Sensor Assembly for a Sensor, Sensor, and Measuring System Formed Therewith

Abstract

The sensor assembly (11) comprises: a bowl shaped, namely at least sectionally dished, membrane (111), with a curved surface (111+) and an oppositely lying surface (111#); and a sensor blade (12) extending from the surface (111+) of the membrane. The membrane (11) is so formed that at least one region of the surface (111+) adjoining the sensor blade is convex. A sensor formed by means of such a sensor assembly and by means of a transducer element (12) coupled therewith and serving for generating a sensor signal representing movements of the sensor blade changing as a function of time and/or deformations of the membrane changing as a function of time, respectively a measuring system formed by means of the sensor and a measuring electronics connected thereto, can be used for registering pressure fluctuations in a flowing fluid, such as, for instance, a 400 C hot steam, for instance, in order to measure a flow parameter of the fluid.

Claims

1-26. (canceled)

27. A sensor assembly for a sensor, especially for a sensor for registering pressure fluctuations in a Kármán vortex street formed in a flowing fluid, which sensor assembly comprises: a bowl shaped, namely at least sectionally dished, membrane, with a curved, first surface and an oppositely lying, second surface, especially a curved, second surface and/or a second surface at least partially parallel and/or at least partially non parallel, to the first surface; and a sensor blade extending from said first surface of said membrane, especially a rod-shaped or plate-shaped or wedge-shaped, sensor blade, wherein: said membrane is so formed that at least one region of said first surface adjoining said sensor blade is convex.

28. The sensor assembly as claimed in claim 27, wherein: said membrane is so formed that the region of said first surface adjoining said sensor blade is aspherical; and/or said membrane is so formed that the region of said first surface adjoining said sensor blade is axially symmetric relative to at least one imaginary axis of symmetry, especially in such a manner that the symmetry axis is parallel to a principle axis of inertia of said sensor blade and/or in such a manner that the symmetry axis is perpendicular to a principle axis of inertia of said sensor blade.

29. The sensor assembly as claimed in claim 27, wherein: said membrane is so formed that the region of said first surface adjoining said sensor blade is axially symmetric relative to exactly two imaginary axes of symmetry, which are perpendicular to one another, especially in such a manner that at least one of the axes of symmetry is parallel to a principle axis of inertia of said sensor blade and/or in such a manner that a principle axis of inertia of said sensor blade is perpendicular to one of the imaginary axes of symmetry and parallel to the other imaginary axis of symmetry.

30. The sensor assembly as claimed in claim 27, wherein: said membrane is so formed that a region of said first surface adjoining said sensor blade is rotationally symmetric, especially spherical.

31. The sensor assembly as claimed in claim 27, wherein: a segment of said membrane carrying said sensor blade has a first zone forming a center of said membrane and having a first thickness and a second zone adjoining said first zone, especially surrounding said first zone, and having a second thickness different from said first thickness, especially in such a manner that said first thickness is less than said second thickness; and/or at least one region of said second surface lying opposite the region of said first surface adjoining said sensor blade is concave; and/or said membrane is so formed that a membrane height, measured as a minimum separation of a center of area of said first surface from an imaginary projected area inscribed by a peripheral outer edge of the region of said first surface adjoining said sensor blade is less than a membrane diameter, measured as a greatest diameter of the projected area, especially in such a manner that said membrane diameter is less than a greatest semi axis, respectively less than a radius, of said projected area, and/or that a diameter to-height ratio of said membrane, defined as a ratio of the membrane diameter to the membrane height is less than 30 and/or greater than 2, especially less than 20 and/or greater than 5, and/or in such a manner that a ratio of said membrane diameter to a length of said sensor blade, measured as the minimum separation between a proximal end of said sensor blade, namely an end adjoining said membrane, and a distal end of said sensor blade remote from said membrane, or its surface, amounts to less than 2 and/or greater than 0.5.

32. The sensor assembly as claimed in claim 27, wherein: said membrane is at least partially conical.

33. The sensor assembly as claimed in claim 27, wherein: said membrane is so formed that at least the region of said first surface adjoining said sensor blade corresponds to a surface of a spherical zone, especially in such a manner that a top area of said spherical zone corresponds to a cross sectional area of said sensor blade.

34. The sensor assembly as claimed in claim 27, wherein: said membrane is so formed that at least the region of said first surface adjoining said sensor blade corresponds to a lateral surface of a frustum.

