TRANSDUCER, MANUFACTURING METHOD AND FLOW MEASURING DEVICE

Abstract

Transducer, manufacturing method, and flow measurement device. The present invention pertains to the field of fluid flow measurement technology and relates specifically to a type of transducer, its method of manufacture, and the flow measurement device. The transducer comprises a body and an acoustic communication probe. The body is attached to the acoustic communication probe, and the radiating surface of the body is in contact with one end of the acoustic communication probe, thus enabling signal transmission. The key feature is that the acoustic adaptation layer of the body is made of a composite material containing a mixture of silver and epoxy resin. This composite material consists, by mass ratio, of 2-4 parts silver powder and 6-8 parts two-component epoxy adhesive (AB adhesive).This transducer features excellent electrical properties and a superior acoustic adaptation effect; at the same time, the flow measurement device that incorporates said transducer offers results with a reduced margin of error.

Description

TRANSDUCER, MANUFACTURING METHOD AND MEASURING DEVICE OF CAUDAL FIELD OF TECHNOLOGY The present invention relates to the field of fluid flow measurement technology, and specifically to a type of transducer, its method of manufacture, and the flow measurement device. BACKGROUND An ultrasonic flow meter is a type of instrument that uses the time difference measurement principle to determine the flow rate of fluids in pipes. It measures the time it takes for an ultrasonic pulse to propagate between two transducers in the direction of the fluid flow, both forward and reverse, thus determining the fluid velocity in the pipe and subsequently calculating the flow rate. An ultrasonic flow meter consists primarily of a main unit and transducers, whose electrical conductors are connected to the main unit. These transducers comprise a body and an acoustic communication probe. The body is permanently connected to the acoustic communication probe, and the radiating surface of the body makes contact with one end of the acoustic communication probe to allow signal transmission. Until now, in conventional transducers, the acoustic matching layer has been made of plastic, PEEK, or low-viscosity epoxy resin. However, due to the inherent properties of these materials (plastic, PEEK, or low-viscosity epoxy resin), the resulting acoustic matching layers exhibit poor electrical properties and an inadequate acoustic matching effect, leading to significant errors in flow measurements performed by the measuring devices. DESCRIPTION OF THE INVENTION The present invention aims to provide a transducer, its method of manufacture, and a flow measurement device, wherein said transducer exhibits improved electrical properties, a superior acoustic adaptation effect, and reduces errors in measurement results. To solve the above problems, the following technical solutions are adopted: The transducer according to the invention comprises a body and an acoustic communication probe, the body being permanently connected to the acoustic communication probe, and the radiating surface of the body being in contact with one end of the acoustic communication probe to enable signal transmission. It is characterized in that the acoustic adaptation layer of the body is made of a composite material consisting of a mixture of silver and epoxy resin; said composite material contains, by mass, 2 to 4 parts of silver powder and 6 to 8 parts of two-component epoxy adhesive (AB adhesive). The body comprises a housing and an electrical conductor. The housing includes a support cylinder, within which a cylindrical backing element is concentrically arranged. The inner surface of the backing element is smooth, while its outer surface has an irregular configuration with rough surfaces. This inner surface of the backing element is covered by a piezoelectric ceramic sheet that acts as an acoustic emitter and receiver. This acoustic adaptation layer is located between the piezoelectric ceramic sheet and the base of the internal cavity of the support cylinder. A clamping mechanism is located between the backing element and the cavity of the support cylinder, securing the backing element, the piezoelectric ceramic sheet, and the acoustic adaptation layer within the support cylinder.The backup element connects to one end of the electrical conductor, and the other end extends outward through the opening in the support cylinder. The outer surface of the base of the support cylinder corresponds to this radiating surface. The clamping mechanism comprises a positioning collar and a compression nut. The positioning collar is mounted around the piezoelectric ceramic sheet and the backing element, with its outer peripheral surface in contact with the inner surface of the support cylinder. The inner surface of the opening in the support cylinder has an internal thread; the compression nut is located within this opening and is engaged by this internal thread. A compression spring is positioned between the inner surface of the compression nut and the outer surface of the backing element. The outer surface of the backup element has a concentrically arranged connecting column extending outwards. The outer end of this connecting column has a threaded hole oriented radially with respect to the support cylinder. A screw is inserted into this threaded hole, and one end of the electrical conductor is positioned between the screw and the connecting column. The compression nut has a through-hole that allows the electrical conductor to pass through, with the other end of the electrical conductor extending outwards through the through-hole and the