CN203535010U - Intelligent and dynamic control system for compaction quality of rock-fill dam - Google Patents
Intelligent and dynamic control system for compaction quality of rock-fill dam Download PDFInfo
- Publication number
- CN203535010U CN203535010U CN201320482493.8U CN201320482493U CN203535010U CN 203535010 U CN203535010 U CN 203535010U CN 201320482493 U CN201320482493 U CN 201320482493U CN 203535010 U CN203535010 U CN 203535010U
- Authority
- CN
- China
- Prior art keywords
- data
- cmv
- rock
- compaction
- dispensing device
- 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.)
- Expired - Lifetime
Links
Images
Landscapes
- Investigation Of Foundation Soil And Reinforcement Of Foundation Soil By Compacting Or Drainage (AREA)
Abstract
The utility model discloses an intelligent and dynamic control system for the compaction quality of a rock-fill dam. The intelligent and dynamic control system comprises a data acquiring device, a data receiving and sending device and a data analyzing device, wherein the data acquiring device is arranged on the rack at the inner side of a vibrating wheel of a vibrating roller; the data receiving and sending device is arranged in an observing room; the data analyzing device is used for carrying out remote quality control. A method for carrying out the compaction quality control on the rock-fill dam by adopting the system comprises the following steps: I, carrying out tests to obtain a CMV (Compaction Meter Value) corresponding to the dry density rho that satisfies design requirements; II, in the site construction process, obtaining accelerated speed data of each vibrating roller; III, carrying out FFT (Fast Fourier Transform) after data integration and digital filtering are carried out on the accelerated speed data to obtain fundamental wave data and secondary harmonic wave data; IV, calculating the real-time CMV according to a formula of CMV=C*A2 Omega/A Omega; and V, comparing the real-time CMV with the CMV corresponding to the dry density rho that satisfies the design requirements, so that the intelligent and dynamic control on the compaction quality of the rock-fill dame is realized. The intelligent and dynamic control system disclosed by the utility model not only ensures the construction quality, but also quickens construction progress.
Description
Technical field
The utility model relates to the rock-fill dams roller compaction construction field in Construction of Hydropower Engineering, particularly a kind of rock-fill dams compaction quality intelligence, kinetic-control system and method.
Background technology
Along with the development of the development of the national economy, China's rock-fill dams development is very fast, and Concrete Face Rockfill Dam, soil property core wall rockfill dam and asphaltic concrete core wall rock-fill dams have become three kinds of main dam types of modern rock-fill dams.
Instantly rock-fill dams high dam occurs on a large scale, and the type dam construction period is short, special landform, geology, the compaction quality that dam foundation conditional request is high, but existing real-time monitoring means lack, and detection means lacks real-time; Therefore be extremely necessary to carry out Rockfill Dam in real time, the research of kinetic-control system and Fast Detection Technique.
Chongqing Jiaotong University's master thesis, disclose in April, 2009 a kind of < < based on COSMOS vibroll vibration acceleration and compactness relation research > >, the three-dimensional modeling of giving chapter and verse, be combined with finite element analysis, extract vibration acceleration, road surface rigidity, find out under reasonable conditions along with the roughly variation tendency of road surface stiffness variation vibration acceleration, simulate curve map.Draw and between vibration acceleration and soil stiffness, really have certain contacting.
Summary of the invention
Technical problem to be solved in the utility model is to provide a kind of rock-fill dams compaction quality intelligence, kinetic-control system, can obtain in real time and control rock-fill dams compaction quality, to shorten the Rockfill Dam filling construction duration.
For solving the problems of the technologies described above, the technical scheme that the utility model adopts is: a kind of rock-fill dams compaction quality intelligence, kinetic-control system, and it comprises:
Be arranged on the data collector on the interior side frame of vibrating roller vibrating wheels;
Be arranged on data receiver and dispensing device in observation room;
Carry out the data analysis set-up of long-range quality control.
Between described data collector and data receiver and dispensing device, adopt wireless connections, between data receiver and dispensing device and data analysis set-up, adopt wireless connections.
Data collector adopts acceleration transducer image data, and is connected with data receiver and dispensing device by RF-wise;
In data receiver and dispensing device, be provided with less radio-frequency receiver in order to receive acceleration information, be also provided with signal conditioning circuit, A/D converter, processor and for the wireless launcher of transmitting data;
In data analysis set-up, be provided with the radio receiver that receives wireless signal, be also provided with for calculating and compare Rockfill Dam material compactness value, the i.e. calculation element of CMV value.