35. The sensor assembly as claimed in claim 27, wherein: the membrane is so formed that at least the region of the first surface adjoining the sensor blade corresponds to a segment of a surface of an ellipsoid.

36. The sensor assembly as claimed in claim 27, wherein: said sensor blade and said membrane are so positioned and oriented relative to one another that a principle axis of inertia of said sensor blade is parallel to or coincides with a principle axis of inertia of said sensor assembly, and/or said sensor blade and said membrane are so positioned and oriented relative to one another that a principle axis of inertia of said membrane, when lengthened, extends parallel to a principle axis of inertia of said sensor assembly, especially coincides therewith.

37. The sensor assembly as claimed in claim 27, wherein: said membrane is composed, at least partially, especially predominantly or completely, of a metal, especially a stainless steel, or a nickel based alloy; and/or said sensor blade is composed, at least partially, especially predominantly or completely, of a metal, especially a stainless steel, or a nickel based alloy; and/or said membrane and said sensor blade are of the same material; and/or said membrane and said sensor blade are components of one and the same, monolithic, molded part, for example, one cast or manufactured by 3D laser melting.

38. The sensor assembly as claimed in claim 27, wherein: said membrane and said sensor blade are connected with one another by material bonding, especially welded, respectively soldered or brazed.

39. The sensor assembly as claimed in claim 27, further comprising: a compensating body extending from said second surface of the membrane, especially a rod-shaped or plate-shaped or sleeve-shaped, compensating body, for compensating forces and/or moments resulting from movements of the sensor assembly.

40. The sensor assembly as claimed in claim 39, wherein: at least one region of said second surface adjoining said compensating body is concave; and/or said membrane and said compensating body are connected with one another by material bonding, especially welded, respectively soldered or brazed; and/or said sensor blade and said compensating body are arranged aligned with one another; and/or said membrane is so formed that the region of said second surface adjoining said compensating body is rotationally symmetric; and/or said compensating body and said membrane are so positioned and oriented relative to one another that a principle axis of inertia of said membrane, when lengthened, extends parallel to a principle axis of inertia of said compensating body, especially coincides therewith; and/or said sensor blade, said compensating body and said membrane are so positioned and oriented relative to one another that a principle axis of inertia of the sensor assembly is parallel both to a principle axis of inertia of said sensor blade as well as also to a principle axis of inertia of said compensating body, as well as also to a principle axis of inertia of said membrane, respectively the principle axis of inertia of said sensor assembly coincides both with the principle axis of inertia of the sensor blade as well as also with the principle axis of inertia of said compensating body, as well as also with the principle axis of inertia of said membrane; and/or said membrane and said compensating body are components of one and the same, monolithic, molded part, especially in such a manner that said sensor blade, said membrane and said compensating body are components of the molded part; and/or said compensating body is composed at least partly, especially predominantly or completely, of a metal, especially a stainless steel, respectively a nickel based alloy; and/or said membrane and said compensating body are of the same material, especially in such a manner that said sensor blade, said membrane and said compensating body are of the same material.

41. The sensor assembly as claimed in claim 27, wherein: said membrane has an external edge segment, especially an annular external edge segment and/or one equipped with a sealing surface.

42. The sensor assembly as claimed in claim 41, wherein: said outer edge segment is adapted to be connected, especially by material bonding and/or hermetically sealedly, with a seat serving for mounting of said membrane to a wall of a tube, especially in such a manner that said membrane covers, especially hermetically seals, an opening provided in the wall of said tube and/or in such a manner that the first surface of said membrane is facing a lumen of said tube, so that said sensor blade protrudes inwardly into the lumen; and/or said at least one sealing surface, especially a surrounding and/or circular ring like, sealing surface, is embodied in said outer edge segment; and/or said outer edge segment forms a peripheral outer edge of the convex region of said first surface adjoining said sensor blade.

