Ultrasonic measuring devices and systems for measuring flowing fluids

Abstract

An ultrasonic measuring device for measuring a flowing fluid is proposed, the ultrasonic measuring device having a measuring tube with a central axis defining a flow direction for the fluid, the ultrasonic measuring device having a first chamber in which a first ultrasonic transducer is arranged, and having a second chamber in which a second ultrasonic transducer is arranged, wherein the measuring tube has an inlet and an outlet for the fluid, wherein the first ultrasonic transducer and the second ultrasonic transducer define a rectilinear measuring section for the fluid, wherein the first chamber and the second chamber are designed and arranged such that the fluid can flow around each of them, and wherein the first ultrasonic transducer and the second ultrasonic transducer are arranged such that the measuring section extends in the flow direction. Furthermore, the invention proposes a method for manufacturing such an ultrasonic measuring device.

Description

Technical Field

[0001] The invention relates to an ultrasonic measuring device for measuring a flowing fluid and to an ultrasonic measuring system. Background Art

[0002] Ultrasonic measuring devices for measuring flowing fluids are used, for example, to determine the flow of a fluid through a pipe, such as a flexible or rigid plastic hose. In particular for flexible hoses, it is a well-known measure to design the measuring device as a clamping device so that it can be clamped onto a flexible pipe or the pipe is clamped by the measuring device. An ultrasonic signal is then applied to the pipe in which the fluid flows. After passing through the pipe and the fluid, the ultrasonic signal is received by the ultrasonic transducer and the received signal is evaluated.

[0003] There are also ultrasonic measuring devices through which a liquid flows. Such measuring devices have a measuring tube with an inlet for the fluid and an outlet for the fluid. Ultrasonic signals are then applied to the flowing fluid in the measuring device.

[0004] Both types of measuring devices have the advantage that they allow non-invasive measurements of flowing fluids. Such non-invasive methods are particularly used for such high-purity or very sensitive fluids, where contact between the fluid and the measuring device is to be avoided so that, for example, the fluid is not contaminated. The pharmaceutical industry and the biotechnology industry are examples of this. Here, solutions and suspensions are often produced and transported, which place very high demands on the purity and / or integrity of the fluid. In many cases, such fluids even have to be handled under sterile conditions. However, these non-invasive methods are also preferably used for the measurement of chemically aggressive fluids (e.g. acids), for example in the semiconductor industry.

[0005] Especially for the measurement of very sensitive or very aggressive materials, the cleaning or sterilization of measuring device represents a very large expenditure of time, material and cost. Therefore, it is necessary to design the parts in contact with the material as disposable parts for disposable use. When designed for disposable use, those parts in contact with the treated fluid are preferably used only once, and then replaced with new (i.e. unused) disposable parts, for the next application. When manufacturing or designing the disposable parts, an important criterion is that they can be assembled with other parts of the measuring device in the simplest possible way. It is expected that this assembly and of course separation can be implemented with as little effort as possible, only requiring a few hand movements, fast and preferably without tools.

[0006] Ultrasonic measuring devices which are particularly suitable for non-invasive measurement of high-purity or aggressive substances are offered and distributed by the applicant both as a clamping device and as a flow-through measuring device with a measuring tube under the trade name LEVIFLOW. Both designs operate essentially according to the same principle. In both designs at least two ultrasonic transducers are provided, each of which can emit and receive ultrasonic signals.

[0007] The ultrasonic transducers are arranged and aligned so that one ultrasonic transducer transmits a signal that is aligned obliquely to or along the flow direction, while the other ultrasonic transducer transmits a signal that is aligned obliquely against or against the flow direction. Then, a measurement signal is transmitted by the first ultrasonic transducer and received by the second ultrasonic transducer. Subsequently, a measurement signal is transmitted by the second ultrasonic transducer and received by the first ultrasonic transducer.

[0008] The measurement signal emitted obliquely in the flow direction or emitted in the flow direction is accelerated in the flow, and the measurement signal emitted obliquely against the flow direction or emitted against the flow direction is decelerated by the flow. The transmission time difference between the two measurement signals is proportional to the flow velocity of the fluid, so that the flow rate through the pipeline can be determined based on the transmission time difference.

[0009] Both designs have their own advantages and disadvantages. In the case where the device is designed as a clamping device, the first ultrasonic transducer is arranged on one side of the clamped pipe and the second ultrasonic transducer is arranged on the other side of the pipe. The two ultrasonic transducers are offset relative to the flow direction of the fluid and aligned so that the first ultrasonic transducer can receive the signal emitted by the second ultrasonic transducer and the second ultrasonic transducer can receive the signal emitted by the first ultrasonic transducer. Due to the offset from each other, the two ultrasonic transducers are aligned so that they each transmit their ultrasonic signals obliquely to the flow direction of the fluid, one of the ultrasonic transducers transmits the signal obliquely with the flow direction, and the other ultrasonic transducer transmits the signal obliquely against the flow direction.

[0010] This design has the advantage that the fluid flow in the pipe is virtually unaffected. The pipe is straight. The flow is essentially free of turbulence and cavitation, and there are no corners or peripheral areas where fluid stagnation, condensation or other deposits may occur. In addition, the clamping device can be designed to be very compact and space-saving. The disadvantage of this design is that the ultrasonic signal must be introduced into the fluid at an angle relative to the flow direction. The angle at which the ultrasonic signal propagates in the fluid after penetrating the pipe wall depends on the properties of the fluid, which can cause problems when detecting the ultrasonic signal. In addition, in this design, the measuring section is relatively short, which leads to a low time resolution.

[0011] In designs in which the measuring device has a measuring tube through which the fluid flows, the measuring tube usually has a U-shaped or Z-shaped configuration. An inlet tube arranged at right angles to the central part and an outlet tube also arranged at right angles to the central part are provided. If the inlet tube is arranged on the same side as the outlet tube, a U-shaped design of the measuring tube is obtained. If the inlet tube is arranged on the opposite side of the outlet tube, a Z-shaped design of the measuring tube is obtained. Two ultrasonic transducers are then arranged on the outside of the measuring tube, one of which is arranged at one end of the central part of the measuring tube and the other at the other end of the central part. The central part of the measuring tube thus serves as a measuring section.

[0012] This design has the advantage that the two ultrasonic transducers can be arranged exactly at right angles to the measuring section. As a result, the ultrasonic signal can each be introduced into the measuring tube exactly in the flow direction of the fluid or exactly against the flow direction of the fluid. In this way, it can be ensured that the angle at which the ultrasonic signal propagates in the measuring tube is independent of the acoustic properties of the fluid. In addition, this design has the advantage that the measuring section can be made much longer than the clamping device. A longer measuring section has the advantage that the temporal resolution of the measurement is increased.

[0013] The disadvantage of this design is that the fluid is deflected twice, by 90°, when passing through the measuring tube, i.e. at the transition from the inlet tube to the central section and at the transition from the central section to the outlet tube. This double deflection leads to turbulence and cavitation in the fluid, as well as stagnation or even sedimentation of the fluid, especially in the critical corner areas of the measuring tube. For biological fluids, caking or condensation may also occur. These effects particularly reduce the accuracy and reliability of the measurement. Another disadvantage of this design is its space requirement. The double bend of the measuring tube requires much more space for the measuring device.

[0014] Although these two designs of ultrasonic measuring devices have proven themselves very well in practice, there is still room for improvement in view of increasingly higher requirements, for example with regard to measuring accuracy or the flexibility of the measuring devices. Summary of the invention

[0015] Starting from the prior art, the object of the present invention is therefore to propose an ultrasonic measuring device for measuring a flowing fluid, which allows a very accurate determination of the flow velocity. In particular, the device should be able to efficiently introduce ultrasonic signals into the fluid, while at the same time significantly reducing turbulence and stagnation in the fluid. Furthermore, the object of the present invention is to propose an ultrasonic measuring system with such an ultrasonic measuring device, wherein in particular certain components of the ultrasonic measuring system are designed for single use.

[0016] The object of the invention is solved by an ultrasonic measuring system.

[0017] According to the present invention, an ultrasonic measuring device for measuring a flowing fluid is proposed, the ultrasonic measuring device comprising: a measuring tube having a central axis defining a flow direction of the fluid; a first chamber in which a first ultrasonic transducer is arranged; and a second chamber in which a second ultrasonic transducer is arranged, wherein the measuring tube has an inlet and an outlet for the fluid, wherein the first ultrasonic transducer and the second ultrasonic transducer define a straight measuring section for the fluid, wherein the first chamber and the second chamber are designed and arranged so that the fluid can flow around each of them, and wherein the first ultrasonic transducer and the second ultrasonic transducer are arranged so that the measuring section extends along the flow direction.

[0018] Thus, the two ultrasonic transducers are arranged in the flowing fluid without being in physical contact with the fluid, since the ultrasonic transducers are arranged in chambers such that the fluid in the measuring tube flows around the chambers with the ultrasonic transducers without being able to penetrate into these chambers.

[0019] Therefore, the ultrasonic measuring device according to the invention enables, on the one hand, the measuring signals to be introduced into the fluid in the flow direction or against the flow direction, wherein the measuring signals are not introduced obliquely with respect to the flow direction, but their main propagation direction forms an angle of 0° or 180° with the flow direction. Therefore, the angle at which the corresponding measuring signal propagates in the fluid no longer depends on the acoustic properties of the fluid. Each measuring signal propagates in the flow direction of the fluid or against the flow direction of the fluid, regardless of the acoustic properties of the fluid. Due to the fact that the measuring signal propagates in the flow direction of the fluid or against the flow direction of the fluid, the measuring section can also be made particularly long, resulting in a very high time resolution of the corresponding measurement.

[0020] In addition, the fluid in the measuring tube is not deflected at right angles, ie the fluid flow in the measuring tube is only slightly affected, if at all. In particular, the measuring tube has no corners or other critical areas that would cause significant stagnation, turbulence or sedimentation of the fluid.

[0021] Furthermore, the ultrasonic measuring device according to the invention can be designed in a particularly space-saving manner, since no inlet or outlet pipe is required, which is arranged at an angle of approximately 90° to the measuring section. Both the inlet and the outlet of the measuring tube can be arranged on the central axis of the measuring tube.

[0022] Preferably, the first chamber and the second chamber are arranged in the measuring tube between the inlet and the outlet.

[0023] A further preferred measure is that the first ultrasonic transducer and the second ultrasonic transducer are arranged on the central axis of the measuring tube. This means that the fluid flows symmetrically around the two ultrasonic transducers, resulting in a particularly low influence on the fluid flow.

[0024] According to a preferred embodiment, the measuring tube has a flow cross section for the fluid between the first ultrasonic transducer and the second ultrasonic transducer which is smaller than the flow cross section at the inlet of the measuring tube. Due to this measure, the fluid flows over the measuring section at a higher speed than at the inlet of the measuring tube. In particular, the time resolution of the measurement can be increased with higher flow velocities, since the difference in the transmission time of the measurement signal in the flow direction and against the flow direction becomes greater.

