open position (i.e. with the opening O facing upwards). The clamp 35 comprises two elastically flexible and substantially parallel arms which extend horizontally towards the operator (along the axis Z) from a vertical bar. The ends of the two arms are coated with an adhesive material intended to make the edges of the bag S adhere at its opening O, facilitating the holding of the bag S in the open position.The clamp 35 is configured to be movable in translation relative to the vertical bar so as to be able to adjust the height of the clamp relative to the height of the bag S placed on the support 30. The dimensions of the clamp are adapted to the dimensions of the bag used. As for the support 30, it is shaped in the form of a tray to serve as a receptacle capable of possibly recovering liquid flowing outside the bag S or in the absence of a bag (in the event of accidental flow for example). To ensure this receptacle function, the support 30 extends at least over the upper face of the base 20. Preferably, the contour of the support 30 fairly widely surrounds the entire periphery of the base 20 of the device. Furthermore, the support 30 is mechanically connected to a sensitive member of the weighing means configured to transmit the weight force measured by the dilutor 10.In the example illustrated here, the support 30 and the opening clamp 35 are integral with each other, and form removable reception means in one piece, in particular to facilitate the cleaning of the device 10. According to a variant, the opening clamp 35 is integral with the base 20 of the device.

[0061] The injection means 40 of the dilutor 10 are configured to inject the dilution liquid into the bag S when the container S is placed on the support 30. The injection means 40 have an injection axis Xi directed towards the opening O of the bag. In the In the present example, the injection means 40 consist of an injection nozzle and a system for attaching and adjusting the latter. Conveying means (not shown) connected on the one hand to the injection nozzle and on the other hand to an injection pump (not shown) make it possible to convey the dilution liquid from the pump to the injection nozzle.

[0062] The injection means 40 according to the invention are arranged relative to the receiving means 30 and 35 so that during an injection of the liquid into the bag S, the injection axis Xi is directed towards the lateral edge SI of the bag S so that the liquid pours substantially onto this lateral edge of the bag S. Thus, in the present configuration in portrait mode, the injection means are oriented so that the injection axis Xi extends substantially along the axes Y and Z.

[0063] Thus, when a quantity of liquid is poured into the bag S, splashing outside the bag S is reduced, unlike traditional dilutors where the injection axis is directed towards one of the front or rear walls of the bag. This clever approach thus offers the possibility of increasing the speed of distribution of the liquid while limiting the risk of splashing outside the container (and thus gaining in productivity).

[0064] Figures 2 and 3 illustrate the operating principle of the dilutor 10 when it is housed in a standard protective enclosure 100, for example a standardized “ESB” type microbiological safety enclosure. The dilutor 10 and the enclosure 100 then form a secure gravimetric dilution system according to the invention. Such an enclosure 100 is provided with a front window (or opening) 110 allowing access of the operator's arms within the enclosure 100 substantially along the Z axis. Such a window (or opening) 110 has a limited height and width (for example a height of 18 cm and a width of 120 cm to prevent the exit of contaminating products.

[0065] We subsequently consider:

[0066] - the PA plane, the plane of the reception means 30 and 35 corresponding to a median plane vertical passing substantially through the lateral edges SI and S2 of the bag S (when the bag S is placed in the open position on the support 30 and between the arms of the clamp 35);

[0067] - the PF plan, the plan of the access window 110.

[0068] In this first embodiment, the receiving means of the dilutor 10 are configured so that the receiving plane PA is perpendicular to the window plane PF. Thus, once placed on the support 30 and between the arms of the clamp 35, the bag S (and more precisely the axis of the bag passing through its two lateral edges) is positioned (in the open position) perpendicular to the access window 110 and therefore to the operator, as illustrated in [Fig. 8]. Such a configuration thus allows greater ease of handling within the enclosure 100 (unlike the dilutor of the prior art). The weighing and dilution manipulations are thus easier because the work space provided on either side of the reception plane PA offers greater freedom of movement and allows the possible placement of tools. It should be noted that this configuration is all the more interesting as it also offers the possibility of using bags of different formats while maintaining a work space convenient for handling under a controlled atmosphere. This is the case for “large format” type bags intended to contain samples with a mass typically between 100 and 550 g, compared to smaller volume bags, of the “small format” type, intended to contain samples with a mass typically between 10 and 50 g. Thus, the dilutor 10 according to the invention is therefore more convenient to use, in particular under a standard standardized enclosure.

