DE102020103211A1 - Vessel arrangement for an imaging volumetric method and volumetric method for determining a volume of liquid - Google Patents

Abstract

The present invention relates to a vessel arrangement (10) for receiving an amount of liquid for a determination of a volume of the amount of liquid received in the vessel arrangement (10) on the basis of a wetting situation of a solid surface, the vessel arrangement (10) having a vessel body (14) which is impermeable to liquid. and has a cavity (16) formed in the vessel body (14) which extends into the vessel body (14) along a depth axis (TA), the solid surface being connected to the vessel body, the cavity (16) being connected by a A plurality of wall surfaces extending along the depth axis (TA) is enclosed, with the wall surfaces parallel to the depth axis (TA) when viewed in a local cavity height section, which extends symmetrically over a third of the cavity height and contains the height center of the cavity and to the respective wall section orthogonal wall section plane to the depth ac hse (TA) are oriented parallel or include a mean local wall inclination angle with the depth axis (TA). According to the invention, it is provided that the solid body surface is at least one level surface running along a level track (K1, K2, K3) which along the level track (K1, K2, K3) has its largest dimension, the at least one level surface when viewed in a local first level section plane parallel to the depth axis (TA) and orthogonal to the level track (K1, K2, K3) to the depth axis (TA) is orthogonal or includes a local latitude inclination angle with the depth axis (TA), the magnitude of which is greater than the largest mean wall inclination angle, and wherein the level surface when viewed in a parallel to the depth axis (TA) and the level trace (K1, K2, K3) containing or to the level track (K1, K2, K3) tangential local second level section plane with the depth axis (TA) includes a local longitudinal inclination angle, wel cher smaller than 90 ° and larger than the largest wall inclination angle.

Description

The present invention relates to a vessel arrangement for receiving an amount of liquid for a determination of a volume of the amount of liquid received in the vessel arrangement on the basis of a wetting situation of a solid surface, the vessel arrangement having a vessel body impermeable to liquid and a cavity formed in the vessel body which extends along a The depth axis extends into the vessel body, the solid surface being connected to the vessel body, the cavity being framed by a plurality of wall surfaces extending along the depth axis, with a local central cavity height section extending symmetrically over a third of the length of the Depth axis to be measured local cavity height extends and contains the local height center of the cavity, the wall surfaces when viewing the wall surfaces in a local wall section parallel to the depth axis and orthogonal to the respective wall section t plane are oriented parallel to the depth axis or include a mean local wall inclination angle with the depth axis.

Such a vessel arrangement for the imaging volume determination of a quantity of liquid is from US 7,204,960 B2 famous. The cavity of the known vessel arrangement extends along a straight longitudinal axis of the cavity over a predetermined distance. The length of the cavity is to be measured along the longitudinal axis of the cavity. In a sectional plane orthogonal to the longitudinal axis of the cavity, the cavity has a constant cross-sectional area along the longitudinal axis of the cavity. The end walls of the cavity are parallel to the depth axis, the side walls of the cavity and the cavity bottom are either inclined relative to the depth axis about a mold axis parallel to the longitudinal axis of the cavity or curved about a mold axis parallel to the longitudinal axis of the cavity. Depending on the design of the cavity bottom, the mold axis can be a tilt axis or an axis of curvature or, if appropriate, both. During a determination of a volume of an amount of liquid filled into the cavity, the depth axis of the cavity is arranged parallel to the direction of the action of gravity, so that the fill level of the liquid in the cavity is to be measured along the depth axis.

If the cross section of the cavity is known, the free surface area occupied by an amount of liquid filled into the cavity is dependent on the filling level and thus dependent on the volume of the amount of liquid. Since the width of the free liquid surface with a given cross-section of the cavity that is constant along the cavity path depends solely on the filling level, the volume of the amount of liquid filled in the cavity can be inferred from the width of the free liquid surface alone.

For example, with an equilateral triangular cavity cross-section, the tip of the triangular cavity cross-section with half an opening angle α forms the lowest point of the cavity and the free liquid surface forms a side of the triangle opposite the lowest point, the side length of which is the width b of the free liquid surface, the volume V of the liquid filled into the cavity with a length I of the cavity to: $$V=\frac{b^2\cdot l}{\mathrm{4th}\cdot \text{tan}\left(\alpha \right)}$$

Of these variables, only the width b as a function of the fill level is a variable variable, while all other variables on the right-hand side of the equation are determined by the structural shape of the cavity and are therefore constants. The angle α is the wall inclination angle with which each flat side wall is inclined relative to the depth axis. The width b is determined according to the US 7,204,960 B2 Imaging determined, ie an image of the free surface of the amount of liquid received in the cavity is recorded with an optical axis parallel to the filling level or the depth axis and thus orthogonal to the free surface and the width b is determined from the recorded image. If the width b is known, the liquid volume can be determined directly from the otherwise known shape of the cavity.

With the one from the US 7,204,960 B2 Known methods and the vessel arrangement used for their application can, as in the present case also with the present invention, be calibrated with metering systems with small metering volumes in the range of single-digit µl amounts.

Another volumetric imaging method and a vessel arrangement used for its application is from US Pat WO 2019/068724 A1 famous. In contrast to the US 7,204,960 B2 uses the WO 2019/068724 A1 around a respective virtual cavity channel path, circumferentially closed cavity channel sections into which the liquid to be volumetrically detected flows either by exerting a pressure or preferably by capillary effects. The virtual cavity channel path is intended to centrally penetrate its assigned cavity channel section in the longitudinal direction.

The ones from the WO 2019/068724 A1 known cavity has a reservoir section and several cavity channel sections proceeding therefrom. The ones from the WO 2019 / - 068724 A1 known Cavity channel sections extend with a rectangular cross section that is constant along the respective cavity channel path in a plane that is orthogonal both to the depth axis and to the direction of the action of gravity. Your cavity channel floor lies in the plane orthogonal to the direction of gravity. Several cavity channel sections communicating with one another via the common reservoir section are either located in a common plane of extent or are each offset from one another in the direction of gravity in parallel planes, with each cavity channel bottom being located in a plane orthogonal to the depth axis and the direction of gravity.

First, the reservoir section from the WO 2019/068724 A1 known cavity is filled with an amount of liquid to be determined volumetrically, whereupon the liquid flows completely out of the reservoir section into the cavity channel sections by the capillary effect or by an overpressure exerted on the liquid in the reservoir section. Subsequently, the volume of the liquid can be inferred by imaging volumetry from the length of the constant cross-section of the known constant cross-section recorded in the cavity channel sections.

Disadvantageous from the US 7,204,960 B2 The known vessel arrangement is, on the one hand, that the cavity must always be filled with liquid over its entire length in order to be able to deduce the volume of the liquid filled into the cavity with sufficient accuracy from the width of the free liquid surface in the cavity channel section. Thus defined from the US 7,204,960 B2 known vessel arrangement over the length of the cavity channel section both a lower limit and an upper limit for the usable volume measurement range.

Disadvantageous from the US 7,204,960 B2 The known vessel arrangement is, on the other hand, that the inclination of the side wall surfaces, which determine the width of the free liquid surface to be measured, relative to the depth axis determines on the one hand the sensitivity of the volume detection and on the other hand a surface requirement on the opening side of the vessel body. Unfortunately, these two parameters can only be changed in an optimizing manner in opposite directions: a reduction in the inclination of the side wall surfaces relative to the depth axis, i.e. a steeper arrangement of the side wall surfaces, reduces the opening area on the filling side of the cavity and thus the space required by the cavity. This is advantageous when, as is often the case, several cavities are to be arranged in one plane.

The reduction in the inclination of the side wall surfaces relative to the depth axis, however, also reduces the amount of a change in width .DELTA.b associated with a given volume change .DELTA.V, so that not only is the maximum detectable volume reduced for a given cavity length, but also a system-related error Volume error δV corresponds. As a result, as the maximum detectable volume decreases, the volume errors made during an imaging volume determination become greater in absolute terms and even more so in terms of percentage. The opposite is actually desired.

In addition, the measurement inaccuracy increases if the known vessel arrangement is undesirably and unrecognized not exactly matched to the direction of the action of gravity.

Disadvantageous from the WO 2019/068724 A1 The known vessel arrangement is that, in order to fill the cavity, a reservoir section must be provided, which must be completely emptied into the cavity channel sections extending from it for an accurate measurement of the filled liquid volume. This justifies the utilization of capillary effects or the expulsion of liquid by excess pressure from the reservoir section into the cavity channel sections. Any residual liquid that remains in the reservoir section increases the measurement inaccuracy of an imaging volumetric method carried out with this known vessel arrangement. Because of the unavoidable frictional effects in the capillaries, which counteract the desired capillary effects, the measuring range in which the known vessel arrangement can be used is limited.

It is the object of the present invention to further improve the known vessel arrangements and the imaging volumetric methods to be carried out with them.

