Ultrasonic transducer, ultrasonic flow measuring device and method
By setting a buffer element in the ultrasonic transducer to form a reflective boundary layer and monitoring the reflected signal, the problem of distinguishing between empty pipes and faulty states is solved, and fault identification and status monitoring of the equipment are realized.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- KROHNE MESSTECHNICK GMBH & CO KG
- Filing Date
- 2021-09-16
- Publication Date
- 2026-07-10
AI Technical Summary
Existing ultrasonic flow measurement equipment has difficulty distinguishing between empty pipe conditions and converter malfunctions, resulting in an inability to accurately identify the equipment's operating status.
A buffer element is provided in or on the converter housing to form a boundary layer that reflects at least partially. The fault condition of the converter is identified by monitoring the reflected signal components, and the operating status of the equipment is determined by the control and evaluation unit.
It enhances the fault identification capability of ultrasonic converters and flow measurement equipment, and can easily and effectively distinguish between converter faults and empty pipe conditions, providing fault signal notifications.
Smart Images
Figure CN114199330B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to an ultrasonic transducer for an ultrasonic flow measurement device, the ultrasonic transducer having a transducer housing and a transducer element, wherein the transducer housing has an ultrasonic window and wherein the transducer element is arranged within the transducer housing and configured to transmit ultrasonic signals onto a signal path and receive ultrasonic signals from the signal path, and the ultrasonic transducer has a control and evaluation unit for manipulating the transducer element and evaluating the ultrasonic signals. Furthermore, this invention relates to an ultrasonic flow measurement device, a method for functional monitoring of an ultrasonic transducer, and a method for operating an ultrasonic flow measurement device. Background Technology
[0002] Ultrasonic flow measurement devices are widely known from the prior art and used to determine the flow rate of a flowing medium through a measuring tube. For this purpose, ultrasonic flow measurement devices typically have at least two ultrasonic transducers configured as ultrasonic transmitters and / or ultrasonic receivers, arranged spaced apart from each other in the flow direction (axially relative to the axis of the measuring tube). To determine the flow rate, an ultrasonic signal is emitted once in the flow direction of the medium and once in the opposite direction along a signal path between the ultrasonic transducers, and the propagation time of the ultrasonic signal, which differs from each other due to the entrainment effect of the medium, is determined. The flow velocity of the medium can be determined from the propagation time difference, and the volumetric flow rate of the medium is derived from the flow velocity and the cross-section of the measuring tube.
[0003] The ultrasonic signal is generated and received by a converter element located within the converter housing of the ultrasonic transducer. In practice, the converter element is mostly implemented using an electromechanical converter element, the operating principle of which is based on the piezoelectric effect. The ultrasonic signal is then either emitted into the measuring tube via an ultrasonic window in the converter housing or received via an ultrasonic window in the converter housing.
[0004] Ultrasound travels well in liquids, where liquids demonstrate minimal attenuation. In air, however, the ultrasonic signal is significantly attenuated. Without a medium in the measuring tube, the transmission of ultrasound from one transducer to another is greatly attenuated, making it impossible or almost impossible to receive the signal. However, in practice, the case of an empty measuring tube cannot be easily distinguished from that of a defective transducer element. In both cases, the transducer attempting to receive the signal receives no signal or only a very small signal.
[0005] The drawback of existing ultrasonic transducers and ultrasonic flow measurement devices is that it is not easy to distinguish between an empty pipe and a faulty ultrasonic transducer. Summary of the Invention
[0006] Therefore, the objective of this invention is to provide an ultrasonic flow measurement device and ultrasonic transducer with improved fault identification capabilities. Furthermore, the objective of this invention is to provide corresponding methods for functional monitoring and for operating the ultrasonic transducer and ultrasonic flow measurement device.
[0007] This task is primarily solved, and essentially, by the ultrasonic transducer according to the invention, in the case of a buffer element arranged in or on the transducer housing within the signal path, and the buffer element forming at least one at least partially reflective boundary layer in the signal path. During operation of the ultrasonic transducer, the transducer element emits an ultrasonic signal, which is at least partially reflected at the boundary layer of the buffer element. The reflected signal component is then received by the transducer element. The transmitted signal component is emitted via the ultrasonic window.
[0008] If we say that the buffer element is arranged inside the converter housing, it means that the buffer element is arranged inside the converter housing. If we say that the buffer element is arranged on the converter housing, it means that the buffer element is at least indirectly, and preferably directly, connected to the converter housing. It does not mean that the buffer element is arranged outside the converter housing, spaced apart from and not connected to the converter housing.
[0009] According to a further provision of the invention, the control and evaluation unit is designed to monitor the reception of reflected signal components during the operation of the ultrasound transducer. In the absence of reflected signal components, the control and evaluation unit identifies a fault condition of the ultrasound transducer.
[0010] The ultrasonic transducer, according to the design of the present invention, allows for a simple detection of whether the transducer element has generated and emitted an ultrasonic signal. If not, no signal component is reflected at the boundary layer of the buffer element and therefore not received again by the transducer element. The failure to receive the reflected signal component is identified by the control and evaluation unit. This allows the user to easily track whether a fault condition exists in the ultrasonic transducer. In a preferred design, the control and evaluation unit is further designed to signal the identified fault condition via a fault signal. Signal notification can be performed in various ways and methods, such as by outputting optical or acoustic alarm signals. However, fault codes can also be generated and output, for example. The invention is not limited to the methods mentioned for signal notification of fault conditions.