[0069] According to another aspect of the invention, the dilutor 10 is further equipped with a telescopic mast 80 at the end of which is fixed a head-up display 90, and means for controlling the telescopic mast configured to modify the position of the head-up display 90 along the vertical axis defined by the telescopic mast 80. This offers the possibility of adjusting the head-up display 90 according to the height of the bag used, and thus gaining in ergonomics. The dilutor 10 is also equipped with a removable injection pump (not shown) connected to the injection means via conveying means, said pump being placed outside the enclosure 100. Thus, unlike the prior art, the volume usually used by the injection pump within the enclosure is freed up to gain working space. The device under enclosure therefore gains in compactness.Additionally, this helps reduce the weighing system's exposure to the pump's inherent mechanical vibrations.

[0070] According to another aspect of the invention, the injection means 40 are configured to be movable in rotation relative to the support member 50 along at least two orthogonal axes: a first horizontal axis Xh extending along the X axis (merged with the support member 50 and s') and a second substantially vertical axis Xv extending along the Y axis, as illustrated in Figures 3 and 4. Thus, the liquid injected by means of the injection means can be directed onto the desired part of the bag S. Such a characteristic is particularly interesting on two points. On the one hand, making the injection means movable makes it possible to offer flexibility in the choice of the configuration of the device (orientation of bag S perpendicular or parallel to the operator) while respecting the general principle of the invention (namely that the injection axis Xi is oriented towards a lateral edge of the bag S).On the other hand, this provides the possibility of orienting the injection means 40 in a direction that does not interfere with non-injection handling (introduction of the bag, removal of the bag, manual filling of the bag with the sample, etc.). Indeed, in the injection position, the injection nozzle is located at a point substantially above the bag at a non-zero distance from the opening O of the bag. Thus, moving the injection nozzle away from the opening O of the . bag S allows on the one hand to gain more working space under enclosure, and on the other hand to reduce the risk of inter-sample contamination. Furthermore, the injection means 40 can cooperate with nozzle orientation means capable of orienting said nozzle along at least two orthogonal axes, such as for example orientation means comprising a double pivot connection or a spherical connection of the ball joint type, without being exhaustive. It could be envisaged, without departing from the scope of the invention, that these orientation means cooperate with control means to allow automatic adjustment of the axis Xi of the injection means 40.

[0071] On each end of the support member 50 is fixed a carrying arm, each carrying arm 60a and 60b being itself fixed in a movably rotatable manner about an axis on a lateral face of the head-up display 90, allowing a tilting of the injection means 40 from an injection position (the injection nozzle 40 is then arranged substantially towards the front of the head-up display 90 as illustrated in the figures with the nozzle situated substantially above the bag) to a rest position (the injection nozzle 40 is then arranged substantially towards the rear of the head-up display 90, i.e. outside the work space).

[0072] A cable passage may be provided on one of the side faces of the protective enclosure, for example, on the rear side face for convenience, in order to allow the passage of electrical cables and / or means for conveying the dilution liquid. Otherwise, the conveying means may be arranged so as to pass through the access window so as to allow the presence of the injection pump outside said enclosure.

[0073] We now present, in relation to Figures 5 and 6, a gravimetric dilutor 11 according to a second embodiment of the invention. The dilutor 11 is housed in a protective enclosure 200, for example a standardized microbiological safety enclosure. The device 11 and the protective enclosure 200 form a secure gravimetric dilution system according to the invention. The configuration proposed in this second embodiment is particularly well suited, but not exclusively, to the distribution of liquid in a small format bag.

[0074] This second embodiment differs mainly from the first embodiment in that the bag S is positioned parallel to the operator. This landscape configuration is particularly well illustrated in the top view of [Fig.9].

[0075] In this second embodiment, the means for receiving the dilutor 11 comprise a rack of traditional shape, referenced 36. Such a rack 36 is formed of two side walls and a bottom wall connecting the two side walls, the assembly defining a volume capable of receiving the bag S in an open position substantially in a plane PA'. The plane PA' corresponding to the vertical median plane between the two side walls of the rack 36. The vertical walls of the rack 36 are shaped to hold the container in the open position: they are elastically flexible so that they can be manually brought together by elastic deformation and allow the bag S to be held in the open position once the walls are released. Their free end is coated with an adhesive material intended to make the edges of the bag S adhere and thus facilitate the placing in the open position of the bag S and its maintenance in this position. The dimensions of the rack 36 are adapted to the dimensions of the bag used.

