CN110987360A - Shock tube test system for PSP dynamic calibration device - Google Patents
Shock tube test system for PSP dynamic calibration device Download PDFInfo
- Publication number
- CN110987360A CN110987360A CN201911355427.2A CN201911355427A CN110987360A CN 110987360 A CN110987360 A CN 110987360A CN 201911355427 A CN201911355427 A CN 201911355427A CN 110987360 A CN110987360 A CN 110987360A
- Authority
- CN
- China
- Prior art keywords
- pressure
- low
- section
- shock tube
- sensor
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
- G01M9/00—Aerodynamic testing; Arrangements in or on wind tunnels
- G01M9/06—Measuring arrangements specially adapted for aerodynamic testing
Landscapes
- Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- General Physics & Mathematics (AREA)
- Measuring Fluid Pressure (AREA)
Abstract
The invention relates to the technical field of surface pressure measurement of aircrafts, and discloses a shock tube testing system for a PSP dynamic calibration device, which comprises a pressure measuring system, a speed measuring system and a temperature measuring system, wherein the pressure measuring system, the speed measuring system and the temperature measuring system are arranged on a shock tube, the pressure measuring system comprises a first pressure sensor arranged on the inner wall of a driving section and a low-pressure section respectively, the speed measuring system comprises at least two second pressure sensors arranged in sequence along the length direction of the low-pressure section, the temperature measuring system comprises a temperature sensor arranged on the inner wall of the low-pressure section, the signal output ends of the first pressure sensor, the second pressure sensor and the temperature sensor are all connected to. The pressure in the shock tube is measured through the first pressure sensor, and the temperature of the low-pressure-section pre-charging gas is measured through the temperature sensor; and at least two pressure sensors are adopted to measure the time of the shock wave passing through any two pressure sensors, so that the on-line measurement of the shock wave speed in the shock tube is realized, and the measurement accuracy is high.
Description
Technical Field
The invention relates to the technical field of aircraft surface pressure measurement, in particular to a shock tube test system for a PSP dynamic calibration device.
Background
Pressure Sensitive Paint (PSP) technology is a non-contact measurement method for obtaining Pressure distribution. The PSP technology utilizes the phenomenon that the fluorescence intensity of luminous coating molecules changes along with pressure under the irradiation of exciting light with specific wavelength, converts the pressure into light intensity information, then carries out image processing, calculates the pressure distribution on the surface of the model, and has the advantages of high spatial resolution, no limitation of the model structure, no damage to the flow field on the surface of the model, capability of realizing large-area pressure distribution measurement and the like.
At present, the application of the PSP technology covers a plurality of fields such as aerospace craft surface pressure distribution measurement, helicopter rotor surface pressure distribution measurement, aero-engine fan/compressor blade component surface pressure distribution measurement, complex flow mechanism research and the like. In a series of tasks such as aerodynamic research and model development in the fields of foreign aviation and aerospace, the PSP technology plays an extremely important key technical support role. The fast response PSP technology also plays an extremely important role in the measurement of unsteady pressure of a model with complex aerodynamic characteristics, such as the measurement of the surface pressure distribution of a helicopter rotor wing and the measurement of the surface pressure distribution of the model in unsteady complex flow such as turbulence.
In the process of measuring the response time of the pressure-sensitive paint by adopting the shock tube, relevant parameters such as pressure and temperature in the shock tube and the speed of the generated shock wave are important influencing factors, so that the pressure, the temperature and the speed of the shock wave in the shock tube need to be detected.
Disclosure of Invention
Based on the problems, the invention provides a shock tube testing system for a PSP dynamic calibration device, which measures the pressure in a shock tube through a pressure sensor I and measures the temperature of pre-charging gas at a low-pressure section through a temperature sensor I; and at least two pressure sensors are adopted to measure the time of the shock wave passing through any two pressure sensors, so that the on-line measurement of the shock wave speed in the shock tube is realized, and the measurement accuracy is high.
