Delay time self-correction method and system in ultrasonic flow measurement steady state

Abstract

The invention provides a delay time self-correction method and system in an ultrasonic flow measurement steady state, and belongs to the technical field of ultrasonic flow measurement. The method comprises the following steps: acquiring multiple periods of forward and reverse flow time of ultrasonic waves in a medium in a steady state, and respectively forming a forward flow array and a reverse flow array by the obtained multiple periods of forward and reverse flow time; performing similarity processing on the downstream array and the countercurrent array to obtain a downstream similarity coefficient and a countercurrent similarity coefficient; compensating the delay time based on the downstream similarity coefficient and the countercurrent similarity coefficient to obtain new downstream delay time and countercurrent delay time; and calculating the sound velocity of the ultrasonic wave after compensation based on the newly obtained downstream delay time and the newly obtained countercurrent delay time, and finally determining the flow velocity of the ultrasonic wave in the medium in a steady state based on the sound velocity so as to complete delay time self-correction. The method can effectively improve the accuracy and stability of ultrasonic measurement on the medium in a steady state.

Description

Technical Field

[0001] The invention belongs to the technical field of ultrasonic flow measurement, and in particular relates to a delay time self-correction method and system in a steady state of ultrasonic flow measurement. Background Art

[0002] The statements in this section merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] With the development of flow measurement technology, ultrasonic technology has been applied to various fields. At present, the methods of measuring flow using ultrasonic principles are generally divided into propagation difference method and Doppler method, etc. Among them, the propagation difference method can be divided into time difference method, phase difference method and frequency difference method. The time difference method is widely used in actual application scenarios because of its simple measurement principle, easy implementation and good effect. The ultrasonic flowmeter designed based on the time difference method is a flow meter that uses the flight time of ultrasonic waves to measure the flow rate of the medium in the pipeline. The working principle of this type of flowmeter is to stimulate an ultrasonic transducer to emit ultrasonic pulses based on the inverse piezoelectric effect; another ultrasonic transducer receives the ultrasonic signal and converts it into an echo electrical signal based on the piezoelectric effect, and determines the ultrasonic signal's upstream and downstream flight time based on a stable characteristic point in the echo signal, and then determines the time difference based on the signal's upstream and downstream propagation time, and then determines the flow rate of the medium based on the time difference, and then calculates the flow rate of the medium.

[0004] The forward and reverse flow time will directly affect the measurement accuracy of the ultrasonic flowmeter. However, in actual application scenarios, the amplitude stability of the ultrasonic signal is poor and is easily affected by various environmental factors such as temperature, which causes the delay time of the forward and reverse flow time to drift. This drift will directly affect the measurement of the medium flow rate and has a great impact on the measurement accuracy of the flowmeter. If it is necessary to further improve the measurement accuracy and stability of the flowmeter and make the flowmeter more accurate, the drift problem becomes a key issue that must be solved.

[0005] However, the existing ultrasonic flow measurement methods that can avoid temperature drift problems still have some technical problems, such as:

[0006] For example, the patent application number is 201911273146.2, which is a flow meter temperature compensation method. This method obtains the flow rate, temperature and other parameters of the ultrasonic flow meter to design a correction model, and then corrects the flow rate based on the correction model. This single correction method that only relies on temperature compensation not only requires additional hardware design and temperature acquisition modules, but also the compensation value mainly depends on the empirical value, resulting in poor stability and low accuracy of the ultrasonic flow meter when measuring in a steady state. Summary of the invention

[0007] In order to overcome the above-mentioned deficiencies of the prior art, the present invention provides a method and system for self-correcting the delay time of ultrasonic flow measurement in steady state, which can effectively improve the accuracy and stability of ultrasonic measurement of the medium in steady state.

[0008] To achieve the above objectives, one or more embodiments of the present invention provide the following technical solutions:

[0009] A first aspect of the present invention provides a delay time self-correction method in a steady state of ultrasonic flow measurement.