[0076] In accordance with the general principle of the invention, the injection means 40 are arranged relative to the holder 36 so that during an injection of the liquid into the bag S, the injection axis Xi is directed towards the lateral edge SI of the bag S so that the liquid pours substantially onto this lateral edge, thus reducing the risk of splashing and allowing a higher liquid distribution speed. In fact, the holder 36 is arranged on the support 37 so that the receiving plane PA' is located along the axes X and Y, and the axis Xi of the injection means oriented towards the lateral edge SI, is substantially along the axes X and Y (i.e. in the plane PA')•

[0077] In the present example, the enclosure 200 is provided with a lateral window (or opening) 210 allowing access for the operator's arms within the enclosure 200 along the axis of the bag S. Such a window (or opening) 210 has a limited height and width to prevent the possible exit of contaminating products. As illustrated in FIGS. 5, 6 and 9, the plane PF' of the lateral window 210 is perpendicular to the receiving plane PA'. This enclosure with a lateral window has the advantage of greatly facilitating the operator's handling because it allows access from either side of the front and rear walls of the bag S with greater freedom of movement.It should be noted, however, that the use of a standard protective enclosure, i.e. an enclosure with a front window (such as the enclosure 100 illustrated in Figures 3 and 4), would constitute a completely feasible alternative with this second embodiment without departing from the scope of the invention, although less optimal in terms of working space.

[0078] The dilutor 11 further comprises a receptacle 37 mechanically connected to the sensitive member of the weighing means. The receptacle 37 extends at least over the upper face of the base 20 and can fulfill the same function as the support 30 of the dilutor 10. Optionally, to facilitate the positioning of the rack 36 and ensure its maintenance, the dilutor 11 can also comprise a guide plate 38 extending at least partly over the upper face of the receptacle 37 and shaped to receive the lower part of the rack 36.

[0079] [Fig. 7] illustrates a variant of the reception means equipping the diluter 10 (in accordance with the first embodiment of the invention). Unlike figures 2 to 4, in this example, the receiving means comprise a rack 70. This rack 70 is formed of two side walls 70a and 70b and a bottom wall 70c connecting the two side walls, defining a volume capable of receiving the bag S in an open position substantially in the plane PA (the PA then corresponding to the vertical median plane between the two side walls of the rack 70). The dimensions of the rack 70 are adapted to the dimensions of the sampling bag used. In the present example, the configuration of the dilutor 10 is particularly well suited to the use of “large format” bags.

[0080] [Fig. 8] is a top view of the diluter 10 described above in relation to figures 2, 3, 4, while [Fig. 9] is a top view of the diluter 11 described above in relation to figures 5 and 6. The plane PF represents the plane of the front access window of a standard enclosure. The planes PA and PA' represent the reception planes of the sampling bag respectively of the first and second embodiments of the device according to the invention. The operator OP is represented by a black icon. From this point of view, like the format of a photo or an image, the diluter 10 is configured in a “portrait” mode ([Fig. 8]), the reception plane PA being perpendicular to the plane of the window PF. As for the diluter 11, it is configured in a “landscape” mode ([Fig. 9]).

[0081] [Fig. 9] presents, in the form of a flowchart, the method according to a particular embodiment of the invention. The method is implemented by means of the gravimetric dilutor 10, the principle of which is described above in relation to figures 2, 3, 4.

[0082] In step S100, the operator places a sterile sampling bag, of the large format type, via the access window 110 of the protective enclosure 100, in the vertical median plane of the receiving means of the dilutor 10. The operator then performs by elastic deformation a pinching of the free ends of the clamp 35 to make the front and rear walls of the bag S adhere to the adhesive material, releases these free ends so that they return to their rest position, keeping the sampling bag open. The sampling bag is arranged such that the filling opening O is positioned upwards and the axis of the bag S is perpendicular to the plane of the window 110. Although the bag S has a certain volume in the enclosure 100, due to the clever configuration of the dilutor 10, the principle of which has been described above, the positioning of the bag S and its access is relatively easy despite its volume.As a precaution and for convenience, the operator will tilt the injection means 40 (via the elements 60a and 60b, 50) behind the head-up display 90 so as to move the injection means 40 away from the work space during the preparation of the dilution operation.

[0083] In step S200, the operator pours a 375g solid sample from a product agri-food into bag S through opening O. While the sample is poured into bag S, the dilutor 10 continuously weighs bag S. The head-up display 90 displays in real time the mass contained in bag S.

[0084] In step S300, once the sample has been poured into the bag S, the operator tilts the assembly of injection means 40 back in front of the head-up display 90 and orients the injection nozzle 40 along the axes Xv and Xh so that the injection axis Xi is directed towards the desired part of the bag S (the lateral edge SI of the bag S in this case).

