JPH0785074B2 - Metal flaw detector - Google Patents
Metal flaw detectorInfo
- Publication number
- JPH0785074B2 JPH0785074B2 JP2318379A JP31837990A JPH0785074B2 JP H0785074 B2 JPH0785074 B2 JP H0785074B2 JP 2318379 A JP2318379 A JP 2318379A JP 31837990 A JP31837990 A JP 31837990A JP H0785074 B2 JPH0785074 B2 JP H0785074B2
- Authority
- JP
- Japan
- Prior art keywords
- tube
- signal
- coil
- lissajous waveform
- lissajous
- 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 - Fee Related
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- Investigating Or Analyzing Materials By The Use Of Magnetic Means (AREA)
Description
【発明の詳細な説明】 ［産業上の利用分野］ 本発明は金属材探傷装置に係わり、特に油井管、パイプ
ライン、ガス配管、化学プラント配管、熱交換器配管等
の管路の保存、管理をリモートフィールド渦流法で行う
金属材探傷装置に関する。TECHNICAL FIELD The present invention relates to a metal material flaw detector, and in particular, preservation and management of pipelines such as oil well pipes, pipelines, gas pipes, chemical plant pipes, and heat exchanger pipes. The present invention relates to a metal material flaw detector for performing a remote field eddy current method.
［従来の技術及び発明が解決しようとする課題］ リモートフィールド渦流法を用いて、金属材の探傷を行
うには、励磁コイルと一つ又はそれ以上の受信コイルを
管径の２倍程度以上離して管軸方向に配置して構成した
センサを信号伝送用のケーブルに取付け、管路内に挿入
し、励磁コイルに励磁信号を印加する。印加される励磁
信号は比較的低い周波数（数10Hz〜数100Hz）で、電圧
は数Ｖ〜数10Vが用いられる。[Problems to be Solved by the Related Art and Invention] In order to detect a flaw in a metal material by using the remote field eddy current method, the exciting coil and one or more receiving coils are separated from each other by at least twice the pipe diameter. A sensor configured by arranging in the tube axis direction is attached to a signal transmission cable, inserted into the tube, and an excitation signal is applied to the excitation coil. The applied excitation signal has a relatively low frequency (several 10 Hz to several 100 Hz), and the voltage used is several V to several 10 V.
励磁信号により発生した電磁波は、供試管路の肉厚を通
過するものと、管路内を伝播するものにわけられ、管路
内を伝播する電磁波は管路を導波管と考えたときの遮断
周波数よりはるかに低い周波数であるから、急激に減衰
してほとんど伝播しない。一方、管路の肉厚を通過する
ものは間接伝播波と呼ばれ、管内を管路に沿って伝播
し、ゆっくり減衰し、同時に一部は管路肉厚を再度通過
し、管路内に浸透して受信コイルに検知される。The electromagnetic waves generated by the excitation signal are divided into those that pass through the wall thickness of the test pipe and those that propagate inside the pipe. The electromagnetic waves that propagate inside the pipe are Since the frequency is much lower than the cutoff frequency, it is rapidly attenuated and hardly propagates. On the other hand, what passes through the wall thickness of the pipe is called indirect propagation wave, and propagates along the pipe in the pipe and is slowly attenuated, while at the same time, it partially passes through the wall thickness again and enters the pipe. It penetrates and is detected by the receiving coil.
受信コイルにより検知された信号（以下、受信信号とい
う）は管路肉厚を２度通過していることから非常に微弱
（数μＶ〜数10μＶ）であり、管路肉厚通過による表皮
効果の影響で位相変化を受ける。リモートフィールド渦
流法においては、管路肉厚とのリニアリティーのよい位
相変化を情報として用いることが多い。The signal detected by the receiving coil (hereinafter referred to as the received signal) is extremely weak (several μV to several tens of μV) because it passes through the pipe wall thickness twice, and the skin effect due to the passage of the pipe wall thickness It is affected by the phase change. In the remote field eddy current method, the phase change with good linearity with the pipe wall thickness is often used as information.