43. A sensor for registering pressure fluctuations in a flowing fluid, especially for registering pressure fluctuations in a Kármán vortex street formed in the flowing fluid, which sensor comprises: a sensor assembly comprising: a sensor assembly for a sensor, especially for a sensor for registering pressure fluctuations in a Kármán vortex street formed in a flowing fluid, which sensor assembly comprises: a bowl shaped, namely at least sectionally dished, membrane, with a curved, first surface and an oppositely lying, second surface, especially a curved, second surface and/or a second surface at least partially parallel and/or at least partially non parallel, to the first surface; and a sensor blade extending from said first surface of said membrane, especially a rod-shaped or plate-shaped or wedge-shaped, sensor blade, wherein: said membrane is so formed that at least one region of said first surface adjoining said sensor blade is convex; and a transducer element for generating a sensor signal, especially an electrical or optical, sensor signal, representing movements of said sensor blade changing as a function of time, especially movements, which are at least at times periodic, and/or deformations of said membrane changing as a function of time, especially deformations, which are at least at times periodic.

44. A measuring system for measuring at least one flow parameter, especially a flow parameter varying as a function of time, especially a flow velocity and/or a volume flow rate, of a fluid flowing in a pipeline, which measuring system comprises: a sensor, comprising: a sensor for registering pressure fluctuations in a flowing fluid, especially for registering pressure fluctuations in a Kármán vortex street formed in the flowing fluid, which sensor comprises: a sensor assembly comprising: a sensor assembly for a sensor, especially for a sensor for registering pressure fluctuations in a Kármán vortex street formed in a flowing fluid, which sensor assembly comprises: a bowl shaped, namely at least sectionally dished, membrane, with a curved, first surface and an oppositely lying, second surface, especially a curved, second surface and/or a second surface at least partially parallel and/or at least partially non parallel, to the first surface; and a sensor blade extending from said first surface of said membrane, especially a rod-shaped or plate-shaped or wedge-shaped, sensor blade, wherein: said membrane is so formed that at least one region of said first surface adjoining said sensor blade is convex; and a transducer element for generating a sensor signal, especially an electrical or optical, sensor signal, representing movements of said sensor blade changing as a function of time, especially movements, which are at least at times periodic, and/or deformations of said membrane changing as a function of time, especially deformations, which are at least at times periodic for registering pressure fluctuations in the flowing fluid, especially for registering pressure fluctuations in a Kármán vortex street formed in the fluid flowing; and measuring electronics, which is adapted to receive said sensor signal and to process such, especially to generate measured values representing at least one flow parameter.

45. The measuring system as claimed in claim 44, further comprising: a tube insertable into the course of the pipeline and having a lumen, which is adapted to guide the fluid flowing in the pipeline.

46. The measuring system as claimed in claim 45, wherein: said sensor blade has a length, measured as the minimum separation between a proximal end of said sensor blade, namely an end adjoining said membrane, and a distal end of said sensor blade, namely an end remote from said membrane, or its surface, which length corresponds to less than 95% of a caliber (DN) of the tube and/or greater than half the caliber (DN).

47. The measuring system as claimed in claim 45, wherein: there is embodied in the wall of the tube an opening, especially an opening having a seat serving for the mounting of said membrane to the wall; and said sensor is inserted into said opening in such a manner that said membrane covers said opening, especially hermetically seals said opening, and that said first surface of said membrane faces the lumen of the tube, so that said sensor blade protrudes inwardly into the lumen.

48. The measuring system as claimed in claim 47, wherein: said opening has a seat serving for mounting of said membrane to the wall.

49. The measuring system as claimed in claim 48, wherein: said seat at least one sealing surface is embodied, especially a surrounding and/or circular ring like, sealing surface.

50. The measuring system as claimed in claim 48, wherein: said membrane has an external edge segment, especially an annular, external edge segment, in which at least one sealing surface is embodied, especially a surrounding and/or circular ring like, sealing surface; and said sealing surface and said sealing surface of the seat are adapted to close, or to seal hermetically, said opening, especially with interpositioning of at least one seal.

51. The measuring system as claimed in claim 44, further comprising: a bluff body arranged in the lumen of said tube and adapted to bring about a Kármán vortex street in the flowing fluid.

52. Use of a measuring system as claimed in claim 44 for measuring a flow parameter, especially a flow velocity and/or a volume flow rate and/or a mass flow rate, of a fluid, especially a vapor, flowing in a pipeline, especially vapor having a temperature greater than 400° C. and/or acting on said membrane of said sensor with a pressure greater than 140 bar.