[0011] In an alternative design of the ultrasonic transducer according to the invention, a buffer element is also arranged in the signal path and forms at least one at least partially reflective boundary layer (10) in the signal path. Unlike the previously described design, the second transducer element is arranged within the transducer housing. During operation of the ultrasonic transducer, the transducer element emits an ultrasonic signal that is at least partially reflected at the boundary layer of the buffer element. The second transducer element is arranged in the transducer housing such that the reflected signal component is received by the second transducer element. Particularly preferably, the second transducer element is designed solely for receiving ultrasonic signals. In this alternative design, a control and evaluation unit is designed to monitor the reception of the reflected signal component during operation of the ultrasonic transducer and to identify a fault condition of the ultrasonic transducer in the absence of reception of the reflected signal component.
[0012] This alternative design is particularly advantageous if the emitted ultrasonic signal is not perpendicular to the partially reflective boundary layer and is therefore reflected at an exit angle corresponding to the incident angle. This is especially true in the ultrasonic transducers of clamp-on ultrasonic flow measurement devices. Clamp-on ultrasonic flow measurement devices are clamped from the outside onto a measuring tube in which the medium to be measured flows. Such flow measurement devices typically have two ultrasonic transducers. The ultrasonic transducers, or transducer elements of the ultrasonic transducers, are then oriented at an angle relative to the surface of the measuring tube, such that the ultrasonic signal is emitted into the measuring tube at an angle. This is ensured by the geometry of the buffer element. For this purpose, the buffer element, for example, has a triangular cross-section.
[0013] The buffer element is implemented in different ways in different designs of the ultrasonic transducer according to the present invention.
[0014] Preferably, a boundary layer is formed on the side of the buffer element away from the transducer element. The emitted ultrasonic signal is partially reflected on the side of the buffer element away from the transducer element and then preferably travels along the entire length of the buffer element along the signal path. The reflected signal component travels back along the signal path through the buffer element before being received by the transducer element again. The buffer element thus ensures the time interval between the transmission of the ultrasonic signal and the reception of the partially reflected signal component.
[0015] In a particularly preferred design of the ultrasonic transducer according to the invention, the buffer element is formed through an ultrasonic window. More preferably, in one design, the ultrasonic window has an increased thickness, wherein the thickness is defined as the extension of the ultrasonic window along the signal path of the ultrasonic signal.
[0016] In one variant, a buffer element formed through the ultrasonic window extends into the transducer housing. In an alternative design, the buffer element formed through the ultrasonic window extends out of the transducer housing.
[0017] In principle, the ultrasonic window can be integrally formed with the transducer housing, where "integratedly" should be understood as the transducer housing and the ultrasonic window being manufactured as a single component and not connected to each other. Alternatively, the ultrasonic window can be implemented as a separate component, however, directly connected to the transducer housing. In particular, a media-sealed connection between the ultrasonic window and the transducer housing is necessary to prevent media from entering the interior of the transducer housing. For example, the ultrasonic window can be welded to the transducer housing.
[0018] In another design of the ultrasonic transducer according to the invention, the buffer element is configured as a separate component. This design has the advantage that the buffer element can be replaced if needed.
[0019] Particularly preferably, the buffer element is arranged inside the transducer housing between the transducer element and the ultrasonic window. More preferably, the transducer element and the buffer element are arranged directly adjacent to each other.
[0020] In another particularly preferred embodiment of the ultrasonic transducer according to the invention, a buffer element forms a first boundary layer and at least one second boundary layer in the signal path of the ultrasonic signal. The ultrasonic signal is at least partially reflected at the first boundary layer, wherein the reflected signal component is reflected by the first boundary layer onto the second boundary layer. Particularly preferably, the reflected signal component strikes the second boundary layer perpendicularly. The reflected signal component is reflected by the second boundary layer back onto the first boundary layer, and from there back to the transducer element, where it is again received by the transducer element.
[0021] This design is particularly advantageous if the ultrasonic transducer is used in a clamp-on ultrasonic flow measurement device.
[0022] To further enhance partial reflection of the ultrasonic signal at the boundary layer, a particularly preferred variant of the ultrasonic transducer according to the invention specifies that an enhancing partial reflection coating is applied to the boundary layer formed by a buffer element. This design is particularly advantageous when the measurement medium has acoustic properties similar to the transducer element or the ultrasonic window of the transducer element, such that partial reflection occurs or is negligible without the additional coating.
[0023] A particularly preferred feature of the ultrasonic transducer according to the invention is that a control and evaluation unit is designed such that, during the operation of the ultrasonic transducer, this control and evaluation unit determines a variable describing the reflected signal component and compares this variable with a reference value for said variable. In a preferred variant, this variable is the intensity of the reflected signal component. The reference value is the value of this variable in a good condition of the ultrasonic transducer. If the deviation of the determined variable from the reference value exceeds a pre-given tolerance range, the control and evaluation unit outputs a fault signal. This design of the ultrasonic transducer enables extended fault diagnosis. Therefore, not only can the effectiveness of the transducer element be identified by monitoring the partially reflected signal component, but more precisely, it can be identified by monitoring the variable describing the reflected signal component to determine whether the transducer element has changed its position in the ultrasonic transducer (e.g., due to it becoming loose and slipping), or whether there are other defects that do not lead to the complete failure of the transducer element. All such events will affect the variable describing the reflected signal component.