リモートフィールド渦流法で用いられるセンサ部36は第
３図に示すように励磁コイルECと受信コイルRC3で構成
され、受信コイルRC3で構成され、受信コイルRC3の巻線
Ｗは供試管TUの周方向に沿って巻かれている。なお、受
信コイルRC3は供試管TU内に複数個設けられ、設けられ
る位置は管円周に沿って環状に又は励磁コイルECに対し
直列に配設される。The sensor unit 36 used in the remote field eddy current method consists of receiving coil RC 3 and the exciting coil EC as shown in Figure 3, consists of a receiver coil RC 3, winding W of the receiving coil RC 3 is subjected試管TU It is wound along the circumferential direction. A plurality of receiving coils RC 3 are provided in the test tube TU, and the positions where they are provided are annularly arranged along the circumference of the tube or in series with the exciting coil EC.
上記構成のセンサ部36を設けた金属材探傷装置では欠陥
の深さと開口面積で定まる欠陥体積により位相差信号に
大きな差が生じるので、欠陥の深さを精度よく評価でき
ないという難点がある。In the metal flaw detector provided with the sensor unit 36 having the above-described configuration, a large difference occurs in the phase difference signal due to the defect depth and the defect volume determined by the opening area, so that the defect depth cannot be accurately evaluated.
［発明の目的］ 本発明は上述した点に鑑みなされたもので、励磁コイル
から供試金属材に励磁信号を印加し、この励磁信号によ
り供試金属材で形成されるリモートフィールド渦流によ
る磁路に対しコイル軸が直角方向となるよう受信コイル
を設け、受信コイルから出力される受信信号と励磁信号
の位相差によるリサージュ図形から探傷データを生成す
ることにより、供試金属材の欠陥を簡単な論理で精度よ
く評価できる金属材探傷装置を提供することを目的とす
る。[Object of the Invention] The present invention has been made in view of the above-mentioned points, and a magnetic path by a remote field vortex flow formed by a test metal material by applying an excitation signal from the excitation coil to the test metal material. On the other hand, by installing a receiving coil so that the coil axis is in the perpendicular direction and generating flaw detection data from the Lissajous figure based on the phase difference between the receiving signal and the excitation signal output from the receiving coil, it is possible to easily detect defects in the metal material under test. It is an object of the present invention to provide a metal material flaw detector which can be evaluated accurately by logic.
［課題を解決するための手段］ そこで本発明では上記目的を達成するため、金属材探傷
装置を、基準信号を発生する基準信号発生器と、前記基
準信号と同相の10Hz〜500Hz程度の比較的低い周波数の
励磁信号を強磁性体から成る管に印加し、リモートフィ
ールド渦流をその管の管肉部に発生させる励磁コイル
と、前記リモートフィールド渦流による磁路に対してコ
イル軸が直角方向になるように、且つ、前記リモートフ
ィールド渦流により発生する間接磁界のうち、一旦管の
外側に出て再度管内に入った間接磁界のみを有効に受信
するように前記励磁コイルから十分に離れた位置に配設
された受信コイルと、前記受信コイルから出力される前
記間接磁界の受信に対応した受信信号と前記励磁信号の
位相に基づいてリサージュ波形を生成するリサージュ波
形生成手段と、前記リサージュ波形生成手段で生成され
たリサージュ波形から前記受信信号と前記励磁信号の位
相差を演算し、前記管の管肉部の外周面から内周面にお
ける傷を探知するための探傷データを生成する探傷デー
タ生成手段とを備えた構成にすることである。[Means for Solving the Problems] Therefore, in order to achieve the above object in the present invention, a metal material flaw detector is provided with a reference signal generator for generating a reference signal, and a relatively high frequency of about 10 Hz to 500 Hz in phase with the reference signal. An exciting coil that applies a low-frequency excitation signal to a tube made of a ferromagnetic material to generate a remote field vortex in the tube wall of the tube and the coil axis are perpendicular to the magnetic path due to the remote field vortex. Of the indirect magnetic field generated by the remote field eddy current, the magnetic field is placed at a position sufficiently distant from the exciting coil so as to effectively receive only the indirect magnetic field that once exited the outside of the tube and entered the inside of the tube again. A receiving coil provided and a Lissajous waveform generating a Lissajous waveform based on the phases of the receiving signal corresponding to the reception of the indirect magnetic field output from the receiving coil and the excitation signal. A phase difference between the received signal and the excitation signal from the Lissajous waveform generating means and the Lissajous waveform generated by the Lissajous waveform generating means, and detects a flaw from the outer peripheral surface to the inner peripheral surface of the tube wall portion of the tube. And a flaw detection data generating means for generating flaw detection data for the purpose.
