CN107121496B - Storage tank bottom plate corrosion evaluation experiment system and method for water immersion type ultrasonic detection - Google Patents
Storage tank bottom plate corrosion evaluation experiment system and method for water immersion type ultrasonic detection Download PDFInfo
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- G01N29/00—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object
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Abstract
The invention discloses a storage tank bottom plate corrosion evaluation experiment system and method for water immersion type ultrasonic detection, and belongs to the field of nondestructive detection. Constructing a water immersion type ultrasonic detection corrosion evaluation system based on the water immersion type ultrasonic scanning system; respectively setting corresponding parameters of an excitation signal and a received signal, and observing a received time domain waveform signal through an oscilloscope to finely adjust the corresponding parameters of the excitation signal and the received signal; and after parameter setting and detection condition selection are completed, performing water immersion type ultrasonic scanning on the detection test piece, and storing detection data. Calculating a region segmentation threshold value and a characteristic value corresponding to a standard grade according to the characteristic value data of the plate-shaped test piece obtained by ultrasonic detection; respectively calculating the difference between the characteristic value of each position point and the standard grade, and evaluating the corrosion grade of each position point; and finally, determining the weight ratio of the corrosion area to the depth according to the actual working condition requirement, calculating the corrosion grade of the whole test piece, and realizing the corrosion grade evaluation of the plate structure test piece.
Description
Technical Field
The invention relates to a storage tank bottom plate corrosion evaluation method for water immersion type ultrasonic detection, in particular to an evaluation algorithm for large-scale normal pressure storage tank bottom plate corrosion, and belongs to the field of nondestructive detection.
Background
The normal pressure storage tank is an important component of petrochemical equipment and storage and transportation systems, and has the characteristics of large volume, centralized distribution, storage of inflammable, explosive and toxic media and the like. In the use process of the normal pressure storage tank, due to the common influence of the pressure and the temperature of a bearing medium and external environmental factors, the storage tank can generate various defects such as corrosion and cracks, wherein the corrosion of the tank bottom is one of the main reasons for failure of the normal pressure storage tank. When the storage tank leaks, not only can environmental pollution be caused, but also serious fire and explosion accidents can be caused, and irretrievable economic loss and severe social influence are brought to enterprises. Therefore, it is necessary to develop research work for corrosion detection and safety evaluation of the bottom plate of the storage tank.
For tank bottom corrosion, the conventional nondestructive detection method mainly comprises the following steps: magnetic particle detection, magnetic flux leakage detection, penetration detection and ultrasonic detection. The magnetic powder detection is that the bottom of the storage tank is magnetized, and magnetic powder forms visible magnetic marks at the defect position, so that defect information is displayed. The magnetic flux leakage detection has the advantages of convenience in operation, high detection efficiency, high precision and the like, but the magnetic flux leakage detection only can roughly judge the defect state and has poor detection effect on depth defects. The permeability detection can realize one-time comprehensive detection on the defects with complex shapes, and has the limitations that the detection procedure is complicated, the buried defects or closed surface defects cannot be detected, and the surface smoothness of the detected object is required. The ultrasonic detection method is simple to operate and mature in detection process, but cannot visually reflect the corrosion condition of a detection area. In the detection method, magnetic powder detection, penetration detection and magnetic flux leakage detection are carried out by opening the tank, the tank opening inspection with higher cost is carried out every six years according to related specified storage tanks, and the safe use risk of the storage tanks is aggravated by a longer detection period.
Therefore, for the detection of the bottom plate of the storage tank, a nondestructive detection strategy which can preliminarily know the corrosion condition of the bottom plate of the tank without opening the tank is required; and further selecting a more effective detection mode through the result of the preliminary evaluation on the damage degree of the storage tank. On the basis of reducing the tank opening detection cost, the detection period of the pipeline can be shortened, and in-service maintenance of the storage tank is realized. Therefore, the invention develops the storage tank bottom plate corrosion evaluation method for water immersion type ultrasonic detection, realizes early evaluation on corrosion damage of the storage tank bottom plate, improves the detection efficiency and reduces the detection cost.
For the structural corrosion evaluation method, a large amount of research is carried out by domestic scholars. The mechanical engineering college of the western-Ann Petroleum university provides an oil-gas pipeline internal corrosion evaluation method based on information fusion. The method carries out multi-level, multi-aspect and multi-level treatment on the mass production process parameters and the corrosive physico-chemical parameters, and converts the parameters into equivalent corrosion evaluation information so as to realize the evaluation on corrosion safety and corrosion prevention effect.