Adopt above-mentioned system to carry out a method for rock-fill dams compaction quality control, comprise the following steps:
One, by test, obtain and meet the corresponding CMV value of designing requirement dry density ρ;
Two,, at the scene in work progress, degree of will speed up sensor setting, on the interior side frame of each vibrating roller vibrating wheels, obtains the acceleration information of each vibrating roller;
Three, acceleration information, after Data Integration, digital filtering, carries out FFT conversion, obtains first-harmonic data and second harmonic data;
Four, by formula
calculate real-time CMV value;
In formula: CMV is compactness value,
C is constant value 300;
A
Ω-vibration first-harmonic composition acceleration amplitude;
A
2 Ω-vibration second harmonic composition acceleration amplitude.
Five, by real-time CMV value with meet the corresponding CMV value of designing requirement dry density ρ and compare;
By above-mentioned steps, realize the intelligence of rock-fill dams compaction quality, dynamically control.
In step 1, adopt vibrating roller and the vibrating compacting technological parameter identical with the construction period;
Dam material, water cut and the filling-up thickness of field compaction test are identical with the follow-up construction period;
Vibrating roller vibration frequency variation range in vibroroller cmpacting process is no more than 5%;
Every kind of dam material of field compaction test should have different number of rolling, so that its density has a variable gradient.
The CMV value that every kind of number of rolling test is obtained averages, and averaged adopts survey method in hole to obtain the dam material dry density ρ under this position;
The dam material of every kind of bed thickness, different number of rolling is recorded and under CMV mean value the same terms, obtains dam material dry density ρ curve plotting figure, then find in the drawings and meet the corresponding CMV controlling value of design dry density, this value is the control index of this kind of dam material on-site rolling.
In described Data Integration, by spy's card value of acceleration information, determine the acceleration transducer under these data, the Data Integration of an exclusive acceleration transducer, to together, is processed for subsequent step.
In described data filtering, adopt the bandpass filter of 0.5～100Hz to carry out filtering.
In step 2, the acceleration information that acceleration transducer gathers, passes to data receiver and dispensing device by RF-wise;
Receive and dispensing device employing less radio-frequency receiver reception acceleration information, data entering signal modulate circuit, conditioning signal later enters A/D converter, simulating signal is converted to data-signal, then enter processor, by processor, data are integrated, final data adopts gprs or 3G pattern to send to data analysis set-up.
Principle of the present utility model is: when Dam material starts to roll, because filler is more loose, can be similar to and regard a soft elasticoplastic body as.When vibrating wheels is vibrated thereon, the reacting force being subject to is less, substantially does sinusoidal motion.Carrying out along with vibroroller cmpacting positive activity, packing and the elastic modulus of inserts constantly increase, interaction force between inserts and compact wheel also constantly increases, so the acceleration amplitude of compact wheel is also in continuous increase, as can be seen here, between vibrating roller vibration wave sex distortion degree and filling compaction degree, exist certain correlationship as shown in Figure 2; Thereby can change the compacting situation of indirectly measuring filler by sense acceleration amplitude, the dynamic response by vibrating wheels detects filling compaction degree situation on the other hand, can better reflect and fill stratiform condition and bearing capacity.Acceleration sensor is arranged in steel vibrating wheels, transmits continuously treated signal and shows with CMV numerical value form, and CMV value is the initial letter of English Compaction Meter Value, and the meaning of its expression is compactness value.Compare with the compactness of traditional detection, the error of the utility model system is controlled in 2%, and can revise by empirical data and on-site proving.
A kind of rock-fill dams compaction quality intelligence that the utility model provides, kinetic-control system, by the acceleration transducer being arranged on vibrating roller, gather accumulation signal, in roller compaction construction process, system gathers at any time, record related data and data wireless is transferred in data analysis set-up, operating personnel can be by observing the data of instrument, image, real-time monitor compaction quality, do not need extra holding time or stop to measure, when showing, data roll after quality desk lattice, vibrating roller can arrive next unit and roll, for underproof region, equipment can automatic alarm, and definite underproof concrete position, so both guaranteed construction quality, accelerated again construction speed.
Accompanying drawing explanation
Below in conjunction with drawings and Examples, the utility model is described in further detail.
Fig. 1 is the one-piece construction schematic diagram of the utility model system.