opening in the support cylinder. The portion of the support cylinder located outside the compression nut is filled with a sealing block, through which the electrical conductor passes. The Acoustic Communication Probe comprises a long tube, the end of which, closest to the body, is sealed. The interior of the long tube is filled with a transmission element consisting of cylindrical filaments or thin sheets. One end of the transmission element is in contact with the inner surface of the closed end of the long tube, while the other end has a connection plate attached. This connection plate is located on the outside of the open end of the long tube, and a protective cover is provided between the outer surface of the connection plate and the open end of the long tube. The closed end of the long tube is fitted with a connecting sleeve, the inner end of which is attached externally to the long tube by a fixed connection.Ventilation holes are arranged axially along the acoustic communication bar between the inner wall of the connecting sleeve and the outer wall of the long tube. The base end of the support cylinder is inserted from the outer end of the connecting sleeve into the sleeve. The transducer manufacturing method described above is characterized by comprising the following steps: First step, separate manufacturing of the body and the acoustic communication bar Body manufacturing: Individual preparation of support cylinder, piezoelectric ceramic sheet, backing element, compression spring, positioning collar, compression nut, electrical conductor and screw. Connection process between the connection column and the electrical conductor: Wrap one end of the electrical conductor around the screw, then insert the screw into the threaded hole, tighten the screw until the electrical conductor is firmly secured against the connection column. The installation process includes the following operations: A. Preparation of the acoustic adaptation layer on the base of the internal cavity of the support cylinder: First, select silver powder in a mass ratio of 2 to 4 parts and add it to 6-8 parts epoxy adhesive (AB adhesive), mixing thoroughly to obtain a viscous composite material. Next, apply the composite material evenly to the base of the internal cavity of the support cylinder, with an application thickness equivalent to 1 / 4 of the ultrasonic wavelength. Then, allow the applied composite material to dry on the support cylinder until the acoustic adaptation layer is obtained. B. After completing the preparation of the acoustic adaptation layer, first sequentially insert the positioning collar, the piezoelectric ceramic sheet, the backing element, the compression spring, and the compression nut into the support cylinder. Pass the outer end of the electrical conductor through the through-hole to the outside of the support cylinder. Then, tighten the compression nut to compress the compression spring, thus securing the backing element within the support cylinder. C. Pour high-temperature sealant adhesive into the portion of the support cylinder located outside the compression nut. Once the high-temperature sealant adhesive has cooled, the sealing block is formed, thus obtaining the body. Acoustic communication probe: Prepare separately the long tube, transmission element, connection plate, protective cover, and connecting sleeve. The installation process is as follows: Connection process between the transmission element, the connection plate, the protective cover, and the long tube: A. By welding, distribute and evenly fix one end of all the cylindrical filaments or thin sheets of the transmission element onto the connection plate, sequentially. B. Subject the transmission element to cryogenic treatment and insert it inside the long tube. C. Fix the protective cover to the opening of the long tube. When it recovers to room temperature, the transmission element expands, becoming firmly attached to the internal cavity of the long tube, while the protective cover remains in contact with the connection plate. Connection process between the connecting sleeve and the long tube: Mount the connecting sleeve onto the outer surface of the closed end of the long tube, securing it by welding. During the welding process, ensure that a gap is maintained between a portion of the connecting sleeve and the long tube, thus forming the ventilation holes. Second step: Installation of the body and the acoustic communication probe First, apply coupling material to both the outer surface of the support cylinder base and the outer surface of the closed end of the long tube. Next, insert the end of the support cylinder base into the connecting sleeve, securing it with a screw or clamp. Ensure the end of the support cylinder base makes contact with the closed end of the long tube, allowing the coupling material to flow under pressure into the space between the support cylinder, the long tube, and the connecting sleeve. This creates a tight seal between the radiating surface of the body and the acoustic communication probe, guaranteeing stable signal transmission. The flow measurement device, comprising a main unit and at least two groups of transducers, each group consisting of two transducers, and the electrical conductors of the transducers being connected to said main unit, characterized in that said transducers are the transducers according to the above solutions. Adopting the above solution offers the following advantages: 1. Because the acoustic adaptation layer of the transducer of the present invention is made of a composite material formed from a mixture of silver and epoxy resin, this composite material exhibits excellent electrical properties and a superior acoustic adaptation effect, which allows the flow measurement device incorporating said transducer to provide accurate measurement results. 