An insertable portable gas ultrasonic flowmeter with online traceability function

Abstract

The application provides an insertable portable gas ultrasonic flowmeter with an online tracing function. The portable host of the application can directly collect 4-20mA or RS485 signals of a flowmeter to be traced, and can perform temperature and pressure compensation and high-precision flow calculation according to measured data of the self-standard table and upstream and downstream pressure and temperature sensors, so as to realize real-time comparison under the same working condition. The host also has functions of multi-mode comparison, automatic error calculation, over-standard coefficient correction and various communication protocol data export. Compared with the traditional mode, the application greatly reduces the manpower, material resources and production cost of flowmeter periodic inspection, has low safety risk, high site adaptability and high reuse rate, and provides a set of efficient and reliable flowmeter periodic intermediate verification and online tracing equipment for the site, and effectively fills the value control chain in the industrial site.

Description

Technical Field

[0001] This invention relates to the field of ultrasonic transducers, and in particular to an insertable portable ultrasonic gas flow meter with online traceability function. Background Technology

[0002] With the continuous improvement of industrial production scale and automation, ultrasonic flow meters, with their advantages of non-contact measurement, no pressure loss, and wide range, have been widely used in trade measurement and handover, energy consumption and carbon accounting, and safety production monitoring in the petroleum, chemical, metallurgical, and power industries. In recent years, national legal metrological supervision has become increasingly stringent, and enterprises have placed extremely high demands on the long-term operational accuracy management of large-diameter gas pipeline flow meters under actual working conditions, hoping to establish a complete value transfer chain from the laboratory to the field operating conditions.

[0003] However, in current industrial production practices, the annual inspection and traceability of the vast majority of flow meters still rely on traditional offline laboratory calibration methods. This offline mode has many inherent drawbacks: First, disassembling the flow meter from the pipeline and sending it to the laboratory for calibration requires interrupting continuous on-site production operations, resulting in significant economic losses from production stoppages. Frequent disassembly and assembly also increases the risk of damage to pipeline flange surfaces and seal failure, posing safety and environmental hazards. Second, the standard calibration environment provided by the laboratory is usually an idealized state of normal temperature and pressure, which differs significantly from the complex high-pressure and variable-temperature flow field conditions in actual operation. The calibration certificate cannot truly reflect the actual measurement accuracy of the equipment on the production line, nor can it prove its long-term accuracy stability between two calibration cycles. Third, requiring every flow meter on-site to be regularly disassembled and sent for calibration requires enormous manpower, material resources, and high testing costs, which is often difficult to implement in practice. At present, the industry lacks a portable standard device that can perform real-time accuracy verification of in-operation flow meters without disassembling the meter or interrupting production, resulting in a significant break in the on-site measurement control chain and failing to effectively meet the needs of enterprises for refined measurement management.

[0004] Therefore, the urgent technical problem to be solved in this field is to develop an insertion-type ultrasonic gas flow meter that is highly accurate, portable, flexible, and capable of real-time online flow accuracy comparison, so that it can serve as a standard meter and achieve periodic intermediate verification and online traceability of the flow meter at low cost and high efficiency without affecting on-site production. Summary of the Invention

[0005] The purpose of this invention is to provide an insertable portable ultrasonic gas flow meter with online traceability function to solve the problems existing in the prior art.

[0006] To achieve the above objectives, the present invention provides the following solution: This invention provides an insertable portable ultrasonic gas flow meter with online traceability function, including a portable flow meter main unit, mounting components, transducer assembly, environmental parameter sensor and signal acquisition interface; The installation assembly includes a welded short pipe, a flange ball valve, and a flange sleeve. The welded short pipe is used to be fixedly connected to the main pipeline on site, and the flange ball valve is connected between the welded short pipe and the flange sleeve. The transducer assembly includes a transducer mounting rod, a transducer, and a signal junction box. The transducer mounting rod passes through the flange sleeve and can extend into the main pipeline at the site. The transducer is installed at the end of the transducer mounting rod that extends into the main pipeline at the site. The transducer is connected to the signal junction box via a transducer signal line. The signal junction box is connected to the portable flow meter host for signal connection. The environmental parameter sensors include a pressure sensor for collecting on-site gas pressure and a temperature sensor for collecting on-site gas temperature. Both the pressure sensor and the temperature sensor are connected to the portable flow meter host for signal transmission. The portable flow meter host is equipped with a signal acquisition interface for connecting the output signal of the flow meter to be traced. The portable flow meter host calculates the standard flow rate based on the data collected by the transducer, pressure sensor and temperature sensor, and compares it with the signal of the flow meter to be traced in real time online, and outputs the traceability result.