Patent application No.: 201410602563.8, a quantitative evaluation method for corrosion risk of oil tank bottom plate. The method can detect the corrosion leakage risk index of the oil tank bottom plate, but needs to master a large number of relevant parameters of the detected storage tank, and has higher difficulty in predicting the risk of old storage tanks lacking detailed data. The southwest petroleum institute shows that the West Chong and the like propose a water injection pipeline corrosion evaluation method based on fuzzy comprehensive evaluation, but the method has a plurality of consideration factors and is not suitable for ultrasonic corrosion detection rating.
The structural corrosion grade evaluation method based on image colors is provided by Chongqing university of science, and the method describes the colors of structural corrosion characteristic images by using RGB space and realizes quantitative evaluation of structural corrosion by means of an image segmentation technology. The method comprises the steps of obtaining an image of a detection area, and quantitatively analyzing the corrosion condition; however, in the detection of the bottom plate of the storage tank, the image of the corrosion area is difficult to directly acquire, and the condition of the corrosion area is represented by acquiring the form of ultrasonic data of a position point.
The detection data obtained by the traditional ultrasonic detection cannot visually reflect the corrosion condition of a detection area and realize the evaluation of the corrosion grade; and the existing structural corrosion evaluation method has a lot of using limiting conditions and is not suitable for the evaluation of ultrasonic detection corrosion.
In summary, on the basis of the previous research, aiming at the defects of the existing detection method for plate structure corrosion, the patent provides a plate structure corrosion evaluation algorithm based on ultrasonic detection data. The algorithm can realize the grade evaluation of the corrosion of the plate structure, particularly the evaluation of the corrosion degree of the bottom plate of the storage tank, and provides reliable reference information for the safe operation and the life prediction of the large-scale atmospheric storage tank.
Disclosure of Invention
The invention develops a method for evaluating the corrosion grade of a plate structure for water immersion type ultrasonic detection, and particularly evaluates the corrosion degree of a bottom plate of a storage tank. The method mainly comprises the following steps: threshold segmentation, feature value difference calculation and corrosion grade evaluation. Firstly, acquiring characteristic value data of a plate-shaped test piece detection area, and calculating an area segmentation threshold value and a characteristic value corresponding to a standard grade; respectively calculating the difference between the characteristic value of each position point and the standard grade to realize the corrosion grade evaluation of each position point; and determining the weight ratio of the corrosion area to the depth according to the actual working condition requirement, calculating the corrosion grade of the whole test piece, and realizing the evaluation of the corrosion degree of the plate-shaped test piece.
The corrosion evaluation method based on water immersion type ultrasonic detection provided by the invention has the following basic principle:
1) erosion area segmentation-threshold segmentation method
By selecting an appropriate segmentation threshold using feature value information that is different for each location in the ultrasound scan, the original image can be segmented into target and background portions, which may be one or more. Firstly, discretizing the whole detection area, and regarding each scanning point as a small corrosion area, wherein each corrosion area is closed. And selecting a reasonable threshold value through characteristic value data of all position points acquired by ultrasonic detection, dividing the corrosion region into a corrosion region and a non-corrosion region, dividing the corrosion region into different grades and calculating the characteristic values corresponding to the standard corrosion grades.
2) Characteristic value difference calculation-minimum difference method
And acquiring characteristic data of each position point through ultrasonic C scanning detection, and characterizing the corrosion condition of each position point by using the characteristic value. And sequentially subtracting the corresponding characteristic value of each position point from the corresponding characteristic value of the standard grade, and solving the minimum value in the difference of the characteristic values, wherein the standard grade corresponding to the minimum difference value is the corrosion grade of the position point, so that the quantitative evaluation of the corrosion grade of the position point is realized. The method comprises the following specific steps:
(1) and generating a grade standard according to the parameters set by the operation and the ultrasonic scanning data.
(2) And (3) sequentially subtracting the characteristic value corresponding to each position point from the standard grade characteristic value, namely the characteristic value difference degree of the position point, and defining the characteristic value difference degree of the position point by using a formula 1:
D(i,j)＝|X(i,j)-Bz| (1)
in the formula, i and j are horizontal and vertical coordinates of scanning points corresponding to characteristic values, X is a characteristic value of a position point of a top level, B is a characteristic value corresponding to a certain specific corrosion level, and z is a grade level corresponding to the B characteristic value.