[0010] A delay time self-correction method for ultrasonic flow measurement in steady state, comprising:

[0011] Acquire the downstream time and the upstream time of multiple cycles of the ultrasonic wave in the medium under steady state, and form the downstream time and the upstream time of multiple cycles into a downstream array and a downstream array respectively;

[0012] The downstream array and the upstream array are respectively subjected to similarity processing to obtain a downstream similarity coefficient and a downstream similarity coefficient; based on the downstream similarity coefficient and the downstream similarity coefficient, the delay time of the downstream time and the downstream time is respectively compensated to obtain a new downstream delay time and a downstream delay time;

[0013] The sound velocity of the ultrasonic wave after compensation is calculated based on the newly obtained downstream delay time and upstream delay time, and the flow velocity of the ultrasonic wave in the medium under steady state is finally determined based on the obtained sound velocity to complete the delay time self-correction.

[0014] Furthermore, the downstream time and the upstream time of the obtained multiple cycles are respectively formed into a downstream array and a upstream array. Specifically, the array capacity of the downstream array and the upstream array is consistent with the number of cycles of the collected downstream time and the upstream time.

[0015] Furthermore, when the data collected in the next cycle arrives, the first data in the queue will be kicked out, and the newly collected data will enter the queue.

[0016] Furthermore, the first data is the first data to enter the queue among the existing data in the array.

[0017] Further, the delay time is compensated based on the downstream similarity coefficient and the upstream similarity coefficient, including: averaging multiple coefficients in the downstream similarity coefficient and the upstream similarity coefficient respectively to obtain the downstream average similarity coefficient and the upstream average similarity coefficient.

[0018] Furthermore, based on the obtained downstream average similarity coefficient and upstream average similarity coefficient, the delay time of the downstream time and the upstream time are compensated respectively to obtain a new downstream delay time and a new upstream delay time.

[0019] Furthermore, the pipe diameter and the obtained flow velocity of the ultrasonic wave in the medium in the steady state are combined to determine the flow rate of the ultrasonic wave in the medium in the steady state.

[0020] A second aspect of the present invention provides a delay time self-correction system in a steady state of ultrasonic flow measurement.

[0021] A delay time self-correction system for ultrasonic flow measurement in steady state, comprising:

[0022] The array building module is configured to: obtain the downstream time and the upstream time of multiple cycles of the ultrasonic wave in the medium under steady state, and form a downstream array and a upstream array with the downstream time and the upstream time of multiple cycles respectively;

[0023] The delay time updating module is configured to: perform similarity processing on the downstream array and the upstream array respectively to obtain a downstream similarity coefficient and a downstream similarity coefficient; and compensate the delay time of the downstream time and the downstream time based on the downstream similarity coefficient and the downstream similarity coefficient to obtain a new downstream delay time and a downstream delay time;

[0024] The delay time self-correction module is configured to: calculate the sound velocity of the ultrasonic wave after compensation based on the newly obtained downstream delay time and upstream delay time, and finally determine the flow velocity of the ultrasonic wave in the medium under steady state based on the obtained sound velocity to complete the delay time self-correction.

[0025] The third aspect of the present invention provides a computer-readable storage medium having a program stored thereon, which, when executed by a processor, implements the steps of a delay time self-correction method in a steady state of ultrasonic flow measurement as described in the first aspect of the present invention.

[0026] The fourth aspect of the present invention provides an electronic device, including a memory, a processor, and a program stored in the memory and executable on the processor. When the processor executes the program, the steps of the delay time self-correction method in a steady state of ultrasonic flow measurement as described in the first aspect of the present invention are implemented.

[0027] One or more of the above technical solutions have the following beneficial effects:

[0028] The present invention calculates a new delay time by calculating the average value of the similarity between the forward and reverse flow time and time of multiple cycles of the flow meter in a steady state; then, the forward and reverse flow time calculated according to the new delay time enters the forward and reverse flow time queue again. The system is adaptive through repeated iterative optimization, so the difference between the forward and reverse flow time after optimization of the present invention has a strong ability to adapt to environmental factors such as temperature, and truly realizes self-calibration; and there is no need to add hardware design and temperature acquisition modules. Therefore, the present invention can effectively improve the accuracy and stability of the flow meter in measuring the medium using ultrasound in a steady state.