Fig. 2 is the utility model flow chart of data processing figure.
Fig. 3 is the relation curve of CMV value and number of rolling in the utility model.
Fig. 4 is CMV-dry density ρ graph of relation in the utility model.
Fig. 5 is CMV-dry density ρ graph of relation in the utility model.
In figure: data collector 1, data receiver and dispensing device 2, data analysis set-up 3, Transition Materials 4, vibrating roller 5.
Embodiment
In Fig. 1, a kind of rock-fill dams compaction quality intelligence, kinetic-control system, it comprises:
Be arranged on the data collector 1 on the interior side frame of vibrating roller 5 vibrating wheels, in this example, adopt acceleration transducer; Between described data collector 1 and data receiver and dispensing device 2, adopt wireless connections, between data receiver and dispensing device 2 and data analysis set-up 3, adopt wireless connections.
Be arranged on data receiver and dispensing device 2 in observation room; Data collector 1 adopts acceleration transducer image data, and is connected with data receiver and dispensing device 2 by RF-wise;
Below the technical parameter of acceleration transducer:
Range: ± 10g;
Frequency band range: 0～200Hz-3dB;
Nonlinearity: 1%;
Amplitude accuracy: ± 5%;
Signal resolution :≤0.006g;
Working temperature :-40 ℃～70 ℃;
Temperature drift: ± 0.01%/℃;
Overload capacity (g): 10000 (0.1ms);
Transmission mode: wireless transmission;
Work duration: 12h;
Signal intensity: wireless communication distance is greater than 500m;
Signal accuracy: data transmission stability reaches more than 97%.
Little owing to adopting the radio transmission apparatus of radio frequency transmission mode to have volume, the advantage such as low in energy consumption, therefore adopts the mode of radio frequency transmission to carry out the transmission of wireless data.Radio frequency is Radio Frequency, and RF conventionally abridges.Expression can be radiated the electromagnetic frequency in space, and frequency range is between 300KHz～30GHz.Radio-frequency current, it is that a kind of high-frequency ac changes electromagnetic abbreviation.Variation per second is less than the alternating current of 1000 times and is called low-frequency current, be greater than the high-frequency current that is called of 10000 times, and radio frequency is exactly a kind of like this high-frequency current.Cable television system adopts radio frequency transmission mode exactly.In theory of electronics, electric current flows through conductor, and conductor can form magnetic field around; Exchange current is by conductor, and conductor can form the electromagnetic field of alternation around, is called electromagnetic wave.At wave frequency during lower than 100khz, electromagnetic wave can be absorbed by earth's surface, can not form effective transmission, but wave frequency is during higher than 100khz, electromagnetic wave can be propagated in air, and through the ionospheric reflection of atmospheric envelope outer rim, forms long-distance transmissions ability, conventionally the frequency electromagnetic waves with long-distance transmissions ability is called to radio frequency, radio-frequency technique is widely used in wireless communication field.
In data receiver and dispensing device 2, be provided with less radio-frequency receiver in order to receive acceleration information, be also provided with signal conditioning circuit, A/D converter, processor and for the wireless launcher of transmitting data.
Below data receiver and transmitting system technical parameter:
Range: acceleration ± 10g;
Resolution: acceleration 0.1mg;
Precision: acceleration ± 5%;
Frequency range: acceleration 0Hz～500Hz;
Analog to digital conversion: 24Bit quantizes step 1,677 ten thousand;
Data receiver and transmission: use wireless receiving and send data;
Port number: support minimum 16 collecting devices simultaneously to access;
Working time: support to work long hours minimum 12h;
Signal intensity: wireless communication distance is greater than 500m;
Signal accuracy: data receiver and transmission stability reach more than 97%.
Carry out the data analysis set-up 3 of long-range quality control.In data analysis set-up 3, be provided with the radio receiver that receives wireless signal, be also provided with for calculating and compare Rockfill Dam material compactness value, the i.e. calculation element of CMV value.
Concrete data analysis flow process as shown in Figure 3.
Also include the power-supply unit to said apparatus power supply: because radio transmission apparatus needs power supply, and longevity of service, the accumulator that therefore need to be equipped with larger capacity is powered to it, and should have standby power supply, to support long-time continual working condition.