This object is achieved by the present invention by means of a vessel arrangement of the type mentioned at the outset, in which the solid body surface is at least one level surface running along a level track orthogonal to the depth axis, the level surface having its largest dimension along the level track, the at least a level surface when viewed in a local first level section plane parallel to the depth axis and orthogonal to the level track is orthogonal to the depth axis or includes a local latitude inclination angle with the depth axis which is greater in magnitude than the largest mean wall inclination angle, and where the Level surface when viewed in a local second level section plane parallel to the depth axis and containing the level trace or tangential to the level trace, with the depth axis having a local longitudinal Includes angle of inclination which is less than 90 ° and greater than the largest wall inclination angle.

The local mean cavity height section mentioned at the beginning is used to determine the wall inclination angle in order to obtain the most objective possible parameter about the inclination of the wall surfaces, without disruptive special effects in the area of a transition from the wall surface to the cavity floor or in the area of an opening-side end of the wall surface. The local mean cavity height section therefore extends only over a third of the local cavity height.

Since the cavity height changes depending on the considered location of the cavity discussed here, the cavity height itself, the location or value of the local height center and the mean cavity section symmetrically extending around this local height center depend on the particular location considered. Therefore, these locations and dimensions are referred to as “local” in the present application.

The stated relations of wall inclination angle, width inclination angle and length inclination angle preferably apply to a plurality of points along a level track, with the cutting planes mentioned: wall cutting plane and first and second level cutting plane being applied in each of the plurality of points . The stated relations preferably apply to all points of a level track.

If the longitudinal inclination angle of a level track is greater than 80 ° in terms of magnitude and a wall surface runs parallel to the level track, the wall section plane through a point on the level track can also be used as the first level section plane because of the negligible error that occurs.

The level surface creates a surface in the cavity which is more inclined relative to the depth axis than the wall surfaces enclosing the cavity or which is less inclined than the wall surfaces to a reference plane orthogonal to the depth axis. A cavity can thus be created which at the same time has a small area requirement on a filling side of the vessel body and which nevertheless allows the amount of liquid filled into it to be determined very precisely, since the wall surfaces delimiting the cavity and running along the depth axis are steep, i.e. with a small wall -Angles of inclination can be formed relative to the depth axis. At the same time, the level surface can be designed with a large longitudinal inclination angle relative to the depth axis, so that a predetermined small change in volume ΔV leads to a large change ΔI in the length of the portion of the level surface wetted by the filled liquid along the level track. Thus, the volume error δV corresponding to an unavoidable system-related length detection error δI can be kept small in terms of amount, so that, despite steep wall surfaces, a volume of an amount of liquid filled into the cavity can be determined very precisely by recording a length of the level surface along the level track, which is dependent on the wetting situation.

The latitude inclination angle is preferably 90 °. In other words: the level surface is preferably orthogonal to the depth axis in the width direction. However, this does not have to be the case. It can also be inclined relative to the depth axis with a width inclination angle different from 90 °, but then the width inclination angle is greater than the local wall inclination angle at the relevant point of the gauge, so that the gauge surface is always less steep in the width direction is than the wall surfaces. As a result, it can be easily observed during imaging of the cavity, in particular the cavity at least partially filled with liquid, with the optical axis of the imaging detection device parallel to the depth axis.

The angle that a surface encloses with the depth axis in a section plane should be the smaller of the two angles that can be determined in the section plane.

Since the longitudinal inclination angle of the level surface is a local longitudinal inclination angle, which can vary in amount along the level track, the level surface can be formed around a shape axis that is orthogonal to both the level track and the depth axis relative to the depth axis or to one to the depth axis orthogonal reference plane be inclined or / and curved. Depending on the shape of the level surface, the shape axis can be a tilt axis or an axis of curvature.

In the case of curved wall surfaces, the local wall inclination angle at a point on the wall surface is determined by a plane tangential to the curved wall surface at this point.

The level surface can be formed on a level body which is formed separately from the vessel body and which is arranged in the cavity. The level surface is preferably formed on a section of the vessel body and is consequently connected in one piece, monolithically, to the rest of the vessel body.

The level surface preferably has a longitudinal angle of inclination which is as large as possible in terms of absolute value, but which is smaller than 90 °, so that a slope of the level surface along the Level track is available. The longitudinal inclination angle is preferably more than 80 °. The longest possible and thus volume-sensitive level surface can be obtained in that the length of the at least one level surface along the level track is more than five times the width of the level surface to be measured orthogonally to the level track. In the present case, the width of the level surface is technically important only to the extent that it has to be wide enough to be able to clearly determine its wetting by the liquid filled into the cavity. In addition, it is advantageous to choose the width in such a way that influences on the liquid distribution due to capillary effects are kept as small as possible or at a negligible level. The greater the ratio of length to width of the level surface, the longer the level surface can be designed without any loss in volume of the cavity volume. The length of the at least one level surface is therefore preferably more than eight times, particularly preferably more than twelve times its width.

In principle, the width of the level surface can vary along the level track. However, the width of the level surface along the level track is preferably constant in order to ensure uniform and equal measurement conditions along the level surface.

For an imaging determination of the volume of the liquid filled into the cavity, knowledge of the fill level of the liquid filled into the cavity is of great importance in the case of the presently discussed vessel arrangement.

For the simplest possible determination of the volume of an amount of liquid filled into the cavity, it is preferred if the filling level can be determined along the depth axis. This is the case when the depth axis runs parallel to the direction of gravity in the volumetric determination mode. Because then the free liquid surface, which is always orthogonal to the direction of gravity, is also orthogonal to the depth axis. To facilitate discussion of the vessel arrangement, the vessel arrangement is therefore assigned a reference plane which is orthogonal to the depth axis and which touches a cavity floor at its deepest point. As described above, the reference plane is to be oriented orthogonally to the direction of the action of gravity in order to determine a quantity of liquid received in the vessel arrangement.

According to a preferred embodiment, which allows a very precise volume determination, the cavity has at least one cavity channel section which extends along the depth axis into the vessel body and which runs along the level track, with a surface of a cavity channel bottom of the cavity channel section pointing into the cavity -Surface is.

The cavity channel bottom is preferably straight in the width direction. However, a curved design of the cavity channel bottom should not be ruled out either. A curved design is preferred when considering the cavity channel bottom along the depth axis, a concave-curved design so that the cavity channel bottom can form a channel running along the level track.

By local inclination of the level surface of the cavity channel bottom with the local longitudinal angle of inclination, which, as already stated above, includes its curvature around a shape axis orthogonal to the level track and the depth axis, the depth of the at least one cavity channel section to be measured along the depth axis is reduced the level track. With a known shape of the cavity with an inclined and / or curved cavity channel base, the volume of the amount of liquid filled into the cavity can be inferred with high accuracy from the length of the free liquid surface present in the cavity channel section alone, that is, the liquid surface opposite the cavity base along the depth axis become.

If a liquid can level itself in interaction with the material of the vessel arrangement and its wetting by the liquid in the cavity, there is no minimum amount of liquid to be filled into the cavity, since from every free liquid surface existing above the cavity channel bottom with a known cavity shape on the volume of the filled liquid can be closed. The fact that the cavity channel bottom is inclined and / or curved not only about a shape axis that is orthogonal to the depth axis but also to the level track relative to the depth axis or to the reference plane should not exclude the possibility that the cavity channel bottom is also relative to a further shape axis running along the level track Depth axis or can be designed inclined and / or curved to the reference plane, for example having a V- or U-shaped border when viewed in a sectional plane orthogonal to the level track. Then, in cases of such small amounts of liquid that they do not completely fill the width of the cavity channel section, the volume of the amount of liquid filled can be calculated from the length and the width of the free liquid surface. Knowledge of the specific shape of the cavity is always a prerequisite for this. Such a configuration of the cavity channel base inclined and / or curved about the further mold axis is, according to a preferred embodiment, only configured in a section of the level trace, starting from the one in the Volumetric determination operation lowest point of the cavity channel section. Starting from this lowest point, the opening angle of a V-shaped border can increase along the level track or the curvature of a U-shaped border can decrease along the level track until a flat edge is reached that is orthogonal to the depth axis.

The cavity is preferably designed in such a way that the liquid filled into it - in which case distilled water at 20 ° C and an atmospheric pressure of 1013 hPa should be used as the reference liquid in this case - flows smoothly into a state of equilibrium solely due to its weight, thus capillary effects for filling of cavity channel sections should not play a role or should only play a subordinate role because of unavoidable surface effects at the boundary between liquid and vessel body. Additional pressurization of the liquid in order to displace it in the cavity is not intended in the present case. The width of the cavity channel section is therefore preferably at least 1.7 mm, more preferably at least 1.9 mm.

The at least one cavity channel section has its largest dimension along the level track.

The cavity is preferably open at at least one point for filling in liquid. For simple, automated filling of liquid into the cavity, it is particularly preferably open along the depth axis in the direction away from the cavity bottom.

As a rule, the vessel body will have a flat end face. This can be a standing surface with which the vessel body can be set up on a surface. Alternatively or preferably, this can additionally be an end face remote from the cavity bottom, from which the cavity extends along the depth axis into the vessel body. If one of these named end faces is present on the vessel body, the reference plane can be determined very easily as a plane parallel to this end face.

In the unlikely event that a completely irregularly shaped vessel body is present, with an edge of a filling opening of the cavity opposite the cavity bottom lying in one plane, it can be assumed as a first approximation that the reference plane runs parallel to the plane of the cavity edge.

