CN212228815U - Nondestructive testing sensor based on weak magnetic principle - Google Patents
Nondestructive testing sensor based on weak magnetic principle Download PDFInfo
- Publication number
- CN212228815U CN212228815U CN202020947120.3U CN202020947120U CN212228815U CN 212228815 U CN212228815 U CN 212228815U CN 202020947120 U CN202020947120 U CN 202020947120U CN 212228815 U CN212228815 U CN 212228815U
- Authority
- CN
- China
- Prior art keywords
- magnetic field
- magnetic
- magnet
- field signal
- nondestructive testing
- 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.)
- Active
Links
Images
Landscapes
- Investigating Or Analyzing Materials By The Use Of Magnetic Means (AREA)
Abstract
The utility model discloses a nondestructive test sensor based on weak magnetism principle belongs to pipeline defect detection technical field, the utility model discloses a magnetic field signal collector detects the change volume in magnetic field around the magnet to through signal processing circuit with magnetic field signal output, judge whether the determinand surface has the defect according to the magnetic flux density situation of change. The utility model discloses a sensor has simple structure, and is small, with low costs, and the signal rate of accuracy is high, good reliability's advantage, just the utility model provides a defect detection method detects for non-contact, does not have the requirement to the diameter of pipeline, and the occasion that is suitable for is wide.
Description
Technical Field
The utility model relates to a pipeline defect detects technical field, especially relates to a nondestructive test sensor based on weak magnetism principle.
Background
Most of the existing pipeline detection technologies are magnetic flux leakage detection and eddy current detection. The magnetism leakage detects and is surveyed the pipeline with magnet magnetization, if the material of pipeline is continuous, even, then the magnetic induction line in the material will be retrained in the material, the magnetic flux is on a parallel with the material surface, almost no magnetic induction line wears out from the surface, when the pipeline has the defect of cutting the magnetic line of force, the defect on pipeline surface can make magnetic permeability change, because pipeline magnetic permeability is very little, the magnetic resistance is very big, make the magnetic flux in the magnetic circuit take place the distortion, the magnetic induction line flow direction can change, except that partial magnetic flux directly passes through the defect, partial magnetic flux can leak to the surface sky in addition, bypass the defect through the air and get into the material again. The defects are measured by measuring the magnetic flux density leaking in the air. The sensor used in this method is bulky and requires a steel brush and a large permanent magnet to magnetize the pipe so that it becomes magnetically saturated. Although the leakage flux sensor has high accuracy, the method has high cost for some occasions without quantification. The working principle of the magnetic leakage sensor is shown in fig. 1, a detection coil carrying alternating current is close to a pipeline, and eddy current can be induced in the pipeline due to the action of a coil magnetic field. The size, phase and flow mode of the eddy current are affected by the conductivity of the pipeline, and the impedance of the detection coil is changed by the reaction magnetic field generated by the eddy current, so that the conclusion that the detected pipeline has no defect can be obtained by measuring the impedance change of the detection coil. The method has the advantages of complex structure, high technical difficulty and high power consumption, and causes waste on occasions without quantization.
SUMMERY OF THE UTILITY MODEL
To the not enough of above-mentioned prior art, the utility model provides a nondestructive test sensor based on weak magnetism principle, not only simple structure still is applicable to the multiple occasion that does not need the quantization.
The application provides a nondestructive testing sensor based on a weak magnetic principle, which comprises a shell, a magnet, a circuit board and a magnetic field signal collector; the magnet, the circuit board and the magnetic field signal collector are all packaged in the shell; the magnet and the magnetic field signal collector are respectively and electrically connected to the circuit board; the circuit board leads out signals to the outside of the shell through a lead;
the magnet is used for generating a magnetic field around the object to be measured on the surface of the shell;
the magnetic field signal collector is used for detecting magnetic flux density signals around the magnet and outputting the detected magnetic flux density signals after processing.
Optionally, the magnetic field signal collector is a magnetosensitive component or a coil.
Optionally, the number of the magnetic field signal collectors is 1 or more.
Optionally, the magnetic sensing component is one of a digital magnetic sensing component and an analog magnetic sensing component.
Optionally, when the magnetic sensing assembly is an analog magnetic sensing assembly, the circuit board is provided with a filter circuit to reduce noise of the voltage signal collected by the magnetic field signal collector.
Adopt the produced beneficial effect of above-mentioned technical scheme to lie in:
1. the utility model provides a nondestructive testing sensor based on the weak magnetic principle, which has simple structure, small volume, low cost, high signal accuracy and good reliability;
2. the utility model provides a defect detection method is non-contact detection, and the occasion that is suitable for is wider, does not have the requirement to the diameter of pipeline, can detect the pipeline of variable diameter.