(3) Calculating the minimum difference degree minD between the standard grade and the position point characteristic value(i,j)Then the minimum difference corresponding standard grade is the corrosion grade of the point at the position.
3) Corrosion grade evaluation-weighting method
Firstly, discretizing the whole detection area, and regarding each scanning point as a small corrosion area, wherein each small corrosion area is closed. Since the corrosion condition of the test piece presents non-uniformity, the corrosion degree of each small corrosion area is inconsistent. And calculating the corrosion level of the whole area through the corrosion level data of each scanning point.
And evaluating the corrosion degree of the test piece, and only obtaining the corrosion degree of each small corrosion area, which is not enough, and the corrosion grade of the whole structure. The area of the corrosion region in each grade, namely the number of position points in the grade, is counted firstly, then the number of the position points is multiplied by the corresponding grade weight, the products corresponding to all the grades are added and summed, and the sum is divided by the total weight to obtain the comprehensive grade. The formula is shown in fig. 2:
in the formula, NiIndicating the area of the erosion zone in level i, i.e. the number of points in the level, QiIndicating that the corrosion level i is weighted among all levels.
The method not only considers the difference of the corrosion degree of each small corrosion region, but also considers the difference of the contribution of each small corrosion region to the whole corrosion structure due to different area ratios of each small corrosion region, so that the evaluation result is more accurate.
The technical scheme adopted by the invention is as follows:
the invention discloses a corrosion evaluation experiment system for a storage tank bottom plate for water immersion type ultrasonic detection, which adopts an experiment system shown in figure 1 and comprises a computer 1, an ultrasonic excitation receiver 2, a digital oscilloscope 3, a four-axis linkage scanning platform 4, a water immersion type ultrasonic excitation receiving probe 5, a horizontal support rod 6, a vertical support rod 7, a telescopic cylinder 8 and a roller 9. The method is characterized in that: the computer 1 is connected with a control card on the four-axis linkage scanning platform 4 through a cable; the water immersion type ultrasonic excitation receiving probe 5 is arranged in the middle of the four-axis linkage scanning platform 4, and the water immersion type ultrasonic excitation receiving probe 5 is connected with the control card.
The computer 1 is connected with the ultrasonic excitation receiver 2, the ultrasonic excitation receiver 2 is connected with the digital oscilloscope 3, and the water immersion type ultrasonic excitation receiving probe 5 is connected with the ultrasonic excitation receiver 2.
Two 6 symmetries of horizontal support bar set up in the both sides of four-axis linkage scanning platform 4, and 6 levels of horizontal support bar are arranged, and one side of horizontal support bar 6 is connected with vertical support bar 7, and vertical support bar 7 inserts in a section of thick bamboo 8 that stretches out and draws back, and the bottom of a section of thick bamboo 8 that stretches out and draws back is equipped with gyro wheel 9.
The test piece is placed in the water tank, and the water immersion type ultrasonic excitation receiving probe 5 is opposite to the test piece.
The four-axis linkage scanning platform 4 is driven by a servo motor.
The lateral part of the telescopic cylinder 8 is provided with a fastening screw, and the extending height of the vertical supporting rod 7 is fixed by the fastening screw.
Firstly, the position of a four-axis linkage scanning platform 4 is adjusted through a position adjusting system consisting of a horizontal support rod 6, a vertical support rod 7, a telescopic cylinder 8 and a roller 9, so that a water immersion type ultrasonic excitation receiving probe 5 is over against a test piece in a water tank.
Then the roller 9 is locked, and the position of the four-axis linkage scanning platform 4 corresponds to the position of the water tank.
And finally, the computer 1 controls a servo motor through a control card, and the servo motor drives the four-axis linkage scanning platform 4 to move, so that the four-axis linkage scanning platform 4 drives the water immersion type ultrasonic excitation receiving probe 5 to move. The ultrasonic excitation receiving instrument 2 transmits pulse signals according to a set repetition frequency and loads the pulse signals onto the water immersion type ultrasonic excitation receiving probe 5, after ultrasonic waves act on a test piece, the ultrasonic excitation receiving probe 5 receives echo signals and sends the echo signals into the ultrasonic excitation receiving instrument 2, then the echo signals are sent into a data acquisition card of the computer 1 to process received waveforms, characteristic values are extracted, and the characteristic values are sent back to the computer 1; and finally, the computer 1 stores and records the test piece detection data.