An advantage of the presently presented preferred embodiment of a vessel arrangement according to the invention is that the cavity channel section along the level trace can have a constant width orthogonal to both the depth axis and the level trace over at least a large part of its depth to be measured along the depth axis. The cavity channel section can thus be delimited by two cavity wall sections which are opposite one another in the width direction, at least to the depth axis, and preferably also parallel to one another. The wall inclination angle is then 0 °. In addition, the width is preferably constant at least over a large part of the length of the cavity channel section to be measured along the level track. In principle, however, it is sufficient if the width of the cavity channel section, which is constant along the depth, changes along the level track in accordance with a known relationship.

The cavity channel bottom adjoining the side walls of the cavity channel section along the depth axis with the level surface pointing to the cavity volume can be flat or, as described above, at least in an area of greatest depth extension of the cavity channel section around the above-mentioned further shape axis inclined or / or curved relative to the reference plane being. Then, when the liquid in the cavity channel section extends from the cavity channel bottom into the area along the depth axis of constant width, the volume of the liquid can be determined solely from the length of its free surface along the level track.

Due to the constant width of the cavity channel section over a large part of its depth and preferably also over a large part of its longitudinal extent, it can be formed with a great length without requiring excessive space, so that the volume range of very small liquid volumes in the single-digit µl range or even which can be determined with the vessel arrangement discussed here below that it can extend into the ml range. In contrast, for example, the one from the US 7,204,960 B2 Known cavity have inclined walls over its entire depth extension, since only then can the filling level of the liquid and thus the volume of the filled liquid be inferred from the width of the free liquid surface that can be determined in the cavity. Thus, the known cavity with increasingly larger measurable liquid volume on the filling side of the cavity facing away from the cavity bottom, via which liquid is poured into the known cavity, has an increasing space requirement, since the width of the cavity increases steadily with increasing distance from the deepest point of the cavity bottom got to.

The vessel arrangement presented in the present application can obtain an even larger measuring range by virtue of the fact that the level trace has a curved course. Since the level Surface along the level track can have a constant width, the level surface can have a relatively large length in a relatively small installation space of the vessel body due to a curved or even meandering course, which corresponds to a relatively large volume measurement range. The at least one level surface therefore preferably has a multiply curved course, optionally a multiply curved course with locally different curvatures in order to be able to use the construction space provided by the vessel body as intensively as possible to form the cavity.

For example, the level surface can run helically starting from the cavity bottom with the depth axis as the helix axis, the helix radius increasing with increasing distance from the cavity bottom, preferably by at least the width of the level surface of the immediately preceding turn, which is closer to the cavity bottom the level surface can be captured along its entire length by image capture with the optical axis parallel to the depth axis.

The small space requirement of the cavity discussed here enables the provision of a large cavity volume that can be used for volume measurement by forming a plurality of level surfaces, each of which runs along its individual level track orthogonal to the common depth axis.

In principle, the at least one level surface can be provided free and in the width direction on both sides at a distance from the wall surfaces delimiting the cavity, for example as a surface of a web protruding from the cavity bottom facing away from the cavity bottom, although such a design can be complex and technically challenging. The at least one level surface therefore preferably adjoins a wall surface delimiting the cavity wall in its width direction in at least one width end region. The at least one level surface is then physically delimited in the width direction in at least one width area by the adjoining wall surface. If a plurality of level surfaces is present, each of the plurality of level surfaces adjoins such a wall surface in its respective width direction in at least one width end region and is physically delimited by it.

In the above-described embodiment of a level surface as the surface of a cavity channel bottom of a cavity channel section, the level surface thus formed adjoins a wall surface in its width direction at both opposite end areas in width direction and is physically delimited by a wall surface in both opposite width end areas.

In a further development of the embodiment described above, the above-described plurality of level surfaces can be implemented as surfaces of cavity channel bottoms of a plurality of cavity channel sections in the vessel body that communicate with one another by fluid mechanics. The communicating cavity channel sections each extend along a common depth axis into the vessel body, so that in each of the communicating cavity channel sections the filling level of a liquid filled above the cavity bottom can be determined along the same depth axis. However, each of these cavity channel sections runs along its individual level track, which is orthogonal to the common depth axis. According to the invention, at least one cavity channel section, preferably each cavity channel section, has its largest dimension along its individual level track. The cavity channel sections preferably only communicate with one another at one point and do not otherwise cross one another. Each of the cavity channel sections is formed like the at least one cavity channel section described above, i. H. each has a cavity channel bottom which is inclined and / or curved about a shape axis that is orthogonal both to the depth axis and to its individual level track. With regard to the reference plane described above, this should be thought of as touching the lowest point of the cavity.

The above-mentioned mold axis, about which the cavity bottom of the at least one cavity channel section is inclined or and curved with respect to the depth axis or the reference plane, is a local mold axis. Since the shape axis is aligned orthogonally to the level track, the orientation of the shape axis changes in absolute space when the orientation of the level track changes, for example along curved areas of the level track.

The inclination and / or curvature of the plurality of level surfaces around their respective shape axis is preferably such that the distance of the level surfaces from the reference plane along the respective individual level track increases from the point of closest approach of the level surfaces. At the point of greatest approximation, the level surfaces, in particular as surfaces of cavity channel bottoms, of cavity channel sections running along different level tracks are connected to one another in a direct fluid-mechanically communicating manner. This has the advantage that the location of the greatest approximation can serve as a common origin for a length measurement of the free surfaces of the liquid in the respective cavity channel sections.

To facilitate the evaluation of an image obtained from the cavity with the liquid filled therein, the level surfaces, in particular the cavity channel sections, are preferably designed to be non-parallel to one another with an identical shape. For this purpose, the level surfaces can be designed to be rotated with respect to one another about an axis of rotation parallel to the depth axis. The angle of rotation between at least three level surfaces, in particular cavity channel sections, is preferably at least 80 °, preferably at least 90 °, in order to orientate particularly reliably from the length of the level surface wetted and / or not wetted by the filled liquid to be able to close the cavity relative to the direction of gravity. In this way, not only can the volume of an amount of liquid filled into the cavity be calculated, but it can also be assessed whether or not the vessel arrangement is arranged in the correct position specified for a volumetric determination. For this purpose, the level surfaces, in particular the cavity channel sections, do not have to be of identical design. Differences between the level surfaces, in particular the cavity channel sections, can be taken into account in the respective calculation formulas used to assess the wetting situation. However, the use of identically designed level surfaces, in particular cavity channel sections, facilitates the evaluation of an image generated by the cavity with liquid filled therein, not only for determining the liquid volume, but also for determining whether the depth axis of the cavity is oriented sufficiently precisely parallel to the direction of gravity is. Equidistant arrangement of the plurality of level surfaces, in particular cavity channel sections, with the same angular spacings around the rotation axis also facilitates the evaluation of whether the depth axis of the cavity is oriented sufficiently precisely parallel to the direction of the action of gravity. When using identically designed level surfaces, in particular cavity channel sections, an operator working with the vessel arrangement can even easily recognize a faulty arrangement of the vessel arrangement at first glance, independently of a computer evaluation of an image generated by the free surface.

When using identical level surfaces, in particular cavity channel sections, if the vessel arrangement is correctly arranged with the depth axis parallel to the direction of gravity, all level surfaces are uniformly wetted, or all cavity channel sections are uniformly filled, i.e. H. the free liquid surface extends over all level surfaces along the level track to the same extent. If this is not the case, the depth axis of the vessel arrangement is inclined relative to the direction of the action of gravity and should be readjusted if necessary.

Filling the cavity with the amount of liquid to be volumetrically detected can preferably be simplified in that the plurality of level surfaces, in particular cavity channel sections, run from a common original location.

The configuration of the cavity with at least one cavity channel section designed as described above allows the determination of the volume and in particular the filling level of the liquid filled into the cavity solely on the basis of the length of the free liquid surface along the level track. Since the liquid filled into the cavity rests in the cavity after a state of equilibrium has been established and does not flow, in communicating cavity sections with reference to the hydrostatic paradox in the case of a known cavity shape, starting from a locally determined fill height, all locally different fill heights due to the cavity shape can be inferred. As a result, with the presently described cavity, which comprises at least one cavity channel section configured as set out above, a very large amount of liquid can also be determined volumetrically very precisely.

In other configurations of the at least one level surface, in particular in a configuration in which the level surface protrudes on one side from a side wall surface of the cavity, i.e. in which the level surface in its width direction orthogonal to the level track is only in a width end area of one Side wall surface of the cavity is physically limited, the determination of the liquid volume on the basis of another surface that can be detected by imaging can be more advantageous. Such a level surface can form, for example, one step in a side wall surface, or, for example in the case of an above-mentioned helical level surface, several steps. When viewed in a sectional plane parallel to the depth axis and orthogonal to the side wall surface, the level surface can be adjoined in the width direction on both sides of the level surface by a side wall surface section, which run in opposite directions away from the level surface, so that only one side wall surface section the surface of the gauge is physically limited in the width direction. Here, the determination of the liquid volume or a value representing this volume on the basis of a determination of a length of a section of the at least one level surface that is not wetted by liquid and / or on the basis of a determination of a location of a wetting limit can lead to more precise results than the determination a length of a wetted portion of the level surface.