Drawings
In order to more clearly explain the technical solution of the present application, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious to those skilled in the art that other drawings can be obtained according to the drawings without any creative effort.
FIG. 1 is a diagram illustrating a magnetic flux leakage principle in the prior art;
FIG. 2 is a schematic structural diagram of a nondestructive testing sensor based on the weak magnetic principle of the present invention;
FIG. 3 is a schematic view of the variation of magnetic flux density caused by the surface defect of the object to be measured according to the present invention;
fig. 4 is a schematic structural diagram of a nondestructive testing sensor according to a first embodiment of the present invention;
fig. 5 is a waveform diagram of voltage signals detected before and after a defect exists on the surface of a material in an embodiment of the present invention;
fig. 6 is a schematic structural diagram of a nondestructive testing sensor in the second embodiment of the present invention;
fig. 7 is a waveform diagram of the voltage signal detected before and after the defect exists on the surface of the material in the second embodiment of the present invention.
Detailed Description
As shown in fig. 2, the utility model relates to a nondestructive testing sensor's structural schematic diagram based on weak magnetism principle, include: comprises a shell, a magnet, a circuit board and a magnetic field signal collector; the magnet, the circuit board and the magnetic field signal collector are all packaged in the shell; the magnet and the magnetic field signal collector are respectively and electrically connected to the circuit board; the circuit board leads out signals to the outside of the shell through a lead;
the magnet is used for generating a magnetic field around the object to be measured on the surface of the shell; in this embodiment, utilize the weak magnetic principle of magnet, can produce the constant magnetic field around the determinand, this magnetic field need not be too strong, only need can detect magnetic field change can, in addition, adopt magnet to produce magnetic field more small and exquisite, do not occupy great volume, simplified the structure of sensor.
The magnetic field signal collector is used for detecting magnetic flux density signals around the magnet and outputting the detected magnetic flux density signals after processing, and correspondingly, if the magnetic field signal collector is a digital sensor, the output mode is output in a digital signal protocol mode, and if the magnetic field signal collector is an analog sensor, the output mode is output in a voltage signal mode.
In this embodiment, the magnetic flux density signal is based on the principle of weak magnetic nondestructive testing, and the phenomenon of magnetic flux density change caused by a surface defect of the object to be tested is shown in fig. 3, in which the magnetic field around the magnet changes before and after the magnet passes through the defect.
The following detailed description of the embodiments of the present invention is provided with reference to the accompanying drawings and examples. The following examples are intended to illustrate the present application but are not intended to limit the scope of the present application.
Example 1:
the nondestructive testing sensor structure of the present embodiment is shown in fig. 4, and includes a housing, a magnet, a circuit board, and a magnetic field signal collector; the magnet, the circuit board and the magnetic field signal collector are all packaged in the shell; the magnet and the magnetic field signal collector are respectively and electrically connected to the circuit board; the circuit board leads out signals to the outside of the shell through a lead;
the magnet is used for generating a magnetic field around the object to be measured on the surface of the shell;
the magnetic field signal collector is used for detecting magnetic flux density signals around the magnet, converting the detected magnetic flux density signals into voltage signals, and outputting the voltage signals after the voltage signals are processed by the circuit board.
The magnetic field signal collector of the sensor in the embodiment can be composed of two digital magnetic sensing components.
The working principle is as follows: the magnet is used for generating a magnetic field, and two digital magnetic sensitive components near the magnet acquire magnetic field change signals. When the sensor moves on the surface of the ferromagnetic material, if the ferromagnetic surface has defects or cracks, the magnetic field around the magnet can be changed, and the digital magnetic sensing assembly can directly carry out data sorting on the magnetic field change quantities and then output signals to a remote data acquisition and analysis system through a lead.
The weak magnetic probe processing method of the digital magnetic sensor comprises the following steps: the digital element does not need to filter waveforms, the controller is used for collecting data of the magnetic sensing element, then a data structure is arranged, and the data are transmitted to the controller. Namely, the magnetic sensing element sends out a digital signal, and then the digital signal is sent to the acquisition system through the processing circuit.