［実施例］ 以下、本発明による金属材探傷装置の一実施例を第１
図、第２図、第４図〜第７図に基づいて説明する。[Embodiment] The first embodiment of the metallic material flaw detector according to the present invention will be described below.
This will be described with reference to FIGS. 2, 2 and 4 to 7.
本発明による金属材探傷装置は、第１図に示すように、
基準信号発生回路２、端子1a,1bから励磁信号f0を送出
する励磁信号送出回路３、端子1c,1dから受信信号f1が
入力される受信信号回路４を設けた励磁／受信信号モジ
ュール１、２現象オシロスコープ回路11、位相差解析モ
ジュール21及び励磁コイルECと受信コイルRCを設けたセ
ンサ部31で構成する。The metal flaw detector according to the present invention, as shown in FIG.
Excitation / reception signal module 1 provided with reference signal generation circuit 2, excitation signal transmission circuit 3 for transmitting excitation signal f 0 from terminals 1a and 1b, and reception signal circuit 4 to which reception signal f 1 is input from terminals 1c and 1d It is composed of a two-phenomenon oscilloscope circuit 11, a phase difference analysis module 21, a sensor unit 31 provided with an exciting coil EC and a receiving coil RC.
センサ部31の励磁コイルECと受信コイルRCは、相互に供
試管TUの管径の２倍程度以上離れて管軸方向に配置さ
れ、受信コイルRCは励磁コイルECが供試管TUの内壁TUW
に形成するリモートフィールド渦流による磁路に対して
コイル軸が直角方向になるように配設される。励磁コイ
ルECと受信コイルRCのそれぞれの巻線は端子31a,31b,31
c,31dに接続され、端子31a,31bには励磁信号f0が入力さ
れる一方、端子31c,31dからは受信信号f1が送出され
る。The exciting coil EC and the receiving coil RC of the sensor unit 31 are arranged in the tube axial direction so as to be separated from each other by at least twice the tube diameter of the test tube TU, and the exciting coil EC of the receiving coil RC is the inner wall TUW of the test tube TU.
The coil axis is arranged at a right angle to the magnetic path formed by the remote field vortex flow formed in. Each winding of the exciting coil EC and the receiving coil RC has terminals 31a, 31b, 31
The excitation signal f 0 is input to the terminals 31a and 31b, which are connected to c and 31d, while the reception signal f 1 is transmitted from the terminals 31c and 31d.
受信コイルRCは第２図に示すように、中心にフェライト
コアFERを設け、フェライトコアFERの周囲を絶縁材ISU
で囲み、供試管TUの内壁TUWの管軸に対し巻線Ｗが直角
になるよう配設し、巻線Ｗの端部を端子31c,31dと接続
する。As shown in FIG. 2, the receiving coil RC is provided with a ferrite core FER in the center, and an insulating material ISU is provided around the ferrite core FER.
The winding W is arranged at right angles to the tube axis of the inner wall TUW of the test tube TU, and the ends of the winding W are connected to the terminals 31c and 31d.
励磁／受信信号モジュール１の基準信号発生回路２は30
〜80Hzの励磁信号f0を発生し、励磁信号送出回路３へ送
出する。励磁信号送出回路３は励磁信号f0の波形を整形
し端子1a,1bから出力する。The reference signal generation circuit 2 of the excitation / reception signal module 1 is 30
An excitation signal f 0 of ˜80 Hz is generated and sent to the excitation signal sending circuit 3. The excitation signal sending circuit 3 shapes the waveform of the excitation signal f 0 and outputs it from the terminals 1a and 1b.