[0025] According to a further preferred embodiment, the measuring tube has a substantially constant flow cross section for the fluid between the first ultrasonic transducer and the second ultrasonic transducer. With this embodiment, turbulence or stagnation of the fluid in the measuring tube can be reduced particularly efficiently.

[0026] In particular, it is preferred that the first chamber is arranged closer to the inlet and the second chamber is arranged closer to the outlet, wherein the first chamber has a first flow guiding element on its side facing the inlet for reducing turbulence, and / or wherein the second chamber has a second flow guiding element on its side facing the outlet for reducing turbulence. The fluid flow in front of the first chamber is divided by the first flow guiding element particularly smoothly into two partial flows, which flow around the first chamber on both sides without causing significant turbulence or forming stagnant areas. In a similar manner, the second flow element ensures that the two partial flows flowing around the second chamber are brought together again as smoothly as possible downstream of the second chamber without causing significant turbulence or forming stagnant areas.

[0027] According to a preferred embodiment, the measuring section has a first end at the first ultrasonic transducer and a second end at the second ultrasonic transducer, wherein an acoustic lens for focusing the ultrasonic signal is respectively arranged at each end of the measuring section. Due to this measure, the measurement accuracy can be even further improved.

[0028] In order to influence the fluid flow in the measuring tube as little as possible and to reduce or even avoid turbulence and stagnant areas as much as possible, it is advantageous if the first chamber and the second chamber each have a substantially teardrop-shaped contour in the flow direction. In this way, the two chambers are particularly streamlined.

[0029] A further preferred measure is that the ultrasonic measuring device also comprises a temperature sensor for determining the temperature of the fluid. This expands the application range of the measuring device, since parameters of the fluid whose relationship to the speed of sound or the sound attenuation depends on the temperature can also be determined.

[0030] It may also be advantageous if a third ultrasonic transducer and a fourth ultrasonic transducer are arranged on the measuring tube, wherein the third ultrasonic transducer and the fourth ultrasonic transducer are arranged relative to one another and are each arranged and aligned perpendicularly to the flow direction for emitting the ultrasonic signal for emitting the ultrasonic signal. This means that in the third and fourth ultrasonic transducers, the respective emitting and receiving surfaces for the ultrasonic signal are aligned parallel to the flow direction, so that the main propagation direction of the ultrasonic signal generated by the third and fourth ultrasonic transducer is each perpendicular to the flow direction. Thus, the third and fourth ultrasonic transducers can advantageously be used to determine the speed of sound in the fluid independently of the flow velocity of the fluid and thus to determine fluid parameters that depend on the speed of sound or the sound attenuation in the fluid.

[0031] In a preferred embodiment, the ultrasonic measuring device is designed as a disposable part for single use.

[0032] Furthermore, a method for producing an ultrasonic measuring device according to the invention is proposed, in which method the measuring tube, the first chamber and the second chamber are produced from plastic.

[0033] According to a preferred embodiment, the measuring tube and the two chambers are produced in one piece in a single blow-molding process.

[0034] According to a further preferred embodiment, the measuring tube and the two chambers consist of a plurality of individual parts, wherein each individual part is produced in an injection molding process and the individual parts are subsequently joined together, preferably welded together.

[0035] It is particularly preferred if the measuring tube and the two chambers are formed from exactly two separate parts which are produced separately and are then welded together.

[0036] Furthermore, the present invention proposes an ultrasonic measuring system for measuring a flowing fluid, the ultrasonic measuring system having a disposable device designed for single use, a reusable device designed for multiple uses, a first ultrasonic transducer, and a second ultrasonic transducer.

[0037] The disposable device includes a measuring tube, a first chamber and a second chamber, wherein the measuring tube has a central axis that defines a fluid flow direction, wherein the first chamber is designed to transmit a signal of a first ultrasonic transducer, wherein the second chamber is designed to transmit a signal of a second ultrasonic transducer, wherein the measuring tube also has an inlet and an outlet for the fluid, wherein the first chamber and the second chamber define a straight measurement section for the fluid extending from the first chamber to the second chamber, wherein the first chamber and the second chamber are designed and arranged so that the fluid can flow around each of them, and the measurement section extends along the flow direction.

[0038] The reusable device includes a control device designed to actuate the ultrasonic transducer and receive signals from the ultrasonic transducer.

[0039] The reusable set is removably connectable to the disposable set such that the reusable set and the disposable set are fixed relative to each other.

[0040] According to the invention, an ultrasonic measuring system is thus proposed, which comprises a disposable device which can be used only once as intended and has to be replaced by a new, i.e. unused, disposable device for the next application and a reusable device designed for multiple use. Furthermore, a first and a second ultrasonic transducer are provided which, depending on their design, can be part of the disposable device or part of the reusable device.

[0041] Preferably, the ultrasonic measuring system comprises an ultrasonic measuring device according to the invention. Embodiments are also possible in which the first and second ultrasonic transducers are not arranged directly in the first and second chambers, respectively, but the signals of the two ultrasonic transducers are coupled into the two chambers, which is effective similarly to the arrangement of the ultrasonic transducers in the chambers.

[0042] In order to ensure that the connection between the disposable set and the reusable set is as easy to handle as possible, it is preferred that the disposable set and the reusable set can be connected together by means of a clip connection.

[0043] Furthermore, it is preferred that the reusable device comprises a protrusion that engages in a recess of the disposable device when assembled with the disposable device. The protrusion and recess are preferably designed for a form-locking fit so that the disposable device can be easily placed on or removed from the reusable device.

[0044] Preferably, the first ultrasonic transducer and the second ultrasonic transducer are part of a disposable device, ie are also designed for single use.

[0045] According to the present invention, a disposable device for an ultrasonic measurement system designed according to the present invention is further proposed.

[0046] Further advantageous measures and embodiments of the invention emerge from the following detailed description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] The invention is explained in more detail below in terms of apparatus and process technology with reference to exemplary embodiments and the accompanying drawings. The drawings show:

[0048] Figure 1: A schematic cross-sectional view of a first embodiment of an ultrasonic measuring device according to the present invention;

[0049] Figure 2 : A schematic cross-sectional view of a second embodiment of an ultrasonic measuring device according to the present invention;

[0050] Figure 3 : A schematic cross-sectional view of a third embodiment of an ultrasonic measuring device according to the present invention;

[0051] Figure 4 : A schematic cross-sectional view of a fourth embodiment of an ultrasonic measuring device according to the present invention;

[0052] Figure 5 : Representation of variations of acoustic lens design;

[0053] Figure 6 : A schematic cross-sectional view of a fifth embodiment of an ultrasonic measuring device according to the present invention;

[0054] Figure 7 : A perspective representation of a fifth embodiment,

[0055] Figure 8 : A schematic cross-sectional view of a first variation of the fifth embodiment;

[0056] Fig. 9 : A schematic cross-sectional view of a second variation of the fifth embodiment;

[0057] Fig.10 : A perspective representation of an embodiment of an ultrasonic measuring device according to the invention, which is manufactured in one piece,

[0058] Figure 11-14 : Different variants of parts of the ultrasonic measuring device according to the invention can be manufactured;

[0059] Fig.15 : A schematic representation of a first embodiment of an ultrasonic measurement system according to the present invention;

[0060] Fig.16 : A perspective representation of a first variant of the first embodiment of the ultrasonic measurement system;

[0061] Fig.17 :Observed from different angles Fig.16 The first variant of;

[0062] Fig.18 : A perspective representation of a second variant of the first embodiment of the ultrasonic measurement system;

[0063] Fig.19 : A perspective exploded view of a preferred embodiment of the disposable device;

[0064] Fig. 20 : From Fig.19 A cross-sectional view of an embodiment of the present invention,

[0065] Fig.21 : Plan view of the chamber insert,

[0066] Fig. 22 : A cross-sectional view of the chamber insert in a section along the flow direction;

[0067] Fig.23 : In a similar Fig. 22 Variations of the chamber insert in the representation;

[0068] Fig.24 : A possible embodiment of a signal connection that enables an electrical connection between a disposable device and a reusable device,

[0069] Fig.25 : Another possible embodiment of a signal connection that enables an electrical connection between a disposable device and a reusable device,

[0070] Fig.26 : Another possible embodiment of a signal connection that enables an electrical connection between a disposable device and a reusable device,

[0071] Fig. 27 : An embodiment of communication between a storage unit of a single-use device and a memory interface of a reusable device,

[0072] Fig.28 : For use from Fig. 27 The two components of the communication,

[0073] Fig.29 : Another embodiment of the communication between the memory interface of the single-use device and the reusable device,

[0074] Fig.30 : A section along the flow direction Fig.29 A cross section of an embodiment of the present invention;

[0075] Fig.31 : Advantageous measures of an embodiment of the disposable device,

[0076] Fig.32 : Further advantageous measures for embodiments of the disposable device,

[0077] Fig.33 : A perspective view of a second embodiment of an ultrasonic measurement system according to the present invention;

[0078] Fig.34: A perspective cross-sectional view of a disposable device according to a second embodiment;

[0079] Fig.35 : Fig.34 A magnified view of the details, and

[0080] Fig.36 : Schematic diagram for explaining the coupling of ultrasonic signals into the measuring section of the second embodiment. DETAILED DESCRIPTION

[0081] Figure 1 A first embodiment of an ultrasonic measuring device according to the invention is shown in a schematic cross-sectional view and is denoted as a whole by reference numeral 1. The ultrasonic measuring device 1 is designed for measuring a flowing fluid and comprises a measuring tube 2 through which the fluid flows. The measuring tube 2 has a central axis M defining a flow direction A of the fluid. In the first embodiment, the measuring tube 2 is designed as a cylindrical straight tube with a circular cross section perpendicular to its central axis M and has a wall 21 that delimits the measuring tube 2 transversely. The measuring tube 2 has an inlet 22 through which the fluid flows into the measuring tube 2 and an outlet 23 through which the fluid leaves the measuring tube 2, as indicated by arrows without reference numerals on the inlet 22 and the outlet 23. The inlet 22 and the outlet 23 are each designed as a circular area, the center of which is each located on the central axis M of the measuring tube 2. The measuring tube 2 has a substantially straight (i.e. non-bent and non-angled) design between the inlet 22 and the outlet 23. Due to this linear design of the measuring tube 2, the ultrasonic measuring device 1 has a particularly space-saving shape.

[0082] Furthermore, a first chamber 3 and a second chamber 4 are provided, wherein a first ultrasonic transducer 5 is arranged in the first chamber 3 and a second ultrasonic transducer 6 is arranged in the second chamber 4. The first ultrasonic transducer 5 and the second ultrasonic transducer 6 delimit a rectilinear measuring section 7 for the fluid, which is located between the two ultrasonic transducers 5, 6. Each ultrasonic transducer 5, 6 is designed for respective emission and reception of ultrasonic signals.

[0083] The first chamber 3 and the second chamber 4 are arranged in the measuring tube 2 between the inlet 22 and the outlet 23, wherein the first chamber 3 is arranged closer to the inlet 22, and the second chamber 4 is arranged closer to the outlet 23 of the measuring tube 2. The first chamber 3 and the second chamber 4 are each designed and arranged so that a fluid can flow around each of the two chambers 3 and 4, and the fluid cannot penetrate into the first chamber 3 and the second chamber 4, so that the ultrasonic transducers 5, 6 are not in contact with the fluid.

