CN117589860A - Device and method for detecting compression joint condition of high-voltage cable steel core based on local magnetization - Google Patents
Device and method for detecting compression joint condition of high-voltage cable steel core based on local magnetization Download PDFInfo
- Publication number
- CN117589860A CN117589860A CN202311573247.8A CN202311573247A CN117589860A CN 117589860 A CN117589860 A CN 117589860A CN 202311573247 A CN202311573247 A CN 202311573247A CN 117589860 A CN117589860 A CN 117589860A
- Authority
- CN
- China
- Prior art keywords
- voltage cable
- magnetization
- probe
- steel
- steel core
- 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
- 229910000831 Steel Inorganic materials 0.000 title claims abstract description 110
- 239000010959 steel Substances 0.000 title claims abstract description 110
- 230000005415 magnetization Effects 0.000 title claims abstract description 49
- 238000000034 method Methods 0.000 title claims abstract description 19
- 230000006835 compression Effects 0.000 title claims abstract description 14
- 238000007906 compression Methods 0.000 title claims abstract description 14
- 239000000523 sample Substances 0.000 claims abstract description 59
- 238000001514 detection method Methods 0.000 claims abstract description 48
- 230000007547 defect Effects 0.000 claims abstract description 20
- 238000002788 crimping Methods 0.000 claims abstract description 17
- 230000008859 change Effects 0.000 claims abstract description 11
- 230000006698 induction Effects 0.000 claims description 26
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 23
- 229910052782 aluminium Inorganic materials 0.000 claims description 23
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical group [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 21
- 230000035699 permeability Effects 0.000 claims description 15
- 230000005389 magnetism Effects 0.000 claims description 4
- 238000005070 sampling Methods 0.000 claims description 4
- 230000005284 excitation Effects 0.000 claims description 3
- 238000001914 filtration Methods 0.000 claims description 2
- 230000009466 transformation Effects 0.000 claims description 2
- 238000011896 sensitive detection Methods 0.000 claims 1
- 230000005540 biological transmission Effects 0.000 abstract description 2
- 230000035945 sensitivity Effects 0.000 abstract description 2
- 210000001503 joint Anatomy 0.000 description 12
- 238000010586 diagram Methods 0.000 description 5
- 230000004907 flux Effects 0.000 description 5
- 230000005674 electromagnetic induction Effects 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- 230000008569 process Effects 0.000 description 3
- 229910052742 iron Inorganic materials 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- 229910000975 Carbon steel Inorganic materials 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 239000010962 carbon steel Substances 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000000605 extraction Methods 0.000 description 1
- 238000009659 non-destructive testing Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
- G01N27/72—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating magnetic variables
- G01N27/82—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating magnetic variables for investigating the presence of flaws
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Investigating Or Analyzing Materials By The Use Of Magnetic Means (AREA)
Abstract
The invention discloses a device and a method for detecting the compression joint condition of a high-voltage cable steel core based on local magnetization. The device comprises a permanent magnet probe and an alternating current probe, wherein the permanent magnet probe is used for locally magnetizing two sides of the steel pressure pipe to a critical magnetic saturation state. The ac probe generates a magnetic field by applying an ac signal to the exciting coil, and outputs a voltage signal through the detecting coil. And calculating the change condition of the magnetic conductivity based on the amplitude value of the voltage signal, so as to judge whether the crimping position of the high-voltage cable steel core has defects or not and the position and the type of the defects. Compared with the traditional electromagnetic detection method, the method has the advantages of high sensitivity, high precision and low power consumption in the aspect of detecting the crimping quality of the steel core in the power transmission line connector.
Description
Technical Field
The invention belongs to the technical field of nondestructive testing, and particularly relates to a device and a method for detecting the compression joint condition of a high-voltage cable steel core based on local magnetization.
Background
The common material of the high-voltage cable is a steel-cored aluminum stranded wire which is formed by jointly stranding a steel stranded wire of a core part and an aluminum stranded wire at the periphery. The end parts of two steel-cored aluminum strands are connected together through a crimping fitting during butt joint, the joint consists of a steel core wire, a steel pipe, an aluminum strand and an aluminum pipe, wherein the two sections of steel cores are crimped by the steel pipe in a hydraulic manner so as to bear the tensile force from the two wires; the external aluminum stranded wire is crimped by an aluminum pipe and is used for transmitting current in the two sections of aluminum stranded wires. The butt joint position of the two sections of steel core wires is positioned at the center of the steel pipe.