Recording corrosion region data obtained by ultrasonic detection according to the computer 1, and calculating a corrosion region segmentation threshold value and a characteristic value corresponding to a standard grade; respectively calculating the difference between the characteristic value of each position point and the standard grade to realize the evaluation of the corrosion grade of each position point; and determining the corrosion area and the depth weight ratio according to the actual working condition requirement, and further obtaining the corrosion grade of the whole test piece structure.
The invention provides a plate structure corrosion evaluation method based on water immersion type ultrasonic detection, which comprises the following specific implementation steps of:
the method comprises the following steps: preparing plate structure test pieces with different corrosion degrees and shapes, recording relevant characteristic parameters of the defect test pieces, and numbering the test pieces with different defect types in groups.
Step two: building a detection system and setting parameters;
1) constructing a water immersion type ultrasonic detection corrosion evaluation system based on the water immersion type ultrasonic scanning system;
2) setting signal parameters: the computer controls the ultrasonic excitation receiver to send the excitation signal into the water immersion type ultrasonic excitation receiving probe;
3) carrying a water immersion type flat probe to carry out ultrasonic C scanning, and respectively carrying out imaging by using a time imaging method and an amplitude imaging method;
4) carrying a water immersion type point focusing probe to carry out ultrasonic C scanning, and respectively carrying out imaging by using a time imaging method and an amplitude imaging method;
5) selecting an imaging mode and a probe for detection according to the experimental results of the step 3) and the step 4).
Step three: and D, completing ultrasonic scanning on the test piece according to the parameters set in the step two and the selected detection conditions, and storing detection data.
Step four: and according to the water immersion type ultrasonic scanning data, the corrosion grade evaluation of the test piece is completed.
1) And importing the obtained ultrasonic scanning data of the corrosion test piece into a corrosion evaluation system.
2) Reading ultrasonic scanning data and drawing a C scanning image of the corrosion area; selecting a reasonable threshold, dividing the corrosion region into a corrosion region and a non-corrosion region, dividing the corrosion region into 6 grades, and calculating the characteristic value corresponding to the standard corrosion grade.
3) Carrying out corrosion rating on each position point, and carrying out corrosion rating on the characteristic value X corresponding to each position point(i,j)Calculating the difference D between the position point characteristic value and the characteristic value corresponding to each standard grade(i,j)＝|X(i,j)-BzL, calculating the minimum value min D of the difference between the position point characteristic values(i,j)And the standard grade corresponding to the minimum difference value is the corrosion grade of the position point.
4) Multiplying the weight of each grade by the number of the position points corresponding to the grade, summing the products of the weights and the number of all grades, and simultaneously adding the weights corresponding to all grades to obtain the total weight; and dividing the sum by the total weight to obtain the comprehensive corrosion grade of the test piece.
Wherein N isiIndicating the area of the erosion zone in level i, i.e. the number of points in the level, QiIndicating that the corrosion level i is weighted among all levels.
5) And according to the calculation result, the corrosion evaluation system gives out the comprehensive corrosion grade of the test piece, and according to the corrosion area proportion and the occurrence condition of the individual depth overrun corrosion points, gives out evaluation opinions and an alarm.
The invention has the following advantages: 1) the accurate evaluation of the corrosion of the plate structure detected by water immersion type ultrasonic can be realized; 2) the corrosion evaluation method has low operation requirements on detection personnel and requires fewer parameters; therefore, the method has the advantages of simple application conditions, stable evaluation result and wider application range.
Drawings
FIG. 1 is a connection diagram of a water immersion type ultrasonic scanning corrosion evaluation system
FIG. 2 is a functional diagram of a corrosion evaluation system for a plate structure
FIG. 3 is a flow chart of a method for evaluating corrosion of a plate structure
FIG. 4 is a sample example of a true corrosion test piece in a structural defect experiment of a water immersion type ultrasonic detection plate
FIG. 5 is a result of rating a typical step (hole) defect steel plate (plate thickness: 19.00mm)
Detailed Description
The following describes in detail the implementation process of the method for evaluating corrosion of a plate structure based on water immersion type ultrasonic scanning with reference to fig. 1 to 5.
The method comprises the following steps: preparing a test piece according to the experimental requirements, wherein the thickness of the test piece with the plate structure is 19mm, 5 stepped hole defects are distributed at fixed positions on the front side and the back side, and the number of the steps and the size of the hole diameter of the defects are gradually reduced. The test piece thus prepared is shown in FIG. 4.
