JPH0894457A - In-pipe pressure calculation method based on magnetstrictive measurement - Google Patents

In-pipe pressure calculation method based on magnetstrictive measurement

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Publication number
JPH0894457A
JPH0894457A JP22533794A JP22533794A JPH0894457A JP H0894457 A JPH0894457 A JP H0894457A JP 22533794 A JP22533794 A JP 22533794A JP 22533794 A JP22533794 A JP 22533794A JP H0894457 A JPH0894457 A JP H0894457A
Authority
JP
Japan
Prior art keywords
pipe
sensor
magnetostrictive
pressure
magnetostrictive sensor
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
Application number
JP22533794A
Other languages
Japanese (ja)
Inventor
Kenji Shimizu
謙司 清水
Yasuo Ogawa
安雄 小川
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Osaka Gas Co Ltd
Original Assignee
Osaka Gas Co Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Osaka Gas Co Ltd filed Critical Osaka Gas Co Ltd
Priority to JP22533794A priority Critical patent/JPH0894457A/en
Publication of JPH0894457A publication Critical patent/JPH0894457A/en
Pending legal-status Critical Current

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Abstract

PURPOSE: To easily determine that a pipe is stationary from the outside of the pipe by turning the detecting direction of a magnetostrictive sensor mounted on the outer circumferential surface of the pipe. CONSTITUTION: A magnetostrictive sensor 2 is mounted on the outer surface of a pipe 6 to be measured. The sensor 2 can be displaced by 180 deg. or more through a drive means 3. Output signal from the sensor 2 is delivered to a processing circuit 4a in a control means 4. The control means 4 processes the received signal and presents the results on a display means and controls the drive means 3 on the other hand. In such apparatus 1, the detecting direction of the sensor 2 is turned by 180 deg. or more around a normal to the outer circumferential surface of the pipe 6 and an amplitude B is determined based on the output from the sensor 2. Subsequently, the pressure P of fluid flowing through the pipe is calculated according to a formula; P=2tB/MD, where B represents the amplitude, D represents the inner diameter of the pipe, (t) represents the thickness of plate and M represents magnetostrictive sensitivity. Pressure in the pipe can be measured and calculated easily at any point of the pipe 6, and the stationary state of the pipe and the magnitude of inner pressure can be determined easily in a short time.

Description

【発明の詳細な説明】Detailed Description of the Invention

【0001】[0001]

【産業上の利用分野】本発明は、管内圧力のある流体を
輸送する鋼管など、磁性材料で作られた管の生死確認の
ために好適に用いられる管内圧力算出方法に関する。
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pipe pressure calculation method suitably used for confirming the life and death of a pipe made of a magnetic material such as a steel pipe for transporting a fluid having a pipe pressure.

【0002】[0002]

【従来の技術】ガス管または水道管などの流体を輸送す
る輸送管の補修作業などを行う際には、作業対象として
いる管が確かに流体の輸送に使われる管であるか否かを
判断する生死確認作業が行われる。
2. Description of the Related Art When repairing a transportation pipe for transporting a fluid such as a gas pipe or a water pipe, it is determined whether or not the pipe to be worked is certainly a pipe used for transporting the fluid. Confirmation work is done.

【0003】前述の生死確認作業は、たとえば、地中に
埋設されている輸送管の補修作業を行う場合は、作業前
に目的の輸送管の周囲を広幅に掘削して他の輸送管と目
的の輸送管との位置関係を確認する方法、またはロケー
タ2点法などの確認法を用いて行っている。さらにま
た、前記方法を用いても輸送管の生死が不明な場合は、
穿孔して確認しなければならないこともある。
For example, when repairing a transportation pipe buried in the ground, the above-mentioned life-and-death confirmation work is performed by excavating a wide area around the intended transportation pipe before the work and another transportation pipe. This is done by using the confirmation method such as the method of confirming the positional relationship with the transportation pipe or the two-point locator method. Furthermore, if the life or death of the transport tube is unknown using the above method,
Sometimes it is necessary to perforate and confirm.

【0004】[0004]

【発明が解決しようとする課題】前述した管の生死確認
作業では、たとえば埋設管では、目的の管の周囲を補修
作業などの本来行うべき作業に必要な範囲以上に広く掘
削する必要があるなど、作業の負担が大きく、また作業
時間も長時間必要とする。
In the above-mentioned pipe life-and-death confirmation work, for example, in the case of a buried pipe, it is necessary to excavate the periphery of the target pipe wider than the range necessary for the original work such as repair work. However, the work load is heavy and the work time is long.