[0007] Preferably, the end of the welded short pipe that connects to the main pipeline on site is provided with a beveled interface at a specific angle (the angle range is generally 15-75 degrees, with 45 degrees being the most common); the flange sleeve is provided with tightening screws for locking the transducer mounting rod; flange gaskets are sandwiched between the flange ball valve and the welded short pipe, and between the flange ball valve and the flange sleeve.

[0008] Preferably, the outer surface of the transducer mounting rod is provided with axial scale lines, which are used to determine the insertion depth of the transducer in the main pipeline according to the installation angle and the inner diameter of the main pipeline on site.

[0009] Preferably, the pressure sensor is positioned 2 to 3 times the diameter of the main pipe upstream of the transducer mounting rod insertion point; the temperature sensor is positioned downstream of the transducer mounting rod insertion point.

[0010] Preferably, the portable flow meter host is an explosion-proof structure, and its internal communication module includes one or more communication methods such as USB interface, RS485, Ethernet, 4G, NB-IoT and Bluetooth, for exporting the traceability results to an external mobile storage device or remote terminal.

[0011] Preferably, the portable flow meter host is connected to the flow meter to be traced on site via a data transmission line.

[0012] Preferably, the portable flow meter host is equipped with a comparison mode selection module, which allows the operator to select either the cumulative flow comparison mode or the average instantaneous flow comparison mode, and the host is equipped with a comparison time setting module, which is used to set the time period for real-time online flow comparison.

[0013] Preferably, the portable flow meter host is equipped with an accuracy determination and coefficient correction module. The accuracy determination and coefficient correction module is used to calculate the flow error between the flow meter to be traced and the portable flow meter in real time, and when the determination error exceeds the preset threshold, the flow correction coefficient of the flow meter to be traced is generated based on the comparison error.

[0014] Preferably, the flange ball valve can be fitted with a pressurized tapping tool on its exterior. This tool is used to close the flange ball valve after the main pipeline is vented and no installation port is reserved, and then the transducer mounting rod can be inserted.

[0015] Preferably, the outer surface of the portable flow meter host is provided with a display screen, which is used to display the standard flow data of the portable flow meter, the metering data of the flow meter to be traced, and the real-time error value between the two in real time during the flow comparison process.

[0016] The present invention achieves the following beneficial technical effects compared to the prior art: This invention provides an insert-type portable ultrasonic gas flow meter with online traceability. Based on an insert-type transducer assembly and a mounting component with a short welded tube at a specific angle, the flow meter supports both pre-drilled installation in newly constructed pipelines and pressurized installation in existing pipelines. This allows for operation without interrupting production or disassembling the flow meter being traced, effectively overcoming the shortcomings of traditional offline verification. The portable host of this invention can directly acquire 4-20mA or RS485 signals from the flow meter being traced and perform temperature and pressure compensation and high-precision flow calculation based on its own standard meter and measured data from upstream and downstream pressure and temperature sensors. This enables real-time comparison under the same operating conditions. The host also features multi-mode comparison, automatic error calculation, out-of-range coefficient correction, and data export via various communication protocols. Compared to traditional methods, this invention significantly reduces the manpower, material resources, and downtime costs associated with periodic flow meter inspections. It also features low safety risks, strong site adaptability, and high reusability, providing a highly efficient and reliable system for periodic flow meter verification and online traceability, effectively completing the value control chain in industrial settings. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 A schematic diagram of the structure of the insertion-type portable ultrasonic gas flow meter with online traceability function provided by the present invention; Figure 2 A schematic diagram of the on-site installation of the insertion-type portable ultrasonic gas flow meter with online traceability function provided by the present invention; Figure 3 Parts diagram of an insertable portable ultrasonic gas flow meter with online traceability function provided by the present invention; Figure 4 The diagram illustrates the online traceability process of the insertable portable ultrasonic gas flow meter with online traceability function provided by this invention. Detailed Implementation

[0019] Unless otherwise specified, the terms "connection" and "linkage" used in this application include both direct and indirect connections (linkages). In the description of this invention, it should be understood that the terms "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention.

