Calibration device and method for ultrasonic detection equipment

Abstract

The invention relates to the technical field of sensor calibration, and provides a calibration device and method for ultrasonic detection equipment, and the calibration device comprises a calibration box body which can be arranged in a sealing manner, and the interior of the calibration box body is divided into an emission source chamber and a detection chamber which are communicated with each other; a first mounting position is arranged in the emission source chamber and is used for fixing a signal emission source or a laser calibrator, and a second mounting position is arranged in the detection chamber and is used for fixing a detected sensor; the spatial positions of the first installation position and the second installation position meet the following condition: when the laser calibrator is installed at the first installation position, the laser axis emitted by the laser calibrator is right opposite to the central point of the measured sensor at the second installation position. By applying the technical scheme provided by the invention, the spatial position between the signal emission source and the tested sensor is ensured to be constant through positioning of the first mounting position and the second mounting position. In this way, the parameters of the ultrasonic sensor can be verified or calibrated in time on the equipment site through the calibration device.

Description

Technical Field

[0001] This application relates to the field of sensor calibration technology, and in particular to a calibration device and method for ultrasonic testing equipment. Background Technology

[0002] Partial discharge (PD) refers to the electrical discharge phenomenon that occurs in localized areas of the insulation system of electrical equipment under the influence of an electric field, caused by uneven electric field strength or weaknesses in the insulation. This phenomenon usually does not penetrate the entire insulation material, but it can still seriously affect the safe operation of the equipment. This discharge phenomenon typically manifests as a short pulse, lasting less than 1 microsecond, and may be accompanied by physical phenomena such as sound, light, and heat, as well as chemical reactions.

[0003] Partial discharge detection is an important method for evaluating the insulation performance of electrical equipment. Its main purpose is to detect the physical phenomena generated by partial discharge, such as acoustic detection methods: using ultrasonic sensors to detect the sound wave signals generated by partial discharge. This method has strong anti-interference capabilities and is suitable for the detection of equipment such as transformers and GIS (Gas-Insulated Switchgear). The propagation characteristics of the sound wave signal (such as attenuation and dispersion) can be used to locate and analyze the discharge point.

[0004] Before using an ultrasonic sensor to detect the acoustic signal generated by partial discharge, the sensor's parameters need to be calibrated. Traditional calibration methods require the ultrasonic sensor to be calibrated in a laboratory environment before it is installed on the field equipment. However, in practical applications, it is often necessary to verify or calibrate the ultrasonic sensor's parameters on-site in a timely manner. Summary of the Invention

[0005] This application provides a calibration device and method for ultrasonic testing equipment, which allows for timely verification or calibration of ultrasonic sensor parameters at the equipment site.

[0006] The calibration device for ultrasonic testing equipment provided in this application includes: a sealable calibration chamber, the interior of which is divided into an interconnected emission source chamber and a detection chamber; The emission source chamber is provided with a first mounting position for fixing the signal emission source or laser calibrator, and the detection chamber is provided with a second mounting position for fixing the sensor under test; The spatial positions of the first mounting position and the second mounting position satisfy the following condition: when the laser calibrator is installed in the first mounting position, the laser axis emitted by the laser calibrator is directly aligned with the center point of the sensor under test in the second mounting position.

[0007] In one possible implementation, a backing structure is provided on the inner walls of the emission source chamber and the detection chamber; The backing structure includes: Backing substrate that fits the inner wall of the cavity; An acoustic cone array fixed to a backing substrate, with the tips of each cone pointing toward the interior space of the cavity; Microporous structures are set on the backing substrate and the acoustic cone array.

[0008] In one possible implementation, the calibration device further includes a sound barrier structure disposed at the connection between the emission source chamber and the detection chamber; The sound barrier structure is a wedge-shaped structure with a cross-section of a right trapezoid or a right triangle. The inclined surface of the sound barrier structure faces the emission source chamber, and the vertical surface faces the detection chamber; the vertical surface is perpendicular to the bottom surface of the detection chamber. The surface of the sound barrier structure is designed with an uneven texture.

