JPH05296979A - Magnetic flux leakage flow detector - Google Patents
Magnetic flux leakage flow detectorInfo
- Publication number
- JPH05296979A JPH05296979A JP22255291A JP22255291A JPH05296979A JP H05296979 A JPH05296979 A JP H05296979A JP 22255291 A JP22255291 A JP 22255291A JP 22255291 A JP22255291 A JP 22255291A JP H05296979 A JPH05296979 A JP H05296979A
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- JP
- Japan
- Prior art keywords
- output
- phase
- outputs
- detection
- detector
- 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.)
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- Investigating Or Analyzing Materials By The Use Of Magnetic Means (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は磁性または非磁性の導電
性線材、棒材に好適の漏洩磁気探傷装置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a leakage magnetic flaw detector suitable for magnetic or non-magnetic conductive wires and rods.
【０００２】[0002]
【従来の技術】線材、棒材等の製造工程においても、種
々の原因によりこれらの表面や内部に欠陥が生ずる。従
来、欠陥を自動的にインラインまたはオンラインで検出
する装置としては、被検査材料内部に超音波を導入し、
この反射波の状態から欠陥を検出する超音波探傷装置、
被検査材料に交番磁界を作用させて該材料中に渦電流を
発生させ、この渦電流の状況から欠陥を検出する渦流探
傷装置、静止磁界中に検出コイルを置き、その検出コイ
ル内に被検材料を走行させ、該コイルが欠陥による漏洩
磁束を切ることによる起電力から欠陥を検出する漏洩磁
気探傷装置などがある。このうち、高速で探傷が可能で
あることより、渦流探傷装置と漏洩磁気探傷装置が広く
使用されており、欠陥の存在部位、形態等の条件により
使い分けられている。このうち、漏洩磁気探傷装置は、
特に、高速で探傷する場合の、材料の振動による影響で
ＳＮ比が悪化し易く、高精度の探傷ができないという問
題がある。2. Description of the Related Art In the process of manufacturing wire rods and rods, defects are generated on their surfaces and inside due to various causes. Conventionally, as a device for automatically detecting defects inline or online, ultrasonic waves are introduced inside the material to be inspected,
An ultrasonic flaw detector that detects defects from the state of this reflected wave,
Eddy current flaw detector that detects an eddy current in the material to be inspected by applying an alternating magnetic field to the material to be inspected, a detection coil is placed in a static magnetic field, and the inspection coil is placed in the detection coil. There is a leakage magnetic flaw detection apparatus that detects a defect from an electromotive force caused by running a material and cutting a leakage magnetic flux due to the coil. Among them, the eddy current flaw detector and the magnetic leakage flaw detector are widely used because they are capable of flaw detection at high speed, and they are properly used depending on conditions such as a defect existing portion and a form. Of these, the leakage magnetic flaw detector is
In particular, when performing flaw detection at a high speed, there is a problem that the SN ratio is easily deteriorated due to the influence of the vibration of the material, and the flaw detection cannot be performed with high precision.