【0005】ガスまたは水道水などの流体は、輸送のた
めそれぞれ特定の管内圧力を与えられている。その圧力
を測定することができれば、管の生死を判定することが
可能である。しかしながら、埋設管などにおいて、管の
任意の箇所を通過する流体の圧力を管外部から測定する
ことは困難である。
Fluids such as gas or tap water are each given a specific pipe pressure for transportation. If the pressure can be measured, it is possible to determine the life or death of the tube. However, in a buried pipe or the like, it is difficult to measure the pressure of the fluid passing through any part of the pipe from outside the pipe.

【0006】本発明の目的は、管外部から管の生死を容
易に確認可能な管内圧力算出方法を提供することであ
る。
[0006] An object of the present invention is to provide a method for calculating the pressure inside a pipe which enables easy confirmation of the life or death of the pipe from the outside of the pipe.

【0007】[0007]

【課題を解決するための手段】本発明は、管の外周面上
に磁歪センサを配置し、磁歪センサの磁歪検出方向を、
外周面の法線方向を軸として180°以上回転させ、磁
歪センサからの出力の振幅値Bを求め、管の内径D、板
厚tおよび磁歪感度Mを用いて、管内の流体の圧力Pを
According to the present invention, a magnetostrictive sensor is arranged on the outer peripheral surface of a tube, and the magnetostrictive detection direction of the magnetostrictive sensor is
By rotating the outer peripheral surface by 180 ° or more about the normal direction, the amplitude value B of the output from the magnetostrictive sensor is obtained, and the pressure P of the fluid in the pipe is calculated by using the inner diameter D of the pipe, the plate thickness t and the magnetostriction sensitivity M.

【0008】[0008]

【数2】 [Equation 2]

【0009】として算出することを特徴とする磁歪測定
による管内圧力算出方法である。
A method for calculating the pressure inside the tube by magnetostriction measurement, characterized in that

【0010】[0010]

【作用】本発明に従えば、管の外周面上に磁歪センサを
配置し、磁歪センサの磁歪検出方向を、外周面の法線方
向を軸として180°以上回転させて、磁歪センサから
の出力の振幅値Bを求める。また、前記振幅値B、管の
内径D、板厚tおよび磁歪感度Mを用いて、管内の流体
の圧力Pを
According to the present invention, the magnetostrictive sensor is arranged on the outer peripheral surface of the tube, and the magnetostrictive detection direction of the magnetostrictive sensor is rotated by 180 ° or more about the normal line direction of the outer peripheral surface to output from the magnetostrictive sensor. The amplitude value B of is calculated. Further, using the amplitude value B, the inner diameter D of the tube, the plate thickness t, and the magnetostriction sensitivity M, the pressure P of the fluid in the tube is

【0011】[0011]

【数3】 [Equation 3]

【0012】として算出するので、管の任意の箇所で管
内圧力を容易に測定・算出することができる。
Since it is calculated as, it is possible to easily measure and calculate the pressure inside the pipe at an arbitrary position of the pipe.

【0013】[0013]

【実施例】一般に、内径Dで板厚がtである管などの円
筒に内圧Pを作用させるとき、管壁には周方向に応力σ
が生じる。前記応力σの分布は、管に曲げなどの変形が
発生していなければ周方向のみの1軸応力場と考えら
れ、その大きさは内圧Pに比例し、PD/2tと表され
る。
EXAMPLES Generally, when an internal pressure P is applied to a cylinder such as a tube having an inner diameter D and a plate thickness t, a stress σ is applied to the tube wall in the circumferential direction.
Occurs. The distribution of the stress σ is considered to be a uniaxial stress field in only the circumferential direction unless deformation such as bending occurs in the pipe, and its magnitude is proportional to the internal pressure P and is represented by PD / 2t.