[0009] In one possible implementation, the calibration device also includes a support that is detachably disposed at the bottom of the detection chamber; The support includes a lifting rod and a height adjuster that drives its vertical movement, with the sensor under test fixed to the top of the lifting rod.

[0010] In one possible implementation, a leveling device is provided at the bottom of the calibration chamber to adjust the levelness of the calibration chamber.

[0011] In one possible implementation, the calibration device also includes a controller, which is connected to both the signal transmitter and the sensor under test.

[0012] This application provides a calibration method, which is applied to a calibration device and includes: Set the calibration parameters for the sensor under test; If the calibration parameters are compliant, send calibration instructions to the signal source and the sensor under test. Upon receiving confirmation commands from the signal transmitter and the sensor under test, the transmitter's transmission signal parameters are set according to the calibration parameters. Based on the transmitted signal parameters, the control signal source generates a target excitation signal; Receive the measured data uploaded by the sensor under test.

[0013] In one possible implementation, after receiving the measured data uploaded by the sensor under test, the method further includes: The measured data are preprocessed, including removing invalid data points, data alignment and matching, and / or processing of redundant data. The preprocessed measured data is matched with the transmitted signal parameters, and the calibration curve of the sensor under test is fitted.

[0014] In one possible implementation, the transmitted signal parameters include at least: a minimum transmitted signal frequency, a maximum transmitted signal frequency, a minimum transmitted signal strength, a maximum transmitted signal strength, and an interval for signal strength variation at the same frequency; The step of controlling the signal transmission source to generate the target excitation signal based on the transmission signal parameters also includes: Multiple calibration frequencies are generated by interpolation based on the minimum and maximum values ​​of the transmitted signal frequency. Multiple preset signal strengths are generated by interpolation based on the minimum and maximum transmitted signal strengths; Based on multiple calibration frequencies, multiple preset signal strengths, signal strength variation intervals at the same frequency, and frequency variation intervals, the signal emission source is driven to generate a target excitation signal.

[0015] The calibration device and method provided in this application organically combine a calibration box, a first mounting position, a second mounting position, a sound barrier structure, a support, and a leveling device to form a compact and portable calibration device. This allows for the rapid construction of a calibration environment with good interference suppression capabilities at the equipment site, enabling on-site, rapid, and high-precision calibration of ultrasonic sensors, thus improving the efficiency and reliability of partial discharge detection. During actual calibration, while ensuring a constant spatial relationship between the signal source and the sensor under test, the controller precisely controls the excitation signal, generating a standardized sine wave signal with an adjustable frequency range and continuously variable amplitude. Simultaneously, the dynamic response characteristics of the sensor under test are acquired under different frequency bands and excitation intensities, thereby achieving quantitative calibration of core parameters such as sensitivity, linearity, and frequency response of the sensor under test. Attached Figure Description

[0016] To more clearly illustrate the technical solution of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 A schematic diagram of the overall structure of a calibration device for ultrasonic testing equipment provided in this application embodiment. Figure 1 ; Figure 2 This is a schematic diagram showing the spatial positions of the signal transmitting source and the sensor under test provided in an embodiment of this application; Figure 3 A schematic diagram of the overall structure of a calibration device for ultrasonic testing equipment provided in this application embodiment. Figure 2 ; Figure 4 A schematic diagram of the overall structure of a calibration device for ultrasonic testing equipment provided in this application embodiment. Figure 3 ; Figure 5 A schematic diagram of the backing structure provided in the embodiments of this application; Figure 6 A schematic diagram of the sound barrier structure provided in the embodiments of this application. Figure 1 ; Figure 7 A schematic diagram of the sound barrier structure provided in the embodiments of this application. Figure 2 ; Figure 8 This is a schematic diagram of the structure of the bracket provided in the embodiments of this application; Figure 9 This is a schematic diagram of the leveling device provided in the embodiments of this application; Figure 10 A flowchart illustrating a calibration method for an ultrasonic testing device provided in this application embodiment. Figure 1 ; Figure 11 A flowchart illustrating a calibration method for an ultrasonic testing device provided in this application embodiment. Figure 2 .