[0084] The first ultrasonic transducer 5 and the second ultrasonic transducer 6 are arranged and aligned so that they can exchange ultrasonic signals with each other, that is, the second ultrasonic transducer 6 can receive the ultrasonic signal emitted by the first ultrasonic transducer 5, and the first ultrasonic transducer 5 can receive the ultrasonic signal emitted by the second ultrasonic transducer 6. In addition, the ultrasonic transducers 5 and 6 are arranged so that the measurement section 7 extends along the flow direction A. Due to this arrangement, the ultrasonic signals emitted by the two ultrasonic transducers 5 and 6 as measurement signals are introduced into the fluid along the flow direction A or against the flow direction A, rather than being introduced into the fluid obliquely to the flow direction A. Therefore, the main propagation direction of the measurement signal includes an angle of 0° or 180° with the flow direction A. Therefore, the angle at which the corresponding measurement signal propagates in the fluid no longer depends on the acoustic properties of the fluid. Each measurement signal propagates along the flow direction A of the fluid or against the flow direction A of the fluid regardless of the acoustic properties of the fluid.

[0085] In the first embodiment, the first chamber 3 and the second chamber 4 are each designed as an inversion in the wall 21 of the measuring tube 2. Therefore, the first chamber 3 and the second chamber 4 are each a recess in the wall 21 of the measuring tube 2, which points into the interior of the measuring tube 2. The first chamber 3 and the second chamber 4 are each so deep that the first ultrasonic transducer 5 and the second ultrasonic transducer 6 can be arranged on the center axis M of the measuring tube 2. At the same time, the two ultrasonic transducers 5, 6 are protected from contact with the fluid by the wall of the respective chamber 3 or 4.

[0086] The first chamber 3 is delimited on its side facing away from the inlet 22 by a first wall 31 which is designed as a planar (i.e. uncurved) wall and which is perpendicular to the center axis M of the measuring tube 2 and thus perpendicular to the flow direction A. The first ultrasonic transducer 5 is arranged on the first wall 31 in the first chamber 3 so that the main propagation direction of the measurement signal emitted by the first ultrasonic transducer 5 is in the flow direction A. The emitting and receiving surfaces of the first ultrasonic transducer 5 are therefore perpendicular to the center axis M of the measuring tube 2 .

[0087] The second chamber 4 is delimited on its side facing away from the outlet 23 by a second wall 41 which is designed as a planar (i.e. uncurved) wall and which is perpendicular to the center axis M of the measuring tube 2 and thus perpendicular to the flow direction A. The second ultrasonic transducer 6 is arranged on the second wall 41 in the second chamber 4 so that the main propagation direction of the measurement signal emitted by the second ultrasonic transducer 6 is opposite to the flow direction. The emission and receiving surface of the second ultrasonic transducer 6 is therefore perpendicular to the center axis M of the measuring tube 2.

[0088] The measuring tube 2 is designed to have a constant cross-sectional area perpendicular to the center axis M at least between the first wall 31 of the first chamber 3 and the second wall 41 of the second chamber 4, so that the flow cross section of the fluid between the first ultrasonic transducer 5 and the second ultrasonic transducer 6 is at least substantially constant, and preferably constant. With this design, turbulence or even stagnation of the fluid on the measuring section 7 between the first ultrasonic transducer 5 and the second ultrasonic transducer 6 can be reduced or even avoided particularly efficiently. The flow cross section refers to the size of the available area of ​​the fluid perpendicular to its flow direction. In the design according to the first embodiment, the flow cross section is constant along the measuring section and corresponds to a circular area of ​​the cylindrical measuring tube 2 perpendicular to the center axis A.

[0089] The design of the ultrasonic measuring device 1 has the associated advantage that the ultrasonic signal used as measuring signal can be introduced into the fluid at an angle of 0° or 180° to the flow direction A, i.e. in particular not inclined, and at the same time a particularly space-saving design of the ultrasonic measuring device 1 is possible, since a U-shaped or Z-shaped design of the ultrasonic measuring device can be omitted.

[0090] Since the measuring section 7 extends in the flow direction A, the measuring section 7 can also be designed to be much longer than in an arrangement in which the measuring section is arranged obliquely with respect to the flow direction or at an angle to the flow direction. A long measuring section 7 has the advantage that it allows a much higher time resolution and therefore a higher measurement accuracy.

[0091] Each ultrasonic transducer 5, 6 is signal-connected to a control device (not shown) in a manner known per se via a corresponding signal line (not shown). The control device controls the ultrasonic transducers 5, 6 to transmit ultrasonic signals via corresponding signal lines and receives signals received by the ultrasonic transducers 5, 6. The measurement signals received by the ultrasonic transducers 5, 6 are transmitted to an evaluation unit (not shown), which can be integrated in the control device. The received measurement signals are analyzed and evaluated in the evaluation unit. Preferably, at least the flow velocity of the fluid is determined in the evaluation unit, and thus the flow rate of the fluid is determined. The control device and the evaluation unit can also be integrated in a regulating device that regulates the flow of the fluid.

[0092] The ultrasonic transducers 5 , 6 can be designed in any manner known per se, in particular as piezoelectric transducers. The frequency of the ultrasonic signal is usually in the megahertz range, for example in the range from 1 MHz to 30 MHz.

[0093] The first ultrasonic transducer 5 and the second ultrasonic transducer 6 are arranged such that the first ultrasonic transducer 5 can transmit a first measurement signal to the second ultrasonic transducer 6 along the flow direction A and can receive a second measurement signal transmitted by the second ultrasonic transducer 6 against the flow direction.

[0094] The direction of the ultrasonic signal means the main propagation direction of the ultrasonic signal emitted by the corresponding ultrasonic transducer 5, 6. The main propagation direction is usually perpendicular to the surface of the piezoelectric element, which forms the transmitting and receiving surface of the corresponding ultrasonic transducer 5, 6.

[0095] In order to determine the flow rate of a fluid, the measuring tube 2 is installed in the flow path of the fluid so that the fluid flows into the measuring tube 2 through the inlet 22 and leaves the measuring tube 2 through the outlet 23 .

[0096] The first ultrasonic transducer 5 emits a first measuring signal, which is emitted in the flow direction A, ie parallel to the center axis M of the measuring tube 2. After passing through the measuring section 7, the first measuring signal is received by the second ultrasonic transducer 6 and transmitted to an evaluation unit.

[0097] The second measurement signal is emitted by the second ultrasonic transducer 6 , wherein the second measurement signal is also emitted parallel to the central axis M of the measuring tube 2 but counter to the flow direction A. After passing through the measuring section 7 , the second measurement signal is received by the first ultrasonic transducer 5 and transmitted to an evaluation unit.

[0098] The transit time difference between the first measurement signal and the second measurement signal, i.e. the transit time difference between the measurement signal accelerated by the flowing fluid and the measurement signal decelerated by the flowing fluid, is determined in the evaluation unit. The transit time difference between the measurement signal in the flow direction A and the measurement signal counter to the flow direction A depends directly on the flow velocity of the fluid in the measuring tube 2. Therefore, the flow velocity of the fluid through the measuring tube 2 and thus the flow rate can be determined from the transit time difference.

[0099] Apart from the length of the measuring section 7, it is particularly advantageous if the measuring tube 2 does not have any bends but is essentially straight. The cylindrical design of the measuring tube 2 at least between the first chamber 3 and the second chamber 4 is of course not mandatory. Of course, the measuring tube 2 can also be designed with a rectangular or square cross section perpendicular to its center axis M. The flow cross section on the measuring section 7 is then a rectangular or square area in the section perpendicular to the center axis M. It is also not necessary at all for the shape of the cross section of the measuring tube 2 to be constant over the entire measuring tube 2. For example, in Figures 12 to 14 , an embodiment of a measuring tube 2 is shown, wherein the measuring tube 2 has a circular area as a cross section perpendicular to the center axis M at the inlet 22 and the outlet 23, respectively, and has a rectangular or square cross section perpendicular to the center axis M in the area between the first chamber 3 and the second chamber 4.

[0100] Figure 2 Similar to Figure 1The representation of shows a schematic cross-sectional view of a second embodiment of an ultrasonic measuring device 1 according to the invention. In the following description of the second embodiment, only the differences from the first embodiment are discussed in more detail. In other respects, the explanations on the first embodiment also apply to the second embodiment in the same way or in a similar way. In the second embodiment, the same parts or parts with the same function as in the first embodiment are denoted by the same reference numerals.

[0101] The second embodiment of the ultrasonic measuring device 1 according to the invention differs from the first embodiment mainly in the design of the first and second chambers 3 or 4. In the second embodiment, the first chamber 3 and the second chamber 4 are each designed so that they extend completely through the measuring tube 2 as a channel, wherein the longitudinal extension of each chamber 3, 4 is perpendicular to the central axis M of the measuring tube 2. Therefore, each chamber 3, 4 forms a column, which is arranged in the measuring tube 2 perpendicular to the central axis M and each extends completely through the measuring tube 2 and the wall 21 delimiting the measuring tube 2. Each chamber 3, 4 is protected from fluid penetration by the wall delimiting it perpendicular to the central axis M. In a cross section along the central axis M - as shown in FIG. Figure 2 As shown—each chamber 3 , 4 has a rectangular cross-sectional area. In particular, the first wall 31 of the first chamber 3 and the second wall 41 of the second chamber 4 are each again designed as a planar (ie non-curved) wall, which is perpendicular to the center axis M of the measuring tube 2 .

[0102] Figure 3 Similar to Figure 2 A schematic cross-sectional view of a third embodiment of an ultrasonic measuring device 1 according to the present invention is shown in a manner of FIG. 1 . In the following description of the third embodiment, only the differences from the preceding embodiments will be discussed in more detail. In other respects, the explanations on the preceding embodiments also apply to the third embodiment in the same manner or in a similarly same manner. In the third embodiment, the same parts or parts having the same functions as in the preceding embodiments are denoted by the same reference numerals.

[0103] The third embodiment of the ultrasonic measuring device 1 according to the present invention is similar to the second embodiment ( Figure 2 ) is designed in a similar manner to the first ultrasonic transducer 5 and the second ultrasonic transducer 6. However, in the third embodiment, the measuring tube 2 is designed with a tapered region 25, which is arranged between the first chamber 3 and the second chamber 4 as viewed in the flow direction A. In the tapered region 25, the measuring tube 2 has a smaller flow cross section than at the inlet 22, where the measuring tube 2 has a larger flow cross section. This means that the flow cross section of the measuring tube 2 for the fluid between the first ultrasonic transducer 5 and the second ultrasonic transducer 6 is smaller than the flow cross section at the inlet 22.