Description

[0048] The invention and advantageous embodiments thereof will now be explained in greater detail based on examples of embodiments shown in the figures of the drawing. Same, respectively equally acting or equally functioning, parts are provided in all figures with equal reference characters; when perspicuity requires or it otherwise appears sensible, already mentioned reference characters are omitted in subsequent figures. Other advantageous embodiments or further developments, especially also combinations, first of all, of only individually explained aspects of the invention, will become evident, furthermore, from the figures of the drawing and/or from claims. The figures of the drawing show as follows:

[0049] FIGS. 1, 2 schematically in different views, a measuring system (here embodied as a vortex flow measuring device) with a sensor and a measuring electronics for measuring at least one flow parameter of a fluid flowing in a pipeline;

[0050] FIGS. 3a, 3b, schematically, equally as well, in each case, in a to scale manner, in different, partially also 3c, 3d sectioned views, a sensor assembly for a sensor, especially suitable for use in a measuring system of FIG. 1, respectively 2;

[0051] FIG. 4a, 4b schematically in two different, sectioned, side views, another variant of a sensor assembly for a sensor, especially suitable for use in a measuring system of FIG. 1, respectively 2;

[0052] FIG. 5 schematically in plan view, another variant of a sensor assembly for a sensor, especially suitable for use in a measuring system of FIG. 1, respectively 2;

[0053] FIG. 6 schematically in plan view, another variant of a sensor assembly for a sensor, especially suitable for use in a measuring system according to FIG. 1, respectively 2.

[0054] FIGS. 1 and 2 show an example of an embodiment of a measuring system for measuring at least one flow parameter, in given cases, also a flow parameter varying as a function of time, such as e.g. a flow velocity v and/or a volume flow rate V′, of a fluid flowing in a pipeline, for example, a hot gas, especially one having a temperature greater than 400° C., and/or at least at times under a high pressure, especially of greater than 140 bar. The pipeline can be embodied, for example, as a plant component of a heat supply network or a turbine circulatory system; consequently the fluid can, for example, be steam, especially also saturated steam or superheated steam. The fluid can, however, for example, also be a (compressed) natural- or biogas, consequently the pipeline can, for example, also be a component of a natural- or biogas plant or a gas supply grid.

[0055] The measuring system includes a sensor 1, which is provided, respectively is embodied, to register pressure fluctuations in the flowing fluid and to transduce such into a sensor signal s1, for example, an electrical or optical, sensor signal, corresponding to the pressure fluctuations. As evident from the combination of FIGS. 1 and 2, the measuring system comprises, furthermore, a measuring electronics 2, for example, one accommodated in a pressure- and/or shock resistant, protective housing 20, which is connected to the sensor 1, respectively communicates with the sensor 1 during operation of the measuring system. Measuring electronics 2 is, especially, adapted to receive and to process the sensor signal s1, for example, to generate measured values X.sub.M representing the at least one flow parameter, for example, thus the flow velocity v, respectively the volume flow rate V′. The measured values X.sub.M can, for example, be visualized on-site and/or transmitted, by wire via connected fieldbus and/or wirelessly per radio, to an electronic data processing system, for instance, a programmable logic controller (PLC) and/or a process control station. The protective housing 20 for measuring electronics 2 can be made, for example, of a metal, for instance, a stainless steel or aluminum, and/or produced by means of a casting method, such as e.g. an investment casting- or a pressure casting method (HPDC); it can, however, for example, also be formed by means of a plastic molded part manufactured in an injection molding process.

[0056] Sensor 1 comprises, as also shown in FIG. 2 and FIGS. 3a, 3b, 3c, 3d, respectively as directly evident from a combination of these figures, a sensor assembly 11, which is formed by means of a membrane 111 and a sensor blade 112 extending from a first surface 111+ of the membrane 111. Sensor blade 112 has a wedge shape in the example of an embodiment shown here; it can, however, for example, also be embodied rod- or plate shaped, such as quite usual in the case of such sensors. Membrane 111 and sensor blade 112 can, for example, be components of one and the same, monolithic, molded part, which is, for example, cast or produced by 3D laser melting; membrane and sensor blade can, however, also be produced, first of all, separately from one another, embodied as individual parts, and then subsequently be connected with one another by material bonding, for example, welded, respectively soldered or brazed, such that, consequently, the individual parts are of materials correspondingly connectable with one another by material bonding. The membrane can, such as quite usual in the case of such sensor assemblies, be at least partially, for example, predominantly or completely, of a metal, such as e.g. stainless steel, respectively a nickel based alloy. Likewise the sensor blade can also be, at least partially, of a metal, for example namely a stainless steel, respectively a nickel based alloy; especially, membrane and sensor blade can also be produced of the same material.