[0018] In the diagram: 1-calibration chamber, 11-cabinet door, 12-first interface, 13-second interface, 2-emission source chamber, 21-first mounting position, 3-detection chamber, 31-second mounting position, 4-signal emission source, 5-backing structure, 51-backing substrate, 52-acoustic cone array, 6-sound barrier structure, 61-sloping surface, 62-vertical surface, 7-bracket, 71-height adjuster, 711-fixing rod, 712-fixer, 72-lifting rod, 8-leveling device, 100-sensor under test. Detailed Implementation

[0019] This application provides a calibration device and calibration method for ultrasonic testing equipment, such as... Figure 1 As shown, the calibration device is equipped with a cabinet door 11, such as Figure 2 As shown, the calibration chamber 1 is internally divided into an interconnected emission source chamber 2 and a detection chamber 3. The emission source chamber 2 is provided with a first mounting position 21 for fixing the signal emission source 4, or temporarily installing a laser calibrator for spatial alignment during the initial stage of calibration. The detection chamber 3 is provided with a second mounting position 31 for fixing the sensor 100 under test.

[0020] like Figure 1As shown, after the cabinet door 11 is closed, a sealed calibration chamber 1 is formed. The calibration chamber 1 can be made of lightweight aluminum alloy for easy portability. The aluminum alloy material of the calibration chamber 1 can shield against electromagnetic interference from the external environment to a certain extent, thereby reducing the impact of external electromagnetic waves on the components inside the calibration chamber 1. A silicone sealing strip is installed at the cabinet door 11 to isolate external noise after the cabinet door 11 is closed. Figure 3 As shown, after the cabinet door 11 is opened, the sensor 100 to be tested can be installed or removed from the detection chamber 3.

[0021] Among them, such as Figure 2 As shown, the first mounting position 21 can be set on the side wall of the transmitter chamber 2, and the second mounting position 31 can be set at the bottom of the detection chamber 3. The calibration box 1 is provided with a first interface 12 and a second interface 13. The first interface 12 is used to connect the signal transmitter 4, and the second interface 13 is used to connect the sensor under test 100.

[0022] Among them, such as Figure 2 As shown, the spatial positions of the first mounting position 21 and the second mounting position 31 satisfy the following: In the initial stage of calibration, when the laser calibrator is installed in the first mounting position 21, the laser axis emitted by the laser calibrator is directly aligned with the center point of the sensor 100 under test in the second mounting position 31. In this way, after the signal emission source 4 is fixed in the first mounting position 21, it is ensured that the signal emission direction of the signal emission source 4 is directly aligned with the center point of the sensor 100 under test.

[0023] In practical applications, before testing the sensor 100 under test, if the sensor 100 previously installed on the calibration equipment is of the same model as the sensor 100 under test, the sensor 100 under test can be directly installed on the second mounting position 31, and the signal transmitter 4 can be installed on the first mounting position 21 before calibrating the sensor 100 under test. If the sensor 100 previously installed on the calibration equipment is of a different model than the sensor 100 under test, the laser calibrator must first be installed on the first mounting position 21, and with the laser calibrator turned on, the sensor 100 under test can be installed on the second mounting position 31. Then, the laser calibrator should be removed, and the signal transmitter 4 should be installed on the first mounting position 21 before calibrating the sensor 100 under test.

[0024] The calibration device for ultrasonic testing equipment provided in this application ensures a constant spatial position between the signal transmitting source 4 and the sensor under test 100 through the positioning of the first mounting position 21 and the second mounting position 31. This allows the parameters of the ultrasonic sensor to be verified or calibrated on-site at the equipment location.