[0024] In addition to the ultrasonic transducers, the present invention further relates to an ultrasonic flow measurement device for determining the flow rate of a flowing medium. The ultrasonic flow measurement device has a first ultrasonic transducer and a second ultrasonic transducer, and further includes a control and evaluation unit. The ultrasonic transducers are configured to transmit ultrasonic signals onto a signal path and / or to receive ultrasonic signals from the signal path, and the signal paths via the ultrasonic signals are effectively associated with each other.
[0025] If we say that ultrasound transducers are effectively associated with each other via signal paths, it means that at least one ultrasound transducer receives an ultrasound signal transmitted by the other ultrasound transducer via a signal path.
[0026] In the case of the ultrasonic flow measurement device in question, the task is first and essentially solved by having at least one ultrasonic transducer for transmission having a buffer element arranged in or on the transducer housing in the signal path of the ultrasonic signal, and the buffer element forming at least one boundary layer in the signal path that is at least partially reflective.
[0027] In the operation of the ultrasonic flow measurement device, the transducer element of the ultrasonic transducer emits an ultrasonic signal, wherein the ultrasonic signal is at least partially reflected and partially transmitted at the boundary layer of the buffer element.
[0028] In a first variant of the ultrasonic flow measurement device according to the invention, the reflected signal component is received by a converter element of the ultrasonic transducer for transmission. In an alternative variant of the ultrasonic flow measurement device according to the invention, a second converter element is arranged in a converter housing constituting the ultrasonic transducer for transmission. Here, the reflected signal component is received by the second converter element of the ultrasonic transducer for transmission.
[0029] In both variants, the transmitted signal component is received by the transducer element of the ultrasonic transducer.
[0030] According to the invention, in two variants, it is further specified that the control and evaluation unit is designed such that, during the operation of the ultrasonic flow measurement device, the control and evaluation unit monitors the reception of the reflected signal component and the transmitted signal component and identifies one of the following operating states of the ultrasonic flow measurement device:
[0031] The ultrasonic flow measurement device is effective when both the reflected and transmitted signal components are received.
[0032] If the reflected signal component is received but no transmitted signal component is received: the ultrasonic flow measurement device is effective, and the measuring tube is empty.
[0033] In the case where neither the received reflected signal component nor the received transmitted signal component occurs: the ultrasonic flow measurement device is in a fault state, especially the ultrasonic transducer that transmits the signal is in a fault state, and especially the transducer element of the ultrasonic transducer that transmits the signal is in a fault state.
[0034] Particularly preferably, the control and evaluation unit is further configured such that it signals the ultrasonic flow measurement device to indicate the identified operating status. In this case, the signal notification can be made, for example, by various optical or acoustic signals or by other means and methods known in the prior art.
[0035] In a particularly preferred embodiment of the flow measurement device according to the invention, the ultrasonic transducer is equipped with the features of the ultrasonic transducer according to the invention previously described. Correspondingly, all discussions concerning preferred embodiments and their advantages in connection with the ultrasonic transducer according to the invention are similarly applicable to and correspondingly suited to the ultrasonic flow measurement device according to the invention.
[0036] In a particularly preferred design of an ultrasonic flow measurement device, the control and evaluation unit is designed such that if the transmitted signal component is below a pre-defined limit value, the control and evaluation unit evaluates the transmitted signal component as "not received." Here, the limit value can be, for example, an intensity value or an amplitude value. This design takes into account that, although the measuring tube is empty, ultrasonic signals still propagate in principle, but the ultrasonic signals are attenuated very strongly. Therefore, it is conceivable that, although the measuring tube is empty (although the ultrasonic signal is extremely small), the transmitted signal component can be received. However, if the transmitted signal component is below a pre-defined limit value (especially by the user), the measuring tube is still identified as "empty."
[0037] Furthermore, the present invention relates to a method for functional monitoring of an ultrasonic transducer. The ultrasonic transducer has a transducer housing and a transducer element, wherein the transducer housing has an ultrasonic window, and wherein the transducer element is arranged within the transducer housing and configured to transmit ultrasonic signals onto a signal path and to receive ultrasonic signals from the signal path. Similarly, the ultrasonic transducer has control and evaluation units for manipulating the transducer element and for evaluating the ultrasonic signals. Furthermore, a buffer element is provided, which is arranged in the signal path of the ultrasonic signal and forms at least one at least partially reflective boundary layer relative to the surrounding environment of the buffer element. In a variant, a second transducer element is arranged within the transducer housing of the ultrasonic transducer.
[0038] The method according to the invention is characterized in that, firstly, in the transmitting step, an ultrasonic signal is emitted, wherein the ultrasonic signal is at least partially reflected at the boundary surface. The ultrasonic signal is emitted by a transducer element of an ultrasonic transducer. In the subsequent receiving step, the reflected signal component is received by the transducer element of the ultrasonic transducer or a second transducer element arranged in the transducer housing. The reception of the reflected signal component is monitored in the monitoring step. If no reception of the reflected signal component occurs, the absence of a fault condition is identified in the signal notification step, and a fault state is signaled.