Adopt above-mentioned system to carry out a method for rock-fill dams compaction quality control, comprise the following steps:
One, by test, obtain and meet the corresponding CMV value of designing requirement dry density ρ;
In the process of the test of step 1, adopt vibrating roller 5 and the vibrating compacting technological parameter identical with the construction period;
Dam material, water cut and the filling-up thickness of field compaction test are identical with the follow-up construction period;
Vibrating roller vibration frequency variation range in vibroroller cmpacting process is no more than 5%;
Every kind of dam material of field compaction test should have different number of rolling, so that its density has a variable gradient.
The CMV value that every kind of number of rolling test is obtained averages, and averaged adopts survey method in hole to obtain the dam material dry density ρ under this position;
The dam material of every kind of bed thickness, different number of rolling is recorded and under CMV mean value the same terms, obtains dam material dry density ρ curve plotting figure, as shown in Figure 4, then find in the drawings and meet the corresponding CMV controlling value of design dry density, this value is the control index of this kind of dam material on-site rolling.
Two,, at the scene in work progress, degree of will speed up sensor setting, on the interior side frame of each vibrating roller 5 vibrating wheels, obtains the acceleration information of each vibrating roller 5;
In step 2, the acceleration information that acceleration transducer gathers, passes to data receiver and dispensing device 2 by RF-wise;
Receive and dispensing device 2 employing less radio-frequency receivers reception acceleration informations, data entering signal modulate circuit, conditioning signal later enters A/D converter, simulating signal is converted to data-signal, then enter processor, by processor, data are integrated, final data adopts gprs or 3G pattern to send to data analysis set-up 3.
Three, acceleration information, after Data Integration, digital filtering, carries out FFT conversion, obtains first-harmonic data and second harmonic data;
In described Data Integration, by spy's card value of acceleration information, determine the acceleration transducer under these data, the Data Integration of an exclusive acceleration transducer, to together, is processed for subsequent step.Described spy's card value is IP address, MAC Address.
In described data filtering,, by certain algorithm, signal is processed, the signal of certain frequency range is carried out to filtering, this process that obtains new signal is called digital filtering.Common filter type has Hi-pass filter, low-pass filter, bandpass filter, rejection filter.Because the vibration frequency of vibrating roller is generally between 25～33Hz, and in test process, generally there will be the signal of other frequency, the clutter that Here it is disturbs, all clutter must being rejected, so just can obtain useful signal.Therefore, native system adopts the bandpass filter of 0.5～100Hz to carry out filtering, so both can filter out the impact of noise signal and the DC component of high frequency, can because frequency filtering approaches vibration frequency, not make useful signal be filtered out again.
Four, by formula
calculate real-time CMV value;
In formula: CMV is compactness value,
C is constant value 300;
A
Ω-vibration first-harmonic composition acceleration amplitude;
A
2 Ω-vibration second harmonic composition acceleration amplitude.
Five, by real-time CMV value with meet the corresponding CMV value of designing requirement dry density ρ and compare;
Be specially: when the acceleration information of testing enters after the software platform of data analysis set-up 3, software can first read data, then data are carried out to filtering, noise signal is filtered out, obtain useful signal, according to design concept, carry out fast fourier transform, be FFT conversion, fast fourier transform is a kind of data analysis mode of calculating the frequency content of signal.Filtered signal has been useful signal, according to design concept, time domain acceleration signal need be converted to frequency-region signal, therefore need to carry out fast fourier transform to acceleration signal, obtains the frequency components of acceleration signal.Obtain thus the spectrum waveform of acceleration measurement, then take out the data of first-harmonic and second harmonic, then according to formula
calculate CMV value, obtain can carrying out qualification rate contrast conting after CMV value, qualified passing through, defective warning, software platform of the present utility model also has the functions such as data sheet.
Data are preserved: after having tested, the data in whole test process can be preserved, to facilitate the later stage to data analysis.
By above-mentioned steps, realize the intelligence of rock-fill dams compaction quality, dynamically control.
Embodiment:
It is below the result that certain engineering rock Transition Materials adopts native system to test.
A checking experimental study achievement:
According to above-mentioned detection method, in conjunction with a checking field compaction test, Transition Materials is tested, Transition Materials layer thickness 40,50cm test parameters testing result are carried out respectively to Macro or mass analysis, simultaneously by the CMV value counting and number of rolling curve plotting, refer to table 1, table 2 and Fig. 3, wherein CMV, dry density, rate of descent are illustrated in the mean value under this number of rolling.