[0057] Besides the sensor assembly 11, the sensor comprises, furthermore, a transducer element 2 embodied, for example, as a piezoelectric transducer, as a capacitive transducer embodied as a component of a capacitor, or, for example, also an optical transducer embodied as a component a photodetector, for generating a signal here serving also as a sensor signal and representing movements of the sensor blade, respectively, equally, deformations of the membrane, changing as a function of time, typically at least at times periodically as a function of time, for example, a signal in the form of a variable electrical voltage modulated by such movements or correspondingly modulated, laser light.

[0058] In an additional embodiment of the invention, the measuring system comprises, furthermore, a tube 3 insertable into the course of the previously indicated pipeline. Tube 3 has a lumen 3′ surrounded by a wall 3* of the tube, for example, a metal wall 3*, which extends from an inlet end 3+ to an outlet end 3# and which is adapted to guide the fluid flowing in the pipeline. In the example of an embodiment shown here, there is provided on the inlet end 3+, as well as also on the outlet end 3#, in each case, a flange serving for forming a leakfree flange connection with, in each case, a corresponding flange on an inlet-, respectively outlet side, line segment of the pipeline. Furthermore, the tube 3 is here essentially straight, for example, embodied as a hollow cylinder with circularly shaped cross section, in such a manner that the tube 3 has an imaginary straight longitudinal axis L imaginarily connecting the inlet end 3+ and the outlet end 3#. The sensor 1 is inserted externally through an opening 3″ formed in the wall into the lumen of the tube and in the region of the opening affixed, for example, releasably, externally on the wall 3*, and, indeed, in such a manner that the surface 111+ of the membrane 111 is facing the lumen 3′ of the tube 3, so that the sensor blade 112 protrudes inwardly into the lumen. Especially, the sensor 1 is so inserted into the opening 3″ that the membrane 111 covers the opening 3″, respectively hermetically seals it. The opening can, for example, be so embodied that it—such as quite usual in the case of measuring systems of the type being discussed—has an (inner-) diameter, which lies in a range between 10 mm and about 50 mm.

[0059] In an additional embodiment of the invention, there is embodied in the opening 3″ a seat 3a serving for the mounting of the membrane to the wall 3*. Sensor 1 can, in such case, be affixed to the tube 3, for example, by material bonding, especially by welding or soldering or brazing, of membrane 111 and wall 3*; it can, however, for example, also be connected releasably with the tube 3, for example, screwed-, respectively screwed on. Embodied in the seat 3a, furthermore, can be at least one sealing surface, for example, also a surrounding, respectively circular ring like, sealing surface, which is adapted, in cooperation with the membrane 111 and an, in given cases, provided, for example, annular or washer-shaped, sealing element, correspondingly to seal the opening 3″. Particularly for the above-described case, in which the sensor assembly is inserted into seat 3a, respectively that the membrane 111 is to be connected by material bonding with the wall of the tube 3, the membrane 111 includes, according to an additional embodiment of the invention, an external, for example, essentially annular, edge segment 111a having a thickness ta, which—such as indicated in FIGS. 2, respectively 3a, 3b, 3c, 3d—is significantly greater than a minimum thickness tb of an inner segment 111b surrounded by the edge segment 111a and carrying the sensor blade 112. Edge segment 111a can in advantageous manner, furthermore, be provided with a sealing surface, for example, a sealing surface also corresponding to the sealing surface, in given cases, provided in the opening 3″ and/or a circular ring like, sealing surface.

[0060] In the example of an embodiment shown here, the measuring system is especially embodied as a vortex flow measuring device having a bluff body 4 arranged in the lumen of the tube 3—here namely upstream of the sensor 1—and serving to cause the appearance of a Kármán vortex street in the flowing fluid. Sensor and bluff body are, in such case, especially, so dimensioned and arranged that the sensor blade 112 protrudes inwardly into the lumen 3* of the tube, respectively the fluid guided therein, into a region, which during operation of the measuring system is regularly occupied by a (continuously formed) Kármán vortex street, so that the pressure fluctuations registered by means of the sensor 1 are periodic pressure fluctuations caused by vortices of opposite sense shed from the bluff body 4 with a shedding rate (˜1/fv.sub.tx) and the sensor signal s1 has a signal frequency (˜fv.sub.tx) corresponding with the shedding rate of the vortices. In the example of an embodiment shown here, the vortex flow measuring device is additionally embodied as a measuring system in compact construction, in the case of which the measuring electronics 2 is accommodated in a protective housing 20 mounted on the tube, for example, by means of a neck shaped connection nozzle 30.

