JPS6013205A - Device for detecting position of corrosion of tubular body - Google Patents
Device for detecting position of corrosion of tubular bodyInfo
- Publication number
- JPS6013205A JPS6013205A JP12128883A JP12128883A JPS6013205A JP S6013205 A JPS6013205 A JP S6013205A JP 12128883 A JP12128883 A JP 12128883A JP 12128883 A JP12128883 A JP 12128883A JP S6013205 A JPS6013205 A JP S6013205A
- Authority
- JP
- Japan
- Prior art keywords
- magnetic field
- test tube
- corrosion
- detector
- current
- 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.)
- Granted
Links
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
Abstract
Description
【発明の詳細な説明】 本発明は、管体の腐食位置検出装置の改良に関する。[Detailed description of the invention] The present invention relates to an improvement in a corroded position detection device for a pipe body.
従来、被検管の腐食位置を検出する装置としては、超音
波送受器を用いたものと、渦流橡傷法を用いたものとが
ある。前者の超音波送受器を用いたものは、第１図に示
すように被検管１の内部に超音波を送波する送波器２ａ
と超音波を受波する受波器２ｂとを備えだ超音波送受器
２を挿入して走行させながら、送波器２ａからパルス状
の超音波を送波し、この超音波が伝播する際に被検管１
の内面１ａおよび外面１ｂよシ反射されて戻ってくる両
反射波を受波器２ｂによって受波し、その両反射波の到
達時間差から被検管１の肉厚を測定するとともに、被検
管１の腐食による薄肉部分の位置を検出している。Conventionally, there are two types of devices for detecting the corroded position of a tube to be inspected: one using an ultrasonic transceiver and the other using an eddy current incision method. The former type that uses an ultrasonic transceiver has a transmitter 2a that transmits ultrasonic waves into the inside of the test tube 1, as shown in FIG.
and a receiver 2b for receiving ultrasonic waves.While the ultrasonic transmitter/receiver 2 is inserted and run, pulsed ultrasonic waves are transmitted from the transmitter 2a, and when this ultrasonic wave propagates, test tube 1
The receiver 2b receives both reflected waves that are reflected back from the inner surface 1a and outer surface 1b of the test tube 1, and measures the wall thickness of the test tube 1 from the arrival time difference between the two reflected waves. The position of the thin walled part due to corrosion in No. 1 is detected.
ところで、この超音波送受器を用いた装置では、超音波
を効率良く管１内で伝播させるために管１内部に水３を
満たして送波器２ａおよび受波器２ｂと被検管１との音
響的マツチングをとる必要がある。このだめ、測定前の
水の充填作業、測定後の水の抜き取り作業などの工程が
増え、測定作業を厄介なものとしている。また、被検管
１全周を検査する場合、多数の送波器２ａおよび受波器
２ｂを放射状に配置させる必要があるため、装置が大損
りなものとなり、例えばガス管のように１〜２インチの
小径管の場合にはこの種の測定法を用いて被検管１の腐
食位置を検出することが困難となる。By the way, in a device using this ultrasonic transceiver, in order to efficiently propagate ultrasonic waves within the tube 1, the inside of the tube 1 is filled with water 3, and the transmitter 2a, the receiver 2b, and the tube 1 to be inspected are connected. It is necessary to perform acoustic matching. This increases the number of steps, such as filling water before measurement and draining water after measurement, making measurement work more troublesome. In addition, when inspecting the entire circumference of the tube 1 to be inspected, it is necessary to arrange a large number of transmitters 2a and receivers 2b radially, resulting in a large loss of equipment. In the case of a small diameter pipe of inch size, it is difficult to detect the corrosion position of the test tube 1 using this type of measurement method.
