Ultrafast automatic response shock tube dynamic pressure calibration device and calibration method

Abstract

The invention relates to an ultrafast automatic response shock tube dynamic pressure calibration device and calibration method, and the device comprises a plurality of standard sensors which are sequentially arranged on the side surface of a low-pressure section tube of a shock tube along the length of the low-pressure section tube of the shock tube; the to-be-calibrated sensor is detachably mounted at the tail end of the low-pressure section tube of the shock tube; the signal conditioning instrument is electrically connected with the standard sensor and the sensor to be calibrated; the data acquisition module is used for acquiring detection signals of the standard sensor and the sensor to be calibrated through the signal conditioning instrument; and the data analysis module is connected with the data acquisition module and is used for analyzing the detection signals of the standard sensor and the sensor to be calibrated. According to the invention, ultrafast response, automatic acquisition and data analysis of high-frequency pressure signals can be realized, and the test and calibration requirements of the high-frequency response dynamic pressure sensor under different working conditions are met.

Description

Technical Field

[0001] The invention relates to the field of aerospace measurement and testing, and in particular to an ultrafast automatic response shock tube dynamic pressure calibration device and a calibration method. Background Art

[0002] As a metrological calibration equipment for dynamic testing, shock tubes are widely used in the calibration and evaluation of various dynamic pressure sensors or test systems. The shock tube is divided into two parts, a high-pressure section and a low-pressure section, by a diaphragm. By changing the pressure on both sides of the diaphragm, the diaphragm ruptures and a shock wave is formed in the tube. As an ideal step pressure signal, it can be used to calibrate the dynamic indicators of the pressure sensor, such as the rise time, overshoot, and resonant frequency. The performance indicators of the shock tube mainly include the amplitude, rise time, and duration of the step pressure. Therefore, the accurate measurement and calculation of these three parameters are the key to ensuring the reliability of the dynamic calibration results of the sensor.

[0003] In the process of using air pressure to break the membrane of the shock tube to generate shock waves, there are the following difficulties in the collection and analysis of the step pressure signal. First, the rise time of the step pressure signal is extremely short, less than 1s, and the platform time is in the order of ms. Ordinary data acquisition devices cannot realize the collection of such high-frequency signals; secondly, when breaking the membrane, the high-pressure section of the shock tube needs to be steadily inflated to increase the pressure difference on both sides of the diaphragm, which takes a long time. The acquisition device generates a large amount of useless data during the long-term acquisition process, which brings difficulties to subsequent data processing; finally, due to factors such as the processing accuracy of the diaphragm and the on-site environment of the test, the pressure of the membrane will fluctuate within a certain range, resulting in the inability to accurately estimate the time of the membrane breaking. The existing acquisition device may miss the acquisition of the shock wave signal due to the limitation of the acquisition time. Therefore, it is necessary to design a data acquisition device that can automatically respond to and collect such high-frequency signals to solve the problems of high signal frequency, large data volume, and non-fixed membrane breaking time.

[0004] During the test of the shock tube dynamic pressure calibration device, since the rise time of the shock wave signal is extremely short, a high-frequency response data acquisition system is required for signal acquisition and analysis. However, long-term acquisition will result in excessive data volume, affecting subsequent data analysis. For example, the shock tube experimental data acquisition and analysis system provided by the Chinese invention patent CN110057531A describes the operation process of the shock tube test in detail, and provides a data acquisition system suitable for the shock tube test, which can collect shock wave signals at high speed and save data in real time. However, the acquisition system cannot realize automatic response acquisition of shock wave signals, nor can it calculate step pressure. Summary of the invention

[0005] In order to solve the technical problems existing in the above-mentioned prior art, the purpose of the present invention is to provide an ultrafast automatic response shock tube dynamic pressure calibration device, which can achieve ultrafast response, automatic acquisition and data analysis of high-frequency pressure signals, and meet the testing and calibration requirements of high-frequency response dynamic pressure sensors under different working conditions.