For steel-cored aluminum stranded wire type high-voltage cables, common defects of steel-cored crimping include two cases: one is that the position of the butt joint of two sections of steel cores deviates from the axial center of the steel pipe, and the defect of butt joint deviation of the steel cores in the steel pipe is called; another situation is that the two sections of steel cores are pulled apart by a larger distance due to negligence in the process of crimping, which is called as a defect that the butt joint distance of the steel cores in the steel pipe is overlarge. Since the outer steel tube completely encloses the inner steel core, defects cannot be directly observed by naked eyes.
The traditional electromagnetic detection mode generally utilizes magnetic bypass devices to detect defects of steel materials in steel-cored aluminum stranded wires, the devices mostly utilize the magnetic leakage principle and electromagnetic induction to detect faults, if the defects of pressure deviation or pulling-out exist, the magnetic circuits can be changed, and then the magnetic field intensity and direction are changed, and the devices can sense and measure the changes of the magnetic fields, so that possible faults can be identified. However, the common carbon steel used for the steel pipe is a high magnetic permeability material and has a shielding effect on electromagnetism; meanwhile, the outer diameters of the aluminum stranded wires and the aluminum pipes wrapped outside are larger, and the distance between the steel core to be tested and the detection probe is increased. Particularly, the diameter of the extra-high voltage wire is larger, and the distance between the steel core to be detected and the detection probe is correspondingly increased when the defect detection is carried out. The traditional electromagnetic detection mode has poor detection precision on the steel core crimping defect in the steel core aluminum stranded wire. But other detection methods such as X-ray detection methods and the like have limitations.
Disclosure of Invention
Aiming at the defects of the prior art, the invention provides a device and a method for detecting the compression joint condition of a steel core of a high-voltage cable based on local magnetization.
The device for detecting the compression joint condition of the high-voltage cable steel core based on local magnetization comprises a permanent magnet magnetization probe, an alternating current magnetization detection probe and a signal processing module.
The permanent magnet magnetizing probe comprises U-shaped probes arranged at two sides of the high-voltage cable to be detected, and N-pole permanent magnets and S-pole permanent magnets are respectively arranged at two ends of one probe. The ends of the two probes with the same magnetism are opposite. The permanent magnet magnetizing probe magnetizes the part of the steel tube outside the high-voltage cable to be detected to a magnetic saturation state through the two U-shaped probes.
The alternating-current magnetization detection probe comprises an annular iron core, an exciting coil and an induction coil. The annular iron core penetrates through the exciting coil, the induction coil is fixed at one end of the annular iron core, and the induction coil and the other end of the annular iron core are respectively opposite to two sides of the to-be-detected high-voltage cable, on which the permanent magnet magnetization probe is not arranged. And exciting the high-voltage cable to be detected by a magnetic field generated by introducing current into the exciting coil to form a magnetic circuit.
The signal processing module collects output voltage of the induction coil of the alternating-current magnetization detection probe, analyzes magnetic permeability change conditions in a magnetic circuit and outputs defect information.
Preferably, the permanent magnetic probe comprises a U-shaped iron core and a direct current coil, and the U-shaped iron core penetrates through the direct current coil. The excitation intensity of the permanent magnet magnetizing probe to the steel pipe is changed by changing the direct current in the direct current coil, so that the steel pipe reaches critical magnetic saturation or magnetic saturation state.
Preferably, the magnetic field intensity generated by the alternating-current magnetization detection probe is changed by changing the number of turns of the exciting coil and the magnitude of the current flowing in the exciting coil:
L＝N 2 μA/l
i·N＝H·l e ＝u m
wherein L is inductance, N is number of turns of the exciting coil, mu is magnetic permeability, A is sectional area of the exciting coil, and L is length of the exciting coil. H is the magnetic field strength, l e As effective area of magnetic circuit, u m Is magnetomotive force. v is the induced voltage of the voltage source,is magnetic flux, A e The effective magnetic circuit area, B is the magnetic induction intensity.