[0029] Advantages of additional aspects of the present invention will be given in part in the following description, and in part will become obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0031] Figure 1 This is a flow chart of a delay time self-correction method in a steady state of ultrasonic flow measurement in Embodiment 1 of the present invention. DETAILED DESCRIPTION

[0032] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0033] It should be noted that the terms used herein are for describing specific embodiments only and are not intended to be limiting of exemplary embodiments according to the present invention.

[0034] In the absence of conflict, the embodiments of the present invention and the features of the embodiments may be combined with each other.

[0035] Embodiment 1

[0036] This embodiment discloses a delay time self-correction method in a steady state of ultrasonic flow measurement.

[0037] like Figure 1 As shown, a delay time self-correction method in a steady state of ultrasonic flow measurement includes:

[0038] Step S1, obtaining the downstream time and the upstream time of multiple cycles of the ultrasonic wave in the medium under steady state, and forming a downstream array and a upstream array with the obtained multiple cycles of downstream time and upstream time respectively;

[0039] Step S2, performing similarity processing on the downstream array and the upstream array respectively to obtain a downstream similarity coefficient and a downstream similarity coefficient; based on the downstream similarity coefficient and the downstream similarity coefficient, respectively compensating the delay time of the downstream time and the downstream time to obtain a new downstream delay time and a downstream delay time;

[0040] Step S3, calculating the sound velocity of the ultrasonic wave after compensation based on the newly obtained downstream delay time and upstream delay time, and finally determining the flow velocity of the ultrasonic wave in the medium under steady state based on the obtained sound velocity to complete the delay time self-correction.

[0041] Based on the above process, the present invention can effectively improve the accuracy and stability of ultrasonic measurement of the medium in a steady state. Before further describing the technical solution of the present invention, the main technical problems that arise in the actual measurement of the flowmeter are first analyzed based on the basic principle of the time difference ultrasonic flowmeter:

[0042] According to the basic principle of the time difference ultrasonic flow meter, the ultrasonic downstream signal t ab and countercurrent signal t ba The arrival time can be expressed as:

[0043]

[0044] In the formula, C represents the sound velocity of ultrasound in the medium, V represents the linear average velocity of the medium, and L represents the length of the sound channel. ab represents the arrival time of downstream signal, referred to as downstream time; t ba Represents the arrival time of the counterflow signal, referred to as the counterflow time; τ ab Represents the circuit delay time of the downstream signal, τ ba It represents the circuit delay time of the counterflow signal, and β represents the axial angle between the ultrasonic transducer and the pipe.

[0045] Since the sound velocity of ultrasound in the medium will change with the change of temperature and other conditions, it is necessary to use the calculation formula of downstream time and upstream time to calculate the sound velocity C of ultrasound in the medium, which can be expressed as:

[0046]

[0047] Therefore, the sound speed of ultrasonic wave in the medium can be expressed as:

[0048]

[0049] Furthermore, the time difference Δt between the downstream time and the upstream time is:

[0050]

[0051] Therefore, the linear average velocity of the medium can be expressed as:

[0052]

[0053] Among them, V represents the linear average velocity of the medium. From the above calculation formula of the medium velocity, it can be seen that it is very important to maintain a stable sound velocity C; at the same time, from the calculation formula of the sound velocity C, it can be seen that maintaining a stable delay time τ ab , τ ba It is also crucial. However, in the actual measurement process using the flow meter, the delay time of the ultrasonic signal's forward and reverse flow circuit is easily affected by various interference factors, resulting in the phenomenon of delay time drift, resulting in inconsistent data with the increase or decrease of temperature in the steady state. At present, there are few processing algorithms for temperature drift, and most of them rely on methods such as increasing temperature compensation to avoid temperature drift. This method not only requires the design of increasing temperature acquisition, but also the compensation value often depends on the experience value and has no adaptability.

[0054] In this regard, the present invention provides a delay time self-correction method for ultrasonic flow measurement in steady state, which can realize the self-correction of the flow meter based on the delay time in steady state without adding hardware design and temperature acquisition module, realize accurate measurement of the medium flow rate, and thus effectively improve the measurement accuracy of the flow meter. To facilitate the understanding of the technical solution of the present invention, the specific implementation steps in the technical solution of the present invention are further explained and illustrated below.

[0055] Step S1, obtaining the downstream time and the upstream time of multiple cycles of ultrasonic waves in a medium under steady state, and forming a downstream array and a upstream array with the obtained multiple cycles of downstream time and upstream time.