The cavity can have a reservoir section from which the at least one level surface starts. When the reservoir section is provided in addition to the at least one cavity channel section, the cavity channel bottom of which forms the level surface, the at least one cavity channel section communicates with the reservoir section. In at least two spatial directions orthogonal to each other and to the depth axis, the reservoir section has a greater clear width than the width of the at least one cavity channel section starting from the reservoir section, which is orthogonal to both the level trace and the depth axis, preferably constant along the level trace. Thus, the reservoir section can store or absorb a larger amount of liquid in a space cube predetermined in the vessel arrangement than the cavity channel section communicating with it. However, since the absorbed liquid in the reservoir section and in the cavity channel section forms a common free surface, conclusions can also be drawn about the amount of liquid in the communicating reservoir section from the fill level determined on the basis of the length of the free surface in the cavity channel section.

The reservoir section is preferably formed at the original location. Then the at least one level surface, preferably the at least one cavity channel section, or preferably several level surfaces, in particular cavity channel sections, particularly preferably several identical level surfaces, in particular cavity channel sections, start from the reservoir section. Particularly preferably, the plurality of identical level surfaces, in particular cavity channel sections, are arranged rotated at equidistant angles about the axis of rotation, as described above. Due to its dimensions, the reservoir section is preferably designed for filling the cavity with liquid.

A particularly simple design of the cavity with the at least one level surface is made possible by a plate as the vessel body. The plate preferably has two end faces that are orthogonal to its thickness direction, with the cavity advantageously simply extending into the plate from one of the end faces in terms of production technology. The thickness direction of the plate therefore preferably runs parallel to the depth axis. In this case, one end face has an edge of the cavity delimiting an opening of the cavity as the filling end, and the other end face serves as a support side for the plate to be supported on a substrate as evenly as possible. The above-mentioned reference plane is then preferably parallel to at least one end face of the plate.

The use of a plate also offers the possibility, due to its substantially larger orthogonal surface extension relative to the thickness direction, of arranging a plurality of cavities formed separately from one another next to one another. A plate provided with a plurality of separately designed cavities in this way can thus be used for the parallel volumetric detection of a plurality of separate amounts of liquid.

The present invention also relates to a vessel assembly comprising a vessel arrangement as described above and further comprising a carrier arrangement on which the vessel arrangement is received with a depth axis parallel to the direction of gravity. The vessel arrangement is preferably arranged in the vessel assembly ready for operation. The carrier arrangement can therefore be a work table of a pipetting device. As an alternative or in addition, the carrier arrangement can comprise a receptacle for the vessel arrangement or, for example, a carrying or clamping device, which is then brought into a working space of a dosing device, in particular a pipetting device.

• - Einfüllen der Flüssigkeitsmenge in eine Kavität der Gefäßbaugruppe,
• - bildliches Erfassen einer freien Oberfläche wobei die freie Oberfläche eine Flüssigkeitsoberfläche der in der Kavität ausgebreiteten Flüssigkeitsmenge oder/und eine Oberfläche eines von der Flüssigkeitsmenge unbenetzten Abschnitts der wenigstens einen Pegel-Oberfläche umfasst,
• - Ermitteln der Benetzungssituation durch Ermitteln eines Ortes einer Benetzungsgrenze einer Pegel-Oberfläche oder/und Ermitteln einer Länge eines benetzten Abschnitts der wenigstens einen Pegel-Oberfläche oder/und einer Länge eines unbenetzten Abschnitts der wenigstens einen Pegel-Oberfläche längs der Pegelspur aus der bildlichen Erfassung,
• - Ermitteln eines das Volumen der Flüssigkeitsmenge repräsentierenden Werts aus dem ermittelten Ort der Benetzungsgrenze oder/und aus der ermittelten Länge in der Kavität auf Grundlage von gespeicherten Daten betreffend die Gestalt der Kavität.

The present invention also relates to a method for determining an amount of liquid using a vessel assembly as described above. The procedure consists of the following steps:

• - Filling the amount of liquid into a cavity of the vessel assembly,
• - Pictorial detection of a free surface, wherein the free surface comprises a liquid surface of the amount of liquid spread out in the cavity and / or a surface of a section of the at least one level surface that is not wetted by the amount of liquid,
• Determination of the wetting situation by determining a location of a wetting limit of a level surface and / and determining a length of a wetted section of the at least one level surface and / or a length of an unwetted section of the at least one level surface along the level trace from the visual acquisition ,
• Determination of a value representing the volume of the amount of liquid from the determined location of the wetting limit and / or from the determined length in the cavity on the basis of stored data relating to the shape of the cavity.

The image-captured free surface can, in particular in the case of the cavity channel sections described above, comprise or be a free liquid surface which extends along the depth axis above the level surface. In this case, a length of a wetted section of the level surface, from this a fill level and finally a value can be determined from the length of the free liquid surface from the length of the free liquid surface, which represents the volume of the amount of liquid received in the cavity.

If the level surface is not physically delimited on both sides in the width direction by side wall surface sections of the cavity, the filling level is usually less easy to determine from the free surface of the liquid than from the length of a non-wetted section of a level surface, with this length is to be determined along the level trace assigned to the level surface. This length can also be determined by evaluating the image of the free surface recorded in the image.

If, for example, the total length of a level surface along its level track is known, the length of its wetted section easily results from the non-wetted length and thus in turn the fill level of the amount of liquid in the cavity.

Additionally or alternatively, a wetting limit can also be determined from the image-captured free surface, at which a wetted section of the level surface ends and an unwetted section of the same begins. For example, the level surface can be provided with calibration markings arranged at a distance along its level track, which allow a value representing the volume of the amount of liquid in the cavity to be deduced directly from the position of the wetting limit relative to at least one calibration mark.

In order to safeguard a determination result, several of the above-mentioned ways of determining the value representing the volume from the image-captured free surface can also be carried out.

The wetting limit, the length of the wetted section of a level surface and the length of an unwetted section of a level surface are each taken individually and even more in combination represent the wetting situation of the level surface within the meaning of the present application.

Process aspects emerging from the above description of the vessel arrangement of the vessel assembly are further developments of this process. The device aspects arising from the description of the method are also further developments of the vessel arrangement, the vessel assembly and the pipetting device mentioned below.

The filling of the amount of liquid into the cavity can take place by any desired dosing device, in particular a pipetting device, specifically preferably using a component of the dosing device to be calibrated by the volumetric detection of the amount of liquid. Such a component can be a pipette tip of a pipetting device or a pressure changing device for changing the pressure of a working gas in a pipetting channel of the pipetting device. The pressure changing device can, for example, comprise a pipetting plunger which can be displaced in a pipetting channel along a pipetting channel path and through the displacement of which the pressure of a working gas received in the pipetting channel can be changed. The pipetting piston can be driven mechanically via a linkage or a gear or by an electric motor via a magnetic field for the displacement movement. The latter is preferably a linear motor drivability in which the pipetting piston has at least one permanently magnetized section and can thus be displaced by means of a magnetic field generated outside the pipetting channel by a plurality of electromagnetic coils.

The above-mentioned free surface can be captured by any camera. In particular, the free surface is captured by a digital camera or by a scanner, in particular a flat bed scanner. The digital image obtained in this way allows the captured image to be evaluated electronically. One possible embodiment of such a digital camera is a known CCD camera.

The above-mentioned length sections of the level surface or / and the wetting limit are preferably determined by image processing of an electronically generated image. The length can be determined, for example, by determining the relevant number of pixels along the level track. A wetting limit can be determined by determining a contrast limit along the level track.

Shape information of the cavity is preferably stored in a data memory, for example a control device for the dosing device filling the cavity with liquid, or in another control device, which makes it possible to determine a liquid volume depending on the situation determined. Since each level surface has a finite length along its level track, it is sufficient in the The simplest case consists of assigning volume information to length values of a section of a level surface or a location of a wetting boundary. Due to the predetermined shape of the cavity, in particular a cavity channel section mentioned above, liquid filled into the cavity always spreads from the same original location along the level track in the same direction, so that a clear liquid volume can be assigned to each determined length of a section of a level surface.

When the level surface along the level track has a constant uniform slope, a few support points of length values are sufficient, each of which is assigned volume information in the data memory. Intermediate values can then be determined by interpolation. The level surface can, however, also have gradients and / and curvatures of different amounts along the level track. This only increases the calibration effort in order to assign unambiguous volume information to a determined length of a section of the level surface along the level track or to a determined location of a wetting limit. If the shape of the cavity is known, the volume can also be calculated analytically from the determined length.

• - Ermitteln einer jeweiligen Benetzungsgrenze einer Mehrzahl von Pegel-Oberflächen oder/und Ermitteln einer Länge eines benetzten Abschnitts einer Mehrzahl von Pegel-Oberflächen oder/und einer jeweiligen Länge eines jeweiligen unbenetzten Abschnitts einer Mehrzahl von Pegel-Oberflächen längs der der jeweiligen Pegel-Oberfläche zugeordneten Pegelspur aus der bildlichen Erfassung,
• - vergleichen der ermittelten Orte der Benetzungsgrenzen oder/und der ermittelten Längen untereinander,
• - abhängig vom Vergleichsergebnis Verwerfen der bildlichen Erfassung oder Ermitteln eines das Volumen der Flüssigkeitsmenge repräsentierenden Werts aus den ermittelten Orten der Benetzungsgrenzen oder/und der ermittelten Längen der Flüssigkeitsoberfläche.