Preferably, the signal processing module uses an orthogonal lock-in amplifying circuit and an electronic switch type phase-sensitive detecting circuit to preprocess the output voltage of the induction coil, and the stability and the accuracy of signals are enhanced while noise is filtered.
Preferably, the signal processing module uses a wavelet transformation algorithm to extract local characteristics and time-frequency information of the signal by decomposing the output voltage signal of the induction coil into wavelet coefficients of different scales and frequencies.
A method for detecting the compression joint condition of a high-voltage cable steel core based on local magnetization carries out radial permeability detection on the high-voltage cable to be detected and magnetizes a steel pipe at a joint position to a critical magnetic saturation state or a magnetic saturation state. The method specifically comprises the following steps:
step 1, permanent magnet magnetization
And (3) carrying out pre-magnetization treatment on the steel core and the steel pipe inside the high-voltage cable to be detected by using a permanent magnet magnetization probe, so that the local magnetization is in a critical magnetic saturation or magnetic saturation state.
Step 2, AC magnetization detection
And (3) introducing an alternating current signal to an exciting coil on the alternating current magnetization detection probe to radially excite the steel-cored aluminum strand.
Step 3, signal sampling
Meanwhile, the permanent magnet magnetization probe and the alternating current magnetization detection probe are moved along the radial direction of the high-voltage cable to be detected, and the crimping area is comprehensively detected. And simultaneously equidistantly sampling voltage signals output by the induction coil of the alternating-current magnetization detection probe.
Step 4, signal processing
And filtering and amplifying the acquired signals to eliminate noise interference and signal drift so as to obtain stable and accurate signals.
Step 5, algorithm analysis
And (3) extracting characteristic information from the data processed in the step (4), analyzing the change trend of magnetic permeability, judging the condition of the crimping structure, and outputting the position and type of the defect.
Preferably, the amplitude of the alternating current signal is 100mA to 400mA.
Preferably, the frequency of the alternating current signal is smaller than 60Hz, and the lower the frequency of the alternating current signal is, the larger the detection depth is; the higher the frequency of the alternating current signal, the higher the detection accuracy.
Preferably, the wire diameter of the induction coil is 0.05mm to 0.07mm, and the smaller the wire diameter of the induction coil is, the higher the detection accuracy is.
The invention has the following beneficial effects:
1. the upper part and the lower part of the steel pipe are magnetized to a magnetic saturation state through the permanent magnetic probe, so that more magnetic circuits of the alternating current magnetization detection probe pass through the inside of the steel pipe, and more detected signals reflecting the magnetic circuit change reflect the magnetic permeability in the inside of the steel pipe, thereby improving the precision and the sensitivity of the detection of the compression joint condition of the steel core.
2. The method can effectively detect the compression joint condition of the inside of the steel pipe of the steel-cored aluminum strand joint, and has practical value.
Drawings
FIG. 1 is a schematic cross-sectional view of a steel-cored aluminum strand joint;
FIG. 2 is a schematic diagram of a device for detecting the crimping condition of a high-voltage cable steel core based on local magnetization;
FIG. 3 is a schematic diagram of the defect detection of the steel-cored aluminum strand joint;
FIG. 4 is a schematic diagram of a result of scanning a defect of a steel core butt joint center shift in the steel pipe according to the embodiment;
fig. 5 is a schematic diagram of a defect scanning result of an excessive butt joint distance of steel cores inside the steel pipes in the embodiment.
Detailed Description
Fig. 1 is a schematic cross-sectional view of a steel-cored aluminum strand joint, in which two sections of steel-cored aluminum strands are hydraulically crimped with a splicing sleeve when a transmission line is erected, wherein a steel pipe 10 hydraulically crimps two sections of steel cores 9 to bear tensile forces from two steel cores; the external aluminum stranded wire 1 is crimped by an aluminum pipe 2 and is used for transmitting current in two sections of aluminum stranded wires. The butt joint position of the two sections of steel core wires is positioned at the center of the steel crimping sleeve. The utility model provides a nondestructive test device, as shown in fig. 2, high-voltage cable steel core crimping situation detection device based on local magnetization, including permanent magnetism magnetization probe, alternating current magnetization detection probe and signal processing module, can appear two sections steel core butt joint's position skew steel pipe axial center or two sections distance between the steel core too big in the process of crimping.