2. Since the rear surface of the transducer backing element of the present invention has an irregular configuration with rough surfaces, this irregular surface suppresses the propagation of ultrasonic waves within the backing element, exerting a diffuse scattering function and ultimately acting as acoustic damping, thus ensuring a high signal-to-noise ratio. Traditional backing elements have smooth surfaces, resulting in a low signal-to-noise ratio. Current technology also employs backing elements made of multi-component composite materials, adding acoustic damping materials to achieve a high signal-to-noise ratio. However, the use of multiple composite materials complicates the manufacturing process.In contrast, the backing element of the present invention is machined directly from existing graphite-bronze material, eliminating the need to first manufacture a composite material and then machine it, greatly simplifying the manufacturing process. 3. Because ventilation holes exist between the connecting sleeve and the long tube of the transducer of the present invention, these holes allow the coupling material applied between the support cylinder and the long tube to flow into them when the support cylinder is connected. This expels the air between the base of the support cylinder and the closed end of the long tube. This ensures a tight contact between the support cylinder and the closed end of the long tube, guaranteeing excellent acoustic signal strength received by the transducer, reducing measurement errors, and improving measurement stability. BRIEF DESCRIPTION OF THE FIGURES Figure 1: Structural scheme of the transducer according to the present invention. Figure 2: Cross-sectional view of the transducer body according to the present invention. Figure 3: Structural scheme of the transducer backup element according to the present invention. Figure 4: Cross-sectional view of the acoustic communication bar of the transducer according to the present invention (transmission element made up of thin sheets). Figure 5: View of the end of the laminar structure of the transducer transmission element according to the present invention. Figure 6: Cross-sectional view of the connection between the body and the acoustic communication probe of the transducer according to the present invention. Figure 7: Structural scheme of the measuring device according to the present invention. Figure 8: Comparative graph of the signal-to-noise ratio between the transducer according to the present invention and a transducer with a flat surface backing element. Figure 9: Comparative graph of the intensity of the acoustic signal received by the transducer according to the present invention and a transducer without ventilation holes. Figure 10: Comparative graph of the acoustic signals between the transducer according to the present invention and a conventional transducer. DETAILED DESCRIPTION OF IMPLEMENTATION EXAMPLES The present invention is described in detail below with reference to Figures 1-10 and by means of embodiment examples. Example implementation 1: As shown in Figure 1, the transducer of the present invention comprises a body (1) and an acoustic communication probe (2). The body (1) is a piezoelectric transducer. The body (1) is fixedly connected to the acoustic communication probe (2), and the radiating surface of the body (1) is in contact with one end of the acoustic communication probe (2), thus enabling signal transmission. The acoustic adaptation layer (1010) of the body (1) is made of a composite material consisting of a mixture of silver and epoxy resin. The composite material contains, by mass, 3 parts silver powder and 7 parts two-component epoxy adhesive (AB adhesive). This composite material exhibits excellent electrical properties and superior acoustic adaptation, enabling the flow measurement device incorporating this transducer to provide accurate measurement results. By using the Acoustic Communication Probe (2) and the body (1), it is kept separate from the medium, rendering the transducer insensitive to the temperature and pressure of the medium. As shown in Figures 2 and 3, the body (1) comprises a housing and an electrical conductor (1013). The housing includes a support cylinder (104), within which a cylindrical backup element (108) is concentrically arranged. The inner surface of the backup element (108) is a smooth plane, while its outer surface has an irregular configuration with rough surfaces. The irregular outer surface suppresses ultrasonic waves at the back of the backup element (108), inhibiting the propagation of ultrasonic waves within the element, thus providing diffuse scattering and ultimately acting as acoustic damping. Consequently, this reduces the oscillation of the acoustic signal in the original signal, decreasing the residual wave and providing the advantages of increased sensitivity and narrower pulses. The inner surface of the backing element (108) is covered with a piezoelectric ceramic sheet (1011) that acts as an acoustic emitter and receiver. Ceramic sheets are available in two variants: flanged and flangeless. To achieve a better piezoelectric effect, the present invention uses a flangeless piezoelectric ceramic sheet (1011). The acoustic adaptation layer (1010) is located between the piezoelectric ceramic sheet (1011) and the base of the internal cavity of the support cylinder (104). A clamping mechanism is located between the backing element (108) and the cavity of the support cylinder (104) to secure the backing element (108), the piezoelectric ceramic sheet (1011), and the acoustic adaptation