In order to highlight the difference between the defect and the non-defect, the method for detecting the defect by using the nondestructive testing sensor composed of the digital magnetic sensing assemblies adopts the nondestructive testing sensor composed of the two digital magnetic sensing assemblies to detect the surface of the object to be detected, and comprises the following steps:
step 1: two digital nondestructive testing sensors are moved in parallel on the surfaces of two objects to be tested with and without defects;
step 2: the magnetic field signal collector detects whether the magnetic flux density around the magnet changes;
and step 3: if the magnetic field around the magnet changes, the magnetic field signal collector detects the magnetic flux density signal around the magnet and outputs the detected magnetic flux density signal after processing;
and 4, step 4: and if the signal fluctuation output is detected, judging that the surface of the object to be detected at the position where the magnetic field variation is detected has defects. The digital signal is calculated, as shown in fig. 5, and the calculated magnetic flux density value is obtained, wherein the two voltage waveforms on the upper side show no fluctuation, and the two voltage waveforms on the lower side show obvious fluctuation, it can be determined that the ferromagnetic material surface where the magnetic field variation is detected, i.e. where the fluctuation is detected in fig. 5, has a defect.
Compared with the above embodiment, there is also a feasible embodiment that in the magnetic field signal collector of the sensor, the analog magnetic sensing component can be adopted to replace the digital magnetic sensing component to complete the above functions. When the magnetic-sensing assembly is an analog magnetic-sensing assembly, the circuit board is provided with a filter circuit to reduce noise of the voltage signal acquired by the magnetic field signal acquisition device.
The weak magnetic probe processing method of the analog magnetic sensor comprises the following steps: the processing circuit of the analog element is a filter circuit, and the voltage change of the disturbing magnetic signal is over 0.5v when the disturbing magnetic signal passes through the welding seam through actual measurement, and the voltage change with the precision can be easily acquired through AD conversion with 12-bit or 16-bit precision. Therefore, the processing circuit of this type of weak magnetic sensor is a noise filter circuit.
Example 2:
the nondestructive testing sensor structure of the present embodiment is shown in fig. 6, and includes a housing, a magnet, a circuit board, and a magnetic field signal collector; the magnet, the circuit board and the magnetic field signal collector are all packaged in the shell; the magnet and the magnetic field signal collector are respectively and electrically connected to the circuit board; the circuit board leads out signals to the outside of the shell through a lead;
the magnet is used for generating a magnetic field around the object to be measured on the surface of the shell;
the magnetic field signal collector is used for detecting magnetic flux density signals around the magnet, converting the detected magnetic flux density signals into voltage signals, and outputting the voltage signals after the voltage signals are processed by the circuit board. The magnetic field signal collector of the sensor in this embodiment is composed of 4 coils, and the 4 coils output one-way signals.
The working principle is as follows: the magnet is used for generating a magnetic field, and 4 coils near the magnet collect magnetic field change signals. When the sensor moves on the surface of the ferromagnetic material, if the ferromagnetic surface has defects or cracks, the magnetic field around the magnet can be changed, at the moment, the coil assembly converts the magnetic field change into voltage, the voltage signal is filtered and denoised by a signal processing circuit on the circuit board, and finally the signal is output by a lead.
The processing method of the coil element weak magnetic probe comprises the following steps: the weak magnetic probe of the coil element has a close relationship with the selection of the coil, generally, the proper coil is selected, the peak value generated when the coil passes through a welding seam reaches about 200mv, and the signal is amplified after filtering. Typically 5 or 10 times larger to achieve better results. And then the signals are transmitted to an acquisition and storage system. Such a voltage variation of accuracy can be easily acquired by AD conversion of 12-bit or 16-bit accuracy. Therefore, the processing circuit of this type of weak magnetic sensor is a noise filter circuit plus a signal amplifier circuit.
In order to highlight the difference between the defect and the non-defect, the method for detecting the defect by using the nondestructive testing sensor composed of the coil assembly in this embodiment adopts the nondestructive testing sensor composed of 7 coil assemblies to detect the surface of the object to be detected, and the steps are as follows:
step 1: moving 7 coil type nondestructive testing sensors on the surfaces of the objects to be tested with and without defects in parallel;
step 2: detecting whether the magnetic field around the magnet changes by the coil;
and step 3: when the magnetic field around the magnet changes, the coil converts the change amount of the magnetic field into voltage change amount, and the voltage change amount is output after being filtered by the signal processing circuit;
and 4, step 4: the detected voltage signal output quantity is shown in fig. 7, wherein the 3 rd output has obvious fluctuation, and it is determined that there is a defect on the surface of the ferromagnetic material where the magnetic field variation is detected, that is, where the voltage signal fluctuation is detected in fig. 7, and there is no defect on the detection parts of the remaining 6 sensors.
Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the disclosure of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the invention following, in general, the principles of the invention and including such departures from the present disclosure as come within known or customary practice within the art to which the invention pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the invention being indicated by the following claims.
The present invention is not limited to the precise arrangements described above and shown in the drawings, and various modifications and changes may be made without departing from the scope thereof. The scope of the present invention is limited only by the appended claims.