[0025] In one possible implementation, such as Figure 4As shown, a backing structure 5 is provided on the inner wall of the emission source chamber 2 and the detection chamber 3. (As indicated...) Figure 5 As shown, the backing structure 5 includes a backing substrate 51 and an acoustic cone array 52. ​​The backing substrate 51 is attached to the inner wall of the cavity, wherein the cavity includes a source emission cavity 2 and a detection cavity 3. The acoustic cone array 52 is fixed to the backing substrate 51, and the tips of each cone of the acoustic cone array 52 face the internal space of the cavity.

[0026] The backing substrate 51 is made of sound-absorbing cotton, such as polyurethane foam, which can effectively absorb sound wave energy within the cavity, reducing acoustic interference and reverberation. The tips of each cone in the acoustic cone array 52 face the internal space of the cavity. The cone array 52 converts the concentrated energy from specular reflection into diffuse reflection energy, reducing multipath interference. In particular, when the sound wave signal emitted by the signal transmitter 4 diffuses to the inner wall of the cavity, it can prevent the sound wave signal from being concentrated and reflected towards the sensor under test 100. During calibration, the shielding against electromagnetic interference is mainly provided by the aluminum alloy calibration housing 1, while the backing structure 21 acts in the acoustic field.

[0027] In one possible implementation, microporous structures are provided on the backing substrate 51 and the acoustic cone array 52. ​​In practical applications, the pore size of the microporous structure can be set to 0.1-1 mm, and the porosity can be set to greater than or equal to 85%. In this way, the sound absorption effect of the microporous structure effectively reduces the intensity of the sound wave signal reflected by the backing structure 5.

[0028] In one possible implementation, such as Figure 4 As shown, the calibration device also includes a sound barrier structure 6. The sound barrier structure 6 is located at the connection between the emission source chamber 2 and the detection chamber 3, and its surface is designed with an uneven structure to effectively scatter sound waves, reduce multipath interference outside the direct signal, and ensure that the ultrasonic wave reaching the sensor 100 under test is the dominant signal. The sound barrier structure 6 is a wedge-shaped structure, such as... Figure 6 As shown, the cross-section is a right trapezoid, or, as... Figure 7 As shown, the cross-section is a right-angled triangle, in which the inclined surface 61 of the sound barrier structure 6 faces the emission source chamber 2, and the vertical surface 62 faces the detection chamber 3; and the vertical surface 62 is perpendicular to the bottom surface of the detection chamber.

[0029] The wedge-shaped structure has an irregular surface shape. This uneven structure helps increase the contact area between the sound waves and the surface, allowing some sound energy to be absorbed and converted into heat energy. Furthermore, the uneven structure disperses the sound waves during reflection, scattering sound energy in different directions, thus reducing the sound focusing effect and consequently reducing the intensity of multipath interference. The sloping design of the wedge structure facing the emission source chamber 2 further reduces interference intensity because the sloping surface reflects sound waves towards the sensor being measured.

[0030] The calibration device provided in this application overcomes the space limitations of portable devices by combining a backing structure and a sound barrier structure. The wedge-shaped and uneven surface design of the sound barrier structure, combined with the acoustic cone array of the backing structure, effectively scatters and absorbs sound waves, suppressing multipath interference other than the signal directly reaching the sensor under test 100. This allows the calibration device to suppress signal interference within a limited space, approaching the level of a standard acoustic laboratory, thereby meeting the accuracy requirements for on-site sensor calibration.

[0031] In one possible implementation, such as Figure 2 As shown, it also includes a bracket 3. A bracket 7 is detachably mounted at the bottom of the detection chamber 3 to accommodate the positioning requirements of different sensor models. In practical applications, the corresponding bracket 7 needs to be determined according to the model of the sensor 100 being tested. The differences between different brackets 7 lie in their dimensions. For example, they may differ in height, or the structural dimensions on the bracket 7 used to connect the sensor 100 being tested may differ.