【0014】鋼管など磁性材料を用いて作られた管に作
用する応力σの方向および大きさを測定する方法として
磁歪応力測定法がある。磁歪応力測定法は、磁性材料に
応力または荷重による力などの力が作用すると磁性材料
の透磁性に異方性が生じ、たとえば磁化するとその方向
に伸びが生じるような磁性材料では、引張応力が作用す
る方向の透磁率が大小いずれか一方に変化し、反対に圧
縮応力の作用する方向の透磁率が大小いずれか他方に変
化して、力の作用する方向と作用しない方向の透磁率に
差が生じる現象を利用して応力の方向および大きさを測
定する方法である。
There is a magnetostrictive stress measuring method as a method for measuring the direction and magnitude of the stress σ acting on a pipe made of a magnetic material such as a steel pipe. The magnetostrictive stress measurement method is such that when a force such as a stress or a force due to a load acts on a magnetic material, anisotropy occurs in magnetic permeability of the magnetic material. The magnetic permeability in the acting direction changes to either one of the large and small, and the magnetic permeability in the direction in which the compressive stress acts changes to the other in the large or small to the difference between the magnetic permeability in the direction in which the force acts and the magnetic permeability in the direction in which the force does not act. Is a method of measuring the direction and magnitude of stress by utilizing the phenomenon that occurs.

【0015】図1は、本発明の一実施例の管内圧力算出
装置1によって管内圧力を測定する状態を示す斜視図で
ある。管内圧力算出装置1は、磁歪センサ2と、駆動手
段3と、制御手段4と、表示手段5とを含む。
FIG. 1 is a perspective view showing a state in which a pipe pressure is measured by a pipe pressure calculating device 1 according to an embodiment of the present invention. The in-pipe pressure calculation device 1 includes a magnetostrictive sensor 2, a driving unit 3, a control unit 4, and a display unit 5.

【0016】測定対象となる管の外側表面に、磁歪セン
サ2が設置される。磁歪センサ2は、駆動手段3によっ
て設置された1点で少なくとも180°以上角変位する
ことができる。磁歪センサ2の信号は、制御手段4内の
処理回路4aに入力される。また、制御手段4には、メ
モリ4bが備えられる。制御手段4は、入力された信号
を処理して表示手段5に表示し、また駆動手段3を制御
する。
The magnetostrictive sensor 2 is installed on the outer surface of the pipe to be measured. The magnetostrictive sensor 2 can be angularly displaced by at least 180 ° or more at one point installed by the driving means 3. The signal from the magnetostrictive sensor 2 is input to the processing circuit 4a in the control means 4. Further, the control means 4 is provided with a memory 4b. The control means 4 processes the input signal, displays it on the display means 5, and controls the drive means 3.

【0017】図2は、図1の磁歪センサ2の簡略化した
斜視図および平面図である。磁歪センサ2は、第1コア
7、励磁コイル8、交流電源9、第2コア10、検出コ
イル11および電圧測定手段12を備える。第1コア7
は逆U字状に形成され、励磁コイル8が巻回される。励
磁コイル8には交流電源9が接続されて、交流電源9か
ら出力される電圧によって励磁コイル8が励磁される。
第2コア10は逆U字状に形成され、検出コイル11が
巻回される。検出コイル11には、電圧計などで実現さ
れる電圧検出手段12が接続される。第1コア7の一対
の磁極7a,7bと、第2コア10の一対の磁極10
a,10bの各中心は、仮想上の正方形の各頂点位置に
あり、前記磁極7a,7bを結ぶ直線7cと、前記磁極
10a,10bを結ぶ直線10cとは直交し、前記正方
形の対角線に一致する。
FIG. 2 is a simplified perspective view and plan view of the magnetostrictive sensor 2 of FIG. The magnetostrictive sensor 2 includes a first core 7, an exciting coil 8, an AC power supply 9, a second core 10, a detecting coil 11 and a voltage measuring means 12. First core 7
Is formed in an inverted U shape and the exciting coil 8 is wound. An alternating current power supply 9 is connected to the exciting coil 8, and the exciting coil 8 is excited by the voltage output from the alternating current power supply 9.
The second core 10 is formed in an inverted U shape, and the detection coil 11 is wound around it. The detection coil 11 is connected to voltage detection means 12 realized by a voltmeter or the like. The pair of magnetic poles 7a and 7b of the first core 7 and the pair of magnetic poles 10 of the second core 10.
The centers of a and 10b are located at the vertices of a virtual square, and the straight line 7c connecting the magnetic poles 7a and 7b and the straight line 10c connecting the magnetic poles 10a and 10b are orthogonal to each other and coincide with the diagonal line of the square. To do.