Step two: detection system construction and related parameter setting
1) Constructing a water immersion type ultrasonic detection corrosion evaluation system according to the attached figure 1 on the basis of a water immersion type ultrasonic scanning system;
2) setting signal parameters: the experiment selects MODEL5800 as an ultrasonic excitation receiver, and the parameters are set as the following excitation voltage 100V, the excitation frequency 500kHz, the mode P/E, the energy 100uJ, the damping 50ohm, the high-pass cut-off frequency 300KHz, the low-pass cut-off frequency 10MHz and the gain 40 dB. The computer controls the MODEL5800 ultrasonic excitation receiver to send the excitation signal to the ultrasonic excitation receiving probe.
3) Carrying a water immersion type flat probe with the center frequency of 5M and the diameter of a wafer of 20mm, carrying out ultrasonic C scanning detection, and respectively carrying out imaging by using time imaging and amplitude imaging methods;
4) carrying a water immersion type ultrasonic point focusing probe with the central frequency of 5M, the diameter of a wafer of 13mm and the focal length of 20mm, carrying out ultrasonic C scanning detection, and respectively carrying out imaging by using time imaging and amplitude imaging methods;
5) and selecting a water immersion type ultrasonic point focusing probe with a time imaging mode, a center frequency of 5M, a wafer diameter of 13mm and a focusing range of 20mm according to the experimental results of the steps 3) and 4) for carrying out experiments.
Step three: and D, completing water immersion type ultrasonic scanning on the test piece according to the parameters set in the step two and the selected detection conditions, and storing detection data.
Step four: and according to the water immersion type ultrasonic scanning data, the corrosion grade evaluation of the test piece is completed.
1) And importing the obtained ultrasonic scanning data of the corrosion test piece into a corrosion evaluation system.
2) And reading ultrasonic scanning data and drawing a C scanning image of the corrosion area. And selecting a reasonable threshold according to the scanning data, dividing the corrosion region into a corrosion region and a non-corrosion region, dividing the corrosion region into 6 grades, and calculating a characteristic value corresponding to the standard corrosion grade.
3) Carrying out corrosion rating on each position point, and obtaining a characteristic value X corresponding to each position point(i,j)Comparing with grade standard characteristic value step by step, calculating difference D between characteristic value and standard characteristic value(i,j)＝|X(i,j)-BzL. Calculating the minimum min D of the difference between the position point characteristic values(i,j)And the standard grade corresponding to the minimum difference value is the corrosion grade of the position point.
4) Multiplying the weight of each grade by the number of the position points corresponding to the grade, summing the products of the weights and the number of all grades, and simultaneously adding the weights corresponding to all grades to obtain the total weight; and dividing the sum by the total weight to obtain the comprehensive corrosion grade of the test piece. Substituting the above data into equation 2 to calculate.
5) And according to the calculation result, the corrosion evaluation system gives out the comprehensive corrosion grade of the test piece, and according to the corrosion area proportion and the occurrence condition of the individual depth overrun corrosion points, gives out evaluation opinions and an alarm.
Step five: and repeating the third step and the fourth step to finish the ultrasonic scanning and corrosion evaluation of the five step (hole) defects of the test piece, comparing the evaluation result with the actual defect measurement value parameters, and obtaining a comparison result shown in the attached figure 5.