In order to solve the technical problems, the invention provides a shock tube testing system for a PSP dynamic calibration device, which comprises a pressure measuring system, a speed measuring system and a temperature measuring system which are arranged on a shock tube, wherein the shock tube comprises a driving section and a low-pressure section, an inflation valve is arranged on the driving section, and a rupture diaphragm is arranged between the driving section and the low-pressure section; the front end of the low-pressure section is coaxially connected with an optical glass tube, the front end of the optical glass tube is a sealing structure, and a pressure-sensitive paint sample is arranged on the inner side of the sealing structure of the optical glass tube; the pressure measuring system comprises a first pressure sensor arranged on the inner wall of the driving section and a second pressure sensor arranged on the inner wall of the low-pressure section respectively, the speed measuring system comprises a second pressure sensor arranged in the length direction of the low-pressure section in sequence, the temperature measuring system comprises a temperature sensor arranged on the inner wall of the low-pressure section and used for measuring the temperature of gas in the low-pressure section, the signal output ends of the first pressure sensor, the second pressure sensor and the temperature sensor are all connected to the data acquisition system, and the data acquisition system is in communication connection with the.
Further, set up the pressure measurement mouth on the inner wall of the low pressure section of shock tube, the pressure measurement valve is installed to the pressure measurement mouth, and the pressure measurement valve port of keeping away from the low pressure section is provided with sealed chamber for the pressure sensor of measuring the atmospheric pressure in the low pressure section sets up in the sealed intracavity of pressure measurement valve.
Further, the output of the first pressure sensor is a voltage signal of 0-5V.
Furthermore, the temperature sensor and the pressure sensor are in communication connection with the data acquisition system through the charge amplifier.
Further, the data acquisition system is a PCI-6115 data acquisition unit.
Compared with the prior art, the invention has the beneficial effects that: the pressure in the shock tube is measured through the first pressure sensor, and the temperature of the low-pressure-section pre-charging gas is measured through the temperature sensor; and at least two pressure sensors are adopted to measure the time of the shock wave passing through any two pressure sensors, so that the on-line measurement of the shock wave speed in the shock tube is realized, and the measurement accuracy is high.
Drawings
FIG. 1 is a schematic structural diagram of a shock tube testing system for a PSP dynamic calibration apparatus in an embodiment;
wherein, 1, a driving section; 2. a low-pressure section; 3. an inflation valve; 4. breaking the membrane; 5. an optical glass tube; 6. a pressure sensitive paint sample; 7. a first pressure sensor; 8. a second pressure sensor; 9. a temperature sensor; 10. a data acquisition system; 11. a computer; 12. a pressure measuring valve; 13. a charge amplifier; 14. an LED lamp tube; 15. a photomultiplier tube; 16. an oscilloscope.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail below with reference to examples and accompanying drawings, and the exemplary embodiments and descriptions thereof are only used for explaining the present invention and are not meant to limit the present invention.
Example (b):
referring to fig. 1, a shock tube testing system for a PSP dynamic calibration device includes a pressure measuring system, a speed measuring system and a temperature measuring system which are arranged on a shock tube, the shock tube includes a driving section 1 and a low-pressure section 2, an inflation valve 3 is arranged on the driving section 1, and a rupture diaphragm 4 is arranged between the driving section 1 and the low-pressure section 2; the front end of the low-pressure section 2 is coaxially connected with an optical glass tube 5, the front end of the optical glass tube 5 is a sealing structure, and a pressure-sensitive paint sample 6 is arranged on the inner side of the sealing structure of the optical glass tube 5; the pressure measurement system is including setting up respectively in the pressure sensor 7 of the 2 inner walls of drive section 1 and low-pressure section, the system of testing the speed includes two at least pressure sensor two 8 that set gradually along 2 length direction of low-pressure section, the temperature measurement system is including setting up in the temperature sensor 9 that 2 inner walls of low-pressure section are used for measuring 2 interior gas temperature of low-pressure section, pressure sensor one 7, pressure sensor two 8 and temperature sensor 9's signal output part all is connected to data acquisition system 10, data acquisition system 10 and computer 11 communication connection.