[0085] In step S400, the operator injects a predetermined quantity of dilution liquid into the bag S along the injection axis Xi. The quantity of liquid is calculated as a function of the mass of solid sample introduced into the bag S. For example, for 375g of sample, a precise quantity of 0.3 L of liquid is poured into the bag S. The injection axis Xi being oriented in the direction of the lateral edge SI of the bag S, the liquid injected by the injection means 40 pours substantially onto the lateral edge SI of the bag S with a liquid distribution speed which can typically be between 0.1 and 6.0 L / min.

[0086] Once the predetermined quantity of liquid has been poured, the dilutor 10 instantly stops the distribution of liquid and the dilution operation ends. The operator can thus close the sampling bag and remove it from the enclosure 100 without any particular difficulty.

[0087] We now present, in relation to [Fig. 11], an example of use of a transport basket P in the context of the first embodiment of the invention. This characteristic is particularly interesting, notably from a practical point of view, since its role is to facilitate the transport of the bag S, before and after the dilution phase. Such a basket consists of a body comprising a bottom wall and four side walls.

[0088] In the context of the first embodiment, the basket is shaped so as to be able to accommodate the bag alone.

[0089] In the context of the second embodiment, the basket P is shaped so as to be able to accommodate the carrier, itself accommodating the bag S. In other words, the basket P is configured to transport the container via the carrier.

[0090] The basket is sized according to the dimensions of the bag to be transported, but also according to the dimensions of the window of the enclosure in which the dilutor is located (and in particular the height of the side walls thereof) in order to maintain a relatively comfortable working volume for the operator through the access window, while allowing easy transport of the bag outside the enclosure. As illustrated in the figure, the basket P being intended to be placed on the bottom wall of the receptacle 30, the receptacle 30 and the basket P are therefore shaped so that the bottom wall of the receptacle 30 defines a surface capable of receiving the bottom wall of the basket P.

Claims

Claims

1. Device (10) for gravimetric dilution of a sample in a container (S) with a predetermined quantity of liquid, the container comprising two walls joined by opposite lateral edges (S1, S2), a bottom and a filling opening, said device comprising: - means (30; 35) for receiving the container defining a volume capable of receiving the container in an open position; - injection means (40) configured to inject the liquid into the container when the container is received by the receiving means, the injection means having an injection axis directed towards the filling opening; said device being characterized in that the injection means are arranged relative to the receiving means so that during an injection of the liquid into the container, said injection axis is directed towards one of the lateral edges of the container so that the liquid pours onto said lateral edge of the container.

2. Device according to claim 1, in which the injection means are configured to be movable in rotation relative to a support member along at least two orthogonal axes.

3. Device according to any one of claims 1 and 2, said device being intended to be housed under a protective enclosure (100), said protective enclosure being provided with an access window (110) defining a window plane (PF), and in which said receiving means define a receiving plane (PA) in which the lateral edges of the container are intended to be located substantially so that the receiving plane is perpendicular to the window plane.

4. Device according to any one of claims 1 to 3, said access window is a front access window.

5. Device according to any one of claims 1 to 4, in which the receiving means comprise a receptacle (30) capable of supporting the container and an opening clamp (35) capable of holding the container in the open position.

6. Device according to claim 5, in which the opening clamp is integral with the receptacle.

7. Device according to any one of claims 1 to 4, in which the receiving means comprise a rack (36) capable of receiving the container and a receptacle capable of receiving said rack, said rack being formed of two side walls and a bottom wall connecting the two side walls, said vertical walls being shaped to hold the container in the open position.

8. Device according to any one of claims 5 to 7, comprising a removable transport basket shaped to transport said container, said basket being intended to be placed on a bottom wall of the receptacle.

9. Device according to any one of claims 1 to 8, comprising a telescopic mast at the end of which is fixed a head-up display and means for controlling said telescopic mast configured to modify the position of the head-up display along a vertical axis, said head-up display being mechanically connected to the injection means via the support member.

10. Method for gravimetric dilution of a sample in a container (S) with a predetermined quantity of liquid using a dilution device (10), the container comprising two walls joined by opposite side edges (S1, S2), a bottom and a filling opening, the method comprising the following steps: - arranging (S100) the container in an open position via receiving means; - pouring (S200) said sample into the container through the filling opening; - injecting (S400) the liquid into the container via injection means, said injection means having an injection axis directed towards the filling opening;said method being characterized in that it comprises a step, carried out prior to the injection step, consisting of directing (S300) the injection axis of said injection means towards one of the lateral edges of the container so that the injection means inject the liquid onto said lateral edge of the container.;

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