[0061] In an additional embodiment of the invention, the sensor 1 and the tube 3 are, furthermore, so dimensioned that a length I of the sensor blade 112, measured as the minimum separation between a proximal end of the sensor blade 112, namely an end adjoining the membrane, and a distal, (free) end of the sensor blade 112, namely an end remote from the membrane 111, respectively from its surface 111+, corresponds to greater than a half caliber DN of the tube 3, respectively less than 95% of the caliber DN. The length I can, for example, also be so selected—such as quite usual in the case of comparatively small calibers of less than 50 mm, respectively, as also evident from FIG. 2—that the distal end of the sensor blade 112 has only a very small, minimum separation from the wall 3* of the tube 3. In the case of tubes with comparatively large calibers of 50 mm or more, the sensor blade 112 can, such as quite usual in the case of measuring systems of the type being discussed, for example, also be embodied significantly shorter than a half caliber of the tube 3.

[0062] As already mentioned, the sensor assembly, consequently the sensor formed therewith, respectively the measuring system formed therewith, is especially provided to measure, respectively to be able to measure, at least at times, a fluid having a high temperature greater than 400° and a high pressure greater than 140 bar. In order to achieve a required correlation between pressure resistance and operating temperature (pressure-temperature curve), the membrane of the sensor assembly of the invention is, as also shown schematically, in each case, in FIGS. 2, 3c, 3d, 4a, respectively 4b, embodied bowl shaped, namely at least sectionally bulged, in such a manner that the first surface 111+ of the membrane 111 is curved, wherein the membrane is so formed that, such as directly evident from the combination of FIGS. 2, 3c, 3d, 4a, 4b, at least the region of the surface 111+ adjoining the sensor blade 112 is convex. As schematically shown in FIGS. 2, 3c, 3d, the membrane 111 can, in such case, especially, be so formed that a second surface 111# lying opposite the surface 111+, namely in the case of sensor assembly 1 installed in the tube 3 facing away from the lumen 3*, extends—here at least partially likewise curved and/or at least partially concave—completely, respectively at least predominantly, parallel to the first surface 111+ and/or that a region of the second surface 111#, which lies opposite the convex region of the surface 111+ carrying the sensor blade, is concave; in case required, the membrane 111 can also be so formed that the surface 111# is partially, in given cases, predominantly or also completely, non-parallel to the surface 111+, for example, in such a manner that the membrane 111 has in the radial direction, respectively along at least one lateral line, varying thicknesses.

[0063] In an additional embodiment of the invention, the membrane is, furthermore, so formed that the region of the surface 111+ adjoining the sensor blade 112 is axially symmetric relative to at least one imaginary axis of symmetry. Said symmetry axis can correspond, for example, to one of the cutting lines A, respectively B, shown in FIG. 3b. Furthermore, membrane 111 and sensor blade 112 can, in such case, be so embodied and oriented relative to one another that—, as well as also directly evident from a combination of FIGS. 3a, 3b, 3c and 3c—the symmetry axis is parallel to a principle axis of inertia of the sensor blade and/or in such a manner that the symmetry axis is perpendicular to a principle axis of inertia of the sensor blade. Alternatively or supplementally, the sensor blade 112 and the membrane 111 can additionally be so positioned and oriented relative to one another that—as also directly evident from a combination of FIGS. 3a, 3b, 3c and 3c—a lengthened principle axis of inertia of the membrane 111 coincides with a principle axis of inertia of the sensor blade 112 or that the lengthened principle axis of inertia of the membrane 111 extends parallel to the principle axis of inertia of the sensor blade 112, for example, also in such a manner that the lengthened principle axis of inertia of the sensor blade 112 extends parallel to, but separated from, the principle axis of inertia of the membrane 111, so that—as also indicated in FIG. 5—the principle axis of inertia of the sensor blade 112 does not coincide with the principle axis of inertia of the membrane 111. Sensor blade 112 and membrane 111 can additionally also be so positioned and oriented relative to one another that a lengthened principle axis of inertia of the sensor blade extends parallel to a principle axis of inertia of the sensor assembly, respectively coincides therewith, and/or that a principle axis of inertia of the membrane is parallel to, respectively coincides with, a principle axis of inertia of the sensor assembly 11.