[0104] Downstream of the second chamber 4 and in particular at the outlet 23, the measuring tube 2 again has a larger flow cross section than in the tapering region 25. Preferably, the flow cross section of the measuring tube 2 at the outlet 23 is of the same size as at the inlet 22. Viewed in the flow direction A, the measuring tube 2 has a larger flow cross section at the inlet, then tapers to a smaller flow cross section in the region of the first chamber 3, and then widens again in the region of the second chamber 4 to a larger flow cross section, which the measuring tube 2 also has at the outlet 22.

[0105] This embodiment has the advantage that the fluid in the tapered region 25 and therefore on the measuring section 7 has a higher flow velocity than at the inlet 22 of the measuring tube 2. Due to this measurement, the difference in the transmission time between the measurement signal accelerated by the flowing fluid and the measurement signal decelerated by the flowing fluid can be increased. This means that the resolution of the advantageous measurement is higher.

[0106] Figure 4 Similar to Figure 3 The representation of shows a fourth embodiment of an ultrasonic measuring device 1 according to the invention in a schematic cross-sectional view. In the following description of the fourth embodiment, only the differences from the previous embodiment will be discussed in more detail. In other respects, the explanations on the previous embodiment also apply to the fourth embodiment in the same way or in a similarly same way. In the fourth embodiment, the same parts or parts with the same function as in the previous embodiment are denoted by the same reference numerals.

[0107] The fourth embodiment of the ultrasonic measuring device 1 according to the present invention is similar to the third embodiment ( Figure 3 ), but can of course also be designed in a similar manner to the first embodiment ( Figure 1 ) or the second embodiment ( Figure 2 ) is designed in a similar manner, i.e. without the tapered region 25.

[0108] In a fourth embodiment of the ultrasonic measuring device 1 according to the invention, the first chamber 3 has, on its side facing the inlet 22, a first flow guiding element 51 which is designed such that it divides the fluid flow in front of the first chamber 3 (viewed in the flow direction A) as gently as possible into two partial flows S1 and S2, one of which, the partial flow S1, is directed upward around the first chamber 3 according to this representation, and the other, the partial flow S2, is directed downward around the first chamber 3 according to this representation. For this purpose, the first flow guiding element 51 has, for example, a triangular cross section when viewed in the flow direction A, and in particular an isosceles triangle cross section, the tip of which faces the inlet 22 and the base of which is flush with the first chamber 3. Due to this design, the fluid is divided into two substantially equally strong partial flows S1, S2, and undesirable flow phenomena, such as turbulence, cavitation or the formation of stagnant areas, can at least be significantly reduced. The triangular design of the first flow guiding element 51 should be understood as an example. Other streamlined embodiments are also possible, with which the fluid flow can be divided as gently as possible into the two partial flows S1 and S2 .

[0109] Preferably, the second chamber 4 has, on its side facing the outlet 23, a second flow guiding element 52 which is designed such that it merges the two partial flows S1 and S2 as gently as possible behind the second chamber 4 when viewed in the flow direction A. For this purpose, the second flow guiding element 52—in a similar manner to the first flow guiding element 51—has, when viewed in the flow direction A, for example a triangular cross section, and in particular an isosceles triangle cross section, the tip of which faces the outlet 23 and the base of which is flush with the first chamber 4.

[0110] As a further optional measure, one or more acoustic lenses 61, 62 may be provided to focus the ultrasonic signal or the measurement signal. These acoustic lenses 61 and / or 62 may of course also be provided for other embodiments.

[0111] exist Figure 4In the fourth embodiment shown, a total of two acoustic lenses 61, 62 are provided, namely one at each end of the measuring section 7. The measuring section 7 has a first end at the first ultrasonic transducer 5 and a second end at the second ultrasonic transducer 6. The first acoustic lens 61 is arranged at the first end of the measuring section 7 and the second acoustic lens 62 is arranged at the second end of the measuring section 7. The first acoustic lens 61 is preferably arranged externally on the first wall 31 of the first chamber 3 and the second acoustic lens 62 is preferably arranged externally on the second wall 41 of the second chamber 4. Both acoustic lenses 61 and 62 can be designed in a manner known per se so that they focus or parallelize the emitted ultrasonic signals and direct the ultrasonic signals to be received to the respective ultrasonic transducers 5, 6. Preferably, the acoustic lenses 61, 62 are each designed in the same manner similar to the flow guiding elements 51, 52 so that they separate the fluid flows as gently as possible (second acoustic lens 62) or merge the fluid flows as gently as possible (first acoustic lens 61), so that turbulence in the fluid flows is at least reduced. The triangular embodiment of the acoustic lenses 61, 62 is to be understood as an example. Other embodiments are also possible, such as convex and concave curves, with which the ultrasound signal can be focused or parallelized.

[0112] In the fourth embodiment, the two acoustic lenses 61 , 62 are each designed to have a triangular cross section, in particular, an isosceles triangle cross section, when viewed along the flow direction A. The acoustic lenses 61 , 62 are arranged so that the tips of the two isosceles triangles are opposite to each other and their bases are flush with the first wall 31 or the second wall 41 .

[0113] Preferably, the two acoustic lenses 61, 62 are made of a material having the same acoustic properties as the fluid, so that the angle along the main propagation direction of the ultrasonic signal does not change at the corresponding boundary surface between the acoustic lens 61 or 62 and the fluid.

[0114] Figure 5 FIG. 6 shows a variation of the design of two acoustic lenses 61 and 62. In this variation, the two legs of the isosceles triangle cross section of each acoustic lens 61 and 62 each have a stepped structure 65, so that Figure 5 Each ultrasonic signal or each measurement signal represented by a dotted arrow without a reference numeral hits a boundary surface between the acoustic lenses 61, 62 perpendicular to the main propagation direction of the signal, so that the angle of signal propagation does not change at the boundary surface.

[0115] Figure 6 Similar to Figure 4The representation of shows a fifth embodiment of an ultrasonic measuring device 1 according to the invention in a schematic cross-sectional view. In the following description of the fifth embodiment, only the differences from the preceding embodiments will be discussed in more detail. In other respects, the explanations on the preceding embodiments also apply to the fifth embodiment in the same way or in a similarly same way. In the fifth embodiment, the same parts or parts having the same function as in the preceding embodiments are denoted by the same reference numerals.

[0116] For better understanding, Figure 7 Furthermore, a perspective view of a fifth exemplary embodiment of an ultrasonic measuring device 1 according to the invention is shown.

[0117] In a fifth embodiment of the ultrasonic measuring device 1 according to the invention, the first chamber 3 and the second chamber 4 are each designed such that the first flow guiding element 51 is an integral part of the first chamber 3 and the second flow guiding element 52 is an integral part of the second chamber 4 .

[0118] For this purpose, the first chamber 3 and the second chamber 4 are each designed so that they each have a substantially teardrop-shaped profile when viewed in the flow direction A. The tip of the teardrop-shaped profile of the first chamber 3 points to the inlet 22, and the tip of the teardrop-shaped profile of the second chamber 4 points to the outlet 23. The bottom of the teardrop-shaped profile forms a first wall 31 at the first chamber 3 and a second wall 41 at the second chamber, wherein the first ultrasonic transducer 5 is arranged on the first wall 31 in the first chamber 3, and the second ultrasonic transducer 6 is arranged on the second wall 41 in the second chamber 4. The purpose of this design is the most possible streamlined design of the two chambers 3, 4, wherein they are each simultaneously provided with a planar surface, namely the first wall 31 and the second wall 41, on which the two ultrasonic transducers 5, 6 can be arranged so that the main propagation direction of the ultrasonic signals emitted by them is along the flow direction A or opposite to the flow direction A.

[0119] Furthermore, the measuring tube 2 comprising the two chambers 3 and 4 is preferably designed symmetrically with respect to the central axis M. If the measuring tube 2 - e.g. Figure 7 As shown—designed as a cylinder, the measuring tube 2 with the two chambers 3 and 4 is preferably rotationally symmetrical with respect to the central axis M.

[0120] In the fifth embodiment, the measuring tube 2 is designed such that it has an at least approximately constant flow cross section for the fluid from the inlet 22 to the outlet 23 , so that the fluid flows through the measuring tube 2 at a constant speed.

[0121] For this purpose, the measuring tube 2 has a first projection 26 in the region of the first chamber 3 and a second projection 27 in the region of the second chamber 4 , through which projections the fluid can flow around the respective chamber 3 or 4 .

[0122] In the region of the first chamber 3, the first chamber 3, together with the first projection 26 of the wall 21 of the measuring tube 2, delimits two first partial channels 35, which extend around the first chamber 3. Figure 6 The total flow of the fluid indicated by the arrow with the reference symbol G at the inlet 22 of the measuring tube 2 is divided into two partial flows S1 and S2 by the first flow guiding element 51, wherein one partial flow flows through the first partial channel 35 around the upper part of the first chamber 3 according to this representation, and the other partial flow flows through the first partial channel 35 around the lower part of the first chamber 3 according to this representation. Downstream of the first chamber 3, the two partial flows S1 and S2 are combined again by the first protrusion 26 in the wall 21 of the measuring tube 2.

[0123] In the region of the second chamber 4, the first chamber 4 delimits together with the second projection 27 of the wall 21 of the measuring tube 2 two second partial channels 45 which extend around the second chamber 4. The fluid flow is again divided by the second wall 41 of the second chamber 4 into two partial flows S1 and S2, wherein one partial flow flows through the second partial channel 45 which, according to this representation, surrounds the upper part of the second chamber 4 and the other partial flow flows through the second partial channel 45 which, according to this representation, surrounds the lower part of the second chamber 4. Downstream of the second chamber 4, the two partial flows S1 and S2 are combined again via the second flow guiding element 52 and the second projection 27 in the wall 21 of the measuring tube 2. The total flow of the fluid then flows out of the measuring tube 2 via the outlet 23, as shown. Figure 6 As shown by the arrow with reference numeral G at the outlet 23.

[0124] As already mentioned, the measuring tube 2 is designed such that it has a constant flow cross section between the inlet 22 and the outlet 23. This means that the cross-sectional area for the fluid flow at the inlet of the measuring tube 2 is as large as the sum of the cross-sectional areas of the two first partial channels 35 and as large as the sum of the cross-sectional areas of the two second partial channels 45 and as large as the cross-sectional area at the outlet 23 of the measuring tube 2, so that the measuring tube 2 has a constant flow cross section for the fluid over its entire length from the inlet 22 to the outlet 23.

[0125] Preferably, all four partial channels, ie the two first partial channels 35 and the two second partial channels 45 , each have the same flow cross section, ie all four partial channels 35 , 45 have the same cross-sectional area.

[0126] Due to the high degree of symmetry in combination with the streamlined, in particular teardrop-shaped contours of both the first chamber 3 and the second chamber 4, particularly favorable flow conditions can be achieved in the measuring tube 2. The fluid flows at a constant flow rate and deviates only slightly from rectilinearity throughout the entire measuring tube 2. In this way, a fluid flow can be achieved that is essentially free of turbulence or turbulent zones, in particular on the measuring section 7 between the two ultrasonic transducers 5, 6. In addition, undesired stagnant areas or deposits or condensation of the fluid can at least be significantly reduced.