[0020] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] The purpose of this invention is to provide an insertable portable ultrasonic gas flow meter with online traceability function to solve the problems existing in the prior art.

[0023] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0024] Example 1: Please see Figures 1 to 3 This portable ultrasonic gas flow meter with online traceability consists of a portable flow meter main unit 1, mounting components, a transducer assembly, environmental parameter sensors, and a signal acquisition interface. The portable flow meter main unit 1 serves as the core computing and command unit, handling signal reception, flow calculation, data comparison, and human-machine interaction. The mounting components enable rapid physical installation and fixation of the portable flow meter on the pipeline, ensuring the airtight isolation of the gas medium. The transducer assembly directly transmits and receives ultrasonic signals, serving as the core component for sensing the flow state of the medium. The environmental parameter sensors capture the pressure and temperature conditions of the gas within the pipeline, assisting the main unit in performing high-precision temperature and pressure compensation calculations. The device features a compact design and is compatible with mounting components (welded short pipes, ball valves, and flange sleeves, etc.) from DN50 to DN100, meeting the online traceability measurement needs of large-diameter pipelines in various industrial settings.

[0025] Figure 3 The component structure of this portable flow meter is shown below. Figure 3The specific characteristics of each component and their assembly relationships are explained in detail. The welded short pipe 5 is located at the bottom of the mounting assembly. One end of it has a beveled cut at a specific angle (generally 15-75 degrees, with 45 degrees being the most common). This beveled cut is used for welding and fixing to the outer wall of the main pipeline on site. The beveled opening design ensures that after installation, the transducer mounting rod 6 passes through the pipeline wall at an inclined angle, reaching the center of the pipeline. The other end of the welded short pipe 5 has a flange, which is connected to the flange ball valve 4 via bolts. The flange ball valve 4 is the core control component for cutting off and connecting the pipeline. Without flow calibration, rotating the valve core of the flange ball valve 4 to the closed position effectively cuts off the gas in the pipeline, achieving safe isolation. The upper part of the flange ball valve 4 is connected to the flange sleeve 3 via a flange. The flange sleeve 3 has a hollow structure, providing sufficient space and guidance for the transducer mounting rod 6 to pass through. Flange gaskets 9 are sandwiched on the mating surfaces of the welded short pipe 5 and the flange ball valve 4, and on the mating surfaces of the flange ball valve 4 and the flange sleeve 3. The flange gaskets 9 deform under bolt tightening force, filling the fine gaps on the flange surface, thus ensuring that the entire installation assembly does not leak media when subjected to the internal gas pressure of the pipeline. The transducer mounting rod 6 passes through the flange sleeve 3 and inserts into the pipeline. A tightening screw is located at the outer end of the flange sleeve 3. When the transducer mounting rod 6 extends to a predetermined depth, the tightening screw presses against the rod body of the transducer mounting rod 6 through its end, thereby achieving mechanical locking and preventing axial displacement or circumferential rotation of the rod body under the impact of gas flow. The transducer 7 is installed at the foremost end of the transducer mounting rod 6 that extends into the pipeline. It contains a piezoelectric crystal that converts electrical signals into ultrasonic signals for transmission and converts received ultrasonic echo signals back into electrical signals. Transducer 7 is connected to signal junction box 2 via transducer signal line 8. Signal junction box 2 acts as a transfer hub, relaying the weak electrical signal collected by transducer 7 to portable flow meter host 1 via explosion-proof cable. To facilitate precise insertion by on-site construction personnel, the outer surface of transducer mounting rod 6 is pre-engraved with graduation lines along the axial direction. On-site operators only need to determine the inner diameter of the on-site pipeline and the specific angle (generally ranging from 15 to 75 degrees, with 45 degrees being the most common) of the oblique insertion angle, combined with the graduation marks on the rod, to easily and quickly insert transducer 7 precisely into the center of the main pipeline.