【０００３】特開昭６１−２９２５４８号は、渦流探傷
装置において、また、特開昭５７−６０２５８号は、本
願と同一原理の漏洩磁気を利用した銅線材中の磁性異物
検出装置において、それぞれ上記振動に基づくＳ／Ｎ比
の低下の問題を改善することに関するものである。これ
ら２件の提案は、いずれも、低い周波数のノイズ分に対
しては、例えば図１に示すように被探傷材１に対しその
軸方向に間隔を置いて複数個の検出コイルを配し、それ
ぞれのコイルからの信号を差動増幅器等により組み合
せ、振動等によるノイズ信号の成分を減少させる方式で
あり、この方式は、高速で高精度の探傷を行うには有効
な手段であり、本発明の装置もこの技術を利用してい
る。しかし、この差動による低周波成分の相殺方法は、
位相が互いに逆となる信号同士では却って強め合う結果
となる。また、高い周波数のノイズに対して、前記特開
昭５７−６０２５８号は、一軸上に串差し状に配列され
た３個の検出コイルの互いに隣合う２個のうち、一方の
コイルの出力を反転し、これを他方の出力と加算する演
算回路を２個（１３，１６）設け、また、前記互いに隣
合う２個のコイルのうち、一方のコイルの反転出力と他
方のコイルの出力のうち、所定周波数以上の成分を各々
抽出して加算して反転する回路を２個（２６，２７）設
け、この二出力と前記演算回路の二出力を加算してい
る。しかし、上記装置は、装置が複雑であり、調整等の
取扱いも容易でない欠点を有する。Japanese Unexamined Patent Publication No. 61-292548 discloses an eddy current flaw detector, and Japanese Unexamined Patent Publication No. 57-60258 discloses an apparatus for detecting a magnetic foreign substance in a copper wire using the same leakage magnetic principle as that of the present invention. The present invention relates to improving the problem of S / N ratio reduction due to vibration. In both of these two proposals, for low-frequency noise components, a plurality of detection coils are arranged at intervals in the axial direction of the material to be inspected 1 as shown in FIG. 1, This is a method of combining the signals from the respective coils with a differential amplifier or the like to reduce the components of the noise signal due to vibrations, etc. This method is an effective means for performing high-speed and high-precision flaw detection. Device also uses this technology. However, the method of canceling the low frequency component by this differential is
Signals whose phases are opposite to each other result in mutually strengthening. Further, in the case of high frequency noise, the Japanese Patent Laid-Open No. 57-60258 discloses the output of one of two adjacent detection coils of three detection coils arranged in a skewed shape on one axis. Two operation circuits (13, 16) are provided for inverting and adding this to the output of the other, and of the two adjacent coils, the inverted output of one coil and the output of the other coil , Two circuits (26, 27) for extracting, adding and inverting components each having a predetermined frequency or higher are added, and the two outputs are added to the two outputs of the arithmetic circuit. However, the above-mentioned device has a drawback that the device is complicated and handling such as adjustment is not easy.
【０００４】[0004]
【発明が解決しようとする問題点】本発明は、装置的に
比較的単純で、調整も容易な漏洩磁気探傷装置を提供す
ることを目的とする。SUMMARY OF THE INVENTION It is an object of the present invention to provide a leakage magnetic flaw detector which is relatively simple in terms of equipment and easy to adjust.
【０００５】[0005]
【問題点を解決するための手段】本発明は、静止磁界中
に、軸が該磁界と平行となるごとく配置した検出コイル
を貫通して、前記軸の方向に被探傷材を走行させ、前記
コイルの起電力に基づいて前記被探傷材の異常を検出す
る漏洩磁気探傷装置において、前記被探傷材の長さ方向
に沿って配置された少くとも３個の検出コイルと、これ
らの検出コイルのうち、相隣る２個の検出コイルを１対
とする差動回路２個以上を有し、該差動回路それぞれの
出力信号を一方は移相回路を経て、他方は直接に位相検
波回路に入力して位相検波することを特徴とする漏洩磁
気探傷装置である。According to the present invention, in a static magnetic field, a detection coil arranged so that its axis is parallel to the magnetic field is penetrated, and a flaw detection material is run in the direction of the axis, In a leakage magnetic flaw detector for detecting an abnormality of the flaw detection material based on the electromotive force of the coil, at least three detection coils arranged along the length direction of the flaw detection material, and these detection coils Among them, there are two or more differential circuits having two adjacent detection coils as a pair, and one of the output signals of each of the differential circuits is directly passed through the phase shift circuit and the other is directly passed to the phase detection circuit. It is a leakage magnetic flaw detector characterized by input and phase detection.