As already described above, the vessel assembly preferably has a vessel arrangement, the cavity of which has a plurality of level surfaces, in particular cavity channel sections. The above method then preferably comprises the following further steps:

• - Determining a respective wetting limit of a plurality of level surfaces and / or determining a length of a wetted section of a plurality of level surfaces and / or a respective length of a respective unwetted section of a plurality of level surfaces along the associated with the respective level surface Level trace from the visual acquisition,
• - compare the determined locations of the wetting limits and / or the determined lengths with each other,
• - depending on the comparison result, discarding the image recording or determining a value representing the volume of the amount of liquid from the determined locations of the wetting limits and / or the determined lengths of the liquid surface.

• - Ermitteln der Länge der Flüssigkeitsoberfläche jedes Kavitätskanalabschnitts aus einer Mehrzahl von Kavitätskanalabschnitten der Kavität längs der dem jeweiligen Kavitätskanalabschnitt zugeordneten Pegelspur,
• - vergleichen der ermittelten Längen untereinander,
• - abhängig vom Vergleichsergebnis Verwerfen der bildlichen Erfassung oder Ermitteln eines das Volumen der Flüssigkeitsmenge repräsentierenden Werts aus den ermittelten Längen der Flüssigkeitsoberfläche.

In the event that the level surfaces are formed by surfaces of the respective cavity channel bottom of a plurality of cavity channel sections, the above-described further development of the method results in:

• - Determining the length of the liquid surface of each cavity channel section from a plurality of cavity channel sections of the cavity along the level track assigned to the respective cavity channel section,
• - compare the determined lengths with each other,
• - depending on the comparison result, discarding the image recording or determining a value representing the volume of the amount of liquid from the determined lengths of the liquid surface.

If, in the present case, taking into account the known liquid density, a mass of the filled liquid is output, this is also a value in the sense of the present application which represents the volume of the amount of liquid.

As already described above, by comparing the respective locations of a wetting boundary on different level surfaces and / or by comparing the lengths of sections of different level surfaces of the same cavity with the same wetting state, in particular of communicating cavity channel sections, it can be determined whether the vessel arrangement is correctly arranged and aligned for a volumetric determination of the amount of liquid. In the case of the preferred use of identical level surfaces, in particular identical cavity channel sections, the determination of different length values and / or different locations of a wetting boundary for each of the plurality of identical level surfaces, in particular in the form of communicating cavity channel sections, indicates that the vessel arrangement is incorrectly aligned relative to the direction of the action of gravity. In this case, the image capture can be discarded. In this case, an output device, such as a screen and / or a dedicated lighting device and / or a loudspeaker, can output a warning that indicates the determined uselessness of the image capture for a volumetric determination of the amount of liquid and / and specifically to a misalignment of the vessel arrangement is pointed out.

After the comparison step described above, the following further method step can also be carried out depending on the comparison result: Determination of a value which indicates a deviation of the position of the depth axis from the direction of the action of gravity.

With knowledge of the shape of the cavity, one can use the above-mentioned length differences and / or the above-mentioned different locations Wetting limit, an inclination of the cavity and thus of the depth axis with respect to the direction of the action of gravity can be quantified with regard to the direction of inclination and the extent of the inclination.

• - Ausgabe einer Meldung, welche qualitativ oder/und quantitativ auf die Lage der Tiefenachse, insbesondere relativ zur Schwerkraftwirkungsrichtung, hinweist.

Therefore, the procedure can include the following additional step:

• Output of a message which qualitatively and / or quantitatively indicates the position of the depth axis, in particular relative to the direction of the action of gravity.

As an alternative or in addition to outputting the message, the method can have the step that, based on the determined orientation of the depth axis relative to the direction of gravity, a correction algorithm is applied to the liquid volume calculated from the individual determined lengths. The correction of an undesired inclination of the cavity is particularly simple if, as already explained above, several identically designed level surfaces, in particular communicating cavity channel sections, are arranged at the same angular distance around the above-mentioned axis of rotation.

• - einen Pipettierkanal, in welchen eine Flüssigkeit aspirierbar und aus welchem eine Flüssigkeit dispensierbar ist,
• - eine Steuervorrichtung zur Steuerung einer Aspiration und einer Dispensation von Flüssigkeit in den Pipettierkanal bzw. aus dem Pipettierkanal,
• - eine Gefäßbaugruppe, welche wie oben beschrieben ausgebildet ist, und
• - eine Bilderfassungsvorrichtung zur bildlichen Erfassung der Gefäßanordnung der Gefäßbaugruppe längs der Tiefenachse der Gefäßanordnung,

wobei die Pipettiervorrichtung zur Ausführung des oben beschriebenen bildgebenden volumetrischen Verfahrens ausgebildet ist.Finally, the present invention also relates to a pipetting device comprising:

• - a pipetting channel into which a liquid can be aspirated and from which a liquid can be dispensed,
• - a control device for controlling aspiration and dispensing of liquid into the pipetting channel or out of the pipetting channel,
• - A vessel assembly which is designed as described above, and
• - An image acquisition device for the image acquisition of the vessel arrangement of the vessel assembly along the depth axis of the vessel arrangement,

wherein the pipetting device is designed to carry out the imaging volumetric method described above.

Explanations already made above about the pipetting device in connection with the execution of the volumetric method are directly further developments of the aforementioned pipetting device. A work table or generally a work surface of the pipetting device, on which containers to be filled by the pipetting device can be received, can be the above-mentioned carrier arrangement which, together with a vessel arrangement arranged on the work surface, forms a vessel assembly.

The image capturing device, again for example preferably a digital camera or a scanner, in particular a flat bed scanner, can be provided on the pipetting device so that it can be moved separately from the pipetting channel. Alternatively, the image acquisition device can be coupled to a pipetting channel and can be moved in a work space above the work surface of the pipetting device by a displacement device designed and provided for moving the pipetting channel.

The optical axis of the image capturing device is preferably arranged parallel to the direction of the action of gravity and thus also preferably parallel to the depth axis of the cavity. This is to ensure that the free surface of the cavity with the liquid filled therein, which is image-captured by the image acquisition device, extends orthogonally to the optical axis, which reduces or completely avoids parallax errors when determining the length.

The liquid used by the pipetting device is preferably a liquid which is different in color from the vessel body of the vessel arrangement in order to achieve the highest possible contrast between the free surface of the amount of liquid filled into the cavity and the vessel body. The liquid can therefore be colored.

• 1 eine Draufsicht auf eine erste Ausführungsform einer erfindungsgemäßen Gefäßanordnung,
• 2 eine grobschematische Seitenansicht einer zur Ausführung des erfindungsgemäßen Verfahrens ausgebildeten Pipettiervorrichtung mit der Gefäßanordnung von 1, wobei die Gefäßanordnung von 1 mit einer Kavität längs der Schnittebene II-II von 1 geschnitten dargestellt ist,
• 3 eine grobschematische Schnittansicht der Gefäßanordnung von 1 längs der Schnittebene III-III von 1,
• 4 eine grobschematische Draufsicht auf eine zweite Ausführungsform einer erfindungsgemäßen Gefäßanordnung,
• 5 eine vergrößerte Draufsicht auf eine Kavität der Gefäßanordnung von 4,
• 6 eine grobschematische Schnittansicht entlang der Schnittebene VI-VI von 4,
• 7 eine grobschematische Schnittansicht entlang der Schnittebene VII-VII von 4, und
• 8 eine grobschematische perspektivische Ansicht der Gefäßanordnung von 4.

The present invention will be described in more detail below with reference to the accompanying drawings. It shows:

• 1 a plan view of a first embodiment of a vessel arrangement according to the invention,
• 2 a roughly schematic side view of a pipetting device designed for carrying out the method according to the invention with the vessel arrangement from FIG 1 , the vessel arrangement of 1 with a cavity along the section plane II-II of 1 is shown in section,
• 3 a highly schematic sectional view of the vessel arrangement of FIG 1 along the section plane III-III of 1 ,
• 4th a roughly schematic plan view of a second embodiment of a vessel arrangement according to the invention,
• 5 an enlarged plan view of a cavity of the vessel arrangement of FIG 4th ,
• 6th a roughly schematic sectional view along the section plane VI-VI of FIG 4th ,
• 7th a roughly schematic sectional view along the section plane VII-VII from 4th , and
• 8th a highly schematic perspective view of the vessel arrangement of FIG 4th .

In the 1 and 2 is a generally designated 10 first embodiment of a vessel arrangement according to the invention shown in plan view. The vessel arrangement 10 includes a plate 12th as a vessel body 14th . The viewer of 1 looks vertically at the flat face 12a the plate from which along the to the plane of the drawing 1 orthogonal depth axis TA a plurality of cavities 16 into the vessel body 14th extend into it. 2 shows the vessel arrangement 10 in the section plane II-II of 1 . This section plane II-II is both a wall section plane and, because of the large longitudinal inclination relative to the depth axis TA, a first level section plane with respect to that through the cavity channel bottoms 28 and 28 ' the cavity canal sections 22nd and 26th formed level surfaces 29 and 29 ' .