【0018】磁歪センサ2では、第1コア7の磁極7
a,7bは第2コア10の磁極10a,10bと等距離
にある。たとえば管6の管周方向に応力σが発生してい
ない状態では、管周方向および管軸方向の透磁率は等し
い。ゆえに励磁コイル8が交流電源9から出力される電
圧によって励磁されているとき、磁極7aから磁極10
aに入る磁束と、磁極7aから磁極10bに入る磁束と
が等しい。したがって、検出コイル11に誘導される電
流はお互いに打消され、誘導起電力は生じない。また、
管6の管周方向に応力σが作用すると、管6の管軸方向
と管周方向との各透磁率が異なるため、前記両方向の磁
気抵抗に差が生じる。このため、磁極10aに入る磁束
の量と磁極10bに入る磁束の量とに差が生じて検出コ
イル11に電流が流れ、誘導起電力が生じる。この誘導
起電力が電圧検出手段12で検出され、磁歪センサ2の
出力電圧Vとして出力される。前記出力電圧Vは、管周
方向の応力σ2と管軸方向の応力σ1との差、および磁
歪感度Mに比例し、M(σ2−σ1)と表される。仮に
応力が管周方向にのみ作用しているとする場合には、管
軸方向を基準として管外周表面上の1点で磁歪センサ2
を角変位させると、磁極10a方向と磁極10b方向の
磁気抵抗は管軸方向の基準6aと磁歪センサ2との角度
θに応じて変化し、出力電圧Vはcos2θに従って変
動する。
In the magnetostrictive sensor 2, the magnetic pole 7 of the first core 7 is
a and 7b are equidistant from the magnetic poles 10a and 10b of the second core 10. For example, in the state where no stress σ is generated in the tube circumferential direction of the tube 6, the magnetic permeability in the tube circumferential direction is equal to that in the tube axial direction. Therefore, when the exciting coil 8 is excited by the voltage output from the AC power supply 9, the magnetic poles 7a to 10
The magnetic flux entering a is equal to the magnetic flux entering from the magnetic pole 7a to the magnetic pole 10b. Therefore, the currents induced in the detection coil 11 cancel each other out, and no induced electromotive force is generated. Also,
When the stress σ acts in the tube circumferential direction of the tube 6, the magnetic permeability in the tube axial direction of the tube 6 is different from that in the tube circumferential direction, so that a difference occurs in the magnetic resistance in both directions. Therefore, a difference occurs between the amount of magnetic flux entering the magnetic pole 10a and the amount of magnetic flux entering the magnetic pole 10b, and a current flows through the detection coil 11 to generate an induced electromotive force. This induced electromotive force is detected by the voltage detection means 12 and output as the output voltage V of the magnetostrictive sensor 2. The output voltage V is proportional to the difference between the stress σ2 in the tube circumferential direction and the stress σ1 in the tube axis direction, and the magnetostriction sensitivity M, and is represented by M (σ2-σ1). If the stress is acting only in the pipe circumferential direction, the magnetostrictive sensor 2 at one point on the pipe outer peripheral surface with the pipe axial direction as a reference.
Is angularly displaced, the magnetic resistances in the magnetic pole 10a direction and the magnetic pole 10b direction change according to the angle θ between the reference 6a in the tube axis direction and the magnetostrictive sensor 2, and the output voltage V changes according to cos 2θ.

【0019】図3は、本発明を用いた管内圧力算出の動
作を示すフローチャートである。ステップn1では、磁
歪センサ2の角変位量の基準を管軸方向が0°となるよ
うに設定し、また磁歪感度M、管の内径Dおよび板厚t
を入力する初期設定を行う。磁歪感度Mは、管と同一材
質のテストピースなどを用いて、予め測定しておく。ま
た、内径Dおよび板厚tは、予めメモリ4bに記憶さ
せ、必要に応じてメモリから読込むようにしてもよい。
ステップn2では、角変位量θを0にリセットする。ス
テップn3では、磁歪センサ2の励磁コイル8を交流電
源9から出力される電流によって励磁させ、検出コイル
11に接続されている電圧検出手段12で検出した出力
電圧Vθ を処理回路4aに入力する。ステップn4で
は、予め設定されている微小角変位量Δθだけ磁歪セン
サ2を角変位させる。ステップn5では、角変位量θに
微小角変位量Δθを加算して更新する。ステップn6で
は、前記角変位量θが予め定められた一定値θc以上で
あるか否かを判断し、そうであるときはステップn7に
進み、そうでないときはステップn3に戻る。前記一定
値θcは、管軸方向を基準である0°として、少なくと
も180°以上に設定される。これによって、微小角変
位量Δθ毎に出力電圧Vθ を検出することができる。
FIG. 3 is a flow chart showing the operation of calculating the pipe internal pressure according to the present invention. In step n1, the reference of the angular displacement amount of the magnetostrictive sensor 2 is set so that the tube axis direction is 0 °, and the magnetostrictive sensitivity M, the tube inner diameter D and the plate thickness t are set.
Enter the initial settings. The magnetostriction sensitivity M is measured in advance using a test piece made of the same material as the tube. The inner diameter D and the plate thickness t may be stored in the memory 4b in advance and read from the memory as needed.
At step n2, the angular displacement amount θ is reset to zero. In step n3, the exciting coil 8 of the magnetostrictive sensor 2 is excited by the current output from the AC power supply 9, and the output voltage V θ detected by the voltage detecting means 12 connected to the detecting coil 11 is input to the processing circuit 4a. . At step n4, the magnetostrictive sensor 2 is angularly displaced by a preset minute angular displacement amount Δθ. At step n5, the small angular displacement amount Δθ is added to the angular displacement amount θ to update the value. In step n6, it is determined whether or not the amount of angular displacement θ is equal to or greater than a predetermined constant value θc, and if so, the process proceeds to step n7, and if not, the process returns to step n3. The constant value θc is set to at least 180 ° or more with 0 ° being the pipe axis direction as a reference. As a result, the output voltage V θ can be detected for each minute angular displacement amount Δθ.

【0020】ステップn7では、図4の×で示す磁歪セ
ンサ2の出力電圧 Vθ(θ=1〜θc)に基づいて、
最小2乗法などを用いて次式で示される余弦波形で近似
した関数を求める。これによって、前記出力電圧Vθ
の各点での誤差が平均化され、振幅値Bをより正しい値
として求めることができる。
[0020] At step n7, based on the output voltage V of the magnetostrictive sensor 2 shown in × in FIG. 4 θ = 1~θc),
A function approximated by the cosine waveform shown by the following equation is obtained by using the least square method or the like. Accordingly, the output voltage V θ
The errors at the respective points are averaged, and the amplitude value B can be obtained as a more correct value.

【0021】 Vθ = A + B cos2θ …(1) 上述の式で示される関数は、図4の実線で示される。ス
テップn8では、前述の関数の振幅値Bから内圧Pが求
められる。前述したように、検出コイル11の誘導起電
力である磁歪センサ2の出力電圧Vは、応力σに比例す
る。曲げなどの変形が管に生じておらず、管軸方向の応
力が作用していないものとすると、センサ2の角変位量
がθであるとき、前記出力電圧Vθ は次式のように表
すことができる。
V θ = A + B cos2θ (1) The function shown by the above equation is shown by the solid line in FIG. At step n8, the internal pressure P is obtained from the amplitude value B of the above-mentioned function. As described above, the output voltage V of the magnetostrictive sensor 2, which is the induced electromotive force of the detection coil 11, is proportional to the stress σ. Assuming that no deformation such as bending has occurred in the pipe and no stress is applied in the pipe axial direction, when the angular displacement amount of the sensor 2 is θ, the output voltage V θ is expressed by the following equation. be able to.

【0022】 Vθ = M(0−σ cos2θ) …(2) カッコ内の第2項は、管に作用する全応力中の管周方向
の応力による成分にあたり、前記応力σは前述したよう
にPD/2tと表されるので、前述の式は次のように表
すことができる。
V θ = M (0−σ cos 2 θ ) (2) The second term in the parentheses is the component due to the stress in the pipe circumferential direction in the total stress acting on the pipe, and the stress σ is as described above. Since it is expressed as PD / 2t, the above equation can be expressed as follows.

【0023】[0023]

【数4】 [Equation 4]

【0024】上式および式(1)から、振幅値Bと内圧
Pとの関係が求められる。ゆえに、内圧PはP=2tB
/MDと表され、式(1)の振幅値Bから求めることが
できる。ステップn9では、算出した内圧Pを表示画面
に表示して処理を終了する。
From the above equation and equation (1), the relationship between the amplitude value B and the internal pressure P can be obtained. Therefore, the internal pressure P is P = 2tB
/ MD, which can be obtained from the amplitude value B of the equation (1). In step n9, the calculated internal pressure P is displayed on the display screen, and the process ends.

【0025】[0025]

【発明の効果】以上のように本発明によれば、管の外周
面上に磁歪センサを配置し、磁歪センサの磁歪検出方向
を、外周面の法線方向を軸として180°以上回転さ
せ、磁歪センサからの出力の振幅値Bを求める。前記振
幅値Bと、管の内径D、板厚tおよび磁歪感度Mを用い
て、管内の流体の圧力PをP=2tB/MDとして算出
するので、管の任意の箇所で管内圧力を容易に測定する
ことができる。これによって、管補修作業時などにおけ
る作業対象の管の生死確認、または管内圧力の大きさの
確認などを容易に、かつ、短時間に行うことができるた
め、作業時間および作業コストを低減することができ
る。
As described above, according to the present invention, the magnetostrictive sensor is arranged on the outer peripheral surface of the tube, and the magnetostrictive detection direction of the magnetostrictive sensor is rotated by 180 ° or more about the normal line direction of the outer peripheral surface as an axis. The amplitude value B of the output from the magnetostrictive sensor is obtained. Since the pressure P of the fluid in the pipe is calculated as P = 2tB / MD by using the amplitude value B, the inner diameter D of the pipe, the plate thickness t, and the magnetostriction sensitivity M, it is possible to easily calculate the pressure inside the pipe at any position of the pipe. Can be measured. As a result, it is possible to easily check whether the pipe to be worked is alive or dead or to check the magnitude of the pressure inside the pipe during pipe repair work, etc., easily and in a short time, thus reducing work time and work cost. You can

【図面の簡単な説明】[Brief description of drawings]

【図1】本発明の一実施例の管内圧力算出装置1の斜視
図である。
FIG. 1 is a perspective view of a pipe pressure calculation device 1 according to an embodiment of the present invention.

【図2】図1の磁歪センサ2の斜視図および平面図であ
る。
FIG. 2 is a perspective view and a plan view of the magnetostrictive sensor 2 of FIG.

【図3】本発明を用いた管内圧力算出の動作を示すフロ
ーチャートである。
FIG. 3 is a flowchart showing an operation of calculating a pipe internal pressure according to the present invention.

【図4】磁歪センサ2の出力電圧と、センサ角度との関
係を示すグラフである。
FIG. 4 is a graph showing the relationship between the output voltage of the magnetostrictive sensor 2 and the sensor angle.

【符号の説明】[Explanation of symbols]

1 管内圧力算出装置 2 磁歪センサ 3 駆動手段 4 制御手段 4a 処理回路 4b メモリ 5 表示手段 6 管 7 第1コア 8 励磁コイル 9 交流電源 10 第2コア 11 検出コイル 12 電圧検出手段 1 Pipe Pressure Calculation Device 2 Magnetostrictive Sensor 3 Drive Means 4 Control Means 4a Processing Circuit 4b Memory 5 Display Means 6 Pipes 7 1st Core 8 Excitation Coil 9 AC Power Supply 10 2nd Core 11 Detection Coil 12 Voltage Detection Means

Claims (1)

【特許請求の範囲】[Claims] 【請求項1】 管の外周面上に磁歪センサを配置し、 磁歪センサの磁歪検出方向を、外周面の法線方向を軸と
して180°以上回転させ、 磁歪センサからの出力の振幅値Bを求め、 管の内径D、板厚tおよび磁歪感度Mを用いて、管内の
流体の圧力Pを 【数1】 として算出することを特徴とする磁歪測定による管内圧
力算出方法。
1. A magnetostrictive sensor is arranged on an outer peripheral surface of a tube, and a magnetostrictive detection direction of the magnetostrictive sensor is rotated by 180 ° or more about a normal direction of the outer peripheral surface, and an amplitude value B of an output from the magnetostrictive sensor is changed. The pressure P of the fluid in the pipe is calculated by using the inner diameter D of the pipe, the plate thickness t, and the magnetostriction sensitivity M. A method for calculating the pressure inside the tube by magnetostriction measurement, which is characterized by
JP22533794A 1994-09-20 1994-09-20 In-pipe pressure calculation method based on magnetstrictive measurement Pending JPH0894457A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP22533794A JPH0894457A (en) 1994-09-20 1994-09-20 In-pipe pressure calculation method based on magnetstrictive measurement

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP22533794A JPH0894457A (en) 1994-09-20 1994-09-20 In-pipe pressure calculation method based on magnetstrictive measurement

Publications (1)

Publication Number Publication Date
JPH0894457A true JPH0894457A (en) 1996-04-12

Family

ID=16827775

Family Applications (1)

Application Number Title Priority Date Filing Date
JP22533794A Pending JPH0894457A (en) 1994-09-20 1994-09-20 In-pipe pressure calculation method based on magnetstrictive measurement

Country Status (1)

Country Link
JP (1) JPH0894457A (en)

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