layer (1010) within the support cylinder (104). This clamping mechanism comprises a positioning collar (109) and a compression nut (105). The positioning collar (109) is mounted around the piezoelectric ceramic sheet (1011) and the backing element (108), with its outer peripheral surface in contact with the inner surface of the support cylinder (104). The inner surface of the opening of the support cylinder (104) has an internal thread.The compression nut (105) is located within the opening of the support cylinder (104) and is connected by means of the internal thread. A compression spring (106) is provided between the inner surface of the compression nut (105) and the outer surface of the backing element (108). The positioning collar (109) is used to radially limit the backing element (108), ensuring that it remains centered within the support cylinder (104). The positioning collar (109) acts as a structural element to secure the backing element (108), without participating in the effective transmission of acoustic signals and requiring stable properties under temperature variations. For this purpose, Teflon or PEEK material is selected. In the present embodiment, the positioning collar (109) is made of Teflon.During the downward tightening of the compression nut (105), the compression spring (106) is compressed, exerting a force that ensures close contact between the backing element (108) and the piezoelectric ceramic sheet (1011), as well as between the piezoelectric ceramic sheet (1011) and the acoustic adaptation layer (1010). A sealing block (103) is located in the upper portion of the compression nut (105), within the support cylinder (104), providing a secondary clamping effect. The outer surface of the backing element (108) has a concentrically arranged connecting column (107) extending outwards. The outer end of this connecting column (107) has a threaded hole (1012) arranged radially with respect to the support cylinder (104). A screw (1016) is housed in this threaded hole (1012), with one end of the electrical conductor (1013) positioned between the screw (1016) and the connecting column (107). The compression nut (105) has a through-hole (1014) that facilitates the passage of the electrical conductor (1013), with the other end of the electrical conductor (1013) extending outwards through the through-hole (1014) and the opening of the support cylinder (104).To facilitate contact between the electrical conductor (1013) and the connection column (107), the upper end of the connection column (107) is machined with two planes parallel to each other, with the ends of the threaded hole (1012) located respectively on these two planes, as shown in Figure 3. In the present embodiment, a protective tube (1015) made of Teflon is arranged between the compression spring (106) and the connecting column (107). This protective tube (1015) is mounted on the connecting column (107), with its outer surface in contact with the inner surface of the compression spring (106). The compression spring (106) is guided by the circular shape of this protective tube (1015), preventing its deformation. In the present embodiment, for better protection of the central components of the body (1), the open end of the support cylinder (104) is provided with a top cover (101). This top cover (101) is fixedly connected to the support cylinder (104), its side wall having a passage hole (102) that facilitates the passage of the electrical conductor (1013). As shown in Figure 4, the Acoustic Communication Probe (2) comprises a long tube (203), the end of which, closest to the body (1), has a closed configuration. The interior of the long tube (203) is filled with a transmission element (204) consisting of cylindrical filaments or thin sheets, as illustrated in Figure 5. Tests and experiments have determined that when using 316SS stainless steel, the best acoustic transmission performance is obtained with cylindrical filaments of radius 0.5 mm or with sheets of dimensions 1 x 15 mm. In the present embodiment, the transmission element (204) consists of steel strips of dimensions 1 x 15 mm. As shown in Figure 4, one end of the transmission element (204) is in contact with the inner surface of the closed end of the long tube (203), while the other end of the transmission element (204) has a connecting plate (206) attached to it. This plate is made of silver. The connecting plate (206) is located on the outside of the open end of the long tube (203), and a protective cover (205) is provided between the outer surface of the connecting plate (206) and the open end of the long tube (203). This protective cover is made of 316SS stainless steel. The protective cover (205) is fixedly connected to the open end of the long tube (203) by means of a thread. The closed end of the long tube (203) is assembled with a connecting sleeve (201), the inner end of which is attached externally to the long tube (203) by means of a fixed connection.Axially oriented ventilation holes are arranged between the inner wall of the connecting sleeve (201) and the outer wall of the long tube (203), along the acoustic communication bar (2). The end of the base of the support cylinder (104) is inserted from the outer end of the connecting sleeve (201) into the interior of the sleeve. As illustrated in Figure 6, the support cylinder (104) and the connecting sleeve (201) are rigidly connected by either threading or clamping. For the connection or clamping structure, reference can be made to Chinese patent application number 2022103031383. In the present embodiment, the body (1) and the acoustic communication bar (2) are connected by threading. The outer surface of the base end of the support cylinder (104) is machined