【０００６】[0006]
【作用】本発明が対象とする漏洩磁気探傷装置に用いる
静止磁界発生装置は、可能の限り均等な（方向および強
さ）磁場を実現するよう配慮されているが、十分均等な
磁場を実現するに至っていない。このため、該磁場中で
被検材が振動すると、該材料中にその振動に応じた渦電
流が発生し、この渦電流によって磁力が発生し、検出コ
イル内の磁束が変化して振動ノイズ（電圧）を発生す
る。上記ノイズは、その原因である振動に応じた広い周
波数分布を示す。このうち、近接して配置された一対の
検出コイルの相互間隔に比し、十分大きい波長の定在波
または進行波によるノイズ（したがって、比較的低い周
波数のノイズ）は、一対の検出コイルを同特性とし、か
つこれらをその出力が差動となるごとく結線することに
より、ほぼ相殺可能で、前記二提案でも、また、本発明
も採用していることは、前述の通りである。本発明の特
徴は、前述のように差動により増強されたノイズも含
め、差動出力成分のうち、特定の周波数成分のノイズ、
端的には最もレベルが高くＳ／Ｎ比を低下しているノイ
ズを位相敏感検波（以下位相検波と記す）してＳ／Ｎ比
を向上するものである。すなわち、上記の差動により低
周波成分のノイズを相殺除去した二種の信号を得、この
信号のうち、上記特定の周波数成分について、一方の信
号を適当位相角度だけ移相したものと、他方の信号とを
位相検波することにより、例えば両信号の特定周波数の
ノイズに対してその位相差をφ＝π／２、よって、ｃｏ
ｓφ＝０として、該成分のノイズを除去減衰することに
よりＳ／Ｎ比を向上するのである。The static magnetic field generator used in the leakage magnetic flaw detector targeted by the present invention is designed to realize a magnetic field as uniform as possible (direction and strength), but realizes a sufficiently uniform magnetic field. Has not reached. Therefore, when the test material vibrates in the magnetic field, an eddy current corresponding to the vibration is generated in the material, and a magnetic force is generated by the eddy current, and the magnetic flux in the detection coil changes to cause vibration noise ( Voltage) is generated. The noise exhibits a wide frequency distribution according to the vibration that causes it. Of these, noise due to a standing wave or a traveling wave with a sufficiently large wavelength compared to the mutual spacing of a pair of detection coils arranged close to each other (thus, noise of a relatively low frequency) is detected by the pair of detection coils. As described above, the characteristics can be substantially canceled by connecting them so that their outputs are differential, and the two proposals and the present invention are also adopted. A feature of the present invention is that noise of a specific frequency component among the differential output components, including noise enhanced by differential as described above,
In short, the noise whose level is the highest and the S / N ratio is lowered is subjected to phase sensitive detection (hereinafter referred to as phase detection) to improve the S / N ratio. That is, two types of signals are obtained by canceling out the noise of the low-frequency component by the above-mentioned differential, and for this specific frequency component, one of the signals is phase-shifted by an appropriate phase angle, and the other is By detecting the phase difference between the signal and the signal of, for example, the phase difference is φ = π / 2 for noise of a specific frequency of both signals, and
By setting sφ = 0, the noise of the component is removed and attenuated to improve the S / N ratio.
【０００７】[0007]
【実施例】次に本発明を棒鋼材の探傷に応用した装置の
例で説明する。図１は該実施例のブロック図で、Ｌ1〜
Ｌ3は検出コイルで、可能の限り均等な磁界Φを広い空
間内に形成するよう配慮して製作された図示しない界磁
装置内に、軸が該界磁の方向と平行、かつ互いに直列同
軸となるよう配列されている。これらの検出コイルＬ1
〜Ｌ3を貫通するごとく、被検査材１が図示しない走行
装置によりその長手方向に走行している。検出コイルＬ
1とＬ3およびＬ2の出力は、それぞれ同相増幅器１１，
１２および反転増幅器１３，１４で極性を同一および逆
として増幅され、それぞれの出力は、加算回路１５およ
び１６に入力される。ここで同相増幅器、反転増幅器お
よび加算回路、１１，１３および１５ならびに１２，１
４および１６は、それぞれ差動増幅器ａならびｂを形成
しており、それぞれの出力ＡならびにＢは、それぞれＬ
1，Ｌ2間ならびにＬ2，Ｌ3間の低周波ノイズ分を相殺除
去されている。差動増幅器ａ，ｂの出力Ａ，Ｂは、その
まま加算回路ｈに入力され、適当に増幅されて出力Ｈと
される。以上は従来の装置と同様であり、従来の装置で
は、この出力Ｈを適当な表示装置等に導き、不良表示等
に利用している。本発明の装置では、以上の構成の他に
次の構成を有する。複数の差動増幅器の出力の一種を移
相器ｇに導き移相操作を行い、この移相出力と位相しな
い他の出力とを位相検波するものである。すなわち、実
施例では、出力Ａを移相器ｇで移相操作し、その出力Ｇ
と他方の出力Ｂはそのままで、位相検波器ｄに入力して
いる。また、両差動増幅器の出力Ａ，Ｂは、そのまま、
位相検波器ｃに入力されている。位相検波器の出力Ｃお
よびＤは、加算器ｅおよび減算器ｆに入力され、それぞ
れの処理を施されて出力ＥおよびＦとされる。EXAMPLE Next, an example of an apparatus in which the present invention is applied to flaw detection of a steel bar will be described. Figure 1 is a block diagram of the embodiment, L 1 ~
L 3 is a detection coil, and the axis is parallel to the direction of the field and is serially coaxial with each other in a field device (not shown) manufactured in consideration of forming a magnetic field Φ as uniform as possible in a wide space. Are arranged so that These detection coils L 1
The material to be inspected 1 travels in the longitudinal direction by a traveling device (not shown) as it penetrates through L 3 . Detection coil L
The outputs of 1 and L 3 and L 2 are in-phase amplifiers 11 and 11, respectively.