[0026] Figure 1 , 2This demonstrates the overall working environment of the portable ultrasonic gas flow meter in a practical traceability system. Environmental parameter sensors are positioned upstream and downstream of the transducer mounting rod 6 where it extends into the pipe. Specifically, the pressure sensor 10 is installed 2D to 3D upstream of the transducer 7 insertion point. This distance ensures that the pressure value collected by the pressure sensor 10 accurately reflects the gas density at the actual working position of the transducer 7. Furthermore, this location is far from the transducer's acoustic emission area, preventing interference with the ultrasonic field generated by the transducer 7. The temperature sensor 11 is installed downstream of the transducer 7 insertion point. Since the temperature sensor 11's probe also needs to extend into the pipe, installing it upstream of the transducer 7 would create an obstacle in the flow field, causing flow distortion and resulting in errors in the flow velocity measured by the transducer 7. Therefore, placing it downstream of the transducer 7 minimizes disturbance to the flow field. Both pressure sensor 10 and temperature sensor 11 are electrically connected to portable flow meter host 1 via cables. During the flow calculation process, portable flow meter host 1 reads the data from these two sensors in real time, uses the gas state equation to compensate for the temperature and pressure of the sound wave propagation time difference measured by transducer 7, and calculates the standard volume flow rate under the current actual working conditions.

[0027] This device supports two operating modes: pre-drilled installation and pressurized drilling installation. Pre-drilled installation is suitable for newly constructed pipelines or pipelines that are undergoing maintenance. During pre-drilled installation, first, select a suitable positioning point based on the pipeline diameter. Weld the short pipe 5 directly to the pre-drilled hole on the outer wall of the main pipeline at a specific angle (generally 15-75 degrees, with 45 degrees being the most common). After the welding cools, perform an airtightness check. Then, place the flange gasket 9 between the flange of the welded short pipe 5 and the flange of the flange ball valve 4, and tighten the connection using double-ended bolts to ensure a tight fit between the two flange faces. Next, install the transducer 7 on the transducer mounting rod 6, insert the assembly into the flange sleeve 3, and pre-fix it using tightening screws. Simultaneously, install the signal junction box 2. Then, clamp another flange gasket 9 between the flange ball valve 4 and the flange sleeve 3, and finally flange-connect and tighten the entire assembly of the transducer mounting rod 6 and flange sleeve 3 to the flange ball valve 4. After ensuring that all flange connections are securely tightened and there is no gas leakage, slowly open the valve core of flange ball valve 4. While observing the scale marks on transducer mounting rod 6, the operator slowly loosens the screws and pushes the transducer mounting rod 6 smoothly into the pipeline until the predetermined insertion depth is reached. Then, tighten the screws in the reverse direction and use hexagonal screws for anti-loosening locking to complete the hardware installation.

[0028] For situations where the pipeline is already in normal ventilation operation and no installation interface was pre-installed on the pipeline, the installation component of this invention supports pressurized drilling installation. In specific operation, firstly, the welded short pipe 5 is directly welded to the outside of the main pipe section. Then, the flange ball valve 4 is connected and tightened to the welded short pipe 5 via the flange gasket 9, at which point the flange ball valve 4 is in the closed state. After confirming the airtightness of the installation, the matching pressurized drilling tool is tightly installed on the external interface of the flange ball valve 4. After checking the seal again, the flange ball valve 4 is opened, and the drill bit of the pressurized drilling tool is used for penetration drilling. After the drilling is completed, the drill bit is retracted to the outside of the flange ball valve 4, the flange ball valve 4 is closed, and then the pressurized drilling tool is disassembled. Finally, the transducer mounting rod 6 can be inserted and locked according to the aforementioned pre-drilled installation steps. Throughout the entire process, the gas in the main pipeline continues to flow, requiring no factory shutdown or production stoppage.