The cavities 16 in the vascular body 14th are designed identically, which is why there is only one cavity below 16 is described representative of all.

An opening 17th the cavity 16 is on the flat face 12a through a closed, circumferential cavity edge 18th limited. From this cavity edge 18th cavity wall sections extend 19th in the depth direction parallel to the depth axis TA into the vessel body 14th into (s. 2 ).

The cavity wall sections 19th are in the illustrated embodiment of 1 and 2 formed over their entire respective local cavity height parallel to the depth axis. To avoid possibly confusing influences at the end areas of the cavity wall sections 19th near the edge of the cavity 18th and near the cavity floor 35 or near the cavity canal floor 28 According to the present application, it is intended to determine a course of the cavity wall sections that is parallel to the depth axis TA 19th Sufficient if this is symmetrical around a local height center m of the respective location of the cavity under consideration 16 formed local mean cavity height section kh run parallel to the depth axis TA. The local mean cavity height section kh extends over exactly one third of the local cavity height at the considered location of the cavity. Because the cavity 16 has different local cavity heights at different locations, the local height centers and the local cavity height sections kh are also dependent on the cavity height at the respective location under consideration and can therefore have different values at different locations.

A local wall slope angle between the cavity wall sections 19th and the depth axis TA is due to the parallelism of the wall sections 19th to the depth axis TA 0 °.

The cavity 16 includes a reservoir section 20th with locally relatively large capacity. From the reservoir section 20th go three identically designed cavity channel sections 22nd , 24 and 26th from which each along their individual level track K1 , K2 or. K3 get lost. The level tracks K1 , K2 and K3 are virtual level tracks. These are intended to run orthogonally to the depth axis TA in the transverse center (center in the width direction) of an associated cavity channel section.

The cavity canal sections 22nd , 24 and 26th are designed identically and are only arranged rotated by 90 ° about an axis of rotation DA parallel to the depth axis TA. The cavity canal sections 22nd , 24 and 26th show over a large part of their depth extent along the depth axis TA and over a large part of their length extent along the respective gauge K1 , K2 or. K3 a constant to the depth axis TA and to the respective level track K1 , K2 or. K3 locally orthogonal latitude b (s. 2 ).

In the 2 The width direction shown in the section of the section plane II-II through the surfaces of the cavity channel bottoms 28 or. 28 ' formed level surfaces 29 and 29 ' runs in the illustrated embodiment along the entire extent of the level surfaces along the associated level track K1 , K2 and K3 orthogonal to the depth axis TA. The latitude inclination angle β of the level surface is therefore 90 °.

Since the cavity channel sections 22nd , 24 and 26th are designed identically, it is then sufficient to only use the cavity channel section 22nd to describe in more detail, its description also for the identically designed remaining cavity channel sections 24 and 26th is applicable.

A cavity canal floor 28 of the cavity channel section 22nd points at the place 30th its branching off from the reservoir section 20th its lowest point. The one to the cavity 16 indicative surface of the cavity channel bottom 28 forms a level surface 29 . The cavity canal floor 28 and a floor 34 of the reservoir section 20th together form the cavity floor 35 .

Starting from the junction 30th the bottom of the cavity canal approaches 28 along the level track K1 continuously and steadily to the edge of the cavity 18th at the front 12a the plate 12th on. In other words: the depth extension f des Cavity channel section 22nd (see 2 ) starts from its junction 30th up to his from the reservoir section 20th distant longitudinal end 32 , measured from the front 12a starting, continuously decreasing.

The shape of the reservoir section 20th is known. Each fill level above the floor 34 of the reservoir section 20th a filling volume is thus assigned in a data memory.

At the junction 30th is the cavity canal floor 28 of the cavity channel section 22nd flush with the ground 34 of the reservoir section 20th . The filling level of the cavity increases 16 filled liquid, the liquid flows into the to the reservoir section 20th identically connected cavity channel sections 22nd , 24 and 26th , and all the further along the respective level track K1 , K2 and K3 , the higher the column of liquid in the cavity 16 increases.

By determining the length of the viewer from 1 facing free liquid surface in the cavity channel sections 22nd , 24 and 26th along the respective level track K1 , K2 or. K3 can thus directly determine the fill level of the liquid in the cavity 16 be determined. Due to the familiarity of the shape of both the reservoir section 20th as well as the identical cavity channel sections 22nd , 24 and 26th a total filling volume of the filled liquid is assigned to each filling level, and thus to each determined length, which is composed of the filling volume of the reservoir section and the three filling volumes of the cavity channel sections 22nd , 24 and 26th .

Because of the identical design of the cavity channel sections 22nd , 24 and 26th is sufficient if the plate is arranged correctly 12th with the depth axis TA parallel to the direction of the action of gravity g into the cavity 16 filled liquid equally far along the respective level tracks K1 , K2 and K3 into the respective cavity channel sections 22nd , 24 and 26th into it. One from the viewer of the 1 from observable free liquid surface with correctly arranged vessel arrangement 10 , ie the depth axis TA runs parallel to the direction of the action of gravity g, is in 1 in the right column of the cavities 16 , there in the middle, shown hatched and labeled 36.

The cavity is exemplary 16 at which the free liquid surface 36 is shown, a portion wetted by the liquid 29a , a portion not wetted by the liquid 29b and one the two sections 29a and 29b different wetting limit 29c shown.

Used during the volumetric determination of the in the cavity 16 Filled amount of liquid despite an already set state of equilibrium of the liquid, i.e. when in the cavity 16 stationary liquid, a different distance of inflow of liquid along the level tracks K1 , K2 or. K3 into the cavity canal sections 22nd , 24 and 26th determined, the volumetric determination process can be aborted and a corresponding message can be output. If the inflow of liquid into the respective cavity channel sections differs 22nd , 24 and 26th there is a misalignment of the plate 12th before, according to which the depth axis TA is undesirably oriented deviating from the desired parallelism to the direction of gravity action g.

Based on the differences in length of the free liquid surface along the level tracks K1 , K2 and K3 On the one hand, it can be determined in which direction the depth axis TA is inclined relative to the direction of the action of gravity, and it can be determined how strong this inclination is in terms of magnitude. The deviation values determined in this way can also be output to an operator or transmitted to an adjusting device which, based on the transmitted deviation values, determines the orientation of the plate 12th automatically corrected.

The cavity 16 takes on the front side 12a the plate 12th a relatively small area for its capacity, which is possible, among other things, because the level tracks K1 , K2 and K3 have a course that is curved in sections, even multiply and in opposite directions.

In 2 is a roughly schematic diagram of a pipetting device 40 shown, which is designed for the volumetric imaging of a liquid according to the method described above.

The pipetting device 40 includes a work table 42 with a countertop 44 , which as a carrier device 46 the plate 12th serves. With hers to the front 12a than the parallel end face opposite the filling side 12b the plate is on the support side 12th on the plane of the drawing 2 orthogonal work surface 44a the countertop 44 on.

The device 40 furthermore has a frame which is only indicated schematically 48 on which a pipetting channel 50 and a digital camera 52 each parallel and orthogonal to the work surface 44a are movably included.

On the pipetting channel 50 is an exchangeable pipette tip 53 recorded whose from the pipetting channel 50 distant pipetting opening 54 an aspiration of liquid into the pipette tip 53 and dispensing of the aspirated liquid therefrom is permitted. The aspiration and dispensation of Liquid into the pipette tip 53 or out of this through a movement of a piston 56 effected along the pipetting channel axis PA. The piston 56 is via a linkage 58 by an engine 60 displaceable along the pipetting channel axis PA.

The digital camera 52 has an optical axis OA which is parallel to the pipetting channel axis PA and parallel to the depth axis TA of the plate 12th is aligned.

A control device 62 controls the operation of the engine, among other things 60 of the piston 56 , the digital camera 52 and an input / output device 64 . The control device 62 also controls a movement of the pipetting channel 50 and the digital camera 52 in the one above the countertop 44 located work space 66 the pipetting device 40 .

The ones to the drawing plane of 2 parallel direction of gravity is indicated by arrow g. As in the case of the 1 , parallel to the depth axis TA.

In 2 is the reservoir section 20th to recognize the starting from the front side 12a , i.e. the filling side, with the depth extension F into the plate 12th runs into it. The floor 34 of the reservoir section 20th is flat in the example shown and runs orthogonally to the plane of the drawing 2 . The thickness D of the plate as well as the local depth extensions F and f are to be measured along the depth axis TA.

In 2 to the left of the reservoir section 20th is the cavity channel section 22nd shown in cross section, to the right of the reservoir section 20th the cavity channel section 26th . Since the in 1 Section plane II-II shown, which shows the sectional view of the reservoir section 20th as well as the cavity channel sections 22nd and 26th justified, the cavity channel sections 22nd and 26th at exactly the same distance from their respective branch points 30th from the reservoir section 20th intersect, point closer to the reservoir section 20th lying cut branches of the cavity channel sections 22nd and 26th the same depth and point the two further from the reservoir section 20th distant cut branches of the cavity canal sections 22nd and 26th the same but smaller depth extension. The local depth of the farther from the reservoir section 20th distant branch of the cavity canal section 22nd in the section plane II-II is in 2 indicated with f.