The permanent magnet magnetizing probe comprises a first U-shaped probe 5 and a second U-shaped probe 8 which are respectively arranged above and below the high-voltage cable to be detected. N-pole permanent magnet and S-pole permanent magnet 6 are respectively fixed at two ends of the U-shaped probe. The ends of the two probes with the same magnetism are opposite. A magnetic circuit of a part of the permanent magnet-air-steel tube can be formed between each probe and the high-voltage cable to be detected, so that the upper part and the lower part of the steel tube are magnetized to a magnetic saturation state in the detection process.
The alternating-current magnetization detection probe comprises a ring-shaped iron core 3, an exciting coil 4 and an induction coil 7. The annular iron core 3 passes through the exciting coil 4, and the induction coil 7 is fixed at one end of the annular iron core 3, and is opposite to the left side and the right side of the high-voltage cable to be detected respectively with the other end of the annular iron core 3. By supplying current to the exciting coil 4, the generated magnetic field excites the high-voltage cable to be detected, forming a magnetic circuit.
Fig. 3 is a schematic diagram of the detection of the device, where the first U-shaped probe 5 and the second U-shaped probe 8 are respectively located above and below the high voltage cable to be detected, forming a closed magnetic circuit of a U-shaped iron core-magnet-air-steel tube, and magnetizing the upper and lower parts of the steel tube 10 to a magnetic saturation state. An alternating current signal is introduced into the exciting coil 4, a magnetic field is generated through electromagnetic induction to act on the annular iron core 3, a closed magnetic circuit of the annular iron core-air-steel pipe-steel core/air gap-steel pipe is formed, the upper part and the lower part of the steel pipe 10 are in a magnetic saturation state, the magnetic circuit mainly passes through the steel core/air gap inside the steel pipe, the change rate of the magnetic flux density reflects the magnetic permeability of the steel core/air gap inside the steel pipe, and the change can be detected through a voltage signal output by the induction coil 7. According to faraday's law of electromagnetic induction, the magnitude of the induced electromotive force of the closed coil is proportional to the rate of change of magnetic flux in the surrounding area of the coil, and the rate of change of magnetic flux is proportional to the magnetic permeability under the condition that the magnetic field strength is constant, so that the output voltage of the induction coil 7 can reflect the magnetic permeability of the magnetic circuit. And because the permanent magnetic probe magnetizes the upper and lower parts of the steel pipe into a magnetic saturation state, the signal detected by the alternating current magnetization detection probe can reflect the change of the magnetic permeability of substances in the steel pipe.
L＝N 2 μA/l
i·N＝H·l e ＝u m
Wherein L is inductance, N is number of turns of the exciting coil, mu is magnetic permeability, A is sectional area of the exciting coil, and L is length of the exciting coil. H is the magnetic field strength, l e As effective area of magnetic circuit, u m Is magnetomotive force. v is the induced voltage of the voltage source,is magnetic flux, A e The effective magnetic circuit area, B is the magnetic induction intensity.
The position of the high-voltage cable to be detected, which is scanned, is moved at a constant speed, the voltage signal output by the induction coil 7 is sampled at equal intervals, the voltage signal is filtered and amplified, then the signal effective component is extracted by using a characteristic extraction algorithm, an output signal image containing characteristic information is output, as shown in fig. 4, two sections of steel cores are butted inside a steel pipe in the figure, wherein the diameter of each steel core is 7.5mm, the length of the steel pipe is 100mm, the outer diameter of each steel core is 22mm, the butted distance of each steel core inside the steel pipe is 1mm, the scanning direction is from left to right, the output signal is the voltage amplitude of the voltage signal of the induction coil 7 after the voltage signal is filtered and amplified, and x0 and x3 respectively correspond to two ends of the steel pipe 10. x1 is the position of the butt joint of the steel cores in the steel pipe, x2 is the midpoint position of the steel pipe 10, the magnetic permeability of air is lower than that of the steel cores due to the existence of a butt joint air gap of 1mm, the amplitude of an output signal is reduced at the position x1 of the butt joint of the steel cores, the position x2 of the midpoint of the steel pipe 10 is deviated, and the defect of offset of the butt joint center of the steel cores exists in the steel pipe of the high-voltage cable.