[0056] The downstream time and the upstream time of the obtained multiple cycles are respectively formed into a downstream array and a downstream array. Specifically, the array capacity of the downstream array and the upstream array is consistent with the number of cycles of the collected downstream time and the upstream time. When the data collected in the next cycle arrives, the first data in the queue will be kicked out, and the newly collected data will enter the queue. Among them, the first data means the first data in the existing data in the array to enter the queue.

[0057] In the actual implementation process, pure water is used as the medium, and the data collection of the downstream time and the countercurrent time is performed when the medium flow rate is in a steady state. Preferably, this embodiment continuously collects 10 cycles of downstream time and 10 cycles of countercurrent time to form a downstream array and a countercurrent array respectively. Among them, the downstream array is represented by: t ab [1] t ab [2], ..., t ab [9] t ab

[10] ; Similarly, the countercurrent array is represented by t ba [1] t ba [2], ..., t oa [9] t ba

[10] . Therefore, the capacity of the downstream array and the upstream array is 10 data. When the data collected in the next cycle arrives, the first data in the queue will be kicked out and the new data will enter the queue. It can be understood that the first data means the first data in the array that enters the queue.

[0058] Step S2, performing similarity processing on the downstream array and the upstream array respectively to obtain the downstream similarity coefficient and the upstream similarity coefficient; based on the downstream similarity coefficient and the upstream similarity coefficient, respectively compensating the delay time of the downstream time and the upstream time to obtain a new downstream delay time and a reverse delay time.

[0059] Step S2-1, perform similarity processing on the downstream array and the upstream array respectively to obtain the downstream similarity coefficient and the upstream similarity coefficient. The obtained similarity coefficient can be expressed as:

[0060]

[0061] Where ρ represents a downstream similarity coefficient array consisting of multiple downstream similarity coefficients, ρ i represents the downstream similarity coefficient corresponding to the i-th data and the i+1-th data in the downstream array; T1 represents the number of downstream similarity coefficients contained in the downstream similarity coefficient array, which is one less than the amount of data in the downstream array; t ab [i] and t ab [i+1] represents the i-th and i+1-th data in the downstream array respectively. q represents the upstream similarity coefficient array composed of multiple upstream similarity coefficients, q i represents the countercurrent similarity coefficient corresponding to the i-th data and the i+1-th data in the countercurrent array; T2 represents the number of countercurrent similarity coefficients contained in the countercurrent similarity coefficient array, which is one less than the amount of data in the countercurrent array; t ba [i] and t ba [i+1] represents the i-th and i+1-th data in the upstream array respectively.

[0062] In this embodiment, based on the above formula, a downstream similarity coefficient array composed of multiple downstream similarity coefficients and a specific representation of each downstream similarity coefficient in the downstream similarity coefficient array can be obtained. For example, based on the above formula, the first downstream similarity coefficient in the downstream similarity coefficient array and the first upstream similarity coefficient in the upstream similarity coefficient array can be expressed as:

[0063]

[0064] Wherein, ρ1 represents the first downstream similarity coefficient in the downstream similarity coefficient array, q1 represents the first upstream similarity coefficient in the upstream similarity coefficient array; t ab [1] and t ab [2] respectively represent the first and second data in the downstream array (i.e. the first data and the second data in the downstream array), t ba [1] and t ba [2] respectively represent the first and second data in the upstream array (i.e., the first data and the second data in the upstream array). Similarly, the other downstream similarity coefficients in the downstream similarity coefficient array and the other upstream similarity coefficients in the upstream similarity coefficient array can be obtained, that is, and (In this embodiment, T1=T2=9).

[0065] Step S2-2: based on the downstream similarity coefficient and the upstream similarity coefficient, respectively compensate the delay time of the downstream time and the upstream time to obtain a new downstream delay time and a new upstream delay time.