[0039] The method according to the invention provides a very simple way to test the effectiveness of an ultrasonic transducer, more precisely, without requiring a separate testing device. If a reflected signal component is received, then the reflected signal component should have been emitted beforehand, and the transducer element should therefore be effective. If no reflected signal component is received, the user should assume that no ultrasonic signal was emitted and that the transducer element is faulty, for example, defective.
[0040] In a preferred embodiment of the method according to the invention, in the comparison step, variables describing the reflected signal components, particularly the intensity of the reflected signal components, are compared with reference values, and a fault signal is output when the deviation exceeds a predetermined tolerance value. This supplementary method step allows for a more comprehensive functional check of the ultrasonic transducer, as it monitors not only whether the transducer elements emit ultrasonic signals, but also whether the emitted ultrasonic signals change, for example, due to changes in the transducer elements' position within the transducer housing.
[0041] The method according to the invention is particularly suitable for functional monitoring of the ultrasonic transducers described above. Correspondingly, all previous discussions regarding ultrasonic transducers can be similarly applied to this method.
[0042] Furthermore, the present invention relates to a method for operating an ultrasonic flow measurement device, wherein the ultrasonic flow measurement device includes a first ultrasonic transducer, a second ultrasonic transducer, and a control and evaluation unit. The ultrasonic transducers are configured to transmit ultrasonic signals onto a signal path and / or to receive ultrasonic signals from the signal path, and the signal paths via the ultrasonic signals are effectively associated with each other. At least one ultrasonic transducer configured for transmission has a buffer element, wherein the buffer element is arranged in the signal path of the ultrasonic signal and forms at least one at least partially reflective boundary layer in the signal path.
[0043] The method according to the invention is characterized in that, in the transmitting step, the transmitting transducer element emits an ultrasonic signal, wherein the ultrasonic signal is at least partially reflected and partially transmitted at the boundary layer of the buffer element. In the receiving step, the transducer element of the transmitting ultrasonic transducer or a second transducer element arranged in the transmitting ultrasonic transducer receives the reflected signal component, and the transducer element of the receiving ultrasonic transducer receives the transmitted signal component. In the monitoring step, the control and evaluation unit monitors the reception of the reflected signal component and the reception of the transmitted signal component. In the subsequent signal notification step, the control and evaluation unit notifies the ultrasonic flow measurement device of one of the following operating states by signal:
[0044] ● The ultrasonic flow measurement device is effective when both the reflected and transmitted signal components are received.
[0045] ●If the reflected signal component is received but no transmitted signal component is received: the ultrasonic flow measurement device is effective, and the measuring tube is empty.
[0046] ● In the case where neither the reflected signal component nor the transmitted signal component is received: the ultrasonic flow measurement device is in a faulty state, especially the ultrasonic transducer that transmits the signal is in a faulty state, especially the transducer element of the ultrasonic transducer that transmits the signal is in a faulty state.
[0047] The method according to the invention enables a simple distinction between a faulty transducer element or ultrasonic transducer and an empty measuring tube. A particularly preferred embodiment of the method according to the invention is characterized in that if the transmitted signal component is below a predetermined limit value, the transmitted signal component is evaluated as "not received." This limit value can be based, for example, on an intensity or amplitude value. This embodiment of the method is able to identify an empty measuring tube even if the transmitted ultrasonic signal is not completely attenuated.
[0048] The method according to the invention is particularly suitable for operating the ultrasonic flow measurement device according to the invention previously described. Correspondingly, all the discussions already made regarding ultrasonic flow measurement devices can be similarly applied to this method. Attached Figure Description
[0049] In detail, there are now various possibilities for designing and improving the ultrasonic transducer and ultrasonic flow measurement device according to the invention. Furthermore, there are various possibilities for implementing the method according to the invention. For this purpose, reference is made to the claims, which are subordinate to the independent claims, and to the description of preferred embodiments in conjunction with the accompanying drawings. In the drawings...
[0050] Figure 1 This illustrates the first design scheme of the ultrasonic transducer.
[0051] Figure 2 This illustrates a second design scheme for the ultrasonic transducer.
[0052] Figure 3 The third design scheme for the ultrasonic transducer is shown.
[0053] Figure 4 This illustrates a first variant of the ultrasonic flow measurement device.
[0054] Figure 5 This illustrates a second variant of the ultrasonic flow measurement device.
[0055] Figure 6 The fourth design scheme for the ultrasonic transducer is shown.
[0056] Figure 7 The fifth design scheme for the ultrasonic transducer is shown.