12 and inverting amplifiers 13 and 14 are amplified with the same polarity and opposite polarity, and the respective outputs are input to adder circuits 15 and 16. Where common-mode amplifier, inverting amplifier and summing circuit, 11, 13 and 15 and 12, 1
4 and 16 form a differential amplifier a and b, respectively, and their outputs A and B are respectively L
The low-frequency noise components between 1 and L 2 and between L 2 and L 3 are canceled and eliminated. The outputs A and B of the differential amplifiers a and b are input as they are to the adder circuit h, are appropriately amplified and become the output H. The above is the same as that of the conventional device. In the conventional device, this output H is guided to an appropriate display device or the like and used for defect display or the like. The device of the present invention has the following configuration in addition to the above configuration. One of the outputs of a plurality of differential amplifiers is introduced to a phase shifter g, a phase shift operation is performed, and this phase shift output is phase-detected with another output that is not in phase. That is, in the embodiment, the output A is phase-shifted by the phase shifter g and its output G
The other output B is input to the phase detector d as it is. Also, the outputs A and B of both differential amplifiers are as they are,
It is input to the phase detector c. The outputs C and D of the phase detector are input to the adder e and the subtractor f, and subjected to respective processing to be outputs E and F.
【０００８】次に、作動を図２で欠陥による信号につい
て述べる。今被検査材１に微小欠陥がありこの欠陥部分
が左方からＬ1に接近中とすると、Ｌ1には正負いずれか
の誘起起電力ｋが発生する。この後該欠陥部分が、Ｌ1
を通過して遠ざかると、Ｌ1にはｋと極性が逆の誘起起
電力ｌが発生する。この時刻には該欠陥部分は次のコイ
ルＬ2に接近中でＬ2にはｋと同極性のｋ′が続いてｌ′
がそれぞれ発生する。ここでｔ1およびｔ2は、それぞれ
被検材１の欠陥部分がＬ1とＬ2およびＬ2とＬ3のそれぞ
れ中央間を通過するに要する時間である。Ｌ2の出力は
反転増幅器１３，１４で−Ｌ2で示すごとく反転され、
該反転出力は加算回路１５および１６で、それぞれＬ1
およびＬ3と加算され、Ｌ1−Ｌ2（出力Ａと同じ）およ
び−Ｌ2＋Ｌ3（出力Ｂと同じ）で示す波形となる。この
反転加算されることにより、随伴する低周波ノイズ分は
相殺除去される。出力ＡおよびＢは従来の装置と同様に
加算されて（Ｌ1−２Ｌ2＋Ｌ3）出力Ｈとなる。次に移
相器について述べる。図３はＬおよびＲによる移相回路
の例およびそのベクトルを示す図であり、供給電圧ｅS
のベクトルＥSに対し、Ｌの両端の電圧ｅLのベクトルＥ
LはＥSに対しφだけ遅れている。このφは、例えばＲ値
を変化することにより、特定の周波数に対し、ほぼ０〜
π／２（９０°）まで変化することができる。位相器は
本実施例の他Ｃ（容量）を用いるもの等目的により種々
の形式とすることができる。次に位相検波器について述
べる。位相検波器は、基準の交流ＶOに対し同周波数で
位相差がφであるような交流Ｖに対し、ｃｏｓφに比例
する出力を得る検波器である。出力ＡおよびＢのうち、
欠陥による信号は図２から判るように被処理材の走行速
度ｖ、検出コイルＬ1，Ｌ2，Ｌ3の相互間隔によって定
まる。したがって、移相器ｇの調整は、欠陥による信号
が出力Ｄで極端に低下しないよう見当をつけて行うこと
ができる。本実施例の装置では、図１で加算器ｅの出力
Ｅが最大となるよう移相器を調整することにより、減算
器ｆの出力Ｆ中のノイズを最小にすることができる。し
たがって出力Ｆにより不良表示その他の装置を働かせる
ことができる。上記の装置において、出力ＦのＳ／Ｎ比
を、出力Ｈでのそれに比し、１０〜１２倍向上すること
ができた。Next, the operation will be described with reference to a signal due to a defect in FIG. If there is a minute defect in the material to be inspected 1 and this defective portion is approaching L 1 from the left side, either positive or negative induced electromotive force k is generated in L 1 . After this, the defective portion becomes L 1
When passing away from, the induced electromotive force 1 having the opposite polarity to k is generated in L 1 . The defect in this time is in L 2 in approaching the next coil L 2 k of the same polarity as k 'followed by l'