The reduction in depth with increasing distance from the reservoir section 20th along the respective level track is due to the fact that the level surface 29 at least in the in 2 section shown orthogonal to the plane of the drawing 2 branches running around the to the plane of the drawing 2 parallel and orthogonal to the depth axis TA local shape axis FA with respect to the depth axis TA and with respect to an orthogonal to the depth axis TA and to the end face 12a parallel reference plane BE is inclined and that in a tilting sense with which the depth extent decreases continuously along the level track. The longitudinal inclination angle γ, by which level surface 29 is inclined relative to the depth axis TA is related to below 3 explained.

The in 2 Junction point behind section plane II-II 30 ' of the cavity channel section 26th is in 2 shown in dashed lines. In 2 it can be seen that the cavity channel section 26th at the point where it branches off from the reservoir section 20th has exactly the same depth extension F as the reservoir section 20th itself. This also applies to the branch point 30th of the cavity channel section 22nd which, however, is in 2 lies in front of the section plane II-II and is therefore in 2 is not shown. The virtual reference plane BE, which is orthogonal to the depth axis TA, is arranged in such a way that it forms the cavity 16 touched at their deepest point, i.e. at the place of greatest depth.

In the present case, the end face parallel to the virtual reference plane BE could also be used 12b serve as a reference plane.

Because of the inclination of the cavity floor described above 28 The distance from the cavity bottom increases around the local mold axis FA in the form of a tilt axis 28 and thus the level surface 29 from the reference plane BE with increasing distance along the level track K1 to. The cavity canal bottom is in the section plane II-II 28 des closer to the reservoir section 20th located branch of the cavity channel section 22nd a smaller distance a from the reference plane BE than that further from the reservoir section 20th distant branch, the greater distance of which from the reference plane BE is indicated by A.

The cavity floor of the cavity channel section 26th is in 2 indicated with 28 ', the level surface formed by its surface with 29'. Due to the opposite inclinations of the cavity floors 28 and 28 ' is in 2 in the cavity canal section 22nd the cavity canal floor 28 only in the one closer to the reservoir section 20th located branch is recognizable and is the cavity canal floor 28 ' of the cavity channel section 26th just further from the reservoir section 20th distant branch recognizable.

The essentially constant width b of the cavity channel sections is at least approximately 2 mm in the example shown.

With the pipetting device 40 is via the pipette opening 54 Liquid in the reservoir section 20th released, whereupon the in the reservoir section 20th released liquid due to its weight in the cavity 16 distributed and a free surface orthogonal to the depth axis TA forms, which in all sections of the cavity 16 is the same distance from the reference plane. This results when viewed along the optical axis OA of the digital camera 52 to the in 1 with 36 designated free surface, the filling height of the liquid solely from the length of the liquid-covered sections of the level tracks K1 , K2 and K3 can be determined. From knowledge of the shape of the cavity 16 can thus only over the length of the liquid-covered sections of the level tracks K1 , K2 and K3 that in the cavity 16 filled liquid volume can be determined with high accuracy.

With the input / output device 64 can use a keyboard 66 Data and commands to the control device 62 can be entered and can be via a screen 68 Warning notices are issued to operating personnel. One possibility of a warning is the above-described case of an arrangement of the plate 12th with incorrect alignment, so that their depth axis TA does not run parallel to the direction of the action of gravity. If this misalignment is detected, this fact can be qualitative or even quantitative in terms of the direction and extent of the misalignment across the screen 68 are issued.

In 3 is the vessel arrangement 10 from 1 in a sectional view along the section plane III-III of 1 shown. The cutting plane III-III, which is for the cut section of the cavity channel section 22nd and its level surface 29 an associated level track K1 containing local second level section plane shows the above-mentioned inclination of the level surface 29 relative to the depth axis TA by the longitudinal inclination angle γ. The longitudinal inclination angle γ is smaller than 90 ° in the illustrated embodiment and is greater than the largest occurring wall inclination angle for the cavity shown as an example 16 Is 0 °. The longitudinal inclination angle γ is in the illustrated embodiment over the entire length of the level surface 29 along their level track K1 constant and preferably greater than 80 °.

In the 4th until 8th a second embodiment of a vessel arrangement according to the invention is shown. In this second embodiment, the same and functionally identical components and component sections as in the first embodiment are provided with the same reference numerals, but increased by the number 100 . The second embodiment will only be described in the following insofar as it differs from the first embodiment described above, the description of which otherwise also applies to the second embodiment.

In contrast to the vessel arrangement 10 the first embodiment has the vessel arrangement 110 the second embodiment cavities 116 without cavity channel sections. The cavities 116 roughly have the shape of a truncated pyramid with rounded edges on the outer surface. However, this is only an example.

The second embodiment has a total of four level surfaces 129 on, of which only one is indicated for the sake of clarity. In 5 is this level surface 129 with their level track K1 shown. The remaining level surfaces 129 with their level tracks are each arranged offset by 90 ° about the axis of rotation DA.

The level surfaces 129 are on the wall surfaces 119 (please refer 6th ) and rise helically on the side wall surfaces 119 from the ground 135 the cavity 116 to the edge of the opening 118 the cavity 116 up.

6th shows a roughly schematic section along the section plane VI-VI in 4th , this section plane VI-VI also being both a wall section plane and a first section plane in the sense of the present application because of the longitudinal inclination of the level surface of more than 81 °.

Although the level surfaces are 129 of the second embodiment in its width direction to the depth axis TA orthogonal, that is to say the in 6th recognizable latitude inclination angle β is 90 ° as in the first embodiment. However, the level surfaces are 129 the second embodiment in the width direction only physically in one of its width end regions by a wall surface 119 limited. A section of a wall surface closes again at the end region which is opposite in the width direction in each case 119 on, but without the level surface 129 physically limit. In the section plane VI-VI form those of the wall surfaces 119 and the level surfaces 129 formed cutting contours steps.

Due to the stepped and helical level surfaces 129 close the wall surfaces 119 with the depth axis TA a local wall inclination angle α recognizable in the section plane VI-VI. As 6th further shows, the width inclination angle β is larger in magnitude than the wall inclination angle α \.

In the sectional view of 6th is on the sections of the level surfaces located behind the cutting plane 129 on which the viewer from 6th looks orthogonally at least in the area of the drawn depth axis TA, the longitudinal inclination angle γ of the level surfaces 129 the second embodiment recognizable. The amount of the longitudinal inclination angle γ is also greater than the wall inclination angle α.

The 7th the longitudinal inclination angle γ, because the section plane VII-VII is a second level section plane in terms of the present invention with respect to the level surface intersected by it.

In 8th is to complete the understanding of the vessel arrangement 110 of the second embodiment the vessel arrangement 110 shown in perspective.

Then when in the cavities 116 In the second embodiment, liquid is filled in and this forms a stationary liquid surface, as a rule only non-wetted sections of the level surfaces 129 and wetting limits clearly recognizable. Wetted sections of the level surfaces 129 lie completely under the surface of the liquid, due to the step-like design of the wall surfaces 119 also the level surfaces directly 129 In the width direction physically limiting wall surface sections disappear completely under the liquid surface. While in the cavity canal sections 22nd , 24 and 26th the first embodiment is the level surface 29 in the width direction on both sides physically delimiting wall surfaces 19th the course of the wetted sections of the surface of the gauge 29 this information is not shown on the cavities 116 the second embodiment. A volumetric imaging of the inside of the cavities 116 The liquid filled in is therefore preferably carried out via a determination of locations of wetting limits and / or via a determination of a length of a non-wetted level surface section along its assigned level track.

Due to the symmetrical design of the cavities 116 with four identical level surfaces, each rotated by 90 ° to each other 129 is also from a pictorial recording of the free liquid surface of one in the cavity 116 filled liquid can be determined qualitatively and quantitatively whether the depth axis TA is arranged parallel to the direction of gravity action g. If this is not the case, the extent of the deviation from the desired parallelism can also be determined.

The arrangement of the vessels can of course also be understood 110 the second embodiment with the in 2 illustrated pipetting device 110 can be used in place of the first embodiment.