Table 1 Transition Materials layer thickness 40cm experimental study testing result summary sheet
Table 2 Transition Materials layer thickness 50cm experimental study testing result summary sheet
By above-mentioned development test achievement and CMV and number of rolling relation curve, show:
■ is when dam starts to roll, and because filler is more loose, when self-propelled vibrating roller vibrates thereon, the reacting force being subject to is less, substantially does sinusoidal motion, can be similar to and regard a soft elasticoplastic body as.
■ is along with the increase of number of rolling, and compaction rate and the elastic modulus of dam material constantly increase, and CMV is also in continuous increase.
■ is when number of rolling is increased to a certain degree, and because compaction rate and the elastic modulus of dam material tends towards stability, CMV also tends towards stability, and meets dam material Compaction Law.
By the dam material dry density mean value obtaining under the CMV mean value that obtains under every kind of number of rolling and corresponding pass, analyze, see Fig. 4, Fig. 5.
CMV and dry density, rate of descent truly have good linear dependence relation, increase along with dry density, CMV also increases thereupon, if therefore provide dry density, control index, corresponding minimum CMV value in the time of can looking into figure and show that meeting dry density requires by CMV and dry density relation curve, this value is CMV controlling value, according to above-mentioned development test achievement, the CMV controlling value drawing under different layer thickness is added up, and a Transition Materials checking CMV controls parameter recommendation tables the results detailed in Table 3.
A table 3 Transition Materials checking CMV controls parameter recommendation tables
Composite Field field compaction test achievement:
In conjunction with verifying a field compaction test parameter: layer thickness 40cm, number of rolling 10 times, water spray rate 5%, carries out one to Transition Materials and rolls inspection test, the feasibility of sand gravel material being controlled further to study this method; To roll inspection test data and gather, draw CMV and number of rolling relation curve simultaneously, refer to table 4.
Table 4 Transition Materials is checked a first play compacting meter method testing result summary sheet
By above-mentioned data analysis is shown:
■ is along with the increase of number of rolling, and CMV increases thereupon, finally tends towards stability, and meets the rule that dam material elastic parameter finally tends towards stability along with number of rolling increase;
■ analyzes according to checking play test findings, checks an experimental study achievement substantially identical with a checking experimental study achievement, and it is feasible therefore adopting CMV value to control this material source compaction quality.
Claims (1)
1. rock-fill dams compaction quality intelligence, a kinetic-control system, is characterized in that it comprises:
Be arranged on the data collector (1) on the interior side frame of vibrating roller (5) vibrating wheels;
Be arranged on data receiver and dispensing device (2) in observation room;
Carry out the data analysis set-up (3) of long-range quality control;
Between described data collector (1) and data receiver and dispensing device (2), adopt wireless connections, between data receiver and dispensing device (2) and data analysis set-up (3), adopt wireless connections;
Data collector (1) adopts acceleration transducer image data, and is connected with data receiver and dispensing device (2) by RF-wise;
In data receiver and dispensing device (2), be provided with less radio-frequency receiver in order to receive acceleration information, be also provided with signal conditioning circuit, A/D converter, processor and for the wireless launcher of transmitting data;
In data analysis set-up (3), be provided with the radio receiver that receives wireless signal, be also provided with for calculating and compare Rockfill Dam material compactness value, the i.e. calculation element of CMV value and defective warning function.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201320482493.8U CN203535010U (en) | 2013-08-07 | 2013-08-07 | Intelligent and dynamic control system for compaction quality of rock-fill dam |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201320482493.8U CN203535010U (en) | 2013-08-07 | 2013-08-07 | Intelligent and dynamic control system for compaction quality of rock-fill dam |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN203535010U true CN203535010U (en) | 2014-04-09 |
Family
ID=50421205
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201320482493.8U Expired - Lifetime CN203535010U (en) | 2013-08-07 | 2013-08-07 | Intelligent and dynamic control system for compaction quality of rock-fill dam |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN203535010U (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103412046A (en) * | 2013-08-07 | 2013-11-27 | 葛洲坝集团试验检测有限公司 | Intelligent and dynamic control system and method for compaction quality of rockfill dam |