[0032] Among them, such as Figure 8 As shown, the bracket 7 includes a lifting rod 72 and a height adjuster 71 that drives its vertical movement. The sensor 100 under test is fixed to the top of the lifting rod 72. The height adjuster 71 includes a fixed rod 711 and a retainer 712 disposed on the fixed rod 711. When the retainer 712 is in the open state, the lifting rod 72 can slide along the axial direction of the fixed rod 711. After the lifting rod 72 slides to a predetermined position, the retainer 712 is closed, and the lifting rod 72 is locked in the predetermined position and fixedly connected to the fixed rod 711. For example, the retainer 712 is a tightening nut. When the tightening nut is in the loosened state, the retainer 712 is in the open state; when the tightening nut is in the tightened state, the retainer 712 is in the closed state.

[0033] It should be noted that, in order to further optimize the interference suppression effect inside the calibration chamber 1, in addition to the inner wall of the calibration chamber 1, other structural components inside the calibration chamber 1 are also equipped with sound-absorbing and wave-absorbing materials. For example, the sound barrier structure 6 and the support 7 are covered or coated with sound-absorbing / wave-absorbing materials to comprehensively reduce the sound wave reflection and electromagnetic interference effects inside the calibration chamber 1.

[0034] In one possible implementation, a leveling device 8 is provided at the bottom of the calibration chamber 1 to adjust the levelness of the calibration chamber 1. For example, as Figure 9 As shown, the leveling device 8 is an adjustable anchor bolt to adjust the level of the calibration box 1, and the leveling device 8 may also include a bubble level or an electronic tilt sensor to facilitate the detection and measurement of the level of the calibration box 1.

[0035] In one possible implementation, the calibration chamber 1 is equipped with casters at its bottom, facilitating its movement. Furthermore, to facilitate leveling and stable placement of the calibration chamber 1, the casters can be designed for storage. When the calibration chamber 1 needs to be moved, the casters are moved out of the storage space. When the calibration chamber 1 needs to be fixed, the casters are moved back into the storage space for leveling and stable placement.

[0036] In one possible implementation, the calibration device further includes a controller, which is connected to the signal transmitter 4 via a first interface 12 and to the sensor under test 100 via a second interface 13.

[0037] The controller is configured as follows: Set the calibration parameters for the sensor under test, and send calibration signals to the signal source and the sensor under test if the calibration parameters are compliant.

[0038] The calibration parameters include the lower limit of the operating frequency. Operating frequency limit Lower limit of received signal strength Upper limit of received signal strength and sensor response time The calibration parameter compliance is: 0 < < , < , >0.

[0039] Upon receiving confirmation commands from the signal transmitter and the sensor under test, the transmitter's transmission signal parameters are set according to the calibration parameters.

[0040] The transmitted signal parameters include at least the minimum transmitted signal frequency. Maximum value Minimum transmitted signal strength Maximum transmitted signal strength and the interval of signal strength variation at the same frequency ,but , , , , .

[0041] The confirmation command is used to instruct the signal transmitter 4 and the sensor under test 100 to confirm that they can enter the calibration state after receiving the calibration signal.

[0042] Based on the transmitted signal parameters, the control signal transmitter generates a target excitation signal.

[0043] Specifically, multiple calibration frequencies are generated by interpolation based on the minimum and maximum transmitted signal frequencies. For example, based on the minimum and maximum transmitted signal frequencies, a preset calibration frequency is interpolated into 5 equal parts, resulting in multiple calibration frequencies as follows: , , , , , .

[0044] Multiple preset signal strengths are generated by interpolation based on the minimum and maximum transmitted signal strengths; for example, if the preset signal strengths are spaced 5dB apart, then the multiple preset signal strengths are as follows: , , … Among them, in If the value is not a multiple of 5, the smallest value closest to the set signal strength will be used for the final preset signal strength.

[0045] Based on multiple calibration frequencies, multiple preset signal strengths, signal strength variation intervals at the same frequency, and frequency variation intervals, the signal emission source is driven to generate a target excitation signal.

[0046] The controller uses nested loops to control the signal transmission process of the signal transmitter. Specifically, the outer loop of the signal transmitter sequentially traverses the preset equally divided frequency points. to The inner loop adjusts the signal strength in 5dB steps at each frequency point. to The controller sends control commands containing parameters such as current frequency, intensity, and duration to the signal transmitter in real time, driving the signal transmitter to accurately generate the target excitation signal.