[0057] Figure 8 This illustrates a method for functional monitoring of an ultrasound transducer, and
[0058] Figure 9 A method for operating an ultrasonic flow measurement device is shown. Detailed Implementation
[0059] Figure 1 Showing the use of in Figure 4 The ultrasonic flow measurement device 2 shown includes an ultrasonic transducer 1. The ultrasonic transducer 1 has a transducer housing 3 and a transducer element 4. The transducer housing has an ultrasonic window 5 through which the ultrasonic transducer 1 transmits or receives ultrasonic waves. The transducer element 4 is arranged in the transducer housing 3 and is used to transmit ultrasonic signals 6 to or receive ultrasonic signals 6 from the signal path 7. Furthermore, the ultrasonic transducer 1 has a control and evaluation unit 8 for manipulating the transducer element 4 and evaluating the ultrasonic signals 6. Figure 1 In the case of the ultrasonic transducer 1 shown, a buffer element 9 is arranged in the signal path 7 within the transducer housing 3. The buffer element 9 forms a partially reflective boundary layer 10 in the signal path 7, located on the side of the buffer element 9 facing away from the transducer element 4. During operation of the ultrasonic transducer 1, the transducer element 4 emits an ultrasonic signal 6, which is at least partially reflected at the boundary layer 10, as shown in… Figure 1 The reflected signal component 11 is indicated by a dashed line. Similarly, the transmitted signal component 12 is shown, indicated by a dotted line. The transducer element 4 receives the reflected signal component 11 again. The illustrated ultrasound transducer 1 is characterized by a control and evaluation unit 8 designed to monitor the reception of the reflected signal component 11 during the operation of the ultrasound transducer 1. If the reflected signal component 11 is received by the transducer element 4, the ultrasound transducer 1 is in a valid state. However, if no reception of the reflected signal component 11 occurs, that is, no signal is received by the transducer element 4, the control and evaluation unit 8 identifies a fault condition in the ultrasound transducer 1. The illustrated control and evaluation unit 8 is further designed to notify of the fault condition by a signal. Furthermore, the control and evaluation unit 8 is designed to compare the intensity of the reflected signal component 11 with a reference value representing the good condition of the ultrasound transducer 1. If the deviation exceeds a pre-defined tolerance range, the control and evaluation unit identifies a fault condition. For example, this would be the case if converter element 4 has become loose and its position within converter housing 3 has changed.
[0060] Ultrasonic transducer 1 in Figure 1The illustrated embodiment has a buffer element 9 designed as a separate component. The buffer element 9 is formed inside the transducer housing 3 and arranged between the transducer element 4 and the ultrasonic window 5. A reflective boundary layer 10 is formed between the buffer element 9 and the ultrasonic window 5 in this case.
[0061] and Figure 1 The implementation shown is different, in Figure 2 and Figure 3 The image shows an ultrasonic transducer 1, in which a buffer element 9 is formed through an ultrasonic window 5. Figure 2 In the design shown, the ultrasonic window 5 has a thickness d and extends into the converter housing 3. Figure 3 In the design shown, the ultrasonic window 5 extends into the external space of the ultrasonic transducer 1.
[0062] exist Figure 3 In the ultrasonic transducer 1 shown, the buffer element 9 has a cover 13 on its side away from the transducer element 4, which is used to improve, for example, increase the reflectivity of the boundary layer 10.
[0063] Figure 4 Showing two in Figure 1 The ultrasonic flow measurement device 2 is illustrated with ultrasonic transducer 1. Furthermore, the ultrasonic flow measurement device 2 has a control and evaluation unit 14. In the illustrated embodiment, the two ultrasonic transducers 2 are designed not only to transmit ultrasonic signals 6 but also to receive ultrasonic signals 6. The two ultrasonic transducers 1 are arranged on opposite sides of the measuring tube 15 and are further offset from each other in the flow direction indicated by the arrow. The two ultrasonic transducers are effectively associated with each other via signal path 7. In the illustrated design, the ultrasonic transducers 1 are arranged in the transducer pocket 16 of the measuring tube 15. In the operating state of the ultrasonic flow measurement device 2, the transducer element 4 of the transmitting ultrasonic transducer 1 emits ultrasonic signals 6, wherein the ultrasonic signals 6 are at least partially reflected and partially transmitted at the boundary layer 10 of the buffer element 9 of the transmitting ultrasonic transducer 1. The reflected signal component 11 is then received by the transducer element 4 of the transmitting ultrasonic transducer 1, and the transmitted signal component 12 is received by the transducer element 4 of the receiving ultrasonic transducer 1.
[0064] The control and evaluation unit 14 of the ultrasonic flow measurement device 2 is designed to monitor the reception of the reflected signal component 11 and the transmitted signal component 12 during the operation of the ultrasonic flow measurement device 2. Based on which signal components are received by the converter element 4, the control and evaluation unit 14 identifies and signals the ultrasonic flow measurement device 2 to indicate one of the following operating states:
[0065] ●When both the reflected signal component 11 and the transmitted signal component 12 are received: the ultrasonic flow measurement device 2 is effective.
[0066] ●If the reflected signal component 11 is received but the transmitted signal component 12 is not received: the ultrasonic flow measurement device is effective, and the measuring tube 15 is empty.
[0067] ● In the case where neither the reflected signal component 11 nor the transmitted signal component 12 is received: the ultrasonic flow measurement device 2 is in a fault state, especially the ultrasonic transducer that transmits the signal is in a fault state, especially the transducer element 4 of the ultrasonic transducer 1 that transmits the signal is in a fault state.