次に、前記渦流キ栗傷法を用いたものは、第２図に示す
ように被検管１の内部にコイル４を配置し、このコイル
４へ交流電源５より交流の励磁電流を与えることにより
、該コイル４から町なる磁場を発生させて被検管１の内
部に渦電流６を誘起させるとともに、この渦電流６によ
り２次的な磁場Ｈ８を生じさせている。この場合、磁場
Ｈ８は、磁場Ｈ１に対し方向が逆で、Ｈｐを減少させる
方向に働くので、最初の交流に対してはある種の抵抗と
して作用、シ、これによってコイル４のインピーダンス
が変化することになる。従って、コイル４のインピーダ
ンスを測定すれば、渦電流６の変化や大きさを知ること
ができる。ここで、被検管１の内部が腐食によって薄く
なると、被検管１の電気抵抗が大きくなって渦電流６が
小さくなるので、これをコイル４のインピーダンスの変
化として測定すれば、被検管１の腐食位置を検出するこ
とができる。Next, in the method using the eddy current drilling method, a coil 4 is arranged inside the test tube 1 as shown in FIG. As a result, a magnetic field is generated from the coil 4 to induce an eddy current 6 inside the test tube 1, and this eddy current 6 generates a secondary magnetic field H8. In this case, the magnetic field H8 is opposite in direction to the magnetic field H1 and acts in the direction of decreasing Hp, so it acts as a kind of resistance to the initial alternating current, which changes the impedance of the coil 4. It turns out. Therefore, by measuring the impedance of the coil 4, changes and magnitude of the eddy current 6 can be known. Here, when the inside of the test tube 1 becomes thinner due to corrosion, the electrical resistance of the test tube 1 increases and the eddy current 6 decreases, so if this is measured as a change in the impedance of the coil 4, the test tube 1 corrosion position can be detected.
しかし、渦′電流８傷法を用いた場合、被検管１の内部
に生じた渦電流６は交流の表皮効果によってイｊ検管１
の表面に集中する性質がある。However, when the eddy current 8-wound method is used, the eddy current 6 generated inside the test tube 1 is caused by the alternating current skin effect.
It has the property of being concentrated on the surface.
電流が集中している部分の厚さは表皮深さと呼ばれ、鋼
の場合には５０ Ｈｚで約ＩＷＩＩの表皮深さとなる。The thickness of the area where the current is concentrated is called the skin depth, and in the case of steel, the skin depth is approximately IWII at 50 Hz.
従って、本方法のように被検管１の内部にコイル４を配
置したものでは、２〜３瓢以上の肉厚の管外表面腐食に
対しては感度が低く、その腐食位置の検出が困難となる
ことが多い。Therefore, with this method, in which the coil 4 is placed inside the test tube 1, the sensitivity is low for corrosion on the outer surface of a tube with a wall thickness of 2 to 3 or more, and it is difficult to detect the corrosion position. This is often the case.
゛また、周波数を低くすれば、表皮深さは深くなるもの
の、渦電流そのものが減少してくるので、前述と同様に
感度の低下を招く欠点がある。Furthermore, if the frequency is lowered, although the skin depth becomes deeper, the eddy current itself decreases, which has the same drawback as the above-mentioned reduction in sensitivity.
本発明は、上記実情にかんがみてなされたもので、小径
管の場合でもその外表面の腐食位置を容易に検出でき、
また小型の検出器を用いて腐食位置を高感度に検出しイ
０る管体の腐食位置検出装置を提供することにある。The present invention was made in view of the above circumstances, and it is possible to easily detect the corrosion position on the outer surface of a small diameter pipe.
Another object of the present invention is to provide a corrosion position detection device for a pipe body that can detect the corrosion position with high sensitivity using a small-sized detector.