[0066] For each of the multiple downstream similarity coefficients ρ in the downstream similarity coefficient array ρ i and the multiple countercurrent similarity coefficients q in the countercurrent similarity coefficient array q i Take the average value to obtain the average similarity coefficient of downstream and upstream, that is:

[0067]

[0068] in, and Represent the average similarity coefficient of downstream and upstream, respectively. Based on the obtained average similarity coefficient of downstream and countercurrent average similarity coefficient The delay time of the downstream time and the upstream time are compensated respectively to obtain the new downstream delay time τ′ ab and the backflow delay time τ′ ba ,Right now:

[0069] Step S3: Based on the newly obtained downstream delay time τ′ ab and the backflow delay time τ′ ba The sound velocity of the ultrasonic wave after compensation is calculated, and the flow velocity of the ultrasonic wave in the medium under steady state is finally determined based on the obtained sound velocity to complete the delay time self-correction.

[0070] First, the newly obtained downstream delay time τ′ ab and the backflow delay time τ′ba Substitute the ultrasonic sound velocity calculation formula to obtain the sound velocity of the ultrasonic wave in the medium after compensation, that is:

[0071]

[0072] Among them, C' represents the sound velocity of the ultrasonic wave in the medium after compensation. The sound velocity C' after compensation has strong adaptability. When the environmental conditions such as temperature change, the system in this example will eliminate the influence of temperature drift after several cycles of self-calibration, thereby obtaining a stable medium flow rate; and there is no need to add a temperature compensation module to the hardware facilities. Furthermore, by combining the pipe diameter of the ultrasonic flowmeter body and the flow velocity of the ultrasonic wave in the medium under steady state, the flow rate of the ultrasonic wave in the medium under steady state can be determined, that is:

[0073]

[0074] Among them, Q represents the flow rate of ultrasonic waves in the medium under steady state, V represents the flow velocity of the medium in the pipe of the ultrasonic flowmeter body, and D represents the inner diameter of the pipe of the ultrasonic flowmeter body.

[0075] Thus, the present invention finally determines the flow velocity of the ultrasonic wave in the medium under steady state based on the obtained sound velocity, and realizes the self-correction of the delay time.

[0076] Embodiment 2

[0077] This embodiment discloses a delay time self-correction system in a steady state of ultrasonic flow measurement.

[0078] A delay time self-correction system for ultrasonic flow measurement in steady state, comprising:

[0079] The array building module is configured to: obtain the downstream time and the upstream time of multiple cycles of the ultrasonic wave in the medium under steady state, and form a downstream array and a upstream array with the downstream time and the upstream time of multiple cycles respectively;

[0080] The delay time updating module is configured to: perform similarity processing on the downstream array and the upstream array respectively to obtain a downstream similarity coefficient and a downstream similarity coefficient; and compensate the delay time of the downstream time and the downstream time based on the downstream similarity coefficient and the downstream similarity coefficient to obtain a new downstream delay time and a downstream delay time;

[0081] The delay time self-correction module is configured to: calculate the sound velocity of the ultrasonic wave after compensation based on the newly obtained downstream delay time and upstream delay time, and finally determine the flow velocity of the ultrasonic wave in the medium under steady state based on the obtained sound velocity to complete the delay time self-correction.

[0082] Embodiment 3

[0083] The purpose of this embodiment is to provide a computer-readable storage medium.

[0084] A computer-readable storage medium stores a computer program, which, when executed by a processor, implements the steps of a delay time self-correction method in a steady state of ultrasonic flow measurement as described in the first embodiment of the present disclosure.

[0085] Embodiment 4

[0086] The purpose of this embodiment is to provide an electronic device.

[0087] An electronic device includes a memory, a processor, and a program stored in the memory and executable on the processor. When the processor executes the program, the steps of a delay time self-correction method for ultrasonic flow measurement in steady state are implemented as described in Embodiment 1 of the present disclosure.

[0088] The steps involved in the apparatuses of the above embodiments 2, 3 and 4 correspond to the method embodiment 1, and the specific implementation methods can refer to the relevant description part of embodiment 1. The term "computer-readable storage medium" should be understood as a single medium or multiple media including one or more instruction sets; it should also be understood to include any medium that can store, encode or carry an instruction set for execution by a processor and enable the processor to execute any method in the present invention.

[0089] Those skilled in the art should understand that the modules or steps of the present invention described above can be implemented by a general-purpose computer device, or alternatively, they can be implemented by a program code executable by a computing device, so that they can be stored in a storage device and executed by the computing device, or they can be made into individual integrated circuit modules, or multiple modules or steps therein can be made into a single integrated circuit module for implementation. The present invention is not limited to any specific combination of hardware and software.