[0068] In the design scheme shown for the ultrasonic flow measurement device 2, the ultrasonic converter 1 is based on... Figure 1 The embodiment shown is configured as described. However, alternative designs or hybrid designs, such as different designs of the two ultrasound transducers 1, are also conceivable. The control and evaluation unit 14 is further designed such that if the transmitted signal component 12 is below a predetermined limit value, the control and evaluation unit evaluates the transmitted signal component 12 as "not received". Currently, the intensity value of the transmitted signal component 12 is used as the limit value.
[0069] Figure 5An ultrasonic flow measuring device 2, designed as a clamp-on ultrasonic flow measuring device, is shown. The ultrasonic flow measuring device 2 is clamped externally onto a measuring tube 15. The clamping mechanism is not shown here, as it is irrelevant to the present invention. The ultrasonic flow measuring device 2 has two ultrasonic transducers 1. Each ultrasonic transducer 1 has a transducer element 4 and a buffer element 9. The transducer element 4 is oriented such that it emits at an angle onto the surface of the measuring tube. This is achieved by the buffer element 9 having a substantially triangular cross-section. In the current illustration, the signal path of the ultrasonic signal 6 is shown only schematically, as the direction of the signal path 6 depends on the materials used for the buffer element 9, the measuring tube 15, and the medium transported in the measuring tube 15. The transducer element 4 of the transmitting ultrasonic transducer 2 emits the ultrasonic signal 6, which is reflected at a boundary layer 10 formed between the buffer element 9 and the surface of the measuring tube. Here, the incident angle corresponds to the exit angle, such that the reflected signal component 11 is reflected at the same angle as its angle of impact onto the boundary layer 10. The reflected signal component 11 then strikes the second boundary layer 10' that constitutes the buffer element 9. From there, the reflected signal component 11 is reflected back to the boundary layer 10, and from there it is reflected back to the transducer element 4 that receives the reflected signal component. The transmitted signal component 12 is emitted into the measuring tube 15 and reflected at the inside of the measuring tube toward the second transducer element 4 of the second ultrasonic transducer 2. The transducer element 4 then receives the transmitted signal component 12.
[0070] exist Figure 6 The text shows that in Figure 5 The ultrasonic transducer of the ultrasonic flow measurement device 2 shown is illustrated. The ultrasonic transducer 1 has a housing 3, within which the transducer element 4 is located. The ultrasonic transducer 1 has a buffer element 9, which forms a first boundary layer 10 and a second boundary layer 10' in the beam path of the ultrasonic signal 6. (As already combined...) Figure 5 As explained, the transducer element 4 emits an ultrasonic signal 6, which is partially reflected at the boundary layer 10. The exit angle of the reflected signal component 11 corresponds to the incident angle of the ultrasonic signal 6. The reflected signal component 11 is reflected to the second boundary layer 10' and strikes it perpendicularly. From there, the reflected signal component is reflected back to the boundary layer 10 and from there back to the transducer element 4. The control and evaluation unit 8 of the ultrasonic transducer 1 is designed to monitor the reception of the reflected signal component 11 and identify fault conditions of the ultrasonic transducer 1 when they do not occur.
[0071] exist Figure 7An alternative design for the ultrasound transducer 1 is shown. Here, the ultrasound transducer 1 has a first transducer element 4, which is configured for and used to transmit and receive ultrasound signals. However, the ultrasound transducer 1 also has a second transducer element 4' used to receive the reflected signal component 11. (The last sentence appears to be incomplete and possibly refers to a different design.) Figure 6 The embodiment shown differs from the one illustrated here, therefore the reflected signal component 11 is not reflected back to converter element 4, but is instead received by converter element 4'. The control and evaluation unit 8 is thus designed to monitor the reception of the reflected signal component 11 by the second converter element 4'. In the absence of a reflected signal component 11, the control and evaluation unit 8 identifies a fault condition.
[0072] Figure 8 Showing the monitoring as in Figures 1 to 3 and Figure 6 The illustrated method 100 for monitoring the function of an ultrasonic transducer. In the transmitting step 101, an ultrasonic signal is emitted, wherein the ultrasonic signal is at least partially reflected at an interface. In the receiving step 102, the reflected signal component is received by a transducer element. In the monitoring step 103, the reception of the reflected signal component is monitored, and in the signal notification step 104, a fault state is notified by signal if no reception of the reflected signal component occurs.
[0073] Figure 9 Showing the method for running as in Figure 4 Method 200 of the ultrasonic flow measurement device shown. In the shown method, in the transmitting step 201, an ultrasonic signal is emitted by a transducer element performing the transmitting, wherein the ultrasonic signal is at least partially reflected and partially transmitted at the boundary layer of a buffer element. In the receiving step 202, the transducer element of the transmitting ultrasonic transducer receives the reflected signal component, and the transducer element of the receiving ultrasonic transducer receives the transmitted signal component. In the monitoring step 203, a control and evaluation unit monitors the reception of the reflected signal component and the reception of the transmitted signal component. In the signal notification step 204, one of the following operating states of the ultrasonic flow measurement device is notified by the control and evaluation unit by a signal:
[0074] ● The ultrasonic flow measurement device is effective when both the reflected and transmitted signal components are received.
[0075] ●In the case where the reflected signal component is received but no transmitted signal component is received: the measuring tube is empty.