Claims (1)
1. A plate structure corrosion evaluation method based on water immersion type ultrasonic detection is characterized by comprising the following steps: the method comprises the following concrete implementation steps:
the method comprises the following steps: preparing plate structure test pieces with different corrosion degrees and shapes, recording relevant characteristic parameters of the defective plate structure test pieces, and grouping and numbering the plate structure test pieces with different defect types;
step two: building a detection system and setting parameters;
1) constructing a water immersion type ultrasonic detection corrosion evaluation system based on the water immersion type ultrasonic scanning system;
2) setting signal parameters: the ultrasonic excitation receiving instrument is controlled by computer software to send an excitation signal into the water immersion type ultrasonic excitation receiving probe;
3) carrying a water immersion type flat probe to carry out ultrasonic C scanning, and respectively carrying out imaging by using a time imaging method and an amplitude imaging method;
4) carrying a water immersion type point focusing probe to carry out ultrasonic C scanning, and respectively carrying out imaging by using a time imaging method and an amplitude imaging method;
5) selecting an imaging mode and a probe for detection according to the experimental results of the step 3) and the step 4);
step three: completing ultrasonic scanning on the plate structure test piece according to the parameters set in the step two and the selected detection conditions, and storing detection data;
step four: according to the water immersion type ultrasonic scanning data, the corrosion grade evaluation of the plate structure test piece is completed;
1) leading the obtained ultrasonic scanning data of the plate structure test piece into a corrosion evaluation system;
2) reading ultrasonic scanning data and drawing a C scanning image of the corrosion area; selecting a reasonable threshold, segmenting the scanned image of the corrosion region C into an image of the corrosion region and an image of a non-corrosion region, dividing the image of the corrosion region into 6 grades and calculating a characteristic value corresponding to a standard corrosion grade;
3) carrying out corrosion rating on each position point, and carrying out corrosion rating on the characteristic value X corresponding to each position point(i,j)Calculating the difference D between the position point characteristic value and the characteristic value corresponding to each standard grade(i,j)＝|X(i,j)-BzL, calculating the minimum value min D of the difference between the position point characteristic values(i,j)Then the minimum difference value pairThe standard grade is the corrosion grade of the point at the position; b, a characteristic value corresponding to a certain specific corrosion grade, and z is the grade number corresponding to the characteristic value B;
4) multiplying the weight of each grade by the number of the position points corresponding to the grade, summing the products of the weights and the number of all grades, and simultaneously adding the weights corresponding to all grades to obtain the total weight; dividing the sum by the total weight to obtain the corrosion comprehensive grade of the plate structure test piece;
wherein N isiIndicating the area of the erosion zone in level i, i.e. the number of points in the level, QiRepresents the weight of the corrosion grade i in all grades;
5) and according to the calculation result, the corrosion evaluation system gives out the comprehensive corrosion grade of the plate structure test piece, and according to the corrosion area proportion and the occurrence condition of the individual depth overrun corrosion points, gives out evaluation opinions and alarms.
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| CN114878047B (en) * | 2022-04-29 | 2023-12-01 | 北京工业大学 | Water immersion type lamb wave collinear mixing detection system and method for detecting residual stress in metal plate |
| CN114965705A (en) * | 2022-04-29 | 2022-08-30 | 南通俊朗智能科技有限公司 | Temperature interference resistant ultrasonic detection method and system for corrosion of oil storage tank |
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| CN115718061A (en) * | 2022-11-25 | 2023-02-28 | 中国特种设备检测研究院 | Method, system and equipment for evaluating corrosion layer of heat-resistant steel material |
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| CN104391039A (en) * | 2014-11-15 | 2015-03-04 | 中国特种设备检测研究院 | Storage tank bottom plate corrosion noncontact ultrasonic detection method based on dynamic wavelet fingerprint technology |
| CN204832109U (en) * | 2015-07-17 | 2015-12-02 | 上海德奈斯检测技术有限公司 | Axle type part ultrasonic detection device |
| CN105403620A (en) * | 2015-11-01 | 2016-03-16 | 中国民航大学 | Ultrasonic flaw detection system for automatically detecting airplane hub |
| CN106290586A (en) * | 2016-08-04 | 2017-01-04 | 清华大学 | Buried oil and gas pipes guided wave long term monitoring data difference self-adaptation extraction method |
| CN206601365U (en) * | 2017-04-09 | 2017-10-31 | 北京工业大学 | A kind of immersion type ultrasound detection storage tank bottom plate corrosion evaluation experimental system |
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2017
- 2017-04-09 CN CN201710226497.2A patent/CN107121496B/en not_active Expired - Fee Related
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102460113A (en) * | 2009-05-11 | 2012-05-16 | 西安大略大学 | Ultrasonic method of monitoring particle size distribution of a medium |
| CN104391039A (en) * | 2014-11-15 | 2015-03-04 | 中国特种设备检测研究院 | Storage tank bottom plate corrosion noncontact ultrasonic detection method based on dynamic wavelet fingerprint technology |
| CN204832109U (en) * | 2015-07-17 | 2015-12-02 | 上海德奈斯检测技术有限公司 | Axle type part ultrasonic detection device |
| CN105403620A (en) * | 2015-11-01 | 2016-03-16 | 中国民航大学 | Ultrasonic flaw detection system for automatically detecting airplane hub |
| CN106290586A (en) * | 2016-08-04 | 2017-01-04 | 清华大学 | Buried oil and gas pipes guided wave long term monitoring data difference self-adaptation extraction method |
| CN206601365U (en) * | 2017-04-09 | 2017-10-31 | 北京工业大学 | A kind of immersion type ultrasound detection storage tank bottom plate corrosion evaluation experimental system |
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