Fig. 5 is a test result for another high-voltage cable, where x0 and x3 correspond to two ends of the steel pipe 10 respectively, x5 and x6 are two ends of the steel core butted in the steel pipe, a larger air gap exists between x5 and x6, the amplitude of the output signal correspondingly decreases at the position, and it is seen that the defect of overlarge butt joint distance of the steel core exists in the steel pipe of the high-voltage cable.
Claims (10)
1. High-voltage cable steel core crimping situation detection device based on local magnetization, including exchanging magnetization detection probe and signal processing module, its characterized in that: the device also comprises a permanent magnet magnetizing probe;
the permanent magnet magnetizing probe comprises two U-shaped probes, and N-pole permanent magnets and S-pole permanent magnets are respectively arranged at two ends of one probe; the two U-shaped probes are respectively arranged at two sides of the high-voltage cable to be detected, and one ends with the same magnetism are opposite; the permanent magnet magnetizing probe magnetizes the part of the steel tube outside the high-voltage cable to be detected to a magnetic saturation state through the two U-shaped probes.
2. The high-voltage cable steel core crimping condition detection device based on local magnetization as claimed in claim 1, wherein: the permanent magnet magnetizing probe comprises a U-shaped iron core and a direct current coil, wherein the U-shaped iron core penetrates through the direct current coil; the excitation intensity of the permanent magnet magnetizing probe to the steel pipe is changed by changing the direct current in the direct current coil, so that the steel pipe reaches critical magnetic saturation or magnetic saturation state.
3. The high-voltage cable steel core crimping condition detection device based on local magnetization as claimed in claim 1, wherein: the alternating-current magnetization detection probe comprises an annular iron core, an exciting coil and an induction coil; the annular iron core passes through the exciting coil, the induction coil is fixed at one end of the annular iron core, and the induction coil and the other end of the annular iron core are respectively opposite to two sides of the high-voltage cable to be detected, on which the permanent magnetic probe is not arranged; exciting a high-voltage cable to be detected by a magnetic field generated by introducing current into an exciting coil to form a magnetic circuit;
the signal processing module collects output voltage of the induction coil of the alternating-current magnetization detection probe, analyzes magnetic permeability change conditions in a magnetic circuit and outputs defect information.
4. The high-voltage cable steel core compression condition detection device based on local magnetization according to claim 3, wherein: the magnetic field intensity generated by the alternating current magnetization detection probe is changed by changing the number of turns of the exciting coil and the magnitude of the current.
5. A localized magnetization-based high voltage cable steel core crimp condition detection device according to claim 1 or 3, wherein: the signal processing module uses the quadrature lock amplifying circuit and the electronic switch type phase-sensitive detection circuit to preprocess the output voltage of the induction coil, and the stability and the accuracy of signals are enhanced while noise is filtered.
6. A localized magnetization-based high voltage cable steel core crimp condition detection device according to claim 1 or 3, wherein: the signal processing module uses a wavelet transformation algorithm to extract local characteristics and time-frequency information of signals by decomposing the output voltage signals of the induction coil into wavelet coefficients with different scales and frequencies.
7. The method for detecting the compression joint condition of the high-voltage cable steel core based on local magnetization is characterized by comprising the following steps of: when the device of any one of claims 1 to 4 is used for detecting radial permeability of the high-voltage cable to be detected, the steel pipe at the joint position is magnetized to a critical magnetic saturation state or a magnetic saturation state.
8. The method for detecting the compression condition of the steel core of the high-voltage cable based on the local magnetization according to claim 7, wherein the method comprises the following steps: the specific steps of detection are as follows:
step 1, permanent magnet magnetization
Pre-magnetizing the steel core and the steel pipe inside the high-voltage cable to be detected by using a permanent magnetic probe to enable the steel core and the steel pipe to be locally magnetized into a critical magnetic saturation state or a magnetic saturation state;
step 2, AC magnetization detection
Introducing an alternating current signal to an excitation coil on the alternating current magnetization detection probe, and radially exciting the steel-cored aluminum strand;
step 3, signal sampling
Simultaneously, the permanent magnet magnetization probe and the alternating current magnetization detection probe are moved along the radial direction of the high-voltage cable to be detected, and the crimping area is comprehensively detected; simultaneously equidistantly sampling voltage signals output by an induction coil of the alternating-current magnetization detection probe;
step 4, signal processing
Filtering and amplifying the acquired signals to eliminate noise interference and signal drift so as to obtain stable and accurate signals;
step 5, algorithm analysis
And (3) extracting characteristic information from the data processed in the step (4), analyzing the change trend of magnetic permeability, judging the condition of the crimping structure, and outputting the position and type of the defect.