以下、本発明の原理構成について第３図を参照して説明
する。同図において１１は被検管であって、この管１１
の両端まだは所定長間に電源１２よりケーブル１ｓ、１
３を導出して直接または防食ターミナル１４ 、１４１
どを介して接続し、被検管１１の内部内に所定方向の電
流を流すようにしている。一方、被検管１１の内部には
被検管１１の内部内を流れる電流によって生じる磁界を
検出する磁界検出器１５が牽引、自走または圧送手段に
よって走行しうるように設置されている。さらに、磁界
検出器１５には信号ケーブル１６を介して磁界表示器１
７が接続され、磁界検出器１５で検出した磁界を電気信
号に変換した後、磁界表示器１７に磁界として表示する
ようになっている。また、磁界検出器１５にはワイヤド
ラム１８から導出せられたワイヤ１９が接続され、その
ワイヤ１９の途中にワイヤレングスメータ２０が接続さ
れているＯこのワイヤレングスメータ２０は、例えばワ
イヤ１９に付されたマークを計数しまたはワイヤ１９に
接して回転する回転数など計数してワイヤ１９の移動距
離ひいては磁界検出器１５の位置を測定表示するもので
ある。Hereinafter, the principle structure of the present invention will be explained with reference to FIG. In the figure, 11 is a test tube, and this tube 11
The cable 1s, 1 is connected from the power supply 12 to both ends of the
3 and directly or anti-corrosion terminal 14, 141
The test tube 11 is connected through which a current is passed in a predetermined direction inside the test tube 11. On the other hand, a magnetic field detector 15 for detecting a magnetic field generated by a current flowing inside the test tube 11 is installed inside the test tube 11 so as to be movable by towing, self-propelling, or force-feeding means. Furthermore, a magnetic field indicator 1 is connected to the magnetic field detector 15 via a signal cable 16.
7 is connected, and after converting the magnetic field detected by the magnetic field detector 15 into an electric signal, it is displayed as a magnetic field on the magnetic field display 17. A wire 19 led out from the wire drum 18 is connected to the magnetic field detector 15, and a wire length meter 20 is connected in the middle of the wire 19. The movement distance of the wire 19 and the position of the magnetic field detector 15 are measured and displayed by counting the number of marks made or by counting the number of rotations of the wire 19 in contact with the wire 19.
しかして、以上のような構成によれば、被検管１０両端
まだは所定長にわたって所定方向に電流を流すとともに
、被検管１内で磁界検出器１５を走行させながら該検出
器１５の位置とその位置で検出した磁界をワイヤレング
スメータ器２０および磁界表示器１７によって測定表示
することができる。According to the above configuration, a current is passed in a predetermined direction over a predetermined length at both ends of the test tube 10, and while the magnetic field detector 15 is traveling within the test tube 1, the position of the detector 15 is determined. The magnetic field detected at that position can be measured and displayed by the wire length meter 20 and the magnetic field display 17.
ところで、一般に、管内の磁界は、管内に電流が存在し
ないことから、アンペア（Ａｍｐｅｒｅ ）の周回積分
の法則から下式が成立する。By the way, in general, since there is no current in the tube, the following equation holds true for the magnetic field inside the tube based on Ampere's law of circular integrals.
翔ｄｔ＝ｏ ・・・・・・ （１） 但し、Ｈは磁界の強さである。Sho dt=o・・・・・・(1) However, H is the strength of the magnetic field.
今、被検管１１に腐食がない場合には第４図のように被
検管１１の内部に電流工が一様に分布されていることに
なる。このため、この系は点対称となるために、（２）
式が成立する。Now, if there is no corrosion in the test tube 11, the electric currents will be uniformly distributed inside the test tube 11 as shown in FIG. Therefore, since this system has point symmetry, (2)
The formula holds true.
１１−１．（ｒ、θ）＝ａ（ｒ） ・・−・−・ （２
）但しａはベクトルポテンシャルを示ス。11-1. (r, θ)=a(r) ・・−・−・ (2
) However, a indicates the vector potential.
従って、（１）式、（２）式から被検管１１と同心の任
意の円周で周笥積分を行なうと、
２πｒ ａ （ｒ ） ＝ ０ （Δｒ）、’−ａ（ｒ
）＝Ｈ（ｒ、θ）＝Ｏ−聞（３）が成立し、管内部には
磁界が発生しない。Therefore, from equations (1) and (2), if we perform the circumferential integral on an arbitrary circumference concentric with the test tube 11, we get 2πra (r) = 0 (Δr),'-a(r
)=H(r, θ)=O− (3) holds true, and no magnetic field is generated inside the tube.