[0076] ● In the case where neither the reflected signal component nor the transmitted signal component is received: the ultrasonic flow measurement device is in a faulty state, especially the converter element of the ultrasonic transducer that transmits the signal is in a faulty state.
[0077] In the method shown, if the transmitted signal component is below a predetermined limit value, the transmitted signal component is evaluated as "not received". Here, the intensity value of the transmitted signal component is predetermined as a limit value.
[0078] Figure Labels
[0079] 1. Ultrasonic transducer
[0080] 2. Ultrasonic flow measurement equipment
[0081] 3. Converter housing
[0082] 4. Converter Components
[0083] 4' Second converter element
[0084] 5. Ultrasound window
[0085] 6. Ultrasonic signals
[0086] 7. Signal Path
[0087] 8. Control and Evaluation Unit
[0088] 9. Buffer elements
[0089] 10 Boundary Layer
[0090] 10' Second boundary layer
[0091] 11. Reflected signal components
[0092] 12 Transmitted signal components
[0093] 13. Coating
[0094] 14 Control and Evaluation Unit
[0095] 15 Measuring tubes
[0096] 16 Converter Bags
[0097] 100 methods
[0098] 101 Sending Steps
[0099] 102 Receiving Steps
[0100] 103 Monitoring Steps
[0101] 104. Notification steps using signals
[0102] 200 methods
[0103] 201 Sending Steps
[0104] 202 Receiving Steps
[0105] 203 Monitoring Steps
[0106] 204. Notify steps using signals.
Claims
1. An ultrasonic transducer (1) for an ultrasonic flow measurement device (2), having a transducer housing (3) and a transducer element (4), wherein the transducer housing (3) has an ultrasonic window (5) and wherein the transducer element (4) is disposed in the transducer housing (3) and configured to transmit an ultrasonic signal (6) onto a signal path (7) and to receive an ultrasonic signal (6) from the signal path (7), and having a control and evaluation unit (8) for manipulating the transducer element (4) and evaluating the ultrasonic signal (6). In the signal path (7), a buffer element (9) is arranged in or on the converter housing (3), and the buffer element (9) forms at least one boundary layer (10) that is at least partially reflective in the signal path (7). In the operating state of the ultrasonic transducer (1), the transducer element (4) emits an ultrasonic signal (6), wherein the ultrasonic signal (6) is at least partially reflected at the boundary layer (10) of the buffer element (9), wherein the reflected signal component (11) is received by the transducer element (4). Furthermore, the control and evaluation unit (8) is designed to monitor the reception of the reflected signal component (11) during the operation of the ultrasound converter (1), and to identify a fault state of the ultrasound converter (1) in the absence of reception of the reflected signal component (11). Its features are, The buffer element (9) is formed through the ultrasonic window (5). Alternatively, the buffer element (9) may be configured as a separate component and the buffer element (9) may be arranged between the transducer element (4) and the ultrasound window (5).
2. An ultrasonic transducer (1) for an ultrasonic flow measurement device (2), having a transducer housing (3) and a transducer element (4), wherein the transducer housing (3) has an ultrasonic window (5) and wherein the transducer element (4) is arranged in the transducer housing (3) and configured to transmit an ultrasonic signal (6) onto a signal path (7) and to receive an ultrasonic signal (6) from the signal path (7), and having a control and evaluation unit (8) for manipulating the transducer element (4) and evaluating the ultrasonic signal (6). In the signal path (7), a buffer element (9) is arranged in or on the converter housing (3), and the buffer element (9) forms at least one boundary layer (10) that is at least partially reflective in the signal path (7). A second converter element (4') is arranged in the converter housing (3). In the operation of the ultrasonic transducer (1), the transducer element (4) emits an ultrasonic signal (6), wherein the ultrasonic signal (6) is at least partially reflected at the boundary layer (10) of the buffer element (9), wherein the second transducer element (4') is arranged in the transducer housing such that the reflected signal component (11) is received by the second transducer element (4'). Furthermore, the control and evaluation unit (8) is designed such that it monitors the reception of the reflected signal component (11) during the operation of the ultrasound converter (1) and identifies a fault state of the ultrasound converter (1) when no reflected signal component (11) is received. Its features are, The buffer element (9) is formed through the ultrasonic window (5). Alternatively, the buffer element (9) may be configured as a separate component and the buffer element (9) may be arranged between the transducer element (4) and the ultrasound window (5).
3. The ultrasonic transducer (1) according to claim 1 or 2, characterized in that, The buffer element (9) forms at least one at least partially reflective second boundary layer (10') in the signal path (7), wherein, in the operating state of the ultrasonic transducer (1), the reflected signal component (11) is reflected at the boundary layer (10) to the second boundary layer (10').
4. The ultrasonic transducer (1) according to claim 1 or 2, characterized in that, A coating (13) that enhances partial reflection is applied to the boundary layer (10) formed by the buffer element (9).
5. The ultrasonic transducer (1) according to claim 3, characterized in that, An enhanced reflective coating (13) is applied to at least one of the boundary layers (10) and the second boundary layer (10') formed by the buffer element (9).
6. The ultrasonic transducer (1) according to claim 1 or 2, characterized in that, The control and evaluation unit (8) is designed such that, during the operation of the ultrasonic transducer (1), the control and evaluation unit compares the variable describing the reflected signal component (11) with a reference value and outputs a fault signal when the deviation exceeds a pre-given tolerance range.