| CN106245495A (en) * | 2016-08-03 | 2016-12-21 | 四川大学 | Rock-fill dams method for detecting compacting quality based on subgrade reaction test |
| CN107764642A (en) * | 2017-09-28 | 2018-03-06 | 中国十七冶集团有限公司 | A kind of red sandstone roadbed detection methods of compaction degree |
| CN109596202A (en) * | 2018-12-11 | 2019-04-09 | 南京天辰礼达电子科技有限公司 | A kind of vibration rolling vibration information real time detection algorithm based on acceleration value |
| CN114197275A (en) * | 2022-01-21 | 2022-03-18 | 山推工程机械股份有限公司 | Control system and method of road roller |
-
2013
- 2013-08-07 CN CN201320482493.8U patent/CN203535010U/en not_active Expired - Lifetime
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103412046A (en) * | 2013-08-07 | 2013-11-27 | 葛洲坝集团试验检测有限公司 | Intelligent and dynamic control system and method for compaction quality of rockfill dam |
| CN103412046B (en) * | 2013-08-07 | 2016-05-11 | 葛洲坝集团试验检测有限公司 | The method that adopts rock-fill dams compaction quality intelligence, kinetic-control system to carry out the detection of rock-fill dams compaction quality |
| CN106245495A (en) * | 2016-08-03 | 2016-12-21 | 四川大学 | Rock-fill dams method for detecting compacting quality based on subgrade reaction test |
| CN107764642A (en) * | 2017-09-28 | 2018-03-06 | 中国十七冶集团有限公司 | A kind of red sandstone roadbed detection methods of compaction degree |
| CN109596202A (en) * | 2018-12-11 | 2019-04-09 | 南京天辰礼达电子科技有限公司 | A kind of vibration rolling vibration information real time detection algorithm based on acceleration value |
| WO2020119305A1 (en) * | 2018-12-11 | 2020-06-18 | 南京天辰礼达电子科技有限公司 | Real-time detection algorithm for vibration information of vibration roller based on acceleration magnitude |
| CN114197275A (en) * | 2022-01-21 | 2022-03-18 | 山推工程机械股份有限公司 | Control system and method of road roller |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103412046B (en) | The method that adopts rock-fill dams compaction quality intelligence, kinetic-control system to carry out the detection of rock-fill dams compaction quality | |
| CN203535010U (en) | Intelligent and dynamic control system for compaction quality of rock-fill dam | |
| CN103196407B (en) | Method, device and system for vibration displacement measurement of cantilever crane of pump truck and engineering machinery device | |
| CN101674520B (en) | Method and device for analyzing and testing parameter of vibration type pickup | |
| CN103048384B (en) | A kind of concrete humidity monitoring method based on piezoelectric intelligent aggregate | |
| CN106352243A (en) | Gas transmission pipeline leakage detection system based on acoustic method | |
| CN103900661B (en) | Segmented liquid level sensor based on capacitance-to-digital conversion technology | |
| CN110243465A (en) | Bridge vibration acceleration and intrinsic frequency on line real-time monitoring device, terminal and method | |
| CN103954890A (en) | DC partial discharge detection device and method for converter transformer | |
| CN202033101U (en) | Vibration and noise measuring instrument | |
| CN104897780A (en) | Method for positioning acoustic emission source by using acoustic emission signal energy | |
| CN107271022A (en) | A kind of transformer vibration noise Integrated Measurement System | |
| CN107064846A (en) | The sensitivity detection method and device of live testing apparatus for local discharge | |
| CN106124025A (en) | The calibrating installation of low noise vector hydrophone equivalence self noise acceleration spectrum level and calibration steps | |
| CN106872927A (en) | The assay method and error analysis method of the harmonic wave degree of accuracy of electronic type voltage transformer | |
| CN205786484U (en) | A kind of test device of composite sound wave attenuation coefficient | |
| Wu et al. | Experimental study of nonlinear wave—wave interaction and white-cap dissipation of wind-generated waves | |
| CN103063878B (en) | The calibration equipment of speed or acceleration sensor dynamic characteristic, system and method | |
| CN203700917U (en) | Information acquisition device of vibratory roller | |
| CN105509871B (en) | It is a kind of applied to vibrating sensor from calibrating installation and its from calibration method | |
| CN209264895U (en) | Partial discharge of switchgear monitoring device | |
| CN105954353A (en) | Test method and device of comprehensive acoustic attenuation coefficient | |
| CN203759264U (en) | Nuclear magnetic resonance bipolarity superposition de-noising device based on power frequency full cycle | |
| CN204989502U (en) | Metal detector | |
| Hauge | Finite element modeling of ultrasound measurement systems for gas. Comparison with experiments in air. |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CX01 | Expiry of patent term | ||
| CX01 | Expiry of patent term |
Granted publication date: 20140409 |