[0006] To achieve the above-mentioned purpose, the present invention provides an ultrafast automatic response shock tube dynamic pressure calibration device, comprising:

[0007] A plurality of standard sensors are sequentially arranged on the side of the low-pressure section of the shock tube along the length of the low-pressure section of the shock tube;

[0008] The sensor to be calibrated is detachably mounted on the end of the low-pressure section of the shock tube;

[0009] A signal conditioner, electrically connected to the standard sensor and the sensor to be calibrated;

[0010] A data acquisition module, used for acquiring detection signals of the standard sensor and the sensor to be calibrated through the signal conditioner;

[0011] A data analysis module is connected to the data acquisition module and is used to analyze the detection signals of the standard sensor and the sensor to be calibrated.

[0012] According to a technical solution of the present invention, a female flange is provided at the end of the low-pressure section of the shock tube, a detachable end flange is provided on the female flange, and the sensor to be calibrated is mounted on the end flange.

[0013] According to a technical solution of the present invention, a boss is provided on the end face of the end face flange that matches the female flange, a sealing ring groove is provided on the end face of the boss, a sealing ring is provided in the sealing ring groove, and the sensor to be calibrated is arranged on the inner side of the sealing ring;

[0014] A center hole connected to the low-pressure section of the shock tube is provided in the middle of the mother flange, and a protruding platform is provided on the inner wall of the center hole. The platform and the end face of the mother flange form a groove, and the groove is matched with the boss. When the mother flange and the end face flange are installed, the sealing ring rests on the end face of the platform.

[0015] According to a technical solution of the present invention, the end face of the boss is provided with a stepped hole, the stepped hole is arranged at the center of the end face flange, a sensor connector is provided in the stepped hole, and the sensor to be calibrated is mounted on the sensor connector.

[0016] According to a technical solution of the present invention, the standard sensor and the sensor to be calibrated are pressure sensors.

[0017] According to a technical solution of the present invention, the number of the standard sensors is at least three, and the distance between adjacent standard sensors is 280 mm.

[0018] According to a technical solution of the present invention, a calibration method of an ultrafast automatic response shock tube dynamic pressure calibration device as described in any one of the above technical solutions is provided, comprising the following steps:

[0019] Step S1, obtaining a pressure signal through the standard sensor and the sensor to be calibrated;

[0020] Step S2, after conditioning the pressure signal by the signal conditioner, output it to the data analysis module, the data analysis module analyzes whether the size of the pressure signal reaches a threshold value, and determines whether the pressure signal is a shock wave signal;

[0021] Step S3, executing step S4 according to the magnitude threshold of the pressure signal, otherwise, returning to step S1;

[0022] Step S4, outputting the pressure signal reaching the threshold to the data acquisition module;

[0023] Step S5: calibrating the sensor to be calibrated according to the pressure signals of the standard sensor and the sensor to be calibrated acquired by the data acquisition module.

[0024] According to one aspect of the present invention, in step S5, determining the speed of the standard sensor by extrapolation and calibrating the sensor to be calibrated specifically includes:

[0025] According to the pressure signal of the standard sensor, a time-signal relationship diagram of the standard sensor is constructed; according to the sudden change of the pressure signal in the time-signal relationship diagram, the time when the shock wave reaches the standard sensor is determined;

[0026] Assuming that the coordinates of the end face of the low-pressure section of the shock tube away from the end face flange are (0,0), the coordinates of the standard sensor are set to (ti,xi), where ti represents the time when the shock wave reaches the i-th standard sensor, and xi represents the distance between the i-th standard sensor and the end face of the low-pressure section of the shock tube away from the end face flange;

[0027] According to the quadratic function relationship of distance over time x = at 2 +bt+c, using the least squares method to approximate the propagation relationship of the shock wave velocity, we get the instantaneous velocity V of the incident shock wave reaching the end face end ;

[0028] Based on formula (1), the actual incident shock wave Mach number M at the end surface is calculated s ';

[0029] Based on formula (2), the pressure value p5 at the end of the low-pressure section of the shock tube after the shock wave is reflected is calculated:

[0030]

[0031] Where MW1 is the gas molecular weight, T1 is the temperature, p1 is the pressure at the end of the low-pressure section of the shock tube before the shock wave is reflected, and R is the universal gas constant, which is 8.314 J·mol -1 ·K -1 ;γ1 is the gas specific heat ratio;

[0032] The pressure value p5 at the end of the low-pressure section of the shock tube after the shock wave reflection is calculated and compared with the measured value of the sensor to be calibrated for calibration.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] The present invention proposes an ultrafast automatic response shock tube dynamic pressure calibration device, comprising standard sensors arranged at equal intervals on the side of the shock tube low-pressure section along the length of the shock tube low-pressure section and sensors to be calibrated arranged on the end of the shock tube low-pressure section. The standard sensors and the sensors to be calibrated are both wiredly connected to a digital acquisition control system composed of a signal conditioner, a data acquisition module, and a data analysis module. The back end of the digital acquisition control system is connected to the communication interface of an industrial computer, and the collected data is visualized. It can not only achieve ultrafast response, automatic acquisition and data analysis of high-frequency pressure signals, but also calculate and analyze the step pressure signal of the shock wave, fully meeting the testing and calibration requirements of high-frequency response dynamic pressure sensors under different working conditions.

[0035] The present invention can realize ultra-fast automatic response, collection and analysis, can quickly and automatically respond to the generated shock wave signal and perform high-speed collection, and can greatly reduce the collection cost while ensuring the integrity of the test data.

[0036] The present invention can realize the design of a robust shock wave signal response system. Multiple standard sensors installed on the wall of the low-pressure section of the shock tube can back up each other and can all serve as triggers for shock wave signals, greatly improving the reliability of the test device. At the same time, by using multiple standard sensors to measure and analyze the shock wave velocity, more test data points can be obtained, thereby enhancing the accuracy of the calculation.

[0037] The present invention fully exploits the performance of the shock tube device to realize the calculation of the step pressure amplitude and sensor calibration. The standard sensor on the wall can calculate the speed before and after the shock wave reflection, analyze the amplitude of the step pressure, and thus calibrate the sensor, thereby improving the efficiency and accuracy of sensor calibration. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0039] Figure 1 A schematic diagram showing the working process of an ultrafast automatic response shock tube dynamic pressure calibration device in one embodiment of the present invention;

[0040] Figure 2 The terminal tube body of the low-pressure section of the shock tube in one embodiment is schematically shown;

[0041] Figure 3 An embodiment schematically shows a shock tube low-pressure section end face flange;

[0042] Figure 4 A schematic diagram of standard sensor positions in one embodiment is schematically shown;

[0043] Figure 5 Schematic representation of a pressure signal versus time graph of a standard sensor in one embodiment.

[0044] The corresponding relationship between the component names and the reference numerals is as follows:

[0045] 1. Low-pressure section of shock tube; 2. Mounting base; 3. Female flange; 4. End flange; 5. Sensor connector; 6. Sensor to be calibrated; 7. Standard sensor;

[0046] 21. First mounting base; 22. Second mounting base; 23. Third mounting base.

[0047] 71. First standard sensor; 72. Second standard sensor; 73. Third standard sensor. DETAILED DESCRIPTION

[0048] The description of the embodiments of this specification should be combined with the corresponding drawings, which should be considered as part of the complete specification. In the drawings, the shape or thickness of the embodiments may be enlarged and indicated for simplification or convenience. Furthermore, the parts of each structure in the drawings will be described separately. It is worth noting that the elements not shown in the drawings or not described in words are in a form known to ordinary technicians in the relevant technical field.

[0049] The description of the embodiments herein and any reference to directions and orientations are only for the convenience of description and are not to be construed as any limitation on the scope of protection of the present invention. The following description of the preferred embodiments may involve combinations of features, which may exist independently or in combination, and the present invention is not particularly limited to the preferred embodiments. The scope of the present invention is defined by the claims.

[0050] like Figure 1 As shown, an ultrafast automatic response shock tube dynamic pressure calibration device of the present invention comprises a standard sensor 7, a sensor to be calibrated 6, a signal conditioner, a data acquisition module and a data analysis module. The standard sensor 7 and the sensor to be calibrated 6 are pressure sensors.

[0051] A plurality of standard sensors 7 are sequentially arranged on the side of the shock tube low-pressure section 1 along the length of the shock tube low-pressure section 1 ; the standard sensors 7 can be installed on the shock tube low-pressure section 1 through the mounting base 2 .

[0052] The sensor 6 to be calibrated is detachably mounted at the end of the low-pressure section of the shock tube;

[0053] The signal conditioner is electrically connected to the standard sensor 7 and the sensor to be calibrated 6;

[0054] The data acquisition module is used to obtain the detection signals of the standard sensor 7 and the sensor to be calibrated 6 through a signal conditioner;

[0055] The data analysis module is connected to the data acquisition module and is used to analyze the detection signals of the standard sensor 7 and the sensor to be calibrated 6 .

[0056] The present invention continuously monitors the pressure signal in the low-pressure section tube 1 of the shock tube through the standard sensor 7. The signal is amplified by the signal conditioner and then enters the data analysis module to determine whether the signal is a shock wave. If not, the monitoring is continued in the original state. If so, the data acquisition module is triggered to automatically collect the shock wave signal, and the data is transmitted, displayed, and stored in the industrial computer so as to calibrate the sensor 6 to be calibrated.

[0057] By setting a number of standard sensors 7 at different positions of the low-pressure section 1 of the shock tube, the characteristics of the shock wave propagating along the pipeline can be accurately monitored, thereby achieving high-precision calibration of the pressure sensor; the sensor 6 to be calibrated is detachably installed at the end of the low-pressure section 1 of the shock tube, which is convenient for replacing different sensors to be calibrated 6 for testing and calibration, thereby increasing the applicability and flexibility of the device; the use of a signal conditioner ensures that the signals obtained from the standard sensor 7 and the sensor to be calibrated 6 are suitable for subsequent acquisition and analysis in quality and form, thereby improving the accuracy and reliability of the signal; the design of the data acquisition module allows for rapid acquisition of the detection signals of the standard sensor 7 and the sensor to be calibrated 6, which is crucial for capturing rapidly changing dynamic pressure signals.

[0058] In the present invention, a female flange 3 is provided at the end of the shock tube low-pressure section 1 , a detachable end flange 4 is provided on the female flange 3 , and a sensor 6 to be calibrated is mounted on the end flange 4 .

[0059] In some embodiments of the present invention, Figure 2 and Figure 3 As shown, the number of standard sensors 7 is at least three, and the spacing between adjacent standard sensors 7 is 280 mm to ensure shock wave self-repair.

[0060] The mounting base 2 includes a first mounting base 21, a second mounting base 22, and a third mounting base 23. The first standard sensor 71, the second standard sensor 72, and the third standard sensor 73 are respectively mounted on the first mounting base 21, the second mounting base 22, and the third mounting base 23, and are used to monitor the pressure signal in the low-pressure section tube 1 of the shock tube, and calculate the velocity before and after the shock wave reflection.

[0061] In some embodiments of the present invention, a female flange 3 is provided at the end of the shock tube low-pressure section 1 , a detachable end flange 4 is provided on the female flange 3 , and the sensor 6 to be calibrated is installed on the end flange 4 .

[0062] The maximum outer diameter of the flange of the end face flange 4 is 280 mm, and 8 M18 screw holes are opened at a diameter of 220 mm on the end face flange 4. The end face flange 4 and the mother flange 3 are fixed with bolts when assembled.

[0063] In some embodiments of the present invention, a boss is provided on the end face of the end face flange 4 that cooperates with the female flange 3, a sealing ring groove is provided on the end face of the boss, a sealing ring is provided in the sealing ring groove, and the sensor 6 to be calibrated is arranged on the inner side of the sealing ring.

[0064] A center hole connected to the low-pressure section of the shock tube 1 is provided in the middle of the mother flange 3, and a protruding platform is provided on the inner wall of the center hole. The platform and the end face of the mother flange 3 form a groove, and the groove is matched with the boss. When the mother flange 3 and the end face flange 4 are installed, the sealing ring rests on the end face of the platform.

[0065] The outer diameter of the boss can be set to 185 mm, the thickness of the boss can be set to 3 mm, and correspondingly, the depth of the groove on the female flange 3 can be set to 3 mm. The sealing ring groove on the end face flange 4 can be set at a diameter of 154.9-168 mm on the end face flange 4, and the sealing ring groove can be set to a groove with a depth of 4.2 mm. The sealing ring can be an O-ring to ensure the sealing of the shock tube, prevent gas leakage during the test, and ensure the stability of the test environment.

[0066] In some embodiments of the present invention, a stepped hole is provided on the end face of the boss, and the stepped hole is arranged at the center of the end face flange 4. A sensor connector 5 is provided in the stepped hole, and the sensor 6 to be calibrated is installed on the sensor connector 5 to ensure that in order to test the dynamic characteristics of the sensor 6 to be calibrated, different types of sensors to be calibrated 6 can be quickly replaced, thereby improving the flexibility and efficiency of the test.

[0067] The design of the stepped hole allows the sensor connector 5 to be precisely positioned at the center of the end flange 4, ensuring accurate alignment of the sensor 6 to be calibrated and the shock tube, thereby improving measurement accuracy; the sensor 6 to be calibrated is directly mounted on the sensor connector 5, simplifying the installation process and making the loading and unloading of the sensor 6 to be calibrated more convenient and quick. The sensor connector 5 can be designed to adapt to multiple types of sensors 6 to be calibrated, increasing the versatility and flexibility of the device.

[0068] The present invention also provides a calibration method for the ultrafast automatic response shock tube dynamic pressure calibration device, which specifically includes:

[0069] Step S1, obtaining a pressure signal through a standard sensor 7 and a sensor to be calibrated 6;

[0070] Step S2, after conditioning the pressure signal through the signal conditioner, output it to the data analysis module, the data analysis module analyzes whether the size of the pressure signal reaches a threshold value, and determines whether the pressure signal is a shock wave signal;

[0071] Step S3, executing step S4 according to the magnitude threshold of the pressure signal, otherwise, returning to step S1;

[0072] Step S4, outputting the pressure signal reaching the threshold to the data acquisition module;

[0073] Step S5: calibrate the sensor 6 to be calibrated according to the pressure signals of the standard sensor 7 and the sensor 6 to be calibrated collected by the data acquisition module.

[0074] The layout positions of the standard sensor 7 and the sensor to be calibrated 7 in the low-pressure section of the shock tube 1 are as follows: Figure 4 As shown, through and Figure 5 As shown in Figure 1, when the high-pressure driving gas rises to the set pressure, the diaphragm ruptures and forms an incident shock wave. The pressure sensor on the wall can respond to the shock wave signal ultra-fast and transmit the signal to the data acquisition control system for analysis. When the trigger threshold is reached, the data acquisition device is stimulated to automatically collect and analyze the shock wave signal. The relationship between the sensor signal and time obtained by the standard sensor 7 is shown in Figure 1. Figure 5 As shown, curves ①, ②, and ③ in the figure correspond to the test results of the first standard sensor 71, the second standard sensor 72, and the third standard sensor 73 respectively.