7. The ultrasonic transducer (1) according to claim 6, characterized in that, The variable describing the reflected signal component (11) is the intensity of the reflected signal component.
8. An ultrasonic flow measurement device (2) for determining the flow rate of a flowing medium, having a first ultrasonic transducer (1) and a second ultrasonic transducer (1) and having a control and evaluation unit, wherein the ultrasonic transducers (1) are configured to transmit ultrasonic signals (6) onto a signal path (7) and / or to receive ultrasonic signals (6) from the signal path (7), and the signal paths (7) via the ultrasonic signals (6) are effectively correlated with each other. Its features are, At least one ultrasonic transducer (1) for transmission has a buffer element (9) and a transducer housing (3), the buffer element (9) being arranged in or on the transducer housing (3) in the signal path (7) of the ultrasonic signal (6), the buffer element (9) forming at least one boundary layer (10) that is at least partially reflective in the signal path (7). In the operating state of the ultrasonic flow measurement device (2), the transducer element (4) of the ultrasonic transducer (1) emits an ultrasonic signal (6), wherein the ultrasonic signal (6) is at least partially reflected and partially transmitted at the boundary layer (10) of the buffer element (9). The reflected signal component (11) is received by the transducer element (4) of the transmitting ultrasound transducer (1), and the transmitted signal component (12) is received by the transducer element (4) of the receiving ultrasound transducer (1). or A second converter element (4') is arranged in the converter housing constituting the ultrasonic transducer (1) for transmission, and the reflected signal component (11) is received by the second converter element (4') of the ultrasonic transducer (1) for transmission, and the transmitted signal component (12) is received by the converter element (4) of the ultrasonic transducer (1) for reception. Furthermore, the control and evaluation unit is designed to monitor the reception of the reflected signal component (11) and the transmitted signal component (12) during the operation of the ultrasonic flow measurement device (2) and to identify and signal one of the following operating states of the ultrasonic flow measurement device (2): ●When both the reflected signal component (11) and the transmitted signal component (12) are received: the ultrasonic flow measurement device (2) is effective. ●In the case where the reflected signal component (11) is received but no transmitted signal component (12) is received: the measuring tube (15) is empty. ● In the case where no reflected signal component (11) is received and no transmitted signal component (12) is received: the ultrasonic flow measurement device (2) is in a fault state.
9. The ultrasonic flow measurement device (2) according to claim 8, characterized in that, The control and evaluation unit identifies and signals the ultrasonic flow measurement device (2) to indicate the following operating status: In the case where no reflected signal component (11) is received and no transmitted signal component (12) is received: the transducer element (4) of the ultrasonic transducer (1) that is transmitting is in a fault state.
10. The ultrasonic flow measurement device (2) according to claim 8 or 9, characterized in that, At least one ultrasonic transducer (1) is configured according to the features described in claim 1 or 2.
11. The ultrasonic flow measurement device (2) according to claim 8 or 9, characterized in that, The control and evaluation unit is designed such that if the transmitted signal component (12) is below a predetermined limit value, the control and evaluation unit evaluates the transmitted signal component (12) as "not received".
12. A method (200) for operating an ultrasonic flow measurement device, wherein the ultrasonic flow measurement device has a first ultrasonic transducer, a second ultrasonic transducer, and a control and evaluation unit, wherein the ultrasonic transducers are configured to transmit ultrasonic signals onto a signal path and / or receive ultrasonic signals from the signal path and the signal paths via the ultrasonic signals are effectively associated with each other, wherein at least the ultrasonic transducer configured for transmitting has a buffer element and a transducer housing, the buffer element being disposed in or on the transducer housing in the signal path of the ultrasonic signals, and the buffer element forming at least one boundary layer that is at least partially reflective in the signal path. Its features are, In the transmission step (201), the transducer element transmitting emits an ultrasonic signal, wherein the ultrasonic signal is at least partially reflected and partially transmitted at the boundary layer of the buffer element. In the receiving step (202), the transducer element of the transmitting ultrasonic transducer or the second transducer element arranged in the transmitting ultrasonic transducer receives the reflected signal component, and the transducer element of the receiving ultrasonic transducer receives the transmitted signal component. In the monitoring step (203), the control and evaluation unit monitors the reception of the reflected signal component and the transmitted signal component. In the signal notification step (204), the control and evaluation unit notifies the ultrasonic flow measurement device of one of the following operating states by signal: ● The ultrasonic flow measurement device is effective when both the reflected and transmitted signal components are received. ●In the case where the reflected signal component is received but no transmitted signal component is received: the measuring tube is empty. ● If neither the reflected nor the transmitted signal component is received, the ultrasonic flow measurement device is in a faulty state.
13. The method (200) according to claim 12, characterized in that, In the signal notification step (204), the control and evaluation unit notifies the ultrasonic flow measurement device of the following operating status by signal: In the case where neither the reflected signal component nor the transmitted signal component is received: the transducer element of the ultrasonic transducer that is transmitting is in a faulty state.
14. The method (200) according to claim 12 or 13, characterized in that, If the transmitted signal component is below a pre-defined limit, the transmitted signal component is evaluated as "not received".