受信信号回路４は差動増幅器５、ローパスフィルタ６、
受信アンプ７、バンドパスフィルタ８で構成され、差動
増幅器５は端子1cと1dから入力される受信信号f1を入力
側で受信する一方、出力側から同相雑音が除去された受
信信号f1をローパスフィルタ６を介して受信アンプ７へ
送出する。受信アンプ７は入力された受信信号f1を所定
のレベルまで増幅し、バンドパスフィルタ８を経由して
端子1fへ雑音除去済の受信信号f1を送出する。The reception signal circuit 4 includes a differential amplifier 5, a low pass filter 6,
The differential amplifier 5 is composed of a reception amplifier 7 and a bandpass filter 8. The differential amplifier 5 receives the reception signal f 1 input from the terminals 1c and 1d on the input side, while the reception signal f 1 from which common-mode noise is removed from the output side. To the receiving amplifier 7 via the low-pass filter 6. The reception amplifier 7 amplifies the input reception signal f 1 to a predetermined level and sends the noise-removed reception signal f 1 to the terminal 1 f via the bandpass filter 8.
２現象オシロスコープ回路11は端子11aと接続された第
１チャネルインタフェース12、端子11bと接続された第
２チャネルインタフェース13、X,Y軸制御回路14、Ｙ軸
偏向板16a,16b、Ｘ軸偏向板17a,17bを有するCRT15、端
子11cからリサージュ信号を送出するリサージュ信号送
出回路18で構成され、端子11aに励磁信号f0と同相の基
準信号、端子11bに雑音を除去された受信信号f1が入力
されるとリサージュ波形に相応するリサージュ信号が端
子11cから送出される。The two-phenomenon oscilloscope circuit 11 includes a first channel interface 12 connected to the terminal 11a, a second channel interface 13 connected to the terminal 11b, an X, Y axis control circuit 14, Y axis deflection plates 16a, 16b, and an X axis deflection plate. CRT 15 having 17a, 17b, a Lissajous signal sending circuit 18 for sending a Lissajous signal from the terminal 11c, the reference signal in phase with the excitation signal f 0 to the terminal 11a, the noise-free received signal f 1 to the terminal 11b. When input, a Lissajous signal corresponding to the Lissajous waveform is transmitted from the terminal 11c.
位相差解析モジュール21はリサージュ信号受信回路22、
リサージュ信号解析回路23、探傷データ送出回路24及び
位相差解析用CPU25で構成され、端子21aに入力されるリ
サージュ信号をリサージュ信号受信回路22で受信し、リ
サージュ信号解析回路23で受信したリサージュ信号を解
析評価する。解析評価して得た欠陥の深さ、大きさ、形
状を探傷データとして探傷データ送出回路24から端子22
bを経由してプリンタ26へ送出する。The phase difference analysis module 21 is a Lissajous signal receiving circuit 22,
The Lissajous signal analysis circuit 23, the flaw detection data sending circuit 24 and the phase difference analysis CPU 25 is configured, and the Lissajous signal receiving circuit 22 receives the Lissajous signal input to the terminal 21a, and the Lissajous signal analyzing circuit 23 receives the Lissajous signal. Analyze and evaluate. The depth, size, and shape of the defect obtained by analysis and evaluation are used as flaw detection data from the flaw detection data transmission circuit 24 to the terminal 22.
It is sent to the printer 26 via b.