[0029] Figure 4 This demonstration showcases the core workflow of the portable ultrasonic gas flow meter: the online accuracy traceability process. After installation and commissioning, the portable flow meter unit 1 features a dedicated signal acquisition interface. Operators can select an appropriate connection method to connect this interface to the output of the flow meter 13 to be traced on-site. This interface supports reading 4-20mA analog signals from the flow meter 13 and also supports reading RS485 digital communication signals. After connection, the operator needs to access the parameter configuration interface on the portable flow meter unit 1's control panel. On the interface, the operator selects the flow comparison mode using the option buttons. The system provides cumulative flow comparison mode and average instantaneous flow comparison mode for users to switch between according to on-site management requirements. Then, a suitable time period for real-time online flow comparison is set. After setting, the comparison function is activated, and the portable flow meter unit 1 begins continuously performing real-time online flow comparison. During the comparison process, the portable flow meter host 1 will compare its standard flow value, which has been compensated for temperature and pressure, with the real-time flow value of the traceable flow meter 13, which is read through the signal acquisition interface, point by point according to the built-in algorithm, and automatically calculate the real-time flow error between the two.

[0030] The portable flow meter host 1 has an embedded accuracy judgment and coefficient correction module. This module continuously outputs error values ​​during the comparison process and compares them with a pre-set compliance threshold. If, after one cycle of comparison, the calculated average error is within the compliance threshold range, the system determines that the online traceability accuracy meets the standard, and the process will directly jump to the normal result output state, allowing the operator to directly export a qualified report. If the judgment result shows that the comparison error exceeds the preset compliance threshold range, the system will not immediately interrupt the process but will instead trigger a fault handling and correction sub-process. In this sub-process, the portable flow meter host 1 calculates the required flow coefficient correction value based on the currently measured comparison deviation. The operator can adjust the internal flow coefficient parameters of the flow meter 13 to be traced according to this correction instruction. After the adjustment is completed, the system automatically returns to the initial stage of the process and executes the parameter setting and online comparison operation again. If, after one or more adjustments to the flow coefficient, the comparison error still fails to converge within the target threshold range, the system will guide the operator to investigate the cause of the non-compliance. This investigation should include checking for loose installation components, damaged pipe flange seals, and electromagnetic interference in communication signals. After identifying the cause and eliminating interference factors, the operator can restart the comparison process and re-execute the comparison operation. If, after multiple investigations, the cause of the non-compliance cannot be identified, the system will stop looping and directly proceed to the end of the process, outputting the source tracing results of the non-compliance.

[0031] After the traceability results are generated, the portable flowmeter host 1 has multiple built-in data interaction methods to ensure efficient report export. Its communication module supports various communication methods including USB data interface, RS485 communication, Ethernet transmission, 4G mobile network, NB-IoT narrowband IoT, and Bluetooth wireless transmission. Operators can directly copy the traceability results by connecting storage media such as a USB flash drive to the USB interface, or connect the portable flowmeter host 1 to the factory's local area network via RS485 or Ethernet cable to upload the data to the central database. Through this online traceability method, field equipment that previously required frequent disassembly and inspection only needs to be periodically inspected using the portable flowmeter, ensuring the measurement accuracy of all inspected flowmeters. This significantly reduces equipment disassembly and downtime costs, providing a safe, convenient, and efficient online accuracy verification method for the metrology management work of various enterprises.

[0032] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0033] It should be noted that the components mentioned in the above embodiments are all general standard parts or components known to those skilled in the art. Their structures and principles can be learned by those skilled in the art through technical manuals or conventional experimental methods.

[0034] This invention has illustrated its principles and implementation methods using specific examples. The descriptions of these embodiments are merely illustrative of the method and its core ideas; furthermore, those skilled in the art will recognize that modifications may be made to the specific implementation methods and application scope based on the principles of this invention. Therefore, the content of this specification should not be construed as limiting the invention.