[0047] The controller receives the measured data uploaded by the sensor under test.

[0048] Upon receiving the measured data, the controller matches it with the set parameters of the current transmitted signal. For example, it generates a visual display of the data in the form of a table or real-time curve to show key parameters such as the set frequency / intensity, measured response value, and error rate. At the same time, it synchronously stores the complete test data (including original data such as timestamps and device serial numbers) to the controller's local database or a designated file to ensure data traceability.

[0049] Preprocess the measured data.

[0050] Preprocessing includes removing invalid data points, data alignment and matching, and / or processing redundant data. Invalid data points are those that have timed out, contain zero values, or exceed the measurement range; for example, those with a signal-to-noise ratio less than 20 dB or a response time greater than the sensor's response time. Abnormal data. Redundant data processing involves averaging three measurements under the same parameters, and data alignment and matching to handle misaligned data.

[0051] The preprocessed measured data is matched with the transmitted signal parameters, and the calibration curve of the sensor under test is fitted. Based on the test data of the sensor under test, calibration curves are fitted to the sensor's response at different frequencies, completing the quantitative calibration of the sensor's core parameters such as sensitivity, linearity, and frequency response.

[0052] The technical solution provided in this application adopts a modular fixed structure design, organically combining the calibration box 1, the first mounting position 21, the second mounting position 31, the sound barrier structure 6, the bracket 7, and the leveling device 8 to form a compact and portable calibration device. This allows for the rapid construction of a calibration environment with good interference suppression capabilities at the equipment site, enabling on-site, rapid, and high-precision calibration of ultrasonic sensors, thus improving the efficiency and reliability of partial discharge detection. During actual calibration, while ensuring a constant spatial relationship between the signal emission source 4 and the sensor under test 100, the controller precisely controls the excitation signal, generating a standardized sine wave signal with an adjustable frequency range and continuously variable amplitude. Simultaneously, the dynamic response characteristics of the sensor under test 100 under different frequency bands and excitation intensities are acquired, thereby achieving quantitative calibration of core parameters such as the sensor's sensitivity, linearity, and frequency response.

[0053] This application provides a calibration method applied to a calibration device. First, the calibration device is leveled using a leveling device 8. Then, a laser calibrator for the sensor under test 100 is installed in the first mounting position 21. Next, the laser calibrator is installed in the first mounting position 21, and the laser emitted by the laser calibrator is controlled. Based on the position of the laser axis of the laser calibrator, the bracket 7 is adjusted so that the laser axis emitted by the laser calibrator is aligned with the center point of the sensor under test 100 in the second mounting position 31. Finally, the laser calibrator in the first mounting position 21 is replaced with a signal emission source 4, thereby calibrating the sensor under test. Figure 10 As shown, the calibration method includes steps S1010 to S1014.

[0054] S1010: Set the calibration parameters for the sensor under test.

[0055] The calibration parameters include the lower limit of the operating frequency. Operating frequency limit Lower limit of received signal strength Upper limit of received signal strength and sensor response time .

[0056] S1011 sends calibration signals to the signal transmitter and the sensor under test, provided the calibration parameters are compliant.

[0057] Among them, the calibration parameter compliance is: 0 < < , < , >0.

[0058] S1012, upon receiving confirmation commands from the signal transmitter and the sensor under test, sets the transmission signal parameters of the transmitter according to the calibration parameters.

[0059] The transmitted signal parameters include at least the minimum transmitted signal frequency. Maximum value Minimum transmitted signal strength Maximum transmitted signal strength and the interval of signal strength variation at the same frequency ,but , , , , .

[0060] The confirmation command is used to instruct the signal transmitter 4 and the sensor under test 100 to confirm that they can enter the calibration state after receiving the calibration signal.

[0061] S1013, based on the transmitted signal parameters, controls the signal transmission source to generate a target excitation signal.