［作 用］ 上記構成の金属材探傷装置で、センサ部31を供試管TUの
内壁TUWに沿って漸動させると受信コイルRCには、リモ
ートフィールド渦流による磁束が通過する。第４図に示
すベクトルＩ、IIは受信コイルRCから出力される受信信
号に基づくもので供試管TUの電気的、磁気的特性、つま
り励磁信号f0の周波数、供試管TUの透磁率、導電率によ
り振幅及び位相が定まるものである。そして供試管TUの
肉厚に欠陥があればベクトルＩの先端部を基準とし、
欠陥によるベクトルIIが発生する。このベクトルIIの変
化の軌跡はＸ軸をAcosφ、Ｙ軸をAsinφとして８の字パ
ターンのいわゆるリサージュ波形となる。ここで、ベク
トルIIの変化の軌跡で得られる角度φを欠陥位相出力PH
φとして、欠陥形状を平底穴、丸底穴、欠陥開口径を10
φ、15φ、20φとしたときの点をそれぞれ平底穴をP1,P
2,P3、丸底穴をP4,P5,P6とすれば、減肉率が50％に対す
る欠陥位相出力PHφは第６図に示すように０〜15゜の間
に分散する。また、減肉率が70％のときは８〜28゜の間
にP1〜P6が分散し、減肉率が90％になると分散の幅が増
加し、11〜42゜程度にまで分散する。[Operation] When the sensor unit 31 is gradually moved along the inner wall TUW of the test tube TU in the metallic flaw detector with the above-described configuration, the magnetic flux due to the remote field vortex passes through the receiving coil RC. The vectors I and II shown in FIG. 4 are based on the received signal output from the receiving coil RC, and are the electrical and magnetic characteristics of the test tube TU, that is, the frequency of the excitation signal f 0 , the permeability of the test tube TU, and the conductivity. The rate determines the amplitude and phase. If there is a defect in the wall thickness of the test tube TU, the tip of vector I is used as a reference,
Vector II is generated due to the defect. The locus of the change of the vector II is a so-called Lissajous waveform having an 8-shaped pattern with Acos φ on the X axis and Asin φ on the Y axis. Here, the angle φ obtained by the trajectory of the change of the vector II is defined as the defect phase output PH
φ, the defect shape is flat bottom hole, round bottom hole, and defect opening diameter is 10
The points when φ, 15φ, and 20φ are flat bottom holes P 1 and P, respectively.
2, P 3, if the Marusokoana and P 4, P 5, P 6 , thinning ratio is defective phase output PHφ for 50% distributed among 0-15 ° as shown in Figure 6. When the metal loss rate is 70%, P 1 to P 6 are dispersed between 8 and 28 °, and when the metal loss rate is 90%, the range of dispersion increases, and it is dispersed up to about 11 to 42 °. To do.
また、上記の条件を２現象オシロスコープ回路11と位相
差解析モジュール21で解析すると、第５図に示すよう
に、AcosφとAsinφの座標軸を前記第４図のＩベクトル
の先端部点に平行移動した座標軸Ｘ′−Ｙ′により構
成されるリサージュ平面が得られる。このＸ′軸と欠陥
により得られるリサージュ波形との角をリサージュ平面
位相角θｊ（RSjφ）とすれば精度の良い解析評価がで
きる。この解析評価方法によれば第７図に示すようにリ
サージュ平面位相角RSjφは減肉率が50％で162゜〜173
゜、70％では174゜〜188゜、90％では186゜〜196゜程度
の範囲に分散の程度が縮小し、精度の良い解析ができ
る。Also, when the above conditions were analyzed by the two-phenomenon oscilloscope circuit 11 and the phase difference analysis module 21, the coordinate axes of Acosφ and Asinφ were moved in parallel to the tip point of the I vector in FIG. 4 as shown in FIG. A Lissajous plane constituted by the coordinate axes X'-Y 'is obtained. If the angle between the X ′ axis and the Lissajous waveform obtained by the defect is taken as the Lissajous plane phase angle θj (RSjφ), accurate analysis and evaluation can be performed. According to this analysis and evaluation method, as shown in FIG. 7, the Lissajous plane phase angle RSjφ is 162 ° to 173 when the metal loss rate is 50%.
The degree of dispersion is reduced to the range of 174 ° to 188 ° at 70 ° and 186 ° to 196 ° at 90%, and accurate analysis can be performed.
上記実施例における２現象オシロスコープ回路11のCRT1
5及びCRT15を制御するX,Y軸制御回路14を省略し、布線
論理またはプログラム論理でリサージュ波形を生成して
もよい。CRT1 of the two-phenomenon oscilloscope circuit 11 in the above embodiment
It is also possible to omit the X and Y axis control circuit 14 for controlling the CRT 15 and the CRT 15 and generate the Lissajous waveform by wiring logic or program logic.
また、上記実施例における受信コイルは複数個併設して
もよい。Further, a plurality of receiving coils in the above embodiment may be provided together.