[0127] Figure 8 A first variant of a fifth embodiment of an ultrasonic measuring device 1 according to the invention is shown in schematic cross-section. In this first variant, two acoustic lenses 61, 62 are provided for focusing or parallelizing the ultrasonic signal in a similar manner as explained in connection with the fourth embodiment.

[0128] The first acoustic lens 61 is preferably arranged externally on the first wall 31 of the first chamber 3, and the second acoustic lens 62 is preferably arranged externally on the second wall 41 of the second chamber 4. Both acoustic lenses 61 and 62 can be designed in a manner known per se such that they focus or parallelize the emitted ultrasonic signals and direct the ultrasonic signals to be received to the respective ultrasonic transducers 5, 6.

[0129] In the first variation of the fifth embodiment described here, the two acoustic lenses 61, 62 are each as Figure 5 Designed and arranged as shown, combined with Figure 5 Provide explanation.

[0130] Fig. 9 A second variant of a fifth embodiment of an ultrasonic measuring device 1 according to the invention is shown in a schematic sectional view. In this second variant, a temperature sensor 8 is additionally provided for determining the temperature of the fluid. The temperature sensor 8 is here arranged on or in the wall 21 of the measuring tube 2 and is located between the two chambers 3, 4 with respect to the flow direction A. The temperature sensor 8 can be signal-connected to the control unit and the evaluation unit.

[0131] One possibility for arranging the temperature sensor 8 is to provide a continuous hole, such as a drill hole, in the wall 21 and to arrange the temperature sensor 8 in the hole so that the temperature sensor 8 is directly immersed in the fluid, i.e. in direct physical contact with the fluid. If the fluid is a biological substance, the part of the temperature sensor 8 in contact with the fluid should be made of a material that does not contaminate the fluid or otherwise adversely affect the fluid. For example, a suitable material is stainless steel. If the fluid is a biological material or contains biological material, the feedthrough of the temperature sensor 8 through the wall 21 should be sealed in a biocompatible manner.

[0132] Another possibility is to avoid direct physical contact between the fluid and the temperature sensor 8, for example by arranging the temperature sensor 8 on the outside of the wall 21. The difference between the actual temperature of the fluid and the temperature determined by the temperature sensor 8 due to the wall 21 can be determined, for example, by calibration measurements, so that the temperature of the fluid in the measuring tube 2 can then be determined from the temperature determined by the temperature sensor 8. Here, it can be advantageous to provide a gap on the outside of the wall 21 so that the wall 21 has a smaller thickness there. The temperature sensor 8 can then be arranged in this gap and, since the wall is thinner there, a temperature can be measured that is significantly closer to the temperature of the fluid flowing in the measuring tube 2.

[0133] Avoiding direct physical contact between the temperature sensor 8 and the fluid in the measuring tube 2 can be particularly advantageous in applications in which very high demands are made on the purity of the fluid and a risk of contamination arises from contact with the temperature sensor 8. Even in the case of very aggressive fluids in the measuring tube 2 (e.g. acids, such as those used in the semiconductor industry), it can be advantageous to avoid direct physical contact between the temperature sensor 8 and the fluid in the measuring tube 2.

[0134] Furthermore, there may be applications in which the feedthrough through which the temperature sensor reaches the measuring tube cannot be sealed in the desired manner, for example in a biocompatible manner, or can only be sealed with great effort. Even for these applications, a design is preferred in which direct physical contact between the fluid flowing in the measuring tube 2 and the temperature sensor 8 is avoided.

[0135] Determining the temperature of the fluid flowing in the measuring tube 2 by means of the temperature sensor 8 has the advantage that temperature-dependent influences can be compensated for the measurement of the flow rate.

[0136] As an additional measure, which can of course also be implemented independently of the temperature sensor 8 (i.e., without the temperature sensor 8), in a second variant of the fifth embodiment, a third ultrasonic transducer 9 and a fourth ultrasonic transducer 10 are provided on the measuring tube 2. The third and fourth ultrasonic transducers 9, 10 are each arranged on the outer side of the wall 21 of the measuring tube 2 and are aligned so that they can each emit and receive ultrasonic signals perpendicular to the flow direction A. Fig. 9, the ultrasonic signal emitted by the third ultrasonic transducer 9 is indicated by a dotted arrow with reference numeral S9, and the signal emitted by the fourth ultrasonic transducer 10 is indicated by a dotted arrow with reference numeral S10. The third ultrasonic transducer 9 and the fourth ultrasonic transducer S10 are arranged on the wall 21 opposite to each other, so that the fourth ultrasonic transducer 10 can receive the signal S9 emitted by the third ultrasonic transducer 9 perpendicular to the flow direction A, and conversely, the third ultrasonic transducer 9 can receive the signal S10 emitted by the fourth ultrasonic transducer 10 perpendicular to the flow direction A.

[0137] It is understood that the third ultrasonic transducer 9 and the fourth ultrasonic transducer 10 can also be signal-connected to the control unit or the evaluation unit.

[0138] In addition to the measurement signals which have passed through the flowing fluid in the flow direction A and against the flow direction A, the evaluation unit therefore also receives measurement signals which have passed through the fluid perpendicularly to the flow direction A. The evaluation unit can then analyze or evaluate these measurement signals which have passed through the fluid perpendicularly to the flow direction A with respect to their transit time through the fluid, their attenuation by the fluid or of course with respect to transit time and attenuation.

[0139] Since the measurement signals emitted or received by the third and fourth ultrasonic transducers 9 and 10 have each passed through the fluid perpendicularly to the flow direction A, their respective transmission times through the fluid and their respective times of attenuation by the fluid are independent of the flow velocity of the fluid flowing through the measuring tube 2. Therefore, the sound propagation properties in the fluid can be determined from these measurement signals, regardless of the flow velocity of the fluid.

[0140] Thus, at least one parameter of the fluid can be determined from the measurement signal emitted perpendicularly to the flow direction A, which depends on the speed of sound or the sound attenuation in the fluid. Such a parameter is, for example, the viscosity of the fluid, the presence of air or gas bubbles, the concentration of a component in the fluid (e.g. methanol concentration), or the solid content in a suspension, or the cell density in a biological fluid.

[0141] In particular, these measurement signals which pass through the fluid perpendicularly to the fluid flow direction A can also be used to detect changes in the fluid, in particular changes in its composition, such as an increase or decrease in the concentration or density of a component. The ultrasonic measuring device 1 is therefore particularly suitable for process monitoring, for example in pharmaceutical or biological processes, or for controlling such processes. Thus, for example, cell density, protein concentration, salt concentration, nutrient solution concentration, sugar concentration or methanol concentration can be monitored and controlled in a process. If a change in a parameter is detected by means of the ultrasonic measuring device 1, corrective measures can be initiated by means of a suitably designed control loop in order to return the parameter to its set point.

[0142] Due to the fact that in particular the viscosity of the fluid flowing in the measuring tube can also be determined with the third and fourth ultrasonic transducers 9 and 10, it is possible to detect, determine or even compensate for changes in the viscosity of the fluid during flow measurement.

[0143] It is understood that the measures described in connection with the different embodiments can of course be combined with each other and are not limited to the respective specific embodiments.In the explanation given below, an overall explanation is given to the ultrasonic measuring device 1 according to the invention, ie in particular also all embodiments and variants thereof.

[0144] The measuring tube 2 and the chambers 3 and 4 are those parts of the ultrasonic measuring device 1 which come into contact with the fluid in the operating state. The material of which the measuring tube 2 and the two chambers 3 and 4 are made is therefore selected according to the application. Preferably, the measuring tube 2 and the chambers 3, 4 are made of plastic.

[0145] Basic criteria for selecting suitable materials are, for example, whether the fluid is a high-purity fluid, whose contamination should be prevented. Another criterion is whether the fluid is a biological fluid that should only come into contact with biocompatible materials. In addition, it is a criterion whether there should be specific requirements for the tolerance of the measuring tube 2 and the chambers 3, 4 to the fluid. For example, if a chemically aggressive fluid (e.g. acid) passes through the measuring tube 2, materials with good tolerance to aggressive fluids should be selected for the measuring tube 2 and the chambers 3, 4. Such aggressive fluids are, for example, fluids containing acids or highly abrasive suspensions (called slurries). Such fluids are used, for example, in the semiconductor industry.

[0146] In particular for applications with biological fluids or high-purity fluids or biotechnological fluids, or for sterile applications, the measuring tube 2 and the chambers 3, 4 can be made, for example, of plastics that comply with the guidelines of the FDA (Federal Drug Administration) on this subject, such as polypropylene (PP), polyethylene (PE), polytetrafluoroethylene (PTFE), perfluoroalkoxy (PFA), ethylene tetrafluoroethylene copolymer (ETFE), ethylene chlorotrifluoroethylene (ECTFE), polycarbonate (PC), fluorinated ethylene propylene (FEP), polytrifluoroethylene (PCTFE), glycol-modified polyethylene terephthalate (PETG), polyetheretherketone (PEEK). These plastics can of course also be used in other applications of the measuring tube 2 and the chambers 3, 4.

[0147] For many applications it is also preferred that the ultrasonic measuring device 1 or at least the parts which come into contact with the fluid, ie the measuring tube 2 and the two chambers 3 , 4 , are designed as disposable parts for single use.

[0148] Designs as or with disposable parts are particularly suitable for applications in which a very high purity or sterility of those parts in contact with the fluid is necessary. An important aspect regarding disposable parts is that they can be produced as economically and cost-effectively as possible. In this case, emphasis is placed in particular on inexpensive, simple raw materials, such as commercially available plastics. Environmentally conscious handling and responsible use of available resources are also important aspects of disposable part design.

[0149] The term "disposable" in the composition, such as "disposable part", "disposable component", etc., refers to a part or part designed for disposable use, that is, it can only be used once as expected, and then discarded. For new applications, new, previously unused disposable parts must then be used. Therefore, when constructing or designing disposable parts, a basic aspect is that the disposable parts (such as measuring tube 2, first chamber 3 and second chamber 4) can be manufactured as simply and economically as possible, generating very little cost, and can be produced from materials obtained at the lowest possible price. Another aspect is that the disposable parts can be connected together as easily as possible with other parts designed for multiple use (i.e., reusable). Therefore, the disposable parts should be able to be replaced very easily without a large amount of assembly efforts. Another important aspect is that the disposable parts can be discarded as easily as possible after use. For this reason, it is preferred that the material of the disposable parts cause the minimum possible environmental impact during disposal.

[0150] Another aspect is that the disposable parts should be sterilizable for certain applications. In this case, it is particularly advantageous if the disposable parts 2, 3, 4 are gamma sterilizable. In this type of sterilization, gamma radiation is applied to the elements to be sterilized. An advantage of gamma sterilization (compared to steam sterilization, for example) is that sterilization can also be performed through the packaging. In particular in the case of disposable parts, it is common practice to place the parts in packaging after production and then store them for a period of time before delivery to the customer. In this case, sterilization is performed through the packaging, which is not possible with steam sterilization or other methods.