In the embodiment, an LED tube 14 capable of irradiating the pressure-sensitive paint sample 6 to enable the pressure-sensitive paint sample 6 to generate a fluorescent signal is installed on one side of the optical glass tube 5, a photomultiplier 15 for receiving the fluorescent signal is installed on the other side of the optical glass tube 5, and an output end of the photomultiplier 15 is electrically connected with an input end of an oscilloscope 16; the LED lamp tube 14 generates light with a specific wavelength, the light irradiates the surface of the pressure-sensitive paint sample 6 through the optical glass tube 5, and the surface of the pressure-sensitive paint sample 6 is in an excited state to generate a fluorescence signal; the rupture membrane 4 is arranged between the low-pressure section 2 and the driving section 1 through a clamping mechanism, the driving section 1 of the shock tube is inflated through the inflation valve 3, and the rupture membrane 4 gradually deforms under the action of pressure until the rupture membrane is ruptured or the rupture membrane 4 is controlled to rupture by adopting an electric heating mode; after the diaphragm breaks, the high pressure gas in the driving section 1 pushes the gas in the low pressure section 2 to move forward, and the front of the moving gas forms a clean discontinuity, which is called shock wave in aerodynamics. When the shock wave reaches the surface of the sample 6 of pressure-sensitive paint, a brief continuous pressure step is applied to the sample surface, the pressure step has a much faster time-to-climb than the pressure-sensitive paint follow-up time, so that it can be used to calibrate the dynamic characteristics of the sample 6 of pressure-sensitive paint. The photomultiplier 15 is used for collecting the fluorescent signal of the pressure-sensitive paint sample 6 and converting the fluorescent signal into an electric signal, then the electric signal is transmitted to the oscilloscope 16, the response time of the pressure-sensitive paint sample 6 is determined by observing the attenuation time of the fluorescent signal emitted by the pressure-sensitive paint changing along with the step pressure through the oscilloscope 16, and the calibration of the dynamic characteristic of the pressure-sensitive paint sample 6 can be realized. In the measuring process, the two pressure sensors I7 can respectively detect the air pressure in the driving section 1 and the low-pressure section 2 of the shock tube, the at least two pressure sensors II 8 are arranged in the low-pressure section 2, and the speed of the shock wave can be calculated by measuring the time for the shock wave to pass through the two pressure sensors II 8; the temperature sensor 9 can realize the measurement of the gas temperature in the low-pressure section 2 of the shock tube, the pressure sensor I7, the pressure sensor II 8 and the temperature sensor 9 convert respective detected signals into electric signals and transmit the electric signals to the data acquisition system 10, the data acquisition system 10 transmits the electric signal data to the computer 11, and analysis software in the computer 11 can realize the analysis, calculation and storage of the detected data.
Set up the pressure measurement mouth on the inner wall of the low pressure section 2 of shock tube in this embodiment, pressure measurement valve 12 is installed to the pressure measurement mouth, and the pressure measurement valve 12 port of keeping away from low pressure section 2 is provided with sealed chamber for pressure sensor 7 of measuring the atmospheric pressure in the low pressure section 2 sets up in the sealed intracavity of pressure measurement valve 12. When the data acquisition of the air pressure in the low-pressure section 2 is needed, only the pressure measuring valve 12 needs to be opened; when the gas pressure detection in the low pressure section 2 is not required, the pressure measurement valve 12 can be kept in the closed state.
The output of the first pressure sensor 7 is a voltage signal of 0-5V. Because the numerical values detected by the temperature sensor 9 and the second pressure sensor 8 are smaller, the converted electric signals are weaker, and the temperature sensor 9 and the second pressure sensor 8 are in communication connection with the data acquisition system 10 through the charge amplifier 13. In the embodiment, the pressure sensor outputs a voltage signal of 0-5V, and the voltage signal can be directly acquired by the data acquisition system 10; the output signal of the temperature sensor 9 is a current signal of 4-20mA, and the current signal can be acquired by the data acquisition system 10 only after being filtered and amplified by the charge amplifier 13 and converted into a voltage signal; the current signal of 4-20mA output by the second pressure sensor 8 is filtered and amplified by the charge amplifier 13 and converted into a voltage signal, and then the voltage signal can be acquired by the data acquisition system 10. In the embodiment, the 16-channel DH5862 charge amplifier 13 is selected, and the accuracy is less than +/-1%. The data acquisition system 10 is a PCI-6115 data acquisition device, the sampling frequency can reach 10MHz, the highest data bit number can reach 12 bits, and the multichannel synchronous acquisition function can be realized.
The LED lamp 14 in this embodiment is an ultraviolet LED lamp capable of generating ultraviolet light with a central wavelength of 405nm, and the ultraviolet LED lamp is mainly used for exciting the pressure-sensitive paint sample 6, and the excitation light with this wavelength has a higher excitation efficiency for the pressure-sensitive paint sample 6. The brightness of the LED lamp tube 14 is adjustable, external trigger can be accepted, and the maximum digital modulation mode can reach 10000 Hz. The photomultiplier tube 15 in this embodiment has high sensitivity in the light wavelength range of 185nm to 900nm, and is capable of capturing and minute changes in light intensity. The response time of the pressure-sensitive paint sample is about 1.4ns and is far faster than that of the pressure-sensitive paint sample 6, so that the requirement of calibrating the response characteristic of the dynamic pressure-sensitive paint sample 6 can be completely met. The receiving end of the photomultiplier 15 is provided with a filter for removing the excitation light and other non-pressure sensitive paint signal light entering the photomultiplier 15. The filter is a band-pass filter, allows the light to pass through in a wavelength range of 625nm-675nm, is basically overlapped with the signal range of the pressure-sensitive paint, and can allow most of the signal light to enter the photomultiplier 15.
The above is an embodiment of the present invention. The embodiments and specific parameters in the embodiments are only for the purpose of clearly illustrating the verification process of the invention and are not intended to limit the scope of the invention, which is defined by the claims, and all equivalent structural changes made by using the contents of the specification and the drawings of the present invention should be covered by the scope of the present invention.
Claims (5)
1. The utility model provides a be used for PSP dynamic calibration device shock tube test system which characterized in that: the shock tube comprises a pressure measuring system, a speed measuring system and a temperature measuring system which are arranged on the shock tube, wherein the shock tube comprises a driving section (1) and a low-pressure section (2), an inflation valve (3) is arranged on the driving section (1), and a rupture diaphragm (4) is arranged between the driving section (1) and the low-pressure section (2); the front end of the low-pressure section (2) is coaxially connected with an optical glass tube (5), the front end of the optical glass tube (5) is of a sealing structure, and a pressure-sensitive paint sample (6) is arranged on the inner side of the sealing structure of the optical glass tube (5); the pressure measurement system is including setting up respectively in pressure sensor (7) of drive section (1) and low-pressure section (2) inner wall, the system of testing the speed includes two at least pressure sensor (8) that set gradually along low-pressure section (2) length direction, the temperature measurement system is including setting up in temperature sensor (9) that low-pressure section (2) inner wall is used for measuring gas temperature in low-pressure section (2), the signal output part of pressure sensor (7), pressure sensor two (8) and temperature sensor (9) all is connected to data acquisition system (10), data acquisition system (10) are connected with computer (11) communication.
2. The shock tube testing system for the PSP dynamic calibration device of claim 1, wherein: set up the pressure measurement mouth on the inner wall of low pressure section (2) of shock tube, pressure measurement valve (12) are installed to the pressure measurement mouth, and pressure measurement valve (12) port of keeping away from low pressure section (2) is provided with sealed chamber for pressure sensor (7) of measuring atmospheric pressure in low pressure section (2) set up in the sealed intracavity of pressure measurement valve (12).
3. The shock tube testing system for the PSP dynamic calibration device of claim 1, wherein: the output of the first pressure sensor (7) is a voltage signal of 0-5V.
4. The shock tube testing system for the PSP dynamic calibration device of claim 1, wherein: the temperature sensor (9) and the second pressure sensor (8) are in communication connection with the data acquisition system (10) through a charge amplifier (13).