Occurs respectively. Here, t 1 and t 2 are the times required for the defective portion of the test material 1 to pass between the centers of L 1 and L 2 and L 2 and L 3 , respectively. The output of L 2 is inverted by the inverting amplifiers 13 and 14 as indicated by −L 2 ,
The inverted output is added to L 1 by adder circuits 15 and 16, respectively.
And L 3 are added to form a waveform shown by L 1 −L 2 (same as output A) and −L 2 + L 3 (same as output B). By performing this inverting addition, the accompanying low frequency noise component is offset and removed. The outputs A and B are added (L 1 -2L 2 + L 3 ) to produce the output H as in the conventional device. Next, the phase shifter will be described. FIG. 3 is a diagram showing an example of a phase shift circuit using L and R and a vector thereof, and a supply voltage e S
Of the voltage E L across L with respect to the vector E S of
L lags E S by φ. This φ is approximately 0 to a specific frequency by changing the R value, for example.
It can vary up to π / 2 (90 °). The phase shifter may be of various types depending on the purpose such as one using C (capacity) in addition to this embodiment. Next, the phase detector will be described. The phase detector is a detector that obtains an output proportional to cos φ for an AC V having the same frequency and a phase difference φ with respect to the reference AC V O. Of outputs A and B,
The signal due to the defect is determined by the traveling speed v of the material to be processed and the mutual distance between the detection coils L 1 , L 2 and L 3 as can be seen from FIG. Therefore, the adjustment of the phase shifter g can be performed with an estimate so that the signal due to the defect does not drop extremely at the output D. In the apparatus of the present embodiment, the noise in the output F of the subtractor f can be minimized by adjusting the phase shifter so that the output E of the adder e becomes maximum in FIG. Therefore, the output F can be used to display a defect display and other devices. In the above device, the S / N ratio of the output F could be improved by 10 to 12 times as compared with that at the output H.
【０００９】[0009]
【発明の効果】以上述べたように、本発明は、基本的に
は従来の装置に移相器と位相検波器を加えるだけの比較
的単純な構成であり、また、本実施のごとく位相検波器
を二個とし、これに加算器と減算器を付加して、一方の
出力が最大となるよう移相器を操作すればよく、取扱い
が、非常に容易である。そして、効果は、従来のＳ／Ｎ
比に比べ、約１０倍とすることができるから、処理速度
をより高速化する等、漏洩磁気探傷装置の有用性を一層
向上するものである。As described above, the present invention basically has a relatively simple structure in which a phase shifter and a phase detector are added to the conventional device, and the phase detection is performed as in the present embodiment. It is necessary to add two adders and a subtractor to this, and operate the phase shifter so that the output of one becomes maximum, which is very easy to handle. And, the effect is the conventional S / N
Since the ratio can be made about 10 times as high as the ratio, the usefulness of the leakage magnetic flaw detector is further improved by increasing the processing speed.
【図１】本発明の実施例のブロック図である。FIG. 1 is a block diagram of an embodiment of the present invention.
【図２】本発明の実施例の作動を説明する図である。FIG. 2 is a diagram for explaining the operation of the embodiment of the present invention.