[0064] In an additional embodiment of the invention, it is, furthermore, provided, respectively the membrane is so formed, that the region of the first surface 111+ adjoining the sensor blade 112 is axially symmetric relative to exactly two mutually perpendicular, imaginary axes of symmetry, for example, in such a manner that-, as well as also evident from a combination of FIG. 3a, 3b 3c, 3d—at least one of the two axes of symmetry is parallel to a principle axis of inertia of the sensor blade and/or in such a manner that a principle axis of inertia of the sensor blade is perpendicular to one of the imaginary axes of symmetry and parallel to the other imaginary axis of symmetry.

[0065] The membrane 111 is, according to an additional embodiment of the invention, so formed that at least the region of the surface 111+ adjoining the sensor blade 112 is rotationally symmetric. As directly evident from a combination of FIGS. 2, 3a, 3b 3c, 3d, the membrane 111 can, in such case, be developed e.g. at least partially conically, consequently the surface 111+, not least of all also its region adjoining the sensor blade, can at least partially correspond to a lateral surface of a frustum, for example, in such a manner that—, as also directly evident from FIGS. 2, respectively 3c and 3d—an imaginary top area of the frustum corresponds to a cross sectional area of the sensor blade. Alternatively or supplementally, the membrane can, for example, also be so formed that—such as schematically shown in FIGS. 4a, 4b—its surface 111+, not least of all also its region adjoining the sensor blade, corresponds at least partially to a surface of a spherical zone, for example, in such a manner that—as also evident from FIGS. 4a and 4b, respectively their combination—an imaginary top area of the spherical zone corresponds to a cross sectional area of the sensor blade, that thus at least the region of the first surface adjoining the sensor blade 111+ is spherically formed. Alternatively or supplementally, the membrane can, however, also be so formed that the surface 111+ is at least partially aspherical, for example, also its region adjoining the sensor blade.

[0066] The membrane is, furthermore, can be, so formed that at least the segment 111b carrying the sensor blade 112, consequently the segment 111b forming the region of the first surface adjoining the sensor blade 111+, is rotationally symmetric, especially is embodied as a body of revolution having cylindrical symmetry. Alternatively, the membrane can, however, also be so formed, not least of all also for the purpose of an additional optimizing of measuring sensitivity and pressure resistance, that the first surface 111+ of the membrane, respectively its region adjoining the sensor blade 112, is not rotationally symmetric, for example, is only plane symmetric and/or, for example, corresponds to a segment of a surface of an ellipsoid; this, especially, in the manner that, as also shown in FIG. 6, respectively as is evident from a combination of FIG. 2 and FIG. 6, as a result, a greatest semi axis (r′) of the ellipsoid corresponding to the shape of the region of the surface 111+ adjoining the sensor blade extends transversely to the longitudinal axis L of the tube 3 and a middle semi axis (r″) of the ellipsoid extends parallel to the longitudinal axis L.

[0067] Since the membrane is formed in the previously indicated manner, namely embodied basically bowl shaped with convex surface 111+ at least in a region adjoining the sensor blade, it is possible in easy and equally as well very effective manner to achieve a drastic increase of the nominal pressure resistance, respectively a drastic improving of the dependence of the pressure resistance on the operating temperature, without in turn experiencing a sinking of measuring sensitivity, namely sensitivity of the sensor to the pressure fluctuations actually to be registered to an extent unacceptable for the high accuracy of measurement typically required, not least of all, also in industrial use. In an additional embodiment of the invention, the membrane is, especially, so formed that, as also directly evident from a combination of FIGS. 3a, 3b, 3c and 3d, a membrane height h, measured as a minimum separation of a center of area of the surface 111+ from an imaginary projected area inscribed by a peripheral (for example, also directly adjoining the above-mentioned edge segment 111a) outer edge of the region of the first surface adjoining the sensor blade is less than a membrane diameter 2r, measured as a greatest diameter of the projected area, especially less than a radius r, respectively in the case of an elliptical projected area, is less than a greatest semi axis r′ of the projected area, for example, however, also less than a smallest semi axis r″ of the projected area. A very good compromise between as high as possible pressure resistance, on the one hand, and as high as possible measuring sensitivity, on the other hand, can be achieved, for example, by forming the membrane such that a diameter-to height ratio of the membrane (2r/h), defined as a ratio of the membrane diameter to the membrane height, is less than 30 and/or greater than 2, especially less than 20 and/or greater than 5. Alternatively or supplementally, the membrane 111 can, matched to the above-mentioned length I of the sensor blade 112, furthermore, be so dimensioned that a ratio of the membrane diameter 2r to the length I amounts to less than 2 and/or greater than 0.5.