with an external thread, and the inner surface of the connecting sleeve (201) is machined with an internal thread. The base end of the support cylinder (104) is threaded into the connecting sleeve (201) until the surface of the base end of the support cylinder (104) contacts the closed end of the long tube (203). The method of manufacturing the transducer in the present embodiment comprises the following steps: First stage: Separate manufacturing of the body (1) and the acoustic communication bar (2) Body manufacturing (1): Individual preparation of the support cylinder (104), piezoelectric ceramic sheet (1011), backing element (108), compression spring (106), positioning collar (109), compression nut (105), electrical conductor (1013), screw (1016) and protective tube (1015). The support cylinder (104) is machined from SS316 or Ti alloy. In the present embodiment, the support cylinder (104) is machined from Ti alloy. The piezoelectric ceramic sheet (1011) is prepared using flangeless piezoelectric ceramic. The positioning collar (109) is made of Teflon. The backing element (108) and the connecting column (107) are machined as a single unit from graphite bronze, after which the threaded hole (1012) is machined into the upper end of the connecting column (107), followed by a silver plating process for finishing. The advantage of machining the backing element (108) and the connecting column (107) as a single unit is that it eliminates the need for welding, thus preventing silver plating detachment problems associated with welding processes. Connection process between the connection column (107) and the electrical conductor (1013): Wrap one end of the electrical conductor (1013) around the screw (1016), then insert the screw (1016) into the threaded hole (1012), so that the electrical conductor (1013) is firmly held against the connection column (107). The installation process includes the following operations: A. Preparation of the acoustic adaptation layer (1010) on the base of the internal cavity of the support cylinder (104): First, select silver powder in a mass ratio of 3 parts and add it to 7 parts of epoxy adhesive (adhesive AB), mixing thoroughly to obtain a viscous composite material. Next, apply the composite material evenly onto the base of the internal cavity of the support cylinder (104), with an application thickness equivalent to 1 / 4 of the ultrasonic wavelength. Subsequently, allow the applied composite material to dry on the support cylinder (104) until the acoustic adaptation layer (1010) is obtained. The epoxy adhesive (adhesive AB) is formed by mixing, in the following mass ratio, 1 part of component A and 3 parts of component B. B. Once the preparation of the acoustic adaptation layer (1010) is complete, first sequentially insert the positioning collar (109), the piezoelectric ceramic sheet (1011), the backing element (108), the protective tube (1015), the compression spring (106), and the compression nut (105) into the support cylinder (104). Pass the outer end of the electrical conductor (1013) through the through-hole (1014) to the outside of the support cylinder (104). Then, tighten the compression nut (105) to compress the compression spring (106), thus securing the backing element (108) inside the support cylinder (104). C. Pour high-temperature sealing adhesive into the portion of the support cylinder (104) located outside the compression nut (105). Once the high-temperature sealing adhesive has cooled, the sealing block (103) is formed, thus obtaining the body (1). Acoustic communication probe (2): Prepare separately the long tube (203), the transmission element (204), the connection plate (206), the protective cover (205) and the connection sleeve (201). Connection process between the transmission element (204), the connection plate (206), the protective cover (205) and the long tube (203): A. By brazing with AgCu alloy, distribute and fix evenly one end of all the cylindrical filaments or thin sheets of the transmission element (204) onto the connection plate (206), sequentially. B. By cooling with liquid nitrogen, subject the transmission element (204) to cryogenics and insert it inside the long tube (203). C. Secure the protective cover (205) to the opening of the long tube (203) using a threaded connection. After tightening the thread, weld the bevel joint between the protective cover (205) and the long tube (203), ensuring the integrity and watertightness of the acoustic communication bar (2) to withstand high-pressure conditions. Upon reaching ambient temperature, the transmission element (204) expands, becoming firmly attached to the inner cavity of the long tube (203), while the protective cover (205) remains in contact with the connection plate (206). Use AgCu alloy brazing to join the steel bands to the connection plate (206), controlling the brazing thickness to be equivalent to 1 / 4 of the ultrasonic wavelength, thus ensuring optimal acoustic matching. This brazing method ensures that the transmission element (204) maintains its stability and reliability at temperatures up to 800°C. The process of connecting the connecting sleeve (201) and the long tube (203) comprises: Mounting the connecting sleeve (201) onto the outer surface of the closed end of the long tube (203) by welding, during the welding process ensuring that a gap (202) of 0.5 to 1 mm is maintained between a portion of the connecting sleeve (201) and the long tube (203), thus forming the ventilation holes. Second stage, installation of the body (1) and the Acoustic Communication Probe (2) First, apply coupling material to both the outer surface of the base of the support cylinder (104) and the outer surface of the closed end of the long tube (203). Next, screw the end of the base of the support cylinder (104) into the inside of the connecting sleeve (201) until the end of the base contacts the closed end of the long tube (203). The coupling material flows into the space (202) under low pressure, thus expelling the air between the support cylinder (104), the long tube (203), and the connecting sleeve (201) into said space (202), achieving close contact between the radiating surface of the body (1) and the Acoustic Communication Probe (2) and ensuring stable signal transmission. Due to the presence of the gap (202), when the body (1) is squeezed, the pressurized coupling material flows into this gap and compresses the air between the body (1) and the coupling probe. Without this gap, the presence of air between the contact surfaces would prevent a tight seal between the body (1) and the coupling probe after compression, ultimately reducing the transmission amplitude of the acoustic signal and causing anomalous measurement problems. Simultaneously, the gap (202) isolates acoustic noise from the pipe. After the body (1) is installed, thanks to the presence of the gap (202), when acoustic noise caused by high-frequency ambient vibrations in the pipe passes through the coupling probe, the gap (202) acts as a decoupling material. As shown in Figure 7, the flow measurement device of the present invention comprises a main unit (3) and at least two transducer groups. Each transducer group consists of two transducers according to the described embodiment, with the electrical conductors (1013) of the transducers connected to the main unit (3). For the method of connection between the transducers and the fluid pipe, reference may be made to Chinese patent application number 2022103031383. Implementation Example 2 In comparison with Example of Embodiment 1, the composite material contains, by mass ratio, 2 parts of silver powder and 8 parts of epoxy adhesive (AB adhesive). Example Implementation 3 In comparison with Example of Embodiment 1, the composite material contains, by mass ratio, 4 parts of silver powder and 6 parts of epoxy adhesive (AB adhesive). Comparative Example 1 In comparison with Example Implementation 1, the acoustic adaptation layer (1010) is made of plastic. Comparative Example 2 In comparison with Implementation Example 1, the acoustic adaptation layer (1010) is made of PEEK. Comparative Example 3 5 Compared to Implementation Example 1, the acoustic adaptation layer (1010) is made of low viscosity epoxy resin. Comparative Example 4 In comparison with Example Embodiment 1, the composite material contains, in a mass ratio of 10, 1 part silver powder and 9 parts epoxy adhesive (AB adhesive). Comparative Example 5 In comparison with Example of Embodiment 1, the composite material contains, by mass ratio, 5 parts silver powder and 5 parts epoxy adhesive (adhesive 15 AB). The following table shows the performance parameters of the acoustic adaptation layer for all embodiment examples (ER) and comparative examples (EC): 0 From this table, it can be observed that the impedance of the acoustic matching layer (1010) in all embodiments is below 1000 Ω, while in the comparative examples, the impedance of the acoustic matching layer (1010) exceeds 5.5 kΩ. The acoustic impedance of all embodiments and comparative examples meets the established requirements. Therefore, it is clearly demonstrated that the acoustic matching layer (1010) of the transducer of the present invention exhibits low electrical impedance and moderate acoustic impedance, which gives the transducer excellent electrical and acoustic properties. These characteristics ensure that flow measurement devices incorporating the transducer of the present invention provide accurate measurement results and exhibit superior stability. Signal-to-noise ratio tests were performed on the transducer of Example 1, yielding the curve shown in the upper part of Figure 8. By replacing the transducer's backing element in Example 1 with a backing element with a smooth rear surface and repeating the signal-to-noise ratio test, the curve shown in the lower part of Figure 8 was obtained. The comparison demonstrates that the backing element with an irregular surface provides a higher signal-to-noise ratio in the transducer, ensuring a stable flow measurement process and accurate test results. Although the method of manufacturing backing elements using multi-material composites can also ensure a good signal-to-noise ratio, the manufacturing process is complex and less efficient compared to the backing element of the present invention, which is machined entirely from existing graphite-bronze material. Signal strength tests were performed on the transducer of Example Implementation 1, yielding the curve shown at the top of Figure 9. During the manufacturing process of the Example 1 transducer, the vent holes were removed to obtain a transducer without these holes, the signal strength test results of which are shown at the bottom of Figure 9. Comparative analysis reveals that the presence of vent holes allows for close contact between the support cylinder and the closed end of the long tube, significantly improving the intensity of the acoustic signal received by the transducer, reducing measurement errors, and increasing the stability of the measurements. Experimental tests, as shown in Figure 10, demonstrate that the original acoustic echo signal captured by the transducer of the present invention exhibits a marked improvement over conventional transducers, as does the emitted excitation signal. These improvements result in a significant increase in measurement accuracy for flow measurement devices incorporating the transducer of the present invention.