【図３】実施例の移相装置とその作動を説明する図であ
る。FIG. 3 is a diagram illustrating a phase shift device of an embodiment and its operation.
Ｌ1，Ｌ2，Ｌ3 検出コイル １１，１２ 同相増幅器 １３，１４ 反転増幅器 １５，１６ 加算器 ａ，ｂ 差動増幅器 ｇ 移相器 ｃ，ｄ 位相検波器 ｅ，ｈ 加算器 ｆ 減算器 Ａ，Ｂ，Ｃ，Ｄ，Ｅ，Ｆ，Ｇ，Ｈ；出力 ｅS，ｅL，ｅR 電圧 ＥS，ＥL，ＥR 電圧のベクトル φ 位相角 Ｌ インダクタンス Ｒ 抵抗L 1 , L 2 , L 3 detection coil 11, 12 common-mode amplifier 13, 14 inverting amplifier 15, 16 adder a, b differential amplifier g phase shifter c, d phase detector e, h adder f subtractor A , B, C, D, E, F, G, H; output e S , e L , e R voltage E S , E L , E R voltage vector φ phase angle L inductance R resistance
Claims (1)
ごとく配置した検出コイルを貫通して、前記軸の方向に
被探傷材を走行させ、前記コイルの起電力に基づいて前
記被探傷材の異常を検出する漏洩磁気探傷装置におい
て、前記被探傷材の長さ方向に沿って配置された少くと
も３個の検出コイルと、これらの検出コイルのうち、相
隣る２個の検出コイルを１対とする差動回路２個以上を
有し、該差動回路それぞれの出力信号を一方は移相回路
を経て、他方は直接に位相検波回路に入力して位相検波
することを特徴とする漏洩磁気探傷装置。1. A stationary magnetic field passes through a detection coil arranged such that its axis is parallel to the magnetic field, and a flaw-detecting material is caused to travel in the direction of the axis, and based on the electromotive force of the coil, the detected material is moved. In a leaky magnetic flaw detector for detecting an abnormality of a flaw detection material, at least three detection coils arranged along the length direction of the flaw detection material and two adjacent detection coils of these detection coils. It has two or more differential circuits each having a pair of coils, and one of the output signals of each of the differential circuits is directly input to a phase detection circuit and the other is directly input to a phase detection circuit for phase detection. Leakage magnetic flaw detector.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP22255291A JP3205574B2 (en) | 1991-09-03 | 1991-09-03 | Leakage magnetic flaw detector |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP22255291A JP3205574B2 (en) | 1991-09-03 | 1991-09-03 | Leakage magnetic flaw detector |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH05296979A true JPH05296979A (en) | 1993-11-12 |
| JP3205574B2 JP3205574B2 (en) | 2001-09-04 |
Family
ID=16784238
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP22255291A Expired - Fee Related JP3205574B2 (en) | 1991-09-03 | 1991-09-03 | Leakage magnetic flaw detector |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3205574B2 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7214349B2 (en) | 1996-12-31 | 2007-05-08 | Applied Materials, Inc. | Effluent gas stream treatment system having utility for oxidation treatment of semiconductor manufacturing effluent gases |
| CN104215687A (en) * | 2014-08-28 | 2014-12-17 | 山西科为感控技术有限公司 | Magnetic force line balanced detection sensor employing wire rope |
| CN108139362A (en) * | 2015-11-02 | 2018-06-08 | 三菱电机株式会社 | Hawser failure detector |
-
1991
- 1991-09-03 JP JP22255291A patent/JP3205574B2/en not_active Expired - Fee Related
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7214349B2 (en) | 1996-12-31 | 2007-05-08 | Applied Materials, Inc. | Effluent gas stream treatment system having utility for oxidation treatment of semiconductor manufacturing effluent gases |
| CN104215687A (en) * | 2014-08-28 | 2014-12-17 | 山西科为感控技术有限公司 | Magnetic force line balanced detection sensor employing wire rope |
| CN108139362A (en) * | 2015-11-02 | 2018-06-08 | 三菱电机株式会社 | Hawser failure detector |
| CN108139362B (en) * | 2015-11-02 | 2021-07-06 | 三菱电机株式会社 | Cable flaw detection device |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3205574B2 (en) | 2001-09-04 |
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