[0151] On the other hand, because they can only be used once, disposable parts have the great advantage that the design does not have to emphasize good cleanability of the disposable parts, because the disposable parts do not need to be cleaned when used as intended. In addition, it is generally not necessary for the disposable parts 2, 3, 4 that they must be sterilizable more than once. This is particularly advantageous for gamma sterilization, because the application of gamma radiation causes degradation of plastics, making multiple gamma sterilizations unusable.

[0152] Since sterilization at high temperature and / or high (steam) pressure is generally not necessary for single-use parts, more cost-effective plastics can be used, for example those that cannot withstand high temperatures or cannot withstand several cycles of high temperature and pressure.

[0153] Taking all these aspects into account, it is therefore preferred to use such plastics that can be gamma sterilized at least once, in particular for the production of disposable parts. These materials should remain gamma stable at a dose of at least 40 kGy to allow a single gamma sterilization. In addition, no toxic substances should be generated during gamma sterilization. In addition, it is preferred that all materials in contact with the substances to be mixed or mixed substances comply with USP Class VI standards.

[0154] For producing the disposable parts 2, 3, 4 in contact with the fluid, the following plastics are preferred: polyethylene (PE), low-density polyethylene (LDPE), ultra-low-density polyethylene (ULDPE), ethylene-vinyl acetate (EVA), polyethylene terephthalate (PET), polyvinyl chloride (PVC), polypropylene (PP), polyurethane (PU), silicone, polyvinylidene fluoride (PVDF), acrylonitrile-butadiene-styrene (ABS), polyacrylic acid, polycarbonate (PC), polyetheretherketone (PEEK).

[0155] For applications in which the disposable parts 2, 3, 4 should be gamma sterilizable, materials with trade names such as Teflon, polytetrafluoroethylene (PTFE) and perfluoroalkoxy polymer (PFA) are less suitable or even unsuitable, for example. Gamma sterilization of these materials involves the risk of escaping dangerous gases (such as fluorine), which can then form toxic or harmful compounds (such as hydrofluoric acid).

[0156] It is also preferred if the component made of plastic can be produced by means of an injection molding process, since this is a particularly cost-effective production method.

[0157] Furthermore, the invention provides a method for producing an ultrasonic measuring device 1 according to the invention, which is characterized in that the measuring tube 2 , the first chamber 3 , and the second chamber 4 are made of plastic.

[0158] based on Figures 10 to 14 , different preferred variants of the method according to the invention are explained, with reference mainly to the production of a fifth embodiment of an ultrasonic measuring device 1 according to the invention. Of course, these methods or variants are suitable for the production of other embodiments in a similar and identical manner.

[0159] Preferably, the measuring tube 2, the first chamber 3 and the second chamber 4 are manufactured in an injection molding process. For this purpose, the plastic forming the measuring tube 2 and the two chambers 3, 4 is preferably a thermoplastic.

[0160] according to Fig.10 In the embodiment shown, the measuring tube 2, the first chamber 3 and the second chamber 4 are manufactured in one piece. For this purpose, for example, a blow molding process is suitable, which is a special injection molding process. In this process, the molded article is first produced by conventional injection molding. It is then heated, introduced into a tool and blown into the final shape given by the tool by applying gas or air.

[0161] exist Figures 11 to 14 In the variant shown, the unit consisting of the measuring tube 2, the first chamber 3 and the second chamber 4 is joined together by several individual parts, preferably each of which is injection molded. Each individual part is manufactured by injection molding and then joined together, preferably by a welding process.

[0162] exist Figures 11 to 14 In the figures, the measuring tube 2, the first chamber 3 and the second chamber 4 are each shown in an exploded view, each figure showing separate individual parts manufactured by injection molding and then joined together to form a unit consisting of the measuring tube 2, the first chamber 3 and the second chamber 4.

[0163] exist Fig.11 In the variant shown, four separate parts 101, 102, 103 and 104 are provided, each of which is Y-shaped. The first separate part 101 extends from the inlet 22 to a first section, which is made perpendicular to the central axis M and passes through the middle of the first chamber 3. The second separate part 102 extends from the first section to a second section, which is made perpendicular to the central axis M and is located in the middle between the first chamber and the second chamber. The third separate part extends from the second section to a third section, which is made perpendicular to the central axis M and passes through the center of the second chamber 4. The fourth separate part 104 extends from the third section to the outlet 23 of the measuring tube 2. Preferably, the first separate part 101 and the fourth separate part 104 are designed identically, and the second separate part 102 and the third separate part 103 are also designed identically. Due to this fact, only two different tools are required to injection mold the separate parts 101, 102, 103 and 104. Three joining processes, preferably welding processes, are then required to join the four individual parts 101 to 104 together.

[0164] exist Fig.12In the variant shown, four separate parts 201, 202, 203, 204 are provided, namely an inlet part 201 including an inlet 22, an outlet part 204 including an outlet 23, a lower part 202 arranged between the inlet part 201 and the outlet part 204 and open at the top according to this representation, and a cover 203 covering the lower part 202. The inlet part 201 extends from the inlet 22 to a first section, which is made perpendicular to the central axis M and between the inlet 22 and the first chamber 3. The outlet part 204 extends from a second section, which is made perpendicular to the central axis M and between the second chamber 4 and the outlet 23. The lower part 202 and the cover 203 each extend from the first section to the second section, wherein the lower part 202 and the cover 203 are separated from each other by a section parallel to the central axis M.

[0165] In this variant, the inlet part 201 and the outlet part are preferably designed identically. Due to this fact, only three different tools are needed to injection mold the individual parts 201, 202, 203 and 204. Three joining processes (preferably welding processes) are then needed to join the four individual parts 201 to 204 together.

[0166] exist Fig.13 In the variant shown, two separate parts 301, 302 are provided, namely a lower part 301 and a cover part 302. The lower part 301 is separated from the cover part 302 by a section which is made parallel to the center axis M in the region comprising the first chamber 3, the second chamber 4 and the middle section of the measuring tube 2. On the inlet side of the first chamber 3 and on the outlet side of the second chamber 4, the section extends obliquely with respect to the center axis M, extending downwards according to the representation, so that the inlet 22 and the outlet 23 each belong completely to the cover part 302.

[0167] Due to this fact, only two different tools are needed for injection molding the individual parts 301 and 302. Only one joining process (preferably a welding process) is then needed to join the two individual parts 301 and 302 together.

[0168] exist Fig.14 In the variant shown, only two separate parts 401, 402 are also provided, namely a lower part 401 and a cover part 402. The lower part 401 is separated from the cover part 402 by a section substantially parallel to the central axis M, wherein this section ends between the inlet 22 and the first chamber 3 on the one hand and between the second chamber 4 and the outlet 23 on the other hand, so that the lower part 401 is longer than the cover part 402 with respect to the direction defined by the central axis M. Therefore, the inlet 22 and the outlet 23 each belong completely to the lower part 401.

[0169] For this variant of injection molding the separate parts 401 and 402, only two different tools are needed. Then only one joining process (preferably a welding process) is needed to join the two separate parts 401 and 402 together.

[0170] Furthermore, the present invention provides an ultrasonic measuring system for measuring a flowing fluid. Fig.15 A first embodiment of an ultrasonic measuring system according to the invention is shown in a schematic representation and is designated as a whole by the reference numeral 500 .

[0171] The ultrasonic measuring system 500 according to the invention may in particular include the ultrasonic measuring device 1 according to the invention. The aforementioned explanations relating to the embodiment of the ultrasonic measuring device 1 according to the invention and all its variants also apply in the same way or in a similarly same way to the ultrasonic measuring system 500 according to the invention. In the case of the ultrasonic measuring system 500 according to the invention, the same parts or parts with equivalent functions as in the aforementioned embodiment of the ultrasonic measuring device 1 are denoted by the same reference numerals.

[0172] The ultrasonic measuring system 500 according to the present invention comprises a disposable device 510 designed for single use, a reusable device 520 designed for multiple use, and a first ultrasonic transducer 5 and a second ultrasonic transducer 6. In the first embodiment, the two ultrasonic transducers 5, 6 are part of the disposable device 510, that is, the two ultrasonic transducers 5, 6 are designed for single use.

[0173] The disposable device 510 comprises all those components which are designed as disposable parts in the above-mentioned sense. These are in particular the measuring tube 2, the first chamber 3, in which the first ultrasonic transducer 5 is arranged, and the second chamber 4, in which the second ultrasonic transducer 6 is arranged. The measuring tube 2 has a central axis M which defines a flow direction A for the fluid. The measuring tube 2 also has an inlet 22 and an outlet 23 for the fluid. The fluid in Fig.15 4. The surfaces of the first chamber 3 and the second chamber 4 facing each other define a straight measurement section 7 for the fluid, which extends from the first chamber 3 to the second chamber 4. The first chamber 3 and the second chamber 4 are designed and arranged so that the fluid can flow around each of them, and the measurement section 7 extends in the flow direction A.

[0174] The reusable device 520 comprises a control device 540 which is designed to actuate the ultrasonic transducers 5 , 6 and to receive signals from the ultrasonic transducers 5 , 6 and also comprises an evaluation unit for evaluating and analysing the signals received from the ultrasonic transducers 5 , 6 .

[0175] The reusable set 520 can be detachably connected to the disposable set so that the reusable set 520 and the disposable set 510 are fixed relative to each other. The connection of the disposable set 510 to the reusable set 520 is designed so that it can be released and closed by hand without the use of tools.

[0176] In the first embodiment of the ultrasonic measurement system 500, at least one mechanical clamp 531 is provided, which is part of the reusable device 520 and can overlap with the disposable device 510 in the form of a snap connection, so that the disposable device 510 can be clamped to the reusable device 520. Of course, several mechanical clamps 531 can also be provided.

[0177] In order to connect the disposable device 510 to the reusable device 520, a protrusion 532 is also provided on the reusable device, which engages in a recess 533 provided in the disposable device when assembled with the disposable device 510. The protrusion 532 and the recess 533 are preferably designed for a form-locking fit so that the disposable device 510 can be easily placed on or removed from the reusable device 520.

[0178] For better understanding, Fig.15 The schematic representation in still shows the disposable set 510 slightly separated from the reusable set 520. It should be understood that in the assembled state, the protrusion 532 engages in the recess 533 and the disposable set 510 preferably rests on the reusable set 520.

[0179] The control device 540 comprises a supply and communication unit 541, which can be supplied with energy via a signal connection 542 for supplying the ultrasonic measuring system 500. Furthermore, the supply and communication unit 541 serves as an interface for communication and data exchange with a user. The supply and communication unit 541 is signal-connected to a central processing unit 544, as indicated by arrow 543. In the central processing unit 544, signals for actuating the ultrasonic transducers 5, 6 are generated. The central processing unit 544 also comprises an evaluation unit for evaluating and analyzing the signals received from the ultrasonic transducers 5, 6.

[0180] The central processing unit 544 is signal-connected to the analog unit 545, as indicated by the arrow 546, and the memory interface 547 is connected to the first ultrasonic transducer 5 via the first signal connection U1 and to the second ultrasonic transducer U2 via the second signal connection U2. The ultrasonic transducers 5, 6 are actuated via the signal connections U1 and U2, and the measurement signals received from the ultrasonic transducers 5, 6 are fed into the control unit 540.