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• US 7204960 B2 [0002, 0005, 0006, 0007, 0010, 0011, 0042]
• WO 2019/068724 A1 [0007, 0008, 0009, 0014]

Claims (23)

Vessel arrangement (10; 110) for receiving an amount of liquid for a determination of a volume of the amount of liquid received in the vessel arrangement (10; 110) on the basis of a wetting situation of a solid surface, the vessel arrangement (10; 110) having a vessel body (14 ; 114) and a cavity (16; 116) formed in the vessel body (14; 114) which extends along a depth axis (TA) into the vessel body (14; 114), the solid surface being connected to the vessel body , wherein the cavity (16; 116) is bordered by a plurality of wall surfaces (19; 119) extending along the depth axis (TA), wherein in a local central cavity height section (kh) which extends symmetrically over a third of the length along the depth axis (TA) to be measured local cavity height (F, f) and contains the local height center (m) of the cavity, the wall surfaces (19; 119) when looking at the wall surfaces (19; 119) i n a local, to the depth axis (TA) parallel and to the respective section of the wall surface (19; 119) orthogonal wall section plane (II-II) are oriented parallel to the depth axis (TA) or include a mean local wall inclination angle (α) with the depth axis (TA), characterized in that the solid body surface is at least one along one of the Depth axis (TA) orthogonal level trace (K1, K2, K3) running level surface, the level surface (29, 29 '; 129) along the level trace (K1, K2, K3) having its largest dimension, the at least a level surface (29, 29 '; 129) when viewed in a local first level section plane (II-II) parallel to the depth axis (TA) and orthogonal to the level track (K1, K2, K3) is orthogonal to the depth axis (TA) or with the depth axis (TA) includes a local latitude inclination angle (β) which is larger in magnitude than the largest mean wall inclination angle, and wherein the level surface (29, 29 '; 129) when viewed in a direction to the depth axis ( TA) parallel and the level track (K1, K2, K3) contains Old or tangential to the level track (K1, K2, K3) local second level section plane (III-III) with the depth axis (TA) includes a local longitudinal inclination angle (γ) which is smaller than 90 ° and larger than the largest wall -Tilt angle is. Vessel arrangement (10; 110) according to Claim 1 , characterized in that the length of the at least one level surface (29, 29 '; 129) along the level track (K1, K2, K3) is more than five times, preferably more than eight times, particularly preferably more than twelve times, the is orthogonal to the level track (K1, K2, K3) to be measured width (b). Vessel arrangement (10; 110) according to Claim 1 or 2 , characterized in that the vessel arrangement (10; 110) is assigned a reference plane (BE) which is orthogonal to the depth axis (TA) and which touches a cavity floor (35; 135) at its deepest point and which is used for determining one in the vessel arrangement (10 ; 110) the amount of liquid absorbed is to be oriented orthogonally to the direction of the action of gravity (g). Vessel arrangement (10) according to one of the preceding claims, characterized in that the cavity (16) has at least one cavity channel section (22, 24, 26) which extends along the depth axis (TA) into the vessel body (14) and which extends longitudinally the level track (K1, K2, K3) runs, with a surface of a cavity channel bottom (28, 28 ') of the cavity channel section (22, 24, 26) facing in the direction of the cavity (16) being the level surface (29, 29') . Vessel arrangement (10) according to Claim 4 , characterized in that the cavity channel section (22, 24, 26) along the level track (K1, K2, K3) at least over the local mean cavity height section (kh) preferably has a large part of its depth extension (f) to be measured along the depth axis (TA) also has a constant width (b) orthogonal to both the level track (K1, K2, K3) and the depth axis (TA), at least over a large part of its length. Vessel arrangement (10; 110) according to one of the preceding claims, characterized in that the level trace (K1, K2, K3) has a curved course, preferably has a multiple curved course, optionally has a multiple curved course with locally different curvatures. Vessel arrangement (10; 110) according to one of the preceding claims, characterized in that the vessel arrangement (10; 110) has a plurality of level surfaces (29, 29 '; 129), each of which along its to the common depth axis (TA) orthogonal individual level trace (K1, K2, K3) runs. Vessel arrangement (10; 110) according to one of the preceding claims, characterized in that the at least one level surface (29, 29 '; 129) is physically bounded in its width direction in at least one width end area by an adjoining wall surface (19; 119) is. Vessel arrangement (10) according to Claim 7 or 8th , including the Claims 3 and 4th , characterized in that the vessel arrangement (10) has a plurality of cavity channel sections (22, 24, 26) communicating with one another fluid-mechanically, each of which extends into the vessel body (14) along a common depth axis (TA) extends into it, each of which runs along its individual level track (K1, K2, K3) orthogonal to the common depth axis (TA), the cavity channel bottoms (28, 28 ') of the respective cavity channel sections (22, 24, 26) being inclined or / and are curved so that the distance (a, A) between the level surfaces (29, 29 ') formed by the cavity channel bottoms (28, 28') along the respective individual level track (K1, K2, K3) starting from a connection point of the cavity channel sections ( 22, 24, 26) becomes larger. Vessel arrangement (10; 110) according to one of the Claims 7 until 9 , characterized in that the level surfaces (29, 29 '; 129) of identical shape are rotated relative to one another about an axis of rotation (DA) parallel to the depth axis (TA). Vessel arrangement (10; 110) according to one of the Claims 7 until 10 , characterized in that the plurality of level surfaces (29, 29 '; 129) extends from a common point of origin. Vessel arrangement (10; 110) according to one of the preceding claims, characterized in that the cavity (16; 116) has a reservoir section (20; 120), the at least one level surface (29, 29 '; 129) from the reservoir section ( 20; 120) goes out Vessel arrangement (10) according to Claim 12 , including the Claim 4 , characterized in that the reservoir section (20) has a greater clear width in at least two spatial directions orthogonal both to one another and to the depth axis (TA) than the width orthogonal to both the level track (K1, K2, K3) and the depth axis (TA) (b) the at least one cavity channel section (22, 24, 26) extending from the reservoir section (20). Vessel arrangement (10) according to the Claims 11 and 12th or after the Claims 11 until 13th , characterized in that the reservoir portion (20; 120) is formed at the origin. Vessel arrangement (10; 110) according to one of the preceding claims, characterized in that the vessel body (14; 114) is a plate (12) whose thickness direction (D) runs parallel to the depth axis (TA). Vessel arrangement (10; 110) according to Claim 15 , characterized in that the plate (12) has a plurality of cavities (16; 116) formed separately from one another and arranged next to one another. Vessel assembly (10, 46) comprising a vessel arrangement (10; 110) according to one of the preceding claims and further comprising a carrier arrangement (46) on which the vessel arrangement (10; 110) with a depth axis (TA) parallel to the direction of gravity (g) is received is. Method for determining an amount of liquid using a vessel assembly (10, 46) according to Claim 17 , comprising the following steps: - Filling the amount of liquid into a cavity (16; 116) of the vessel assembly (10, 46), - image recording of a free surface (36), wherein the free surface is a liquid surface (36) in the cavity (16 ; 116) comprises the spread out amount of liquid and / or a surface of a section of the at least one level surface (29, 29 '; 129) not wetted by the amount of liquid, - determining the wetting situation by determining a location of a wetting limit (29c) of a level surface ( 29, 29 '; 129) and / or determining a length of a wetted section (29a) of the at least one level surface (29, 29'; 129) and / or a length of an unwetted section (29b) of the at least one level surface (29, 29 '; 129) along the level track (K1, K2, K3) from the visual acquisition, - determining a value representing the volume of the amount of liquid from the determined location of the wetting limit (29c) and / or from the determined length in the cavity on the basis of stored data relating to the shape of the cavity (16; 116). Procedure according to Claim 18 , wherein the vessel assembly (10, 46) comprises a vessel arrangement (10; 110) with the features of Claim 7 comprising the following further steps: determining a respective wetting limit (29c) of a plurality of level surfaces (29, 29 '; 129) and / or determining a length of a wetted section (29a) of a plurality of level surfaces (29 , 29 '; 129) and / or a respective length of an unwetted section (29b) of a plurality of level surfaces (29, 29'; 129) along the level track ( K1, K2, K3) from the visual acquisition, - compare the determined locations of the wetting limits (29c) and / or the determined lengths with each other, - depending on the comparison result, discard the image acquisition or determine a value representing the volume of the amount of liquid from the determined locations the wetting limits and / or the determined lengths of the liquid surface (36). Procedure according to Claim 18 or 19th , wherein the vessel assembly (10, 46) comprises a vessel arrangement (10; 110) with the features of Claim 7 comprising the following further steps: determining a respective wetting limit (29c) of a plurality of level surfaces (29, 29 '; 129) and / or determining a length of a wetted section (29a) of a plurality of level surfaces (29 , 29 '; 129) and / or a respective length of an unwetted section (29b) of a plurality of level surfaces (29, 29'; 129) along the level track ( K1, K2, K3) from the visual acquisition, - compare the determined locations of the wetting limits (29c) and / or the determined lengths with each other, - depending on the comparison result: Determine a value that shows a deviation of the position of the depth axis (TA) from the Indicates the direction of gravity (g). Procedure according to Claim 20 , comprising the following further step: output of a message which qualitatively and / or quantitatively indicates the position of the depth axis (TA). Procedure according to Claim 20 or 21 , comprising the following further step: correcting a value determined from the determined lengths which represents the volume of the amount of liquid on the basis of the comparison result. A pipetting device (40) comprising: - a pipetting channel (50) in which a liquid can be aspirated and from which a liquid can be dispensed, - a control device (62) for controlling an aspiration and a dispensing of liquid into the pipetting channel (50) or from the pipetting channel (50), - a vessel assembly (10, 46) after Claim 17 , and - an image acquisition device (52) for the image acquisition of the vessel arrangement (10; 110) of the vessel assembly (10, 46) along the depth axis (TA) of the vessel arrangement (10; 110), characterized in that the pipetting device (40) for execution of the procedure according to one of the Claims 18 until 23 is trained.

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