［発明の効果］ 本発明による金属材探傷装置は、基準信号を発生する基
準信号発生器と、前記基準信号と同相の10Hz〜500Hz程
度の比較的低い周波数の励磁信号を強磁性体から成る管
に印加し、リモートフィールド渦流をその管の管肉部に
発生させる励磁コイルと、前記リモートフィールド渦流
による磁路に対してコイル軸が直角方向になるように、
且つ、前記リモートフィールド渦流により発生する間接
磁界のうち、一旦管の外側に出て再度管内に入った間接
磁界のみを有効に受信するように前記励磁コイルから十
分に離れた位置に配設された受信コイルと、前記受信コ
イルから出力される前記間接磁界の受信に対応した受信
信号と前記励磁信号の位相に基づいてリサージュ波形を
生成するリサージュ波形生成手段と、前記リサージュ波
形生成手段で生成されたリサージュ波形から前記受信信
号と前記励磁信号の位相差を演算し、前記管の管肉部の
外周面及び内周面における傷を探知するための探傷デー
タを生成する探傷データ生成手段とを備えたため、管の
外周面及び内周面における傷を確実に探知することがで
きるという効果がある。[Effects of the Invention] A metallic material flaw detector according to the present invention comprises a reference signal generator for generating a reference signal, and a tube made of a ferromagnetic material for exciting signals of a relatively low frequency of about 10 Hz to 500 Hz in phase with the reference signal. And an exciting coil for generating a remote field vortex in the tube wall portion of the tube, and a coil axis in a direction perpendicular to the magnetic path by the remote field vortex,
Further, of the indirect magnetic field generated by the remote field vortex, it is arranged at a position sufficiently distant from the exciting coil so as to effectively receive only the indirect magnetic field that once went out of the tube and entered the tube again. A receiving coil, a Lissajous waveform generating means for generating a Lissajous waveform based on the phase of the receiving signal and the exciting signal corresponding to the reception of the indirect magnetic field output from the receiving coil, and the Lissajous waveform generating means. Since a phase difference between the received signal and the excitation signal is calculated from a Lissajous waveform, and flaw detection data generating means for generating flaw detection data for detecting flaws on the outer peripheral surface and the inner peripheral surface of the tube wall portion of the tube is provided. Therefore, it is possible to reliably detect the scratches on the outer peripheral surface and the inner peripheral surface of the pipe.
第１図は本発明による金属材探傷装置の一実施例を示す
ブロック図、第２図は本発明による金属材探傷装置の受
信コイルの一実施例を示す構成説明図、第３図は従来の
金属材探傷装置の受信コイルの一実施例を示す構成説明
図、第４図〜第７図は第１図に示す金属材探傷装置の特
性図である。 ２……基準信号発生回路（基準信号発生器） 11……２現象オシロスコープ回路（リサージュ波形生成
手段） 21……位相差解析モジュール（探傷データ生成手段） EC……励磁コイル RC……受信コイルFIG. 1 is a block diagram showing an embodiment of a metal material flaw detector according to the present invention, FIG. 2 is a configuration explanatory view showing an embodiment of a receiving coil of the metal material flaw detector according to the present invention, and FIG. FIG. 4 is a configuration explanatory view showing an embodiment of a receiving coil of the metal material flaw detector, and FIGS. 4 to 7 are characteristic diagrams of the metal material flaw detector shown in FIG. 2 …… Reference signal generation circuit (reference signal generator) 11 …… 2 phenomenon Oscilloscope circuit (Lissajous waveform generation means) 21 …… Phase difference analysis module (flaw detection data generation means) EC …… Excitation coil RC …… Reception coil
───────────────────────────────────────────────────── フロントページの続き (72)発明者 鈴木 究 神奈川県横浜市磯子区汐見台３丁目３番地 3303号棟345号室 (72)発明者 山岸 隆男 大阪府大阪市中央区平野町４丁目１番２号 大阪瓦斯株式会社内 (72)発明者 越水 雄二郎 大阪府大阪市中央区平野町４丁目１番２号 大阪瓦斯株式会社内 (72)発明者 三村 文三 愛知県名古屋市熱田区桜田町19番18号 東 邦瓦斯株式会社内 (72)発明者 山田 勇 愛知県名古屋市熱田区桜田町19番18号 東 邦瓦斯株式会社内 (56)参考文献 特開 昭63−298052（ＪＰ，Ａ) ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inquirer Suzuki Kaku Kanagawa Prefecture Yokohama City Isogo-ku 3-3-3 Shiomidai 3303 Building 345 Room (72) Inventor Takao Yamagishi 4-1-2 Hiranocho, Chuo-ku, Osaka-shi, Osaka Within Osaka Gas Co., Ltd. (72) Inventor Yujiro Koshimizu 4-1-2 Hirano-cho, Chuo-ku, Osaka-shi, Osaka Inside Osaka Gas Co., Ltd. (72) Bunzo Mimura 19-Sakura-cho, Atsuta-ku, Nagoya-shi, Aichi No. 18 In Toho Gas Co., Ltd. (72) Inventor Yu Yamada No. 19 Sakurada-cho, Atsuta-ku, Nagoya-shi, Aichi Prefecture No. 18 In Toho Gas Co., Ltd. (56) Reference JP-A-63-298052 (JP, A)