[0075] In step S5, the speed of the standard sensor 7 is determined by the extrapolation method and the sensor to be calibrated 6 is calibrated. The extrapolation method is to select the coordinate (0,0) on the end face (the horizontal axis represents time, μs; the vertical axis represents distance, μm). In the process of the incident shock wave passing from the upstream to the end face, it passes through the three side wall sensors in turn, and the time when the shock wave passes is recorded. In this way, four coordinate points can be obtained, which are set as (0,0), (t1,x1), (t2,x2), and (t3,x3). According to the time difference when the shock wave reaches the three sensors, the shock wave velocity at the corresponding position is calculated, and then the quadratic function relationship of distance over time x=at2+bt+c is used. The least squares method is used to approximate the propagation relationship of the shock wave velocity. The instantaneous speed of the incident shock wave reaching the end face is, and then based on the 1-dimensional normal shock wave equation, the pressure value before and after the shock wave reflection can be calculated. The calculated pressure value is compared and calibrated with the measured value of the end face sensor.

[0076] Step S5 specifically includes:

[0077] According to the pressure signal of the standard sensor 7, a time-signal relationship diagram of the standard sensor 7 is constructed; according to the sudden change of the pressure signal in the time-signal relationship diagram, the time when the shock wave reaches the standard sensor 7 is determined;

[0078] Assume that the coordinate of the end face of the shock tube low-pressure section 1 away from the end face flange 4 is (0,0), and set the coordinate of the standard sensor 7 to (ti,xi), where ti represents the time when the shock wave reaches the i-th standard sensor 7, and xi represents the distance between the i-th standard sensor 7 and the end face of the shock tube low-pressure section 1 away from the end face flange 4;

[0079] According to the time difference of the shock wave reaching the standard sensor 7, the shock wave velocity corresponding to the standard sensor 7 is calculated;

[0080] According to the quadratic function relationship of distance over time x = at 2+bt+c, using the least squares method to approximate the propagation relationship of the shock wave velocity, we get the instantaneous velocity V of the incident shock wave reaching the end face end ;

[0081] Based on formula (1), the actual incident shock wave Mach number M at the end surface is calculated s ';

[0082] Based on formula (2), the pressure value p5 at the end of the shock tube low-pressure section tube 1 after the shock wave is reflected is calculated:

[0083]

[0084] Where MW1 is the gas molecular weight, T1 is the temperature, p1 is the pressure at the end of the shock tube low-pressure section 1 before the shock wave is reflected, and R is the universal gas constant, which is 8.314 J·mol -1 ·K -1 ;γ1 is the gas specific heat ratio;

[0085] The pressure value p5 at the end of the low-pressure section tube 1 of the shock tube after the shock wave reflection is calculated and compared with the measured value of the sensor 6 to be calibrated.

[0086] It should be noted that the above is a preferred embodiment of the present invention. It should be pointed out that although the preferred embodiment of the present invention has been described, once the basic creative concept of the present invention is known, a number of improvements and modifications can be made by a person skilled in the art without departing from the principles of the present invention, and these improvements and modifications should also be regarded as the protection scope of the present invention. Therefore, the attached claims are intended to be interpreted as including the preferred embodiment and all changes and modifications that fall within the scope of the embodiments of the present invention.

Claims

1. An ultrafast automatic response shock tube dynamic pressure calibration device, characterized in that: include: A plurality of standard sensors (7) are sequentially arranged on the side surface of the shock tube low-pressure section tube (1) along the length of the shock tube low-pressure section tube (1); A sensor (6) to be calibrated is detachably mounted on the end of the shock tube low-pressure section tube (1); A signal conditioner electrically connected to the standard sensor (7) and the sensor to be calibrated (6); A data acquisition module, used for acquiring detection signals of the standard sensor (7) and the sensor to be calibrated (6) through the signal conditioner; A data analysis module is connected to the data acquisition module and is used to analyze the detection signals of the standard sensor (7) and the sensor to be calibrated (6).

2. The ultrafast automatic response shock tube dynamic pressure calibration device according to claim 1, characterized in that: A female flange (3) is arranged at the end of the shock tube low-pressure section tube (1), a detachable end face flange (4) is arranged on the female flange (3), and the sensor (6) to be calibrated is mounted on the end face flange (4).

3. The ultrafast automatic response shock tube dynamic pressure calibration device according to claim 2, characterized in that: The end face of the end face flange (4) that matches the female flange (3) is provided with a boss, the end face of the boss is provided with a sealing ring groove, a sealing ring is provided in the sealing ring groove, and the sensor to be calibrated (6) is arranged on the inner side of the sealing ring; A central hole connected to the shock tube low-pressure section tube (1) is provided in the middle of the mother flange (3); a protruding platform is provided on the inner wall of the central hole; the platform and the end face of the mother flange (3) form a groove; the groove is matched with the boss; when the mother flange (3) and the end face flange (4) are installed, the sealing ring abuts against the end face of the platform.

4. The ultrafast automatic response shock tube dynamic pressure calibration device according to claim 3, characterized in that: The end face of the boss is provided with a stepped hole, the stepped hole is arranged at the center of the end face flange (4), a sensor connecting piece (5) is arranged in the stepped hole, and the sensor (6) to be calibrated is mounted on the sensor connecting piece (5).

5. The ultrafast automatic response shock tube dynamic pressure calibration device according to claim 1, characterized in that: The standard sensor (7) and the sensor to be calibrated (6) are pressure sensors.

6. The ultrafast automatic response shock tube dynamic pressure calibration device according to claim 1, characterized in that: The number of the standard sensors (7) is at least three, and the spacing between adjacent standard sensors (7) is 280 mm.

7. A calibration method for an ultrafast automatic response shock tube dynamic pressure calibration device according to any one of claims 1 to 6, characterized in that: The following steps are involved: Step S1, obtaining a pressure signal through the standard sensor (7) and the sensor to be calibrated (6); Step S2, after conditioning the pressure signal by the signal conditioner, output it to the data analysis module, the data analysis module analyzes whether the size of the pressure signal reaches a threshold value, and determines whether the pressure signal is a shock wave signal; Step S3, executing step S4 according to the magnitude threshold of the pressure signal, otherwise, returning to step S1; Step S4, outputting the pressure signal reaching the threshold to the data acquisition module; Step S5: calibrate the sensor to be calibrated (6) according to the pressure signals of the standard sensor (7) and the sensor to be calibrated (6) collected by the data collection module.

8. The calibration method according to claim 6, characterized in that: In the step S5, the speed of the standard sensor (7) is determined by extrapolation and the sensor to be calibrated (6) is calibrated, which specifically includes: According to the pressure signal of the standard sensor (7), a time-signal relationship diagram of the standard sensor (7) is constructed; according to the sudden change of the pressure signal in the time-signal relationship diagram, the time when the shock wave reaches the standard sensor (7) is determined; Assuming that the coordinates of the end face of the shock tube low-pressure section tube (1) away from the end face flange (4) are (0, 0), the coordinates of the standard sensor (7) are set to (ti, xi), wherein ti represents the time when the shock wave reaches the i-th standard sensor (7), and xi represents the distance between the i-th standard sensor (7) and the end face of the shock tube low-pressure section tube (1) away from the end face flange (4); Calculating the shock wave velocity corresponding to the standard sensor (7) based on the time difference between the shock wave and the standard sensor (7); According to the quadratic function relationship of distance over time x = at 2 +bt+c, using the least squares method to approximate the propagation relationship of the shock wave velocity, we get the instantaneous velocity V of the incident shock wave reaching the end face end ; Based on formula (1), the actual incident shock wave Mach number M at the end surface is calculated s '; Based on formula (2), the pressure value p5 at the end of the shock tube low-pressure section tube (1) after the shock wave is reflected is calculated: Wherein, MW1 is the gas molecular weight, T1 is the temperature, p1 is the pressure value at the end of the shock tube low-pressure section tube (1) before the shock wave is reflected, and R is the universal gas constant, which is 8.314 J·mol -1 ·K -1 ;γ1 is the gas specific heat ratio; The pressure value p5 at the end of the shock tube low-pressure section tube (1) after the shock wave reflection is calculated and compared with the measured value of the sensor (6) to be calibrated.

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