5. The shock tube testing system for a PSP dynamic calibration device according to any of claims 1-4, wherein: the data acquisition system (10) is a PCI-6115 data acquisition unit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911355427.2A CN110987360A (en) | 2019-12-25 | 2019-12-25 | Shock tube test system for PSP dynamic calibration device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911355427.2A CN110987360A (en) | 2019-12-25 | 2019-12-25 | Shock tube test system for PSP dynamic calibration device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN110987360A true CN110987360A (en) | 2020-04-10 |
Family
ID=70075371
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201911355427.2A Pending CN110987360A (en) | 2019-12-25 | 2019-12-25 | Shock tube test system for PSP dynamic calibration device |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110987360A (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112113704A (en) * | 2020-09-23 | 2020-12-22 | 中国空气动力研究与发展中心高速空气动力研究所 | Pressure-sensitive paint response time calibration method based on non-electric detonator driving type shock tube |
| CN112415228A (en) * | 2020-11-18 | 2021-02-26 | 中国航空工业集团公司北京长城计量测试技术研究所 | Step acceleration calibrating device based on shock tube |
| CN114323543A (en) * | 2022-03-10 | 2022-04-12 | 中国空气动力研究与发展中心高速空气动力研究所 | Method for improving pressure-sensitive paint test efficiency |
| CN114323548A (en) * | 2022-03-14 | 2022-04-12 | 中国空气动力研究与发展中心高速空气动力研究所 | Calibration method for pressure-sensitive paint coating suitable for different reference states |
| CN117990268A (en) * | 2024-04-07 | 2024-05-07 | 中国空气动力研究与发展中心低速空气动力研究所 | Dynamic calibration device for measuring frequency response characteristic of pressure sensitive paint |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102539393A (en) * | 2010-12-27 | 2012-07-04 | 中国航空工业第一集团公司沈阳空气动力研究所 | System for measuring pressure response time of pressure sensitive paint by shock wave method |
| CN103018220A (en) * | 2012-12-11 | 2013-04-03 | 中国航空工业集团公司沈阳空气动力研究所 | Measuring system for pressure response time of pressure-sensitive paint and temperature response time of temperature-sensitive paint |
| CN204359677U (en) * | 2013-08-12 | 2015-05-27 | 河南教育学院 | The device of research energetic material fast reaction mechanism |
| CN109580092A (en) * | 2018-11-20 | 2019-04-05 | 中国航天空气动力技术研究院 | A kind of quick response pressure sensitive paint dynamic calibration apparatus and scaling method |
-
2019
- 2019-12-25 CN CN201911355427.2A patent/CN110987360A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102539393A (en) * | 2010-12-27 | 2012-07-04 | 中国航空工业第一集团公司沈阳空气动力研究所 | System for measuring pressure response time of pressure sensitive paint by shock wave method |
| CN103018220A (en) * | 2012-12-11 | 2013-04-03 | 中国航空工业集团公司沈阳空气动力研究所 | Measuring system for pressure response time of pressure-sensitive paint and temperature response time of temperature-sensitive paint |
| CN204359677U (en) * | 2013-08-12 | 2015-05-27 | 河南教育学院 | The device of research energetic material fast reaction mechanism |
| CN109580092A (en) * | 2018-11-20 | 2019-04-05 | 中国航天空气动力技术研究院 | A kind of quick response pressure sensitive paint dynamic calibration apparatus and scaling method |
Non-Patent Citations (4)
| Title |
|---|
| DI PENG 等: "A fast-responding semi-transparent pressure-sensitive paint based onthrough-hole anodized aluminum oxide membrane", 《SENSORS AND ACTUATORS》 * |
| 于靖波 等: "快速响应压敏涂料测试技术与应用", 《实验流体力学》 * |
| 薛莉: "双膜激波管技术在动压校准中的研究", 《中国优秀硕士学位论文全文数据库 信息科技辑（月刊）》 * |
| 谷丰 等: "多孔压敏荧光粒子的制备与流场压力／速度测量的性能表征", 《实验流体力学》 * |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112113704A (en) * | 2020-09-23 | 2020-12-22 | 中国空气动力研究与发展中心高速空气动力研究所 | Pressure-sensitive paint response time calibration method based on non-electric detonator driving type shock tube |