Claims (1)
記基準信号と同相の10Hz〜50Hz程度の比較的低い周波数
の励磁信号を強磁性体から成る管に印加し、リモートフ
ィールド渦流をその管の管肉部に発生させる励磁コイル
と、前記リモートフィールド渦流による磁路に対してコ
イル軸が直角方向になるように、且つ、前記リモートフ
ィールド渦流により発生する間接磁界のうち、一旦管の
外側に出て再度管内に入った間接磁界のみを有効に受信
するように前記励磁コイルから十分に離れた位置に配設
された受信コイルと、前記受信コイルから出力される前
記間接磁界の受信に対応した受信信号と前記励磁信号の
位相に基づいてリサージュ波形を生成するリサージュ波
形生成手段と、前記リサージュ波形生成手段で生成され
たリサージュ波形から前記受信信号と前記励磁信号の位
相差を演算し、前記管の管肉部の外周面から内周面にお
ける傷を探知するための探傷データを生成する探傷デー
タ生成手段とを備えたことを特徴とする金属材探傷装
置。1. A reference signal generator for generating a reference signal, and an excitation signal having a relatively low frequency of about 10 Hz to 50 Hz, which is in phase with the reference signal, is applied to a tube made of a ferromagnetic material to generate a remote field vortex. The exciting coil generated in the tube wall portion of the tube and the coil field perpendicular to the magnetic path of the remote field eddy current, and of the indirect magnetic field generated by the remote field eddy current, once outside the tube. Corresponding to the receiving coil disposed at a position sufficiently distant from the exciting coil so as to effectively receive only the indirect magnetic field that has come out to the inside of the tube and again and receives the indirect magnetic field output from the receiving coil. The Lissajous waveform generating means for generating a Lissajous waveform based on the phase of the received signal and the excitation signal, and the Lissajous waveform generated by the Lissajous waveform generating means. A flaw detection data generating unit that calculates a phase difference between the received signal and the excitation signal and generates flaw detection data for detecting flaws on the inner peripheral surface from the outer peripheral surface of the tube wall portion of the tube. Metal material flaw detector.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2318379A JPH0785074B2 (en) | 1990-11-22 | 1990-11-22 | Metal flaw detector |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2318379A JPH0785074B2 (en) | 1990-11-22 | 1990-11-22 | Metal flaw detector |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH04188057A JPH04188057A (en) | 1992-07-06 |
| JPH0785074B2 true JPH0785074B2 (en) | 1995-09-13 |
Family
ID=18098492
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2318379A Expired - Fee Related JPH0785074B2 (en) | 1990-11-22 | 1990-11-22 | Metal flaw detector |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0785074B2 (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH06331601A (en) * | 1993-05-26 | 1994-12-02 | Hitachi Building Syst Eng & Service Co Ltd | Eddy current flaw detector |
| JP2012026806A (en) * | 2010-07-21 | 2012-02-09 | Toshiba Corp | Remote field eddy current flow detector, and method |
| CZ2013822A3 (en) * | 2013-10-25 | 2015-02-04 | České Vysoké Učení Technické V Praze Univerzitní Centrum Energeticky Efektivních Budov | Contactless magnetic position sensor of magnetic or electrically conducting objects |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4808927A (en) * | 1987-02-19 | 1989-02-28 | Atomic Energy Of Canada Limited | Circumferentially compensating eddy current probe with alternately polarized receiver coil |
-
1990
- 1990-11-22 JP JP2318379A patent/JPH0785074B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH04188057A (en) | 1992-07-06 |
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