[0062] Specifically, multiple calibration frequencies are generated by interpolation based on the minimum and maximum transmitted signal frequencies. For example, based on the minimum and maximum transmitted signal frequencies, a preset calibration frequency is interpolated into 5 equal parts, resulting in multiple calibration frequencies as follows: , , , , , .

[0063] Multiple preset signal strengths are generated by interpolation based on the minimum and maximum transmitted signal strengths; for example, if the preset signal strengths are spaced 5dB apart, then the multiple preset signal strengths are as follows: , , … Among them, in If the value is not a multiple of 5, the smallest value closest to the set signal strength will be used for the final preset signal strength.

[0064] Based on multiple calibration frequencies, multiple preset signal strengths, signal strength variation intervals at the same frequency, and frequency variation intervals, the signal emission source is driven to generate a target excitation signal.

[0065] The controller uses nested loops to control the signal transmission process of the signal transmitter. Specifically, the outer loop of the signal transmitter sequentially traverses the preset equally divided frequency points. to The inner loop adjusts the signal strength in 5dB steps at each frequency point. to The controller sends control commands containing parameters of current frequency, intensity, and duration to the signal transmitter in real time, driving the signal transmitter to accurately generate the target excitation signal. The duration parameter is determined by the interval between changes in the intensity of the signal at the same frequency and the interval between changes in the frequency. The interval between changes in the intensity of the signal at the same frequency determines the duration of the current intensity, and the interval between changes in the frequency determines the duration of the current frequency.

[0066] S1014, Receive the measured data uploaded by the sensor under test.

[0067] Upon receiving the measured data, the controller matches it with the set parameters of the current transmitted signal. For example, it generates a visual display of the data in the form of a table or real-time curve to show key parameters such as the set frequency / intensity, measured response value, and error rate. At the same time, it synchronously stores the complete test data (including original data such as timestamps and device serial numbers) to the controller's local database or a designated file to ensure data traceability.

[0068] The calibration method provided in this application generates a standardized sinusoidal signal with adjustable frequency range and continuously variable amplitude through precise control of the excitation signal. Simultaneously, it acquires the dynamic response characteristics of the sensor under test (SUT) 100 under different frequency bands and excitation intensities, thereby achieving quantitative calibration of core parameters such as sensitivity, linearity, and frequency response of the SUT. Furthermore, by constructing a precise transfer function between the standard excitation signal and the output of the SUT, this calibration method establishes a reliable sensor performance evaluation standard for partial discharge acoustic detection systems and provides crucial technical support for partial discharge signal analysis in power equipment condition monitoring.

[0069] In one implementation, after receiving the measured data uploaded by the sensor under test, as follows: Figure 11 As shown, the calibration method further includes steps S1110 to S1120.

[0070] S1110, preprocess the measured data, including removing invalid data points, data alignment and matching, and / or processing redundant data.

[0071] Invalid data points include those that timed out, returned zero values, or exceeded the range, such as those with a signal-to-noise ratio <20dB or a response time >20dB. Abnormal data. Redundant data processing involves averaging three measurements under the same parameters, and data alignment and matching to handle misaligned data.

[0072] S1111 matches the preprocessed measured data with the transmitted signal parameters and fits the calibration curve of the sensor under test.

[0073] Preprocessing includes removing invalid data points, data alignment and matching, and / or processing redundant data. Fitting the calibration curve of the sensor under test involves fitting calibration curves to the sensor's responses at different frequencies based on the test data, thereby completing the quantitative calibration of the sensor's core parameters such as sensitivity, linearity, and frequency response.

[0074] The above specific embodiments further illustrate the purpose, technical solution and beneficial effects of this application. It should be understood that the above are only specific embodiments of this application and are not intended to limit the scope of protection of this application. Any modifications, equivalent substitutions, improvements, etc., made on the basis of the technical solution of this application should be included within the scope of protection of this application.