[0181] Furthermore, a memory interface 547 is provided in the control device 540, which is signal-connected to the central processing unit 540, as indicated by arrow 548. The memory interface 547 can also communicate with a memory unit 511 via a third signal connection U3, which is provided in the disposable device 510. In particular, specific calibration data or configuration parameters specific to the respective disposable device 510 are stored in the memory unit 511. Once the disposable device 510 is connected to the reusable device 520, the memory interface 547 of the control device 540 can read these specific calibration data from the memory unit 511 of the respective disposable device 510 and transmit them to the central processing unit 544.

[0182] Additional information can be stored in the memory interface 547 , in particular also information specific to a certain disposable set 510 , such as the service life of the disposable set 510 or the temperature profile over time.

[0183] A temperature sensor 8 is also provided in the control device 540 to determine the temperature of the fluid. The temperature sensor 8 is provided in the protrusion 532 so that after assembling the disposable device 510 and the reusable device 520, the temperature sensor 8 is placed as close as possible to the measurement channel 7 through which the fluid flows. The temperature sensor 8 signal is connected to the central processing unit 544, as indicated by the arrow with reference numeral 81.

[0184] Due to this embodiment, the measuring tube 2 designed as a disposable part (in which the ultrasonic transducers 5, 6 are arranged) can be fixed to the reusable device 520 in a very simple manner and in particular without tools. No further measures are required, because all required calibration data or configuration data are automatically fed into the central processing unit 544, so that the ultrasonic measuring system 500 can be put into operation immediately. It is also particularly advantageous that cost-intensive components (such as the required electronic components) are integrated in the reusable device 520.

[0185] Fig.16 A first variant of the first embodiment of the ultrasound measuring system 500 is shown in a perspective representation, wherein the disposable set 510 has not yet been inserted into the reusable set 520 . Fig.17 The same variation is shown from a different perspective, with a disposable set 510 being inserted into a reusable set 520 .

[0186] In this variant, two mechanical clamps 531 are provided, one of which can clamp the inlet 22 of the measuring tube 2 in the form of a snap connection, and the other can clamp the outlet 23 of the measuring tube 2. In order to connect the disposable device 510 to the reusable device 520, the disposable device 510 is inserted into the reusable device 520 and pressed on it, so that the inlet 22 and the outlet 23 snap into the two mechanical clamps 531. A release mechanism 535 is also provided on each mechanical clamp 531. By pressing the corresponding release mechanism 535, the mechanical clamp 531 releases the disposable device 510.

[0187] A directional arrow R is also provided on the reusable set 520 , which indicates the direction of flow of the fluid A. Such a directional arrow is also provided on the disposable set 510 .

[0188] Optionally, the key 518 may be provided on the disposable set 510, for which purpose the reusable set 520 has a recess 528 for receiving the key 518. In this way, it can be ensured that the disposable set 510 can only be inserted into the reusable set 520 in exactly one orientation.

[0189] Fig.18 A second variant of the first embodiment of the ultrasound measuring system 500 is shown in a perspective representation, wherein the disposable set 510 has not yet been inserted into the reusable set 520 .

[0190] In this second variant, the reusable device 520 comprises a housing 600 which is designed as a lockable housing 600. The housing 600 comprises a first housing part 610 and a second housing part 620 which are connected to each other via an articulated joint 630. Fig.18 The housing 600 is shown in an open state. The control device 540 is arranged in the first housing part 610. The second housing part 620 serves as a cover with which the housing 600 can be closed. The housing 600 also has a continuous central recess 640 which extends through the entire housing 600 and is used to receive the disposable device 510.

[0191] The housing 600 also has a locking mechanism 650 to close the housing 600 and thus fix the disposable device 510 inserted into the recess 640 relative to the reusable device 520. The locking mechanism 650 is arranged on the first housing part 610 and comprises a band 651 designed to cooperate with the recess 621 in the second housing part 620.

[0192] The disposable set 510 is inserted into the central recess 640 so that the protrusion 532 engages in the recess 533. Subsequently, the two housing parts 610, 620 are folded together, i.e. the second housing part 620 is folded over the disposable set 510 so that the band 651 engages in the recess 621 and overlaps with the second housing part 620. In this way, the housing 600 is closed and the disposable set 510 is fixed relative to the reusable set 520.

[0193] Fig.19 A preferred embodiment of the disposable device 510 is shown in a perspective exploded view. For better understanding, Fig. 20 This embodiment is still shown in a cross-sectional view and in the assembled state, wherein the section is taken along the flow direction A.

[0194] In this embodiment, the disposable device 510 comprises three parts, namely a main part 700 , a cover 710 and a base 720 , in addition to the ultrasonic transducers 5 , 6 .

[0195] The main part 710 comprises the inlet 22, the outlet 23, the two chambers 3, 4 and the channel forming the measuring section 7 between the two chambers 3, 4. When the disposable device 510 is inserted into the reusable device 520, the cover 710 closes the disposable device 510 on the side facing away from the reusable device 520. Therefore, the cover 710 is in contact with the fluid during operation, because according to this representation, the cover 710 closes the measuring section 7 at the top. According to this representation, the channel forming the measuring section 7 is delimited downwards by the base plate 701 ( Fig. 20 ), the base plate 701 is an integral part of the main part 700. According to the representation below the base plate 701, a base 720 is provided, which encloses the disposable device 510. When the disposable device 510 is inserted into the reusable device 520, the base 720 rests on the reusable device 520. A cavity 70 is provided between the underside of the main part 700 (i.e., the base plate 701) and the base 720, which connects the first chamber 3 with the second chamber 4.

[0196] Similar to Fig.14 In the embodiment shown, the main part 700 and the cover 710 are separated by a section substantially parallel to the central axis M, wherein the section ends between the inlet 22 and the first chamber 3 on the one hand, and between the second chamber 4 and the outlet 23 on the other hand, so that the main part 700 is longer than the cover 710 relative to the direction defined by the central axis M. Therefore, the inlet 22 and the outlet 23 each completely belong to the main part 700. The cover 710 is designed to form a bevel in the region of both ends. The main part 700 includes complementary bevels in the region of both ends.

[0197] Furthermore, several grooves 702 are provided in the main part 700 , each groove extending in the flow direction A and arranged transversely to the channel forming the measuring section 7 , which increases the mechanical stability of the measuring section 7 .

[0198] The main part 700, the cover 710 and the base 720 are each manufactured separately, preferably by means of an injection molding process, and are then joined together in a joining process. In particular, the joining of the main part 700 to the cover 710 requires special care, because this connection must be designed to be fluid-tight, and in particular liquid-tight. Welding methods such as laser welding or adhesive bonding are particularly suitable as methods for joining the main part 700, the cover 710 and the base 720. Methods such as screwing are also possible.

[0199] A particular advantage of the embodiment described here is that the one-piece main part 700 comprises the entire dimension from the inlet 22 to the outlet 23, i.e. in particular also the chambers 3, 4 and the channel forming the measuring section 7. This increases the mechanical stability of the entire disposable device 510 and prevents misalignment.

[0200] An electrical contact 721 is provided in the base 720, the electrical contact 721 belonging to the signal connections U1, U2 and U3, via which the disposable device 510 and the reusable device 520 exchange signals, and via which energy can be supplied to the disposable device 510. In addition, an opening 722 is provided in the base 720, which is part of the recess 533.

[0201] According to another embodiment, the first chamber 3 and / or the second chamber 4 are each arranged in a separate chamber insert 30. Such an embodiment is Fig.21 —— Fig.23 Shown in.

[0202] Fig.21 1 shows a plan view of a chamber insert 30 which may be provided in both the first chamber 3 and the second chamber 4. For better understanding, Fig. 22 The chamber insert 30 is shown in section along the flow direction A.

[0203] The separate chamber insert 30 is inserted into the opening provided for this purpose and then preferably joined to the disposable device 510 by a welding process, in particular by laser welding. Figure 21 to Figure 23 Indicated by a dotted line or by a point S. Fig. 22 As particularly shown in FIG. 4 , positioning elements 40 , such as grooves and pins engaging in the grooves, can be provided so that the corresponding ultrasonic transducer 5 or 6 is correctly aligned in the flow direction A.

[0204] Fig.23 Similar to Fig. 22 The representation shows a variant of a chamber insert 30 , the fastening of which requires fewer welds S.

[0205] Fig.24 Possible embodiments of signal connections U1 , U2 or U3 are shown, which enable an electrical connection between the single-use set and the reusable set.

[0206] In the surface of the reusable device 520 facing the disposable device 510 in the assembled state, one or more spring contacts 90 are provided, each spring contact 90 comprising a conductive head 91 protruding from the reusable device 520, the conductive head 91 being spring-loaded by a spring element 92. Each spring contact is signal-connected to the analog unit 545 via a signal connection U1 or U2. Preferably, the conductive head 91 is made of gold.

[0207] The electrical contacts 721 are provided in the base 720 of the disposable device 510 and are arranged so that in the assembled state of the disposable device 510 and the reusable device 520 they press on the spring contacts 90 and thus form an electrical connection between the disposable device 510 and the reusable device 520 .

[0208] Each electrical contact 721 is protected by a sealing element 722 (eg, an O-ring) to prevent fluid leakage from the disposable set 510. Each spring contact 90 is protected by a sealing element 93 (eg, an O-ring) to prevent fluid from penetrating into the reusable set 520.

[0209] For each ultrasonic transducer 5, 6 - Fig.24 Only the first ultrasonic transducer 5 is shown in FIG. 7—two electrical contacts 721 are provided, each of which is connected via a signal connection U1 or U2 to a respective ultrasonic transducer 5 or 6. This can be achieved by means of wires, for example.

[0210] Of course, it is also possible to provide a common reference conductor for both ultrasonic transducers 5 and 6 , so that a total of three electrical wires are required, namely a common ground reference conductor and one wire for each ultrasonic transducer 5 or 6 .

[0211] The signal connection U3 between the memory unit 511 and the memory interface in the disposable device 510 can also be designed in a similar manner.

[0212] Fig.25 Similar to Fig.24The representation of shows a further possible embodiment of the signal connections U1, U2, which realizes the electrical connection between the disposable device 510 and the reusable device 520. In this embodiment, instead of the electrical contacts 721, a PCB (printed circuit board) 725 is provided in the disposable device, which is preferably designed as a flexible PCB and is arranged in the cavity 70. Of course, several PCBs can be provided in other embodiments. For example, the PCB 725 can be fixed in the cavity 70 in a waterproof manner by means of gluing or by means of a press-fit technique, so that fluid cannot escape from the disposable device.

[0213] The PCB 725 has a contact surface 726 arranged on the opening 727 so that the spring contact 90 can contact the contact surface 726. In particular, if the PCB 725 is designed as a flexible PCB, the PCB 725 can be directly connected to the ultrasonic transducers 5, 6 via a solder connection.