Claims

1. A portable insertion-type ultrasonic gas flow meter with online traceability function, characterized in that, Includes a portable flow meter main unit (1), mounting components, transducer assembly, environmental parameter sensors, and signal acquisition interface; The installation assembly includes a welded short pipe (5), a flange ball valve (4), and a flange sleeve (3). The welded short pipe (5) is used to be fixedly connected to the main pipeline on site, and the flange ball valve (4) is connected between the welded short pipe (5) and the flange sleeve (3). The transducer assembly includes a transducer mounting rod (6), a transducer (7), and a signal junction box (2). The transducer mounting rod (6) passes through the flange sleeve (3) and can extend into the main pipeline at the site. The transducer (7) is installed at one end of the transducer mounting rod (6) that extends into the main pipeline at the site. The transducer (7) is connected to the signal junction box (2) through a transducer signal line (8). The signal junction box (2) is connected to the portable flow meter host (1) via signal connection. The environmental parameter sensors include a pressure sensor (10) for collecting on-site gas pressure and a temperature sensor (11) for collecting on-site gas temperature. Both the pressure sensor (10) and the temperature sensor (11) are connected to the portable flow meter host (1) via signal connection. The portable flow meter host (1) is equipped with a signal acquisition interface for connecting the output signal of the flow meter (13) to be traced. The portable flow meter host (1) calculates the standard flow rate based on the data collected by the transducer (7), pressure sensor (10) and temperature sensor (11), and compares it with the signal of the flow meter (13) to be traced in real time, and outputs the traceability result.

2. The insertion-type portable ultrasonic gas flow meter with online traceability function according to claim 1, characterized in that: The welded short pipe (5) is connected to the main pipeline at one end with a specific angled interface; the flange sleeve (3) is provided with tightening screws for locking the transducer mounting rod (6); flange gaskets (9) are sandwiched between the flange ball valve (4) and the welded short pipe (5), and between the flange ball valve (4) and the flange sleeve (3).

3. The insertion-type portable ultrasonic gas flow meter with online traceability function according to claim 1, characterized in that: The outer surface of the transducer mounting rod (6) is provided with axial scale lines, which are used to determine the insertion depth of the transducer (7) in the main pipeline according to the installation angle and the inner diameter of the main pipeline on site.

4. The insertion-type portable ultrasonic gas flow meter with online traceability function according to claim 1, characterized in that: The pressure sensor (10) is located 2 to 3 times the diameter of the main pipe upstream of the position where the transducer mounting rod (6) extends; the temperature sensor (11) is located downstream of the position where the transducer mounting rod (6) extends.

5. The insertion-type portable ultrasonic gas flow meter with online traceability function according to claim 1, characterized in that: The portable flow meter host (1) is an explosion-proof structure and has a communication module inside. The communication module includes one or more of the following communication methods: USB interface, RS485, Ethernet, 4G, NB-IoT and Bluetooth, which are used to export the traceability results to an external mobile storage device or remote terminal (12).

6. The insertion-type portable ultrasonic gas flow meter with online traceability function according to claim 1, characterized in that: The portable flow meter host (1) is connected to the flow meter (13) to be traced on site via a data transmission line.

7. The insertion-type portable ultrasonic gas flow meter with online traceability function according to claim 1, characterized in that: The portable flow meter host (1) is equipped with a comparison mode selection module, which allows the operator to select either the cumulative flow comparison mode or the average instantaneous flow comparison mode. The host (1) is also equipped with a comparison time setting module, which is used to set the time period for real-time online flow comparison.

8. The insertion-type portable ultrasonic gas flow meter with online traceability function according to claim 1, characterized in that: The portable flow meter host (1) is equipped with an accuracy determination and coefficient correction module. The accuracy determination and coefficient correction module is used to calculate the flow error between the flow meter to be traced (13) and the portable flow meter in real time, and when the determination error exceeds the preset threshold, the flow correction coefficient of the flow meter to be traced (13) is generated based on the comparison error.

9. The insertion-type portable ultrasonic gas flow meter with online traceability function according to claim 1, characterized in that: The flange ball valve (4) can be fitted with a pressurized tapping tool on the outside. When the main pipeline on site is vented and no installation port is reserved, the flange ball valve (4) can be closed after the pressurized tapping, and then the transducer mounting rod (6) can be inserted.

10. The insertion-type portable ultrasonic gas flow meter with online traceability function according to claim 1, characterized in that: The outer surface of the portable flow meter host (1) is provided with a display screen, which is used to display the standard flow data of the portable flow meter, the metering data of the flow meter to be traced (13), and the real-time error value between the two in real time during the flow comparison process.

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