Claims

1. A calibration device for ultrasonic testing equipment, characterized in that, include: A sealable calibration chamber (1) is provided, the interior of which is divided into an interconnected source chamber (2) and a detection chamber (3). The emission source chamber (2) is provided with a first mounting position (21) for fixing the signal emission source (4) or the laser calibrator, and the detection chamber (3) is provided with a second mounting position (31) for fixing the sensor under test (100). The spatial positions of the first mounting position (21) and the second mounting position (31) satisfy the following: when the laser calibrator is installed at the first mounting position (21), the laser axis emitted by the laser calibrator is directly opposite the center point of the sensor (100) under test at the second mounting position (31).

2. The calibration device for ultrasonic testing equipment according to claim 1, characterized in that, The inner walls of the emission source chamber (2) and the detection chamber (3) are provided with a backing structure (5). The backing structure (5) includes: Backing substrate that fits the inner wall of the cavity (51); An acoustic cone array (52) is fixed to the backing substrate (51), and the tips of each cone of the acoustic cone array (52) face the internal space of the cavity. Microporous structures are provided on the backing substrate (51) and the acoustic cone array (52).

3. The calibration device for ultrasonic testing equipment according to claim 1, characterized in that, It also includes a sound barrier structure (6), which is disposed at the connection between the emission source chamber (2) and the detection chamber (3); The sound barrier structure (6) is a wedge-shaped structure with a cross-section in the shape of a right trapezoid or a right triangle. The inclined surface (61) of the sound barrier structure (6) faces the emission source chamber (2), and the vertical surface (62) faces the detection chamber (3). The vertical surface (62) is perpendicular to the bottom surface of the detection chamber.

4. A calibration device for ultrasonic testing equipment according to claim 3, characterized in that, The surface of the sound barrier structure (6) is configured with a concave-convex structure.

5. A calibration device for ultrasonic testing equipment according to claim 1, characterized in that, It also includes a bracket (7), which is detachably disposed at the bottom of the detection chamber (3); The bracket (7) includes a lifting rod (72) and a height adjuster (71) that drives its vertical movement. The sensor under test (100) is fixed to the top of the lifting rod (72).

6. A calibration device for ultrasonic testing equipment according to claim 1, characterized in that, The bottom of the calibration box (1) is provided with a leveling device (8) to adjust the levelness of the calibration box (1).

7. A calibration device for ultrasonic testing equipment according to claim 1, characterized in that, It also includes a controller, which is connected to the signal transmitter (4) and the sensor under test (100).

8. A calibration method, characterized in that, The calibration method is applied to a calibration apparatus for an ultrasonic testing device as described in any one of claims 1-7, comprising: Set the calibration parameters for the sensor under test; If the calibration parameters are compliant, a calibration command is sent to the signal source and the sensor under test. Upon receiving confirmation commands from the signal transmitter and the sensor under test, the transmitter signal parameters are set according to the calibration parameters. Based on the transmitted signal parameters, the signal transmission source is controlled to generate a target excitation signal; Receive the measured data uploaded by the sensor under test.

9. A calibration method according to claim 8, characterized in that, After the step of receiving the measured data uploaded by the sensor under test, the method further includes: The measured data is preprocessed, including removing invalid data points, data alignment and matching, and / or processing of redundant data. The preprocessed measured data is matched with the transmitted signal parameters, and the calibration curve of the sensor under test is fitted.

10. A calibration method according to claim 8, characterized in that, The transmitted signal parameters include at least: minimum transmitted signal frequency, maximum transmitted signal frequency, minimum transmitted signal strength, maximum transmitted signal strength, signal strength variation interval at the same frequency, and frequency variation interval; The step of controlling the signal transmission source to generate a target excitation signal according to the transmission signal parameters further includes: Multiple calibration frequencies are generated by interpolation based on the minimum and maximum values ​​of the transmitted signal frequency. Multiple preset signal strengths are generated by interpolation based on the minimum and maximum transmitted signal strengths; The signal source is driven to generate a target excitation signal based on multiple calibration frequencies, multiple preset signal strengths, signal strength variation intervals at the same frequency, and frequency variation intervals.

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