Claims (5)
1. A nondestructive testing sensor based on the weak magnetic principle is characterized by comprising a shell, a magnet, a circuit board and a magnetic field signal collector; the magnet, the circuit board and the magnetic field signal collector are all packaged in the shell; the magnet and the magnetic field signal collector are respectively and electrically connected to the circuit board; the circuit board leads out signals to the outside of the shell through a lead;
the magnet is used for generating a magnetic field around the object to be measured on the surface of the shell;
the magnetic field signal collector is used for detecting magnetic flux density signals around the magnet and outputting the detected magnetic flux density signals after processing.
2. The nondestructive testing sensor based on the weak magnetic principle of claim 1, wherein the magnetic field signal collector is a magneto-sensitive component or a coil.
3. The nondestructive testing sensor based on the weak magnetic principle as recited in claim 1 or 2, wherein the number of the magnetic field signal collectors is 1 or more.
4. The nondestructive testing sensor based on the weak magnetic principle as recited in claim 2, wherein said magneto-sensitive element is one of a digital magneto-sensitive element and an analog magneto-sensitive element.
5. The nondestructive testing sensor based on the weak magnetic principle of claim 4, wherein when the magnetic sensing component is an analog magnetic sensing component, the circuit board is provided with a filter circuit for reducing noise of the voltage signal collected by the magnetic field signal collector.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202020947120.3U CN212228815U (en) | 2020-05-29 | 2020-05-29 | Nondestructive testing sensor based on weak magnetic principle |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202020947120.3U CN212228815U (en) | 2020-05-29 | 2020-05-29 | Nondestructive testing sensor based on weak magnetic principle |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN212228815U true CN212228815U (en) | 2020-12-25 |
Family
ID=73929859
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202020947120.3U Active CN212228815U (en) | 2020-05-29 | 2020-05-29 | Nondestructive testing sensor based on weak magnetic principle |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN212228815U (en) |
-
2020
- 2020-05-29 CN CN202020947120.3U patent/CN212228815U/en active Active
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103499404B (en) | Ferromagnetic component alterante stress measurement mechanism and measuring method thereof | |
| CN102759567B (en) | The EDDY CURRENT identification of steel pipe inside and outside wall defect and evaluation method under DC magnetization | |
| CN101216460B (en) | AC and DC composite magnetisation based leakage detection recognition method for inside and outside wall defect | |
| CN103954684B (en) | A kind of method utilizing leakage field rate of change to carry out Non-Destructive Testing | |
| CN110057904B (en) | Method and device for quantitatively detecting defects of moving metal component | |
| CN110108788B (en) | Pipeline magnetic flux leakage internal detection integrated probe based on pulse eddy current and detection method | |
| CN106645387B (en) | Pulse magnetoelastic and magnetic leakage integrated detection system for detecting cable force and damage of stayed cable | |
| CN109115868B (en) | Defect depth detection device and method based on pulse eddy current | |
| CN107300584A (en) | Corrosion of steel structure Magnetic sensing methods in a kind of armored concrete | |
| CN104297338A (en) | Pulse eddy current detecting system based on rectangular difference probe | |
| CN109682882A (en) | A kind of Eddy Current Testing Transducer of high spatial resolution | |
| CN107843642A (en) | A kind of marine structure defect ac magnetic field three-dimensional imaging detection probe | |
| CN204255904U (en) | Based on the Pulsed Eddy Current Testing System of rectangle difference detector | |
| Katragadda et al. | Alternative magnetic flux leakage modalities for pipeline inspection | |
| CN101344595B (en) | Shield excitation quantitative determination probe and method thereof | |
| CN102879462A (en) | Metal defect eddy current detection device and probe thereof | |
| CN1975406B (en) | Ferromagnetic component surface defect far field magnetic field detecting method and apparatus | |
| CN111443127A (en) | Nondestructive testing sensor based on weak magnetic principle and measuring method thereof | |
| CN200975991Y (en) | Ferromagnetic member surface defect far-field magnetic field detector | |
| CN212228815U (en) | Nondestructive testing sensor based on weak magnetic principle | |
| CN213580777U (en) | Cross pulse eddy current testing probe | |
| CN102087245B (en) | Amorphous alloy based electromagnetic detection sensor | |
| CN203350226U (en) | Magnetic flaw detection sensor based on giant magnetoresistance elements | |
| CN112629728A (en) | Aluminum alloy residual stress testing device and method based on eddy current | |
| CN113030241B (en) | Device and method for distinguishing magnetic flux leakage detection signals of inner wall and outer wall of steel pipe in use |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |