JPS6355448A - Method and device for deciding deterioration of covering of buried object - Google Patents
Method and device for deciding deterioration of covering of buried objectInfo
- Publication number
- JPS6355448A JPS6355448A JP61200417A JP20041786A JPS6355448A JP S6355448 A JPS6355448 A JP S6355448A JP 61200417 A JP61200417 A JP 61200417A JP 20041786 A JP20041786 A JP 20041786A JP S6355448 A JPS6355448 A JP S6355448A
- Authority
- JP
- Japan
- Prior art keywords
- buried object
- current
- buried
- magnetic field
- deterioration
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 230000006866 deterioration Effects 0.000 title claims abstract description 23
- 238000000034 method Methods 0.000 title claims description 19
- 238000009826 distribution Methods 0.000 claims abstract description 29
- 238000010408 sweeping Methods 0.000 claims abstract description 7
- 239000011248 coating agent Substances 0.000 claims description 16
- 238000000576 coating method Methods 0.000 claims description 16
- 238000009933 burial Methods 0.000 claims description 2
- 230000007547 defect Effects 0.000 description 5
- 238000010586 diagram Methods 0.000 description 5
- 230000005540 biological transmission Effects 0.000 description 4
- 230000000694 effects Effects 0.000 description 2
- 206010011224 Cough Diseases 0.000 description 1
- 230000002238 attenuated effect Effects 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000002950 deficient Effects 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000000691 measurement method Methods 0.000 description 1
Landscapes
- Investigating Or Analyzing Materials By The Use Of Electric Means (AREA)
- Geophysics And Detection Of Objects (AREA)
Abstract
Description
【発明の詳細な説明】
［産業上の利用分野］
本発明は、地中に埋設された電気伝導性のある物体の被
覆劣化の程度を判定する方法及びその装置に関する。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method and apparatus for determining the degree of coating deterioration of an electrically conductive object buried underground.
［従来技術］
従来、埋設物の被覆劣化による欠陥の検知技術としては
、電位法が一般に使用されている。これは埋設物の一端
と近くに設けたアース棒との間に電圧を加えて電流を流
し、被覆劣化部からもれた電流の分布を地中の電位分布
として検知し、被覆劣化の様子を知るものである。（ｒ
電位法による防食層の欠陥部検知ｊｓ４３．３月 大日
口本電線事報）
また、簡易法として埋設物に電圧印加した時のインピー
ダンスの高低によって被覆劣化の有無を判定する方法も
ある。[Prior Art] Conventionally, the potential method has been generally used as a technique for detecting defects due to deterioration of the coating of buried objects. This involves applying a voltage and flowing a current between one end of the buried object and a grounding rod installed nearby, and detecting the distribution of current leaking from the deteriorated part of the buried object as the potential distribution underground, and detecting the state of the deterioration of the covering. It is something to know. (r
Detection of Defects in Corrosion Protection Layer by Potential Method (March 43, Dainichiguchi Main Electric Cable Newsletter) In addition, as a simple method, there is also a method of determining the presence or absence of coating deterioration based on the level of impedance when voltage is applied to the buried object.
第３図を用いて従来技術を詳細に説明する。地中に埋設
された埋設物ｌと近くに設けたアース棒１１の間に電流
源１２から送信電流１３を流す。The prior art will be explained in detail using FIG. A transmission current 13 is passed from a current source 12 between a buried object l buried underground and a ground rod 11 provided nearby.
埋設物に流れた送信電流１３は、徐々に漏れ出し、漏れ
電流１４となって、アース棒１１に吸収される。もし埋
設物の被覆に欠陥が存在していた場合、そこから集中的
に電流が漏れ出し、アース棒１１にもどる。また、埋設
物の被覆が全体的に劣化すると劣化しないものに比べて
電流は流入部付近で大きく漏れ出し、結果として遠くま
で送信電流が流れないことになる。The transmission current 13 flowing through the buried object gradually leaks out, becomes a leakage current 14, and is absorbed by the earth rod 11. If there is a defect in the covering of the buried object, current will intensively leak from there and return to the earth rod 11. Furthermore, if the covering of the buried object deteriorates as a whole, the current leaks out near the inflow part to a greater extent than if it did not deteriorate, and as a result, the transmission current does not flow far.
以上言いかえると漏れ電流の分布を知ることによって、
埋設物ｌの被覆劣化や欠陥点の存在を検知することがで
きるのである。従来技術では漏れ電流を検知するために
第３図に示すように電位差計１５を用いて地中の２点間
の電位差を測定し、地中の比抵抗で除することにより、
漏れ電流を算出していた。In other words, by knowing the distribution of leakage current,
It is possible to detect the deterioration of the coating of the buried object l and the presence of defective points. In the prior art, in order to detect leakage current, as shown in FIG. 3, a potentiometer 15 is used to measure the potential difference between two points underground, and the difference is divided by the specific resistance of the ground.
The leakage current was calculated.
また、簡易法では、電流源１２の出力電圧と出力電流か
ら、アース棒１１と埋設物間ｌのインピーダンスを測定
し、その高低によって、被覆の劣化を判定していた。In addition, in the simple method, the impedance between the earth rod 11 and the buried object is measured from the output voltage and output current of the current source 12, and the deterioration of the coating is determined based on the height of the impedance.
［従来技術の問題点］
前記従来技術の電位法では、地中電位差を測定するため
に２点に接地棒１５ ａ 、 １５ｂを設置する必要が
あり、広範囲の測定では非常な労力が必要となる。また
簡易法では、埋設物ｌの概略の被覆状況は判断できるが
、局所的な欠陥が存在するのか全体的に被覆が劣化して
いるのかの判断や、欠陥の存在する場所についての情報
は得られない、従来技術では、以上のような問題点を有
していた。[Problems with the prior art] In the potential method of the prior art, it is necessary to install the grounding rods 15a and 15b at two points in order to measure the underground potential difference, which requires a great deal of effort to measure over a wide range. . In addition, with the simple method, it is possible to determine the general coverage status of buried objects, but it is not possible to determine whether there are local defects or overall deterioration of the coverage, and information about the location of defects. However, the conventional technology has the above-mentioned problems.
［本発明の目的１
本発明の目的は、容易な操作で、埋設物の被覆の劣化の
判定を行う方法及びその装置を提供することにある。[Objective 1 of the present invention An object of the present invention is to provide a method and apparatus for determining deterioration of a covering of a buried object with easy operation.
「発明の構成」
特許請求範囲第一項の判定方法では、地中に埋設された
電気伝導性のある物体に電流を通じ、物体から発生する
磁場を地上で平面分布として測定し、その分布から埋設
深度を計算し、その強度から埋設物に流れる電流を計算
して、埋設物に流れる電流の減衰量から被覆の劣化を特
徴する特許請求範囲第二項の判定装置では、一直線状に
配置した３コ以上の複数の磁気センサと、それらの信号
出力をＣＰＵに取り込む手段と、前記磁気センサ配列を
埋設物に沿って掃引する手段と、掃引した距離をＣＰＵ
に取り込む手段と、取り込んだ磁場分布データから埋設
物に流れる電流を計算する手段と、計算した結果を表示
す葛手段と、から構成される。"Structure of the Invention" The determination method in claim 1 involves passing an electric current through an electrically conductive object buried underground, measuring the magnetic field generated by the object as a planar distribution on the ground, and determining whether the buried In the determination device according to claim 2, which calculates the depth, calculates the current flowing through the buried object from its intensity, and characterizes the deterioration of the coating from the attenuation amount of the current flowing through the buried object, three a plurality of magnetic sensors, a means for capturing their signal outputs into a CPU, a means for sweeping the magnetic sensor array along a buried object, and a CPU for measuring the swept distance.
means for calculating the current flowing through the buried object from the acquired magnetic field distribution data, and means for displaying the calculated results.
［発明の原理φ作用］
埋設物に流れる電流や漏れ電流の分布を測定すれば、埋
設物の被覆の状況を知ることができることは前述のとお
りである０本発明では、埋設物に流れる電流の作る磁場
を地上で測定することによって、電流分布を検知する。[Principle of the Invention φ Effect] As mentioned above, by measuring the distribution of the current flowing through the buried object or the leakage current, it is possible to know the state of the covering of the buried object. Current distribution is detected by measuring the generated magnetic field on the ground.
電流の作□る磁場はビオ・サバールの法則により電流値
の大きさに比例し、観測点と電流との距離に反比例する
。したがって、適当な方法で磁場分布から埋設物の深度
を算出し、深度と磁場強度か□′ら電流を逆算すること
ができる。According to the Biot-Savart law, the magnetic field created by a current is proportional to the magnitude of the current, and inversely proportional to the distance between the observation point and the current. Therefore, the depth of the buried object can be calculated from the magnetic field distribution using an appropriate method, and the current can be calculated backward from the depth and the magnetic field strength.
上記の操作を埋設物に沿ってくりかえすことにより埋設
物に流れる電流分布を知ることができ、埋設物の被覆の
状況を知ることができる。By repeating the above operation along the buried object, the current distribution flowing through the buried object can be known, and the state of the covering of the buried object can be known.
［実施例］ 第１図、第２図に本発明の実施例を示す。[Example] Embodiments of the present invention are shown in FIGS. 1 and 2.
第１図（、ａ）、（ｂ）は比較的被覆劣化していない埋
設物に電流を流した時の地上の平面磁場分布である。こ
の場合、埋設物は直線状でＸ軸方向に伸び、ｙ＝ｏｍの
ところに存在する。（ａ）は、地面に水平な方向の磁場
の等磁場曲線表示であり、（ｂ）は、垂直な方向の磁場
の等磁場曲線表示である。これらの分布から、埋設物の
位置や深度を算出することは、従来より種々の方法で行
われている０例えば、磁場が埋設物を中心軸とする円筒
状の分布をすることから、水平方向磁場の極大値をつら
ねた線または垂直磁場のθ値表をっらねた線を埋設位置
とし、深度は、水平方向磁場の減衰が最大値の２０％に
なる２点間の距離で測定する。Figures 1 (a) and (b) show the planar magnetic field distribution on the ground when current is passed through a buried object whose coating has not deteriorated relatively. In this case, the buried object is linear, extends in the X-axis direction, and exists at y=om. (a) is an isomagnetic field curve representation of the magnetic field in the horizontal direction to the ground, and (b) is an isomagnetic field curve representation of the magnetic field in the vertical direction. Calculating the position and depth of a buried object from these distributions has been conventionally done using various methods.For example, since the magnetic field has a cylindrical distribution with the buried object as the central axis, The burial position is a line that connects the maximum value of the magnetic field or a line that connects the θ value table of the vertical magnetic field, and the depth is measured as the distance between the two points where the attenuation of the horizontal magnetic field is 20% of the maximum value. .
このようにして位置と深度を算出し、磁場強度と深度か
ら埋設物に流れる電流値を計算すると第１図（Ｃ）
のようになる。この場合には、埋設物に流れる電流の減
衰は流入点から３０ｍ離れたところでも小さい、したが
って、被覆の劣化は少ないと判定できる。If the position and depth are calculated in this way, and the value of the current flowing through the buried object is calculated from the magnetic field strength and depth, Figure 1 (C)
become that way. In this case, the attenuation of the current flowing through the buried object is small even at a distance of 30 m from the inflow point, so it can be determined that there is little deterioration of the coating.
一方、第１図（ｄ）、（ｅ）に示した平面磁場分布では
被覆劣化が比較的大きく、磁場分布から算出した電流値
は、第１図（ｆ） に示すように大きく減衰している
。On the other hand, in the planar magnetic field distributions shown in Figure 1(d) and (e), the coating deterioration is relatively large, and the current value calculated from the magnetic field distribution is greatly attenuated as shown in Figure 1(f). .
以上の判定方法を実現させるための具体的な装置例を第
２図に示す。A specific example of an apparatus for realizing the above determination method is shown in FIG.
第２図（ａ）は判定装置の外観図で、３コの磁気センサ
３を組み込んだ筐体５を掃引用取手５ａによって手動で
埋設物ｌに沿って掃引するようになっている。掃引した
距離は筐体５を支えるタイヤ部分に取り付けられた掃引
エンコーダ４で検知するものである。同図（ｂ）は、判
定装置のブロック図である。３コの磁気センサ３からマ
ルチプレクサ６に入力された磁場信号は、Ａ／Ｄ変換器
を通してＣＰＵ８に取り込まれる。一方、掃引エンコー
ダ４を通してカウンタ７でカウントされた掃引位置情報
もＣＰＵ８に取り込まれる。ＣＰＵ８では前述のような
演算を行って表示器９やプリンタ１０に結果を出力する
。FIG. 2(a) is an external view of the determination device, in which a housing 5 incorporating three magnetic sensors 3 is manually swept along a buried object 1 using a sweeping handle 5a. The swept distance is detected by a sweep encoder 4 attached to a tire portion that supports the housing 5. FIG. 2B is a block diagram of the determination device. Magnetic field signals input from the three magnetic sensors 3 to the multiplexer 6 are taken into the CPU 8 through the A/D converter. On the other hand, the sweep position information counted by the counter 7 through the sweep encoder 4 is also taken into the CPU 8. The CPU 8 performs the calculations described above and outputs the results to the display 9 and printer 10.
本実施例の構成では、埋設物に沿って手動で判定装置を
掃引するだけで、リアルタイムでＣＰＵ８が演算を行い
、埋設物ｌに流れる電流を表示し、被覆の劣化を判定す
ることができる。従来技術の電位法のように接地棒を何
ケ所も打ち込む必要がないため舗装した道路の上でも手
軽に測定が可能である。In the configuration of this embodiment, simply by manually sweeping the determination device along the buried object, the CPU 8 performs calculations in real time, displays the current flowing through the buried object l, and determines the deterioration of the coating. Unlike the conventional potential method, there is no need to drive ground rods into multiple locations, so measurements can be easily made even on paved roads.
［発明の効果］
本発明は以上のように埋設物に電流を通じ、この埋設物
から発生する磁場を地上で平面分布として測定し、その
分布から埋設位置と深度を計算し、更に磁場の強度から
埋設物に流れる電流を計算して埋設物の劣化場所、劣化
の大小を判定するようにしたので、判定作業を容易にか
つ短時間に行なうことができると共に広範囲な場所に適
用して行なうことができる。[Effects of the Invention] As described above, the present invention passes current through a buried object, measures the magnetic field generated from the buried object as a planar distribution on the ground, calculates the buried position and depth from the distribution, and further calculates the buried position and depth from the strength of the magnetic field. Since the current flowing through the buried object is calculated to determine the location of deterioration of the buried object and the magnitude of the deterioration, the determination work can be done easily and in a short time, and it can be applied to a wide range of locations. can.
又、本発明判定方法に使用される装置はセンサとこのセ
ンサを搭載した掃引手段とＣＰＵで構成されるため、全
体は小型化され、その取り扱いは非常に手軽にできる。Further, since the device used in the determination method of the present invention is composed of a sensor, a sweeping means equipped with the sensor, and a CPU, the device as a whole is miniaturized and can be handled very easily.
第１図は本発明判定方法において測定された磁場分布及
び電流値の分布の説明図にして、（ａ）〜（Ｃ）は被覆
劣化の少ない例であり、（ｄ）〜（ｆ）は劣化の大きい
例である。 （ａ） 、 （ｄ）は地面に水平な方向の
磁場分布の等磁場曲線分布、（ｂ） 、 （ｅ）は垂直
な方向の磁場分布の等磁場曲線分布である。 （ｃ）
、 ＣＦ）は埋設管に流れる電流値の分布図である。
第２図は本発明装置の実施例を示し、（ａ）は装置の外
観図、（ｂ）はブロック図である。第３図は従来の測定
方法の原理説明図である０図中、１は埋設物、２は地面
、３は磁気センサ、４は掃引エンコーダ、５は筐体、５
ａは掃引用取手、６はマルチプレクサ、７はカウンタ、
８はＣＰＵ、９は表示器、ｌＯはプリンタ、１１はアー
ス棒、１２は電流源、１３は送信電流、１４は流れ電流
、１５は電位差計である。
膿 〜
（Ｖｔ１１）隣肩卑
咳
＞ １
第１図
（ｅ）
ｙ （ｍ）
（ｆ）
第２図
（ａ）Figure 1 is an explanatory diagram of the magnetic field distribution and current value distribution measured in the determination method of the present invention, in which (a) to (C) are examples with little coating deterioration, and (d) to (f) are examples of coating deterioration. This is a great example. (a) and (d) are isomagnetic field curve distributions of the magnetic field distribution in the horizontal direction to the ground, and (b) and (e) are the isomagnetic field curve distributions of the magnetic field distribution in the vertical direction. (c)
, CF) is a distribution diagram of the current value flowing through the buried pipe. FIG. 2 shows an embodiment of the apparatus of the present invention, in which (a) is an external view of the apparatus and (b) is a block diagram. Figure 3 is a diagram explaining the principle of the conventional measurement method. In Figure 0, 1 is a buried object, 2 is the ground, 3 is a magnetic sensor, 4 is a sweep encoder, 5 is a housing,
a is a sweep handle, 6 is a multiplexer, 7 is a counter,
8 is a CPU, 9 is a display, IO is a printer, 11 is a grounding rod, 12 is a current source, 13 is a transmission current, 14 is a flowing current, and 15 is a potentiometer. Pus ~ (Vt11) Neighbor shoulder cough > 1 Figure 1 (e) y (m) (f) Figure 2 (a)
Claims (2)
通じ、物体から発生する磁場を地上で平面分布として測
定し、その分布から埋設深度を計算し、さらに、その強
度から埋設物に流れる電流を計算して、埋設物に流れる
電流の減衰量から、減衰量が大きいと被覆劣化が大きい
と判定し、減衰量が小さいと被覆劣化が小さいと判定す
ることを特徴とした埋設物の被覆劣化の判定方法。(1) A current is passed through an electrically conductive object buried underground, the magnetic field generated by the object is measured as a planar distribution on the ground, the burial depth is calculated from that distribution, and the strength of the buried object is measured. A buried object characterized by calculating the flowing current and determining from the amount of attenuation of the current flowing through the buried object that if the amount of attenuation is large, the coating deterioration is large, and if the amount of attenuation is small, it is judged that the coating deterioration is small. Method for determining coating deterioration.
とそれらの信号出力をＣＰＵに取り込む手段と、前記磁
気センサ配列を埋設物に沿って掃引する手段と、掃引し
た距離をＣＰＵに取り込む手段と、取り込んだ磁場分布
データから埋設物に流れる電流を計算する手段と、計算
した結果を表示する手段と、から構成されることを特徴
とした埋設物の被覆劣化の判定装置。(2) A means for capturing three or more magnetic sensors arranged in a straight line and their signal outputs into a CPU, a means for sweeping the magnetic sensor array along the buried object, and a means for capturing the swept distance into the CPU. A device for determining coating deterioration of a buried object, comprising: a means for calculating a current flowing through the buried object from captured magnetic field distribution data; and a means for displaying the calculated result.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61200417A JPS6355448A (en) | 1986-08-26 | 1986-08-26 | Method and device for deciding deterioration of covering of buried object |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61200417A JPS6355448A (en) | 1986-08-26 | 1986-08-26 | Method and device for deciding deterioration of covering of buried object |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS6355448A true JPS6355448A (en) | 1988-03-09 |
Family
ID=16423968
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP61200417A Pending JPS6355448A (en) | 1986-08-26 | 1986-08-26 | Method and device for deciding deterioration of covering of buried object |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6355448A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2004045143A (en) * | 2002-07-10 | 2004-02-12 | Kansai Electric Power Co Inc:The | Nondestructive inspection method and nondestructive inspection apparatus by superconducting quantum interference device |
| US7099145B2 (en) | 2002-06-18 | 2006-08-29 | Tdk Corporation | Solid electrolytic capacitor and method for manufacturing solid electrolytic capacitor |
| JP2012053000A (en) * | 2010-09-03 | 2012-03-15 | Pulstec Industrial Co Ltd | Current distribution measurement device |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS56140276A (en) * | 1980-04-02 | 1981-11-02 | Nippon Telegr & Teleph Corp <Ntt> | Measuring device of buried position of underground cable |
| JPS58168954A (en) * | 1982-03-17 | 1983-10-05 | ブリテイツシユ・ガス・コ−ポレ−シヨン | Device for measuring defect of insulating film |
-
1986
- 1986-08-26 JP JP61200417A patent/JPS6355448A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS56140276A (en) * | 1980-04-02 | 1981-11-02 | Nippon Telegr & Teleph Corp <Ntt> | Measuring device of buried position of underground cable |
| JPS58168954A (en) * | 1982-03-17 | 1983-10-05 | ブリテイツシユ・ガス・コ−ポレ−シヨン | Device for measuring defect of insulating film |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7099145B2 (en) | 2002-06-18 | 2006-08-29 | Tdk Corporation | Solid electrolytic capacitor and method for manufacturing solid electrolytic capacitor |
| JP2004045143A (en) * | 2002-07-10 | 2004-02-12 | Kansai Electric Power Co Inc:The | Nondestructive inspection method and nondestructive inspection apparatus by superconducting quantum interference device |
| JP2012053000A (en) * | 2010-09-03 | 2012-03-15 | Pulstec Industrial Co Ltd | Current distribution measurement device |
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