[0090] Although the above describes the specific implementation mode of the present invention in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art on the basis of the technical solution of the present invention without creative work are still within the scope of protection of the present invention.

Claims

1. A delay time self-correction method for ultrasonic flow measurement in steady state, characterized in that: include: Acquire the downstream time and the upstream time of multiple cycles of the ultrasonic wave in the medium under steady state, and form the downstream time and the upstream time of multiple cycles into a downstream array and a downstream array respectively; The downstream array and the upstream array are respectively subjected to similarity processing to obtain a downstream similarity coefficient and a downstream similarity coefficient; based on the downstream similarity coefficient and the downstream similarity coefficient, the delay time of the downstream time and the downstream time is respectively compensated to obtain a new downstream delay time and a downstream delay time; The sound velocity of the ultrasonic wave after compensation is calculated based on the newly obtained downstream delay time and upstream delay time, and the flow velocity of the ultrasonic wave in the medium under steady state is finally determined based on the obtained sound velocity to complete the delay time self-correction.

2. The delay time self-correction method of ultrasonic flow measurement in steady state as claimed in claim 1, characterized in that: The downstream time and the upstream time of the obtained multiple cycles are respectively formed into a downstream array and a upstream array. Specifically, the array capacity of the downstream array and the upstream array is consistent with the number of cycles of the collected downstream time and the upstream time.

3. A delay time self-correction method for ultrasonic flow measurement in steady state as claimed in claim 2, characterized in that: When the data collected in the next cycle arrives, the first data in the queue will be kicked out and the newly collected data will enter the queue.

4. A delay time self-correction method for ultrasonic flow measurement in steady state as claimed in claim 3, characterized in that: The first data is the first data to enter the queue among the existing data in the array.

5. The delay time self-correction method of ultrasonic flow measurement in steady state as claimed in claim 1, characterized in that: The delay time is compensated based on the downstream similarity coefficient and the upstream similarity coefficient, including: averaging multiple coefficients in the downstream similarity coefficient and the upstream similarity coefficient respectively to obtain the downstream average similarity coefficient and the upstream average similarity coefficient.

6. A delay time self-correction method for ultrasonic flow measurement in steady state as claimed in claim 5, characterized in that: The delay times of the downstream time and the upstream time are compensated respectively based on the obtained downstream average similarity coefficient and the upstream average similarity coefficient to obtain new downstream delay time and upstream delay time.

7. The delay time self-correction method of ultrasonic flow measurement in steady state as claimed in claim 1, characterized in that: The pipe diameter and the obtained ultrasonic flow velocity in the medium under steady state are combined to determine the flow rate of ultrasonic waves in the medium under steady state.

8. A delay time self-correction system for ultrasonic flow measurement in steady state, characterized in that: include: The array building module is configured to: obtain the downstream time and the upstream time of multiple cycles of the ultrasonic wave in the medium under steady state, and form a downstream array and a upstream array with the downstream time and the upstream time of multiple cycles respectively; The delay time updating module is configured to: perform similarity processing on the downstream array and the upstream array respectively to obtain a downstream similarity coefficient and a downstream similarity coefficient; and compensate the delay time of the downstream time and the downstream time based on the downstream similarity coefficient and the downstream similarity coefficient to obtain a new downstream delay time and a downstream delay time; The delay time self-correction module is configured to: calculate the sound velocity of the ultrasonic wave after compensation based on the newly obtained downstream delay time and upstream delay time, and finally determine the flow velocity of the ultrasonic wave in the medium under steady state based on the obtained sound velocity to complete the delay time self-correction.

9. A computer-readable storage medium having a program stored thereon, characterized in that: When the program is executed by a processor, the steps of the delay time self-correction method in a steady state of ultrasonic flow measurement are implemented as described in any one of claims 1 to 7.

10. An electronic device comprising a memory, a processor, and a program stored in the memory and executable on the processor, characterized in that: When the processor executes the program, the steps of the delay time self-correction method in the steady state of ultrasonic flow measurement are implemented as described in any one of claims 1-7.

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