しかし、被検管１１に腐食部１１ｈがあると、第５図（
、）に示すように電流工の分布が不均一となるために、
（２）式、ひいては（３）式が成立しないので、ｌｌ−
１ＮＯとなシ、被検管１１の内部には磁界が発生するこ
とになる。実際、第５図（ａ）の電流分布は、第５図（
ｂ）の均一分布の電流Ｉ＋ｊと第５図（ｃ）の不拘−電
流−ｉとの重畳と考えると、被検管１ノの内部に磁界が
発生していることが理解できる。従って、この被検管１
１内部の管断面方向の磁界を磁界検出器１５で検出すれ
ば、被検管１ノの外面または内面の腐食を知ることがで
きる。However, if there is a corroded part 11h in the test tube 11, as shown in FIG.
, ), the distribution of electric current becomes uneven,
Since equation (2) and, by extension, equation (3) do not hold, ll-
1NO, a magnetic field will be generated inside the test tube 11. In fact, the current distribution in Fig. 5(a) is similar to that shown in Fig. 5(a).
Considering the superposition of the uniformly distributed current I+j in b) and the unconstrained current -i in FIG. 5(c), it can be understood that a magnetic field is generated inside the test tube 1. Therefore, this test tube 1
By detecting the magnetic field in the cross-sectional direction of the tube 1 with the magnetic field detector 15, corrosion on the outer or inner surface of the tube 1 to be inspected can be detected.
被検管１１の管軸方向の磁界に関しても、第６図に示す
ように腐食部１１ｍで電流分布が乱れるので、管肉厚方
向の電流工によって形成さの腐食部１１ａの位置を検出
することができる。As for the magnetic field in the tube axis direction of the test tube 11, the current distribution is disturbed at the corroded portion 11m as shown in FIG. Can be done.
次に、本発明の一実施例として例えば埋設ガス管に適用
した場合について第７図を参照して説明する。つまり、
地中に埋設されている約２００ｍ長、２インチ径のガス
管１１ｍの両端に電源１２よりスイッチ２１、ケーブル
１３および防食用ターミナル１４を介して４０Ａの直流
電流を流す。一方、磁界検出器１５にあっては、第８図
のように例えばプラスチックの筒状ケーシング１５ｈ内
に管断面のＸ方向、Ｙ方向、および管軸方向の磁界を測
定するために計３個のセンサ１５Ｘｓ １５Ｙ、１５Ｚ
が所定の方向をもって配置され、かつケーシング１５ａ
の両端部外周にはセンターライザ１５ｂが取シ付けられ
ている。Next, as an embodiment of the present invention, a case where the present invention is applied to, for example, a buried gas pipe will be described with reference to FIG. In other words,
A direct current of 40 A is applied from a power source 12 to both ends of a gas pipe 11 m long and 2 inches in diameter, which is buried underground, through a switch 21, a cable 13, and a corrosion protection terminal 14. On the other hand, as shown in FIG. 8, the magnetic field detector 15 has a total of three sensors inside a plastic cylindrical casing 15h to measure magnetic fields in the X direction, Y direction, and tube axis direction of the tube cross section. Sensor 15Xs 15Y, 15Z
are arranged in a predetermined direction, and the casing 15a
A center riser 15b is attached to the outer periphery of both ends.
磁界検出器１５は、例えば圧送によって所定位置まで送
シ込んだ後、ワイヤ１９で引き戻す方式をとる。被検管
１１の内部に送り込まれたワイヤ１９の長さはワイヤ１
９に表示されているマークまたは回転体の回転数などを
ワイヤレングスメータ２０で計数表示することにより、
その磁界検出器１５の位置を測定する。一方、磁界検出
器１５で検出された磁界は信号ケーブル１６によって磁
界表示器１７に送られ、ここで磁界の変化を読み取るも
のである。なお、地磁気や管溶接部の残留８気の影響は
電源１２から出力する電流をスイッチ２１によってオン
・オフしてその差を読み取ることによって除去すること
ができる。The magnetic field detector 15 employs a method in which, for example, the magnetic field detector 15 is forced to a predetermined position and then pulled back using a wire 19 . The length of the wire 19 fed into the test tube 11 is wire 1.
By counting and displaying the mark displayed at 9 or the number of revolutions of the rotating body with the wire length meter 20,
The position of the magnetic field detector 15 is measured. On the other hand, the magnetic field detected by the magnetic field detector 15 is sent to a magnetic field indicator 17 via a signal cable 16, where changes in the magnetic field are read. Note that the influence of the earth's magnetism and residual 8 atmospheres in the pipe welding area can be removed by turning on and off the current output from the power source 12 using the switch 21 and reading the difference.
次に、第９図は被検管１１に腐食部１１ｍが存在する場
合の測定例を示している。即ち、電源１２より被検管１
１に２ＯＡの直流電流を流して磁界表示器１７で磁界の
強さを見たところ、第９図（、）のように３００ ｒａ
ｎ３の腐食部１１＆に対し、管断面のＸ方向磁界は第９
図（ｂ）にように現われ、また管軸方向の磁界は第９図
（Ｃ）のように現われ、外面腐食部１１ａを十分検出す
ることができた。Next, FIG. 9 shows an example of measurement when a corroded portion 11m exists in the test tube 11. That is, the test tube 1 is
When I applied a DC current of 2OA to the magnetic field indicator 17 and checked the strength of the magnetic field, it was 300 ra as shown in Figure 9 (,).
For the corroded part 11& of n3, the X direction magnetic field of the tube cross section is the 9th
The magnetic field appeared as shown in FIG. 9(b), and the magnetic field in the tube axis direction appeared as shown in FIG. 9(c), making it possible to sufficiently detect the outer surface corroded portion 11a.
なお、磁界検出器１５は、１０φ×４０閣程度の小型の
ものであり、さらに１インチ管でも使用前ることができ
る。磁界センサ１５Ｘ。The magnetic field detector 15 is small, about 10 mm x 40 mm, and even a 1-inch tube can be used before use. Magnetic field sensor 15X.
１５Ｙ、１５Ｚとしては、例えばホール素子、半導体セ
ンサなどの小型センナを使用できる。As 15Y and 15Z, for example, a small sensor such as a Hall element or a semiconductor sensor can be used.
また、電源１２としては、直流電流と交流電流とを併用
し、内面腐食と外面腐食とを区別することもできる。す
なわち、交流電流の場合には表皮効果により管外表面に
電流が集中するため、内面腐食に対しては感度が低下す
るので、直流電流時と交流電流時とで比較して区別する
とよい。また、実施例では、地下埋設管１１ｈについて
示したが、建築物内部の配管、ボイラーチューブなどの
ように一般の配管についても同様に適用できる。Furthermore, the power source 12 can use both direct current and alternating current to distinguish between internal corrosion and external corrosion. That is, in the case of alternating current, the current concentrates on the outer surface of the tube due to the skin effect, which reduces the sensitivity to internal corrosion, so it is better to compare and distinguish between direct current and alternating current. Further, in the embodiment, the underground pipe 11h is shown, but the invention can be similarly applied to general pipes such as pipes inside buildings and boiler tubes.
以上詳記したように本発明によれば、被検管に電流を流
した状態で被検管の内部に磁界検出器を挿入して走行さ
せながら腐食による電流分布の乱れから生じる磁界を検
出するようにしたので、測定のために被検管内に水を充
填したシする作業が不要になり、また磁界検出器自体を
半導体素子で小型に作シうるだめ小径管であってもその
管の腐食位置を検出できる。また、渦流倹傷法でないの
で表皮効果による不具合もなくなり、感度の低下をきた
す問題も解決できる。As detailed above, according to the present invention, a magnetic field detector is inserted into the test tube while a current is flowing through the test tube, and the magnetic field generated from the disturbance in the current distribution due to corrosion is detected while the test tube is running. This eliminates the need to fill the test tube with water for measurement, and also allows the magnetic field detector itself to be made compact with semiconductor elements, preventing corrosion of the tube even if the tube is small in diameter. Can detect location. Furthermore, since it is not an eddy current abrasion method, there are no problems caused by the skin effect, and the problem of decreased sensitivity can be solved.
第１図および第２図はそれぞれ従来装置を説明するだめ
の概略構成図、第３図は本発明装置の原理構成図、第４
図ないし第６図は被検管肉部の電流分布状態を示す図、
第７図は埋設ガス管に適用した図、第８図は磁界検出器
の構成図、第９図は被検管に腐食部があったときの測定
結果を示す図である。
１１・・・被検管、ｌｌａ・・・腐食部、１２・・・電
源、１５・・・磁界検出器、１７・・・磁界表示器、１
８・・・ワイヤドラム、１９・・・ワイヤ、２０・・・
ワイヤレングスメータ。1 and 2 are schematic configuration diagrams for explaining the conventional device, FIG. 3 is a principle configuration diagram of the device of the present invention, and FIG.
Figures 6 through 6 are diagrams showing the current distribution state of the test tube flesh,
FIG. 7 is a diagram in which the method is applied to a buried gas pipe, FIG. 8 is a configuration diagram of a magnetic field detector, and FIG. 9 is a diagram showing measurement results when there is a corroded part in the pipe to be inspected. DESCRIPTION OF SYMBOLS 11... Test tube, lla... Corrosion part, 12... Power supply, 15... Magnetic field detector, 17... Magnetic field indicator, 1
8...Wire drum, 19...Wire, 20...
wire length meter.
Claims (1)
被検管の内部に設置されこの被検管の腐食による前記電
流分布の乱れによって生じる磁界を検出する磁界検出器
と、この磁界検出器によって検出された磁界を表示する
磁界表示手段と、前記磁界検出器を走行させるだめの駆
動源と、この駆動源によシ走行された前記磁界検出器の
位置を、磁界検出器に接続したワイヤの移動距離からめ
るワイヤレングスメータとを備えだことを特徴とする管
体の腐食位置検出装置。a test tube, a power source for passing current through the test tube, and a magnetic field detector installed inside the test tube to detect a magnetic field generated by disturbance of the current distribution due to corrosion of the test tube; A magnetic field display means for displaying the magnetic field detected by the magnetic field detector, a drive source for driving the magnetic field detector, and a magnetic field detector for detecting the position of the magnetic field detector driven by the drive source. A corrosion position detection device for a pipe body, characterized in that it is equipped with a wire length meter that measures the moving distance of a wire connected to the pipe body.
Priority Applications (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP12128883A JPS6013205A (en) | 1983-07-04 | 1983-07-04 | Device for detecting position of corrosion of tubular body |
| DE19843424308 DE3424308A1 (en) | 1983-07-04 | 1984-07-02 | DEVICE FOR LOCATING A DEFECTIVE AREA OF A METAL PIPE |
| GB08416773A GB2143331A (en) | 1983-07-04 | 1984-07-02 | Apparatus for detecting the defective portion of a metallic tube |
| FR8410647A FR2548785A1 (en) | 1983-07-04 | 1984-07-04 | APPARATUS FOR DETECTING A DEFECTIVE PART IN A METAL TUBE |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP12128883A JPS6013205A (en) | 1983-07-04 | 1983-07-04 | Device for detecting position of corrosion of tubular body |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6013205A true JPS6013205A (en) | 1985-01-23 |
| JPH0457961B2 JPH0457961B2 (en) | 1992-09-16 |
Family
ID=14807542
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP12128883A Granted JPS6013205A (en) | 1983-07-04 | 1983-07-04 | Device for detecting position of corrosion of tubular body |
Country Status (4)
| Country | Link |
|---|---|
| JP (1) | JPS6013205A (en) |
| DE (1) | DE3424308A1 (en) |
| FR (1) | FR2548785A1 (en) |
| GB (1) | GB2143331A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2015111558A1 (en) * | 2014-01-22 | 2015-07-30 | 横河電機株式会社 | Thinning detection device |