Claims

1. A transducer comprising a body (1) and an acoustic communication probe (2), the body (1) being fixedly connected to the acoustic communication probe (2), and the radiating surface of the body (1) being in contact with an end of the acoustic communication probe (2) to allow signal transmission; characterized in that the acoustic matching layer (1010) of the body (1) is made of a composite material formed from a mixture of silver and epoxy resin; said composite material contains, by mass, 2-4 parts of silver powder and 6-8 parts of two-component epoxy adhesive (AB adhesive), the acoustic communication probe (2) comprising a long tube (203), having at the end closest to the body (1) of the long tube (203) a sealed configuration; a connecting sleeve (201) externally coupled to the sealed end of the long tube (203),The interior of the connecting sleeve (201) covers the outer wall of the long tube (203) with a fixed connection; it has axially arranged ventilation holes between the inner wall of the connecting sleeve (201) and the outer wall of the long tube (203), the connecting sleeve (201) being fixed to the long tube (203) by welding, during the welding process, to ensure that a space (202) is formed between one side of the connecting sleeve (201) and the long tube (203), thus forming the ventilation holes.

2. The transducer according to Claim 1, characterized in that the body (1) comprises a Housing and an Electrical Conductor (1013), the housing being provided with a support cylinder (104), inside which a cylindrical backup element (108) is concentrically arranged; presenting the inner surface of the backing element (108) as a smooth plane,while its outer surface shows an irregular configuration with surface holes and dents; the inner surface of the backing element (108) being covered with a piezoelectric ceramic sheet (1011) that acts as an acoustic transmission and reception element; said acoustic adaptation layer (1010) being situated between the piezoelectric ceramic sheet (1011) and the base of the inner cavity of the support cylinder (104); a clamping mechanism is provided between the backing element (108) and the cavity of the support cylinder (104) that fixes the backing element (108), the piezoelectric ceramic sheet (1011) and the acoustic adaptation layer (1010) within the support cylinder (104); the backing element (108) being connected to one end of the electrical conductor (1013),whose other end extends outwards through the opening of the support cylinder (104); the outer surface of the base of the support cylinder (104) corresponding to said radiating surface.

3. The transducer according to claim 2, characterized in that said clamping mechanism comprises a positioning collar (109) and a compression nut (105); the positioning collar (109) being mounted between the piezoelectric ceramic sheet (1011) and the backing element (108), with the outer circumferential surface in contact with the inner surface of the support cylinder (104); the inner threaded surface of the opening of the support cylinder (104) having an internal thread,the compression nut (105) being located within said opening of the support cylinder (104) and connected by said internal thread; a compression spring (106) being disposed between the inner surface of the compression nut (105) and the outer surface of the backing element (108).

4. The transducer according to claim 3, characterized in that the outer surface of the backing element (108) has concentrically a connecting column (107) extending outwards, the outer end of said connecting column (107) having a threaded hole (1012) arranged radially with respect to the support cylinder (104); a screw (1016) being housed in said threaded hole (1012), one end of the electrical conductor (1013) being located between the screw (1016) and the connecting column (107); presenting the compression nut (105) a through hole (1014) that allows the passage of the electrical conductor (1013),the other end of the electrical conductor (1013) extending outwards through the through-hole (1014) and the opening of the support cylinder (104).

5. The transducer according to claim 4, characterized in that the portion of the support cylinder (104) located outside the compression nut (105) is filled with a sealing block (103), through which said electrical conductor (1013) passes.