9. The method for detecting the compression condition of the steel core of the high-voltage cable based on local magnetization according to claim 8, wherein the method comprises the following steps: the amplitude of the alternating current signal is 100 mA-400 mA; the wire diameter of the induction coil is 0.05 mm-0.07 mm, and the smaller the wire diameter of the induction coil is, the higher the detection precision is.
10. The method for detecting the compression condition of the steel core of the high-voltage cable based on local magnetization according to claim 8, wherein the method comprises the following steps: the frequency of the alternating current signal is less than 60Hz; the lower the frequency of the alternating current signal is, the larger the detection depth is; the higher the frequency of the alternating current signal, the higher the detection accuracy.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311573247.8A CN117589860A (en) | 2023-11-23 | 2023-11-23 | Device and method for detecting compression joint condition of high-voltage cable steel core based on local magnetization |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311573247.8A CN117589860A (en) | 2023-11-23 | 2023-11-23 | Device and method for detecting compression joint condition of high-voltage cable steel core based on local magnetization |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN117589860A true CN117589860A (en) | 2024-02-23 |
Family
ID=89911066
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202311573247.8A Pending CN117589860A (en) | 2023-11-23 | 2023-11-23 | Device and method for detecting compression joint condition of high-voltage cable steel core based on local magnetization |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN117589860A (en) |
-
2023
- 2023-11-23 CN CN202311573247.8A patent/CN117589860A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4954777A (en) | Device for defect testing of non-ferromagnetic test samples and for ferromagnetic inclusions | |
| CN102590328B (en) | Permanent magnetic and alternating current direct current composite magnetic flux leakage detecting method | |
| Jomdecha et al. | Design of modified electromagnetic main-flux for steel wire rope inspection | |
| AU595748B2 (en) | Magnetic flux leakage probe with radially offset coils for use in nondestructives testing of pipes and tubes | |
| US20090206830A1 (en) | Sensor for detecting surface defects of metal tube using eddy current method | |
| CN106290558B (en) | A kind of inner and outer walls of pipeline defect detecting device and detection method | |
| JP2013205024A (en) | Detector for non-destructive examination employing alternating field | |
| JP2014044087A (en) | Nondestructive inspection device using pulse magnetic field, and nondestructive inspection method thereof | |
| CN105717191A (en) | Detection method and device for magnetic Barkhausen noise signal and magnetic parameters | |
| CN114113307A (en) | Omnidirectional defect detection device and method for coiled tubing | |
| CN104833720A (en) | Method for single-coil electromagnetic resonance detection of metal pipeline damage | |
| Wait | Review of electromagnetic methods in nondestructive testing of wire ropes | |
| US9222917B2 (en) | Broadband eddy current probe | |
| CN101311714A (en) | High-sensitivity vortex flow dot type probe | |
| Zhou et al. | A new detection method based on magnetic leakage theory and BP neural network for broken steel strands in ACSR conductor | |
| CN103439405B (en) | Iron core and ferrite core synthesize multifunction electric magnetic measurement sensor and detection method thereof | |
| CN109507283A (en) | A kind of PCCP pipeline steel wire fracture of wire far-field vortex checking method | |
| CN117589860A (en) | Device and method for detecting compression joint condition of high-voltage cable steel core based on local magnetization | |
| CN103454339B (en) | A kind of autoexcitation shields full magnetic information induction sniffer | |
| Hartmann et al. | A system for measurement of AC Barkhausen noise in electrical steels | |
| Yanfei et al. | A new detection method of the surface broken wires of the steel wire rope using an eddy current differential probe | |
| CN107576720B (en) | Ferromagnetic slender component shallow layer damage magnetic emission detection method and magnetic emission detection system | |
| Zheng et al. | High-spatial-resolution magnetic Barkhausen noise sensor with shielded receiver | |
| CN214895021U (en) | Cable joint lead sealing position pulse eddy current detection device | |
| CN102087245A (en) | Amorphous alloy based electromagnetic detection sensor |
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 |