Families Citing this family (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5537035A (en) * | 1994-05-10 | 1996-07-16 | Gas Research Institute | Apparatus and method for detecting anomalies in ferrous pipe structures |
| US5479100A (en) * | 1994-05-10 | 1995-12-26 | Gas Research Institute | Method for detecting anomalies in pipes |
| DE19654868A1 (en) * | 1996-12-24 | 1998-06-25 | Forschungsgesellschaft Fuer In | Non=destructive testing for instantaneous testing for corrosion in concrete or lacquer |
| DE19819066A1 (en) * | 1998-04-29 | 1999-11-11 | F I T Messtechnik Gmbh | Test method for non-contact detection of irregularities in the wall thickness of inaccessible metallic pipes |
| US6815946B2 (en) | 1999-04-05 | 2004-11-09 | Halliburton Energy Services, Inc. | Magnetically activated well tool |
| US6411084B1 (en) * | 1999-04-05 | 2002-06-25 | Halliburton Energy Services, Inc. | Magnetically activated well tool |
| DE10030191C2 (en) * | 2000-06-19 | 2002-10-31 | Hahn Meitner Inst Berlin Gmbh | Device and method for locating and determining the extent of invisible bodies made of ferromagnetic materials in a non-ferromagnetic environment |
| JP2003068234A (en) | 2001-08-29 | 2003-03-07 | Nippon Electric Glass Co Ltd | Funnel-and-neck sealing body for projection tube |
| EP1357380A1 (en) * | 2002-04-24 | 2003-10-29 | NP Inspection Services GmbH | Testing method and testing device for the detection of irregularities in the wall thickness of ferromagnetic pipes |
Family Cites Families (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2371176A (en) * | 1945-03-13 | Means for and method of detecting | ||
| US1978252A (en) * | 1930-10-25 | 1934-10-23 | Sperry Prod Inc | Flaw detector for boiler welds |
| GB631988A (en) * | 1947-07-25 | 1949-11-14 | Superheater Co Ltd | Improvements in and relating to apparatus for testing materials by magnetic or electrical analysis |
| US3284702A (en) * | 1963-04-26 | 1966-11-08 | Camco Inc | Apparatus for detecting coating holidays in metal pipeline walls utilizing helically wound pick-up coils and selfcontained power system |
| FR1585918A (en) * | 1967-06-09 | 1970-02-06 | ||
| GB1200146A (en) * | 1967-08-17 | 1970-07-29 | Friedrich M O Foerster | Measuring magnetic fields |
| US3753091A (en) * | 1972-04-10 | 1973-08-14 | Submarine Pipeline Technology | Method and device for detecting faults in non-conductive coatings on under water pipelines |
| GB1586581A (en) * | 1977-01-26 | 1981-03-18 | British Gas Corp | Pipeline inspection equipment |
| JPS5826256A (en) * | 1981-08-07 | 1983-02-16 | Kubota Ltd | Inspecting device for pipe |
-
1983
- 1983-07-04 JP JP12128883A patent/JPS6013205A/en active Granted
-
1984
- 1984-07-02 DE DE19843424308 patent/DE3424308A1/en not_active Ceased
- 1984-07-02 GB GB08416773A patent/GB2143331A/en not_active Withdrawn
- 1984-07-04 FR FR8410647A patent/FR2548785A1/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2015111558A1 (en) * | 2014-01-22 | 2015-07-30 | 横河電機株式会社 | Thinning detection device |
| JP2015137930A (en) * | 2014-01-22 | 2015-07-30 | 横河電機株式会社 | Wastage detector |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0457961B2 (en) | 1992-09-16 |
| FR2548785A1 (en) | 1985-01-11 |
| GB2143331A (en) | 1985-02-06 |
| GB8416773D0 (en) | 1984-08-08 |
| DE3424308A1 (en) | 1985-01-17 |
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