6. The transducer according to claim 5, characterized in that the interior of the long tube (203) is filled with a transmission element (204) consisting of cylindrical filaments or thin sheets; one end of the transmission element (204) contacting the inner surface of the sealed end of the long tube (203), while the other end of the transmission element (204) has a connection plate (206) attached to it.said connection plate (206) being located on the outside of the open end of the long tube (203); a protective cover (205) being provided between the outer surface of the connection plate (206) and the open end of the long tube (203); wherein the end of the base of the support cylinder (104) extends from the outer end of the connection sleeve (201) into the interior thereof.

7. The method of manufacturing the transducer according to claim 6, characterized in that it comprises the following steps: First step, separate manufacturing of the body (1) and the Acoustic Communication Probe (2); Manufacturing of the body (1): preparation for separately manufacturing the support cylinder (104), the piezoelectric ceramic sheet (1011), the backing element (108), the compression spring (106), the positioning collar (109), the compression nut (105),The electrical conductor (1013) and the screw (1016); The connection process between the connecting column (107) and the electrical conductor (1013) consists of: wrapping one end of the electrical conductor (1013) around the screw (1016), and then inserting said screw (1016) into the threaded hole (1012), so that the electrical conductor (1013) is firmly secured against the connecting column (107). The installation process comprises the following operations: A. Preparation of the acoustic adaptation layer (1010) on the base of the internal cavity of the support cylinder (104): First, select silver powder in a mass ratio of 2 to 4 parts and add it to 6-8 parts of epoxy adhesive (AB adhesive), mixing uniformly to obtain a composite material of viscous consistency; Next, apply the composite material evenly on the base of the internal cavity of the support cylinder (104),with an application thickness equivalent to 1 / 4 of the ultrasonic wavelength; Subsequently, allow the composite material applied to the support cylinder (104) to dry until the acoustic adaptation layer (1010) is obtained. B. Once the acoustic adaptation layer (1010) has been prepared, proceed as follows: Sequentially insert into the support cylinder (104) the positioning collar (109), the piezoelectric ceramic sheet (1011), the backing element (108), the compression spring (106), and the compression nut (105); pass the outer end of the electrical conductor (1013) through the through hole (1014) to the outside of the support cylinder (104); Next, tighten the compression nut (105) to compress the compression spring (106).thus fixing the backing element (108) inside the support cylinder (104). C. Pour high-temperature sealing adhesive into the part of the support cylinder (104) located outside the compression nut (105); once the sealing adhesive has cooled, said sealing block (103) is formed, thus obtaining said body (1); Manufacturing the Acoustic Communication Probe (2): separately prepare the long tube (203), the transmission element (204), the connection plate (206), the protective cover (205), and the connection sleeve (201). The installation process comprises: The connection process between the transmission element (204), the connection plate (206), the protective cover (205), and the long tube (203) is as follows: A. By welding,A. Distribute evenly and sequentially fix one end of each of the cylindrical filaments or thin sheets of the transmission element (204) onto the connection plate (206); B. Subject the transmission element (204) to cryogenics and insert it into the long tube (203); C. Fix the protective cover (205) to the opening of the long tube (203); as the temperature increases, the transmission element (204) expands, becoming firmly attached to the internal cavity of the long tube (203), while the protective cover (205) remains in contact with the connection plate (206). The connection process between the connecting sleeve (201) and the long tube (203) comprises: Mounting the connecting sleeve (201) onto the outer surface of the closed end of the long tube (203), fixing the connecting sleeve (201) to the long tube (203) by welding, during the welding process,ensure that a space (202) is maintained between the portion of the connecting sleeve (201) and the long tube (203), thus forming said ventilation holes. Second stage: Installation of the body (1) and the Acoustic Communication Probe (2) First, apply coupling material both on the outer surface of the base of the support cylinder (104) and on the outer surface of the closed end of the long tube (203); Next, insert the end of the base of the support cylinder (104) into the inside of the connecting sleeve (201), fixing the support cylinder (104) to the connecting sleeve (201) by means of threading or clamping, making the end of the base of the support cylinder (104) contact the closed end of the long tube (203), allowing the coupling material under pressure to flow into said space (202), thus expelling the air between the support cylinder (104),The long tube (203) and the connecting sleeve (201) towards the space (202), thereby achieving close contact between the radiating surface of the body (1) and the acoustic communication probe (2), ensuring stable signal transmission.

8. A flow measurement device, comprising a main unit (3) and at least two transducer groups, each group consisting of two transducers, and the electrical conductors (1013) of the transducers being connected to said main unit (3); characterized in that said transducers are according to any one of claims 1 to 6.

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