[0068] For the purpose of an additional optimizing of measuring sensitivity and pressure resistance, the membrane 111 can, additionally, have, for example, also zones of different thickness. Therefore, the membrane 111 according to an additional embodiment of the invention is, furthermore, so embodied that the segment 111b carrying the sensor blade 112 has a first zone forming a center of the membrane with a first thickness and a second zone adjoining the first zone, especially surrounding it, with a second thickness different from the first thickness, for example, in such a manner that the first thickness is less than the second thickness, especially that the first thickness corresponds to the minimum thickness tb.

[0069] For compensating possible forces and/or moments resulting from movements of the sensor assembly, for instance, movements resulting from vibration of the connected pipeline, respectively for preventing undesired movements (namely movements corrupting the sensor signal s1) of the sensor blade, respectively the membrane, resulting therefrom, the sensor assembly 11 includes, according to an additional embodiment of the invention, furthermore, a compensating body 113, for example, a rod-, plate- or sleeve-shaped, compensating body 113, extending from the second surface 111# of the membrane 111. Said compensating body 113 can additionally also serve as a mount for the transducer element 12 or also as a component of the transducer element 12, for example, as a movable electrode of a capacitor forming the (capacitive) transducer element. In an additional embodiment, the membrane is, furthermore, so formed, respectively the compensating body is so positioned, that at least one region of the second surface 111# adjoining the compensating body 113 is concave and/or rotationally symmetric, especially extends parallel to the region of the first surface adjoining the sensor blade 111+.

[0070] The compensating body 113 can, for example, be of the same material as the membrane and/or as the sensor blade, for example, a metal. For example, the compensating body 113 can namely be produced of a stainless steel, respectively a nickel based alloy. In an additional embodiment of the invention, membrane 111 and compensating body 113 are connected with one another by material bonding, for example, welded, respectively soldered or brazed. Consequently, it is provided that compensating body 113 and membrane 111 are manufactured from materials connectable with one another by material bonding. Alternatively, membrane 111 and compensating body 113 can, however, also be components of one and the same, monolithic, molded part, for example, also in such a manner that sensor blade 111, membrane 112 and compensating body 113 are components of the molded part.

[0071] Sensor blade 112 and compensating body 113 can, furthermore, as also evident from a combination of FIGS. 3c and 3d, respectively a combination of FIGS. 4a and 4b, be arranged aligned with one another, in such a manner that a lengthened principle axis of inertia of the sensor blade 112 coincides with a principle axis of inertia of the compensating body 113. Alternatively or supplementally, the compensating body 113 and the membrane 111 can additionally be so positioned and oriented relative to one another that a lengthened principle axis of inertia of the membrane 111 coincides with a principle axis of inertia of the compensating body 113 or also such that the lengthened principle axis of inertia of the membrane 111 extends parallel to the principle axis of inertia of the compensating body 113; this, for example, also in such a manner that sensor blade 112 and compensating body 113 align with one another in the previously indicated manner, however, both the lengthened principle axis of inertia of the compensating body as well as also the lengthened principle axis of inertia of the sensor blade extend parallel to but spaced from the principle axis of inertia of the membrane, so that thus not only the principle axis of inertia of the sensor blade 112—such as, for example, also shown in FIG. 5—, but, instead, also the principle axis of inertia of the compensating body 113 do not coincide with the principle axis of inertia of the membrane 111. Moreover, sensor blade 112, compensating body 113 and membrane 111 can also be so positioned and oriented relative to one another that—as evident, for example, also from a combination of FIGS. 2, 3a, 3b, 3c and 3d—a principle axis of inertia of the sensor assembly 11 is parallel both to a principle axis of inertia of the sensor blade 112 as well as also to a principle axis of inertia of the compensating body 113, as well as also to a principle axis of inertia of the membrane 111 or coincides both with the principle axis of inertia of the sensor blade as well as also with the principle axis of inertia of the compensating body, as well as also with the principle axis of inertia of the membrane.