[0214] Fig.26 Similar to Fig.24 The representation of shows another possible embodiment of the signal connection U1, U2, which realizes the electrical connection between the disposable device 510 and the reusable device 520. In this embodiment, no direct electrical contact is provided between the disposable device 510 and the reusable device 520, but an inductive coupling is provided. For this purpose, a separate power transformer 95 is provided, one side 951 of which is arranged in the reusable device and the other side 952 of which is arranged in the disposable device 510.

[0215] In those embodiments in which a PCB 725 is provided in the disposable device 510, the memory unit 511 can be integrated in the PCB 725, for example as a solid-state memory or a microcontroller. In addition to calibration data or configuration parameters of the disposable device 510, other parameters such as operating time or other information, in particular information specific to the respective disposable device 510, can also be stored there. In addition, simple or intelligent error detection and correction devices can also be integrated in the memory unit 511.

[0216] The communication between the memory unit 511 of the disposable device 510 and the memory interface 547 of the reusable device 520 can also be realized by means of RFID (RFID: Radio Frequency Identification) technology. Fig. 27 For better understanding, Fig.28 Still two components for radio frequency identification are shown.

[0217] A first antenna carrier 810 is provided in the disposable device 510 , which carries a first antenna 820 , which is connected to a passive transponder 830 arranged on the first antenna carrier 810 .

[0218] A second antenna carrier 850 is provided in the reusable device 520, which carries a second antenna 860 connected to an active transceiver 870 arranged on the second antenna carrier 850. The active transceiver 870 is signally connected to the memory interface 547.

[0219] The passive transponder 830 and the active transceiver 870 communicate with each other in a manner known per se via an electromagnetic field EM.

[0220] The passive transponder 830 and the active transponder 870 are each arranged so that they are as close to each other as possible in the assembled state of the disposable set 510 and the reusable set 520. By using appropriate EM field strength and shape of the antennas 820, 860, it can be achieved that only the directly adjacent passive transponder 830 is read, while other passive transponders in close proximity are not read.

[0221] Fig.29 and Fig.30 Another possibility of transferring configuration parameters and / or calibration data of a specific disposable device 510 to a memory interface 547 of a reusable device 520 is shown in FIG. In this embodiment, the disposable device 510 is provided with a label 900, which contains specific information 910 for the disposable device 510, i.e., for example, calibration data. For example, the label 900 is designed as a two-dimensional "barcode", such as a QR code. The label 900 is applied to the disposable device 510, which is visible from the outside on the side of the disposable device 510 facing the reusable device 520 in the assembled state.

[0222] A camera 920 is provided in the reusable set 520, which can record the tag 900. This means that the tag 900 is arranged on the disposable set 510 so that it is within the sight of the camera 920 when the disposable set 510 and the reusable set 520 are in an assembled state.

[0223] The camera 900 is signally connected to the memory interface 547. Optionally, a lens 930 and / or at least one light source 940 can be provided in the reusable device 520 to ensure reliable optical detection of the tag 900 by the camera 920 under all conditions. The light source 940 can in particular be designed as an LED.

[0224] It will be appreciated that in addition to the temperature sensor, other sensors may be provided in the reusable device, such as sensors by which bubbles or particles in the fluid may be detected, or sensors by which changes in the fluid may be detected, such as color changes or changes in pH. These sensors may be, for example, optical sensors or electromagnetic or capacitive or magnetic sensors.

[0225] Fig.31 5 shows a further advantageous measure of an embodiment of the disposable device 510. Several recesses 20 are provided in the wall of the measuring tube 2 along the measuring section 7, which capture reflections of the ultrasonic signal so that these reflections cannot return to the measuring section 7 or are at least strongly attenuated. The recesses 20 are preferably arranged so that they form a symmetrical structure with respect to a center plane E, which is perpendicular to the flow direction A and is located in the middle between the first ultrasonic transducer 5 and the second ultrasonic transducer 6.

[0226] Fig.32 A further advantageous measure for designing a disposable device 510 is shown. In this embodiment, a buffer zone 311 or 411 is each arranged between the first ultrasonic transducer 5 and the first wall 31 of the first chamber 3 and between the second ultrasonic transducer 6 and the second wall 41 of the second chamber 4 in order to attenuate the near field of the generated ultrasonic signal or to prevent the near field from penetrating into the measuring section 7. In the near field directly in front of the ultrasonic transducer 5 or 6, chaotic wave conditions prevail, which will lead to high signal losses if the near field penetrates the measuring section 7. By means of the buffer zones 311 and 411, it can be achieved that essentially only the far field is introduced into the measuring section 7. Preferably, the length of each buffer zone 311 or 411 along the flow direction A is at least four times the extension of the corresponding ultrasonic transducer 5 or 6 along the flow direction A.

[0227] As an alternative to the buffer zone 311 or 411, special ceramics can also be used for the ultrasonic transducer 5 or 6, which only generate a negligible near field. Such special ceramics include, for example, a large number of very small vibrating whiskers arranged in a two-dimensional matrix.

[0228] Fig.33 A perspective view of a second embodiment of an ultrasonic measuring system 500 according to the present invention is shown. In the following description of the second embodiment, only the differences from the first embodiment will be explained in detail. In other respects, the explanations about the first embodiment also apply to the second embodiment in the same way or in a similar way. In the second embodiment, the same parts or parts having the same functions as in the first embodiment are denoted by the same reference numerals.

[0229] The main difference from the first embodiment is that in the second embodiment, the first ultrasonic transducer 5 and the second ultrasonic transducer 6 are part of the reusable device 520, and the disposable device 510 does not include any ultrasonic transducer, which makes the manufacture of the disposable device 510 more cost-effective.

[0230] Fig.34 A perspective cross-sectional view of a disposable device 510 of a second embodiment is shown. For better understanding, Fig.35 Still shows Fig.34 A magnified view of the details. Fig.36 A schematic diagram is shown which explains the coupling of ultrasonic signals into the measuring section 7 .

[0231] In the second embodiment, the first ultrasonic transducer 5 and the second ultrasonic transducer 6 are arranged in the control device 540 so that in the assembled state of the disposable device 510 and the reusable device 520, according to the representation, they are arranged below the first chamber 3 and below the second chamber 4.

[0232] In the following explanation, only the first ultrasonic transducer 5 and the first chamber 3 are mentioned. It should be understood that these explanations also apply similarly to the second ultrasonic transducer 6 and the second chamber 4.

[0233] The waveguide element 39 is disposed in the first chamber 3, and includes a coupling surface 391, the surface normal vector of the coupling surface 391 being perpendicular to the flow direction A and facing the first ultrasonic transducer 5. The waveguide element 39 also has a decoupling surface 392, the surface normal vector of which is along the flow direction A and which is formed by the first wall 31 of the first chamber 3. The waveguide element 39 also has a deflection surface 393, the surface normal vector of which is inclined at 45° relative to the flow direction A, so that the ultrasonic signal arriving through the coupling surface 391 is deflected or reflected along the flow direction A. The deflection surface 393 may be coated with a reflection enhancing material 394 ( Fig.36 ) or is composed of reflection enhancing material 394. Fig.36 In FIG. 1 , the ultrasonic signal is represented by an arrow with reference sign US.

Claims

1. An ultrasonic measurement system for measuring a flowing fluid, comprising a disposable device (510) designed for single use, a reusable device (520) designed for multiple use, a first ultrasonic transducer (5), and a second ultrasonic transducer (6). in, The disposable device (510) comprises a measuring tube (2) having a central axis (M) defining a flow direction (A) of a fluid; a first chamber (3) in which a first ultrasonic transducer (5) is arranged; and a second chamber (4) in which a second ultrasonic transducer (6) is arranged, wherein the measuring tube (2) has an inlet (22) and an outlet (23) for the fluid, and wherein the first ultrasonic transducer (5) and the second ultrasonic transducer (6) define a straight measuring section (7) for the fluid, characterized in that the first chamber (3) and the second chamber (4) are designed and arranged so that a fluid can flow around each of them, and the first ultrasonic transducer (5) and the second ultrasonic transducer (6) are arranged so that the measuring section (7) extends along the flow direction (A), wherein the reusable device (520) comprises a control device (540) designed to actuate the first ultrasonic transducer (5) and the second ultrasonic transducer (6) and receive signals from the first ultrasonic transducer (5) and the second ultrasonic transducer (6), And wherein the reusable device (520) is detachably connectable to the disposable device (510) such that the reusable device (520) and the disposable device (510) are fixed relative to each other.

2. The ultrasonic measurement system according to claim 1, wherein: The first chamber (3) and the second chamber (4) are arranged in the measuring tube (2) between the inlet (22) and the outlet (23).

3. The ultrasonic measurement system according to claim 1, wherein: The first ultrasonic transducer (5) and the second ultrasonic transducer (6) are arranged on the central axis (M) of the measuring tube (2).

4. The ultrasonic measuring system according to any one of claims 1 to 3, wherein: The measuring tube (2) has a flow cross section for the fluid between the first ultrasonic transducer (5) and the second ultrasonic transducer (6), which is smaller than the flow cross section at the inlet (22) of the measuring tube (2).

5. The ultrasonic measuring system according to any one of claims 1 to 3, wherein: The measuring tube (2) has a substantially constant flow cross section for the fluid between the first ultrasonic transducer (5) and the second ultrasonic transducer (6).

6. The ultrasonic measuring system according to any one of claims 1 to 3, wherein: The first chamber (3) is arranged closer to the inlet (22) and the second chamber (4) is arranged closer to the outlet (23), wherein the first chamber (3) has a first flow guiding element (51) on its side facing the inlet (22) for reducing turbulence, and / or wherein the second chamber (4) has a second flow guiding element (52) on its side facing the outlet (23) for reducing turbulence.

7. The ultrasonic measuring system according to any one of claims 1 to 3, wherein: The measuring section (7) has a first end at the first ultrasonic transducer (5) and a second end at the second ultrasonic transducer (6), and wherein an acoustic lens (61, 62) for focusing the ultrasonic signal is respectively arranged at each end of the measuring section (7).

8. The ultrasonic measuring system according to any one of claims 1 to 3, wherein: The first chamber (3) and the second chamber (4) each have a substantially teardrop-shaped contour along the flow direction (A).

9. The ultrasonic measurement system according to any one of claims 1 to 3, further comprising a temperature sensor (8) for determining the temperature of the fluid.

10. The ultrasonic measuring system according to any one of claims 1 to 3, wherein: A third ultrasonic transducer (9) and a fourth ultrasonic transducer (10) are arranged on the measuring tube (2), wherein the third ultrasonic transducer (9) and the fourth ultrasonic transducer (10) are arranged opposite each other and are each arranged and aligned perpendicularly to a flow direction (A) for transmitting ultrasonic signals.

11. The ultrasonic measurement system according to claim 1, wherein: Both the first chamber and the second chamber are free of fluid during operation.

12. The ultrasonic measurement system according to claim 1, wherein: The disposable device (510) and the reusable device (520) can be connected to each other by means of a clip connection.

13. The ultrasonic measuring system according to any one of claims 1 to 3, wherein: The first ultrasonic transducer (5) and the second ultrasonic transducer (6) are part of the disposable device (510) or the reusable device (520).

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