| CN112415228A (en) * | 2020-11-18 | 2021-02-26 | 中国航空工业集团公司北京长城计量测试技术研究所 | Step acceleration calibrating device based on shock tube |
| CN114323543A (en) * | 2022-03-10 | 2022-04-12 | 中国空气动力研究与发展中心高速空气动力研究所 | Method for improving pressure-sensitive paint test efficiency |
| CN114323543B (en) * | 2022-03-10 | 2022-05-17 | 中国空气动力研究与发展中心高速空气动力研究所 | Method for improving test efficiency of pressure-sensitive paint |
| CN114323548A (en) * | 2022-03-14 | 2022-04-12 | 中国空气动力研究与发展中心高速空气动力研究所 | Calibration method for pressure-sensitive paint coating suitable for different reference states |
| CN114323548B (en) * | 2022-03-14 | 2022-06-10 | 中国空气动力研究与发展中心高速空气动力研究所 | Calibration method for pressure-sensitive paint coating suitable for different reference states |
| CN117990268A (en) * | 2024-04-07 | 2024-05-07 | 中国空气动力研究与发展中心低速空气动力研究所 | Dynamic calibration device for measuring frequency response characteristic of pressure sensitive paint |
| CN117990268B (en) * | 2024-04-07 | 2024-05-31 | 中国空气动力研究与发展中心低速空气动力研究所 | Dynamic calibration device for measuring frequency response characteristic of pressure sensitive paint |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN110987360A (en) | Shock tube test system for PSP dynamic calibration device | |
| CN110987358A (en) | Quick-response pressure-sensitive paint dynamic calibration device | |
| CN205374298U (en) | Trace gas concentration detection apparatus based on TDLAS | |
| CN103712914B (en) | Detection aerosol extinction and the laser cavity ring-down spectrometer of scattering coefficient simultaneously | |
| CN2773672Y (en) | Optical detector of sulfur hexafluoride gas concentration | |
| CN111141460A (en) | Equipment gas leakage monitoring system and method based on artificial intelligence sense organ | |
| CN110146220B (en) | Sinusoidal optical pressure dynamic calibration cabin considering temperature control and optical path layout | |
| CN101470073A (en) | Gas concentration measuring method and apparatus | |
| CN108195943B (en) | Optical fiber acoustic emission system for monitoring explosive damage and destruction process and monitoring method thereof | |
| CN111157496A (en) | Pressure-sensitive paint sample wafer test system of PSP dynamic calibration device | |
| CN104697933A (en) | Photoacoustic spectrometry sensing device for three-channel acoustics resonance cavity | |
| CN105842178B (en) | A kind of cell culture fluid acid-base value non-intrusion type on-line measuring device and detection method | |
| CN110987359A (en) | Pressure control system for PSP dynamic calibration device | |
| CN201892526U (en) | Electrical pneumatic micrometer | |
| Beck et al. | Application of temperature and pressure sensitive paints to DLR hypersonic facilities:“lessons learned” | |
| CN111473896A (en) | Optical fiber pressure sensor based on flexible silicon diaphragm and detection method thereof | |
| Dhanagopal et al. | High-Speed Pressure Sensitive Paint Measurements of the Initial Concept 3. X Vehicle at Mach 7 | |
| Sugioka et al. | First results of lifetime-based unsteady PSP measurement on a pitching airfoil in transonic flow | |
| CN105928697A (en) | Gas valve response time measuring device and method | |
| CN113945354A (en) | Test method for identifying flow partition characteristics of acceleration section of expansion wind tunnel | |
| CN205352546U (en) | Flexible construction resonance frequency visual detection system | |
| Kameda et al. | Unsteady measurement of a transonic delta wing flow by a novel PSP | |
| CN102269716A (en) | Test method for optical damage of microzone, and apparatus thereof | |
| CN204086361U (en) | A kind of optical fiber current mutual inductor for high voltage transmission line checking of great current | |
| CN210875818U (en) | Medical centrifugal machine detection device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20200410 |
|
| RJ01 | Rejection of invention patent application after publication |