JP2661580B2 - Ultrasonic longitudinal wave bevel probe - Google Patents
Ultrasonic longitudinal wave bevel probeInfo
- Publication number
- JP2661580B2 JP2661580B2 JP7042749A JP4274995A JP2661580B2 JP 2661580 B2 JP2661580 B2 JP 2661580B2 JP 7042749 A JP7042749 A JP 7042749A JP 4274995 A JP4274995 A JP 4274995A JP 2661580 B2 JP2661580 B2 JP 2661580B2
- Authority
- JP
- Japan
- Prior art keywords
- ultrasonic
- wedge
- longitudinal wave
- probe
- transmission
- 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 - Lifetime
Links
Landscapes
- Investigating Or Analyzing Materials By The Use Of Ultrasonic Waves (AREA)
Description
【発明の詳細な説明】
【０００１】
【産業上の利用分野】この発明は、溶接部の欠陥検出、
角ビレット等の主に表層部の欠陥検出を行う超音波探傷
装置用の超音波縦波斜角探触子に関するものである。
【０００２】
【従来の技術】図３は例えば昭和５７年９月に発行され
た日本非破壊検査協会第２分科会資料、Ｎｏ．２９３１
「クリーピングウェーブとその応用（１）」に示されて
いる超音波縦波斜角探触子を示す図であり、図３（ａ）
は斜視図、図３（ｂ）は側面断面図、図３（ｃ）は後面
断面図である。図において、１は送信用楔、２は受信用
楔、３は送信用楔１に取付けられた送信用振動子、４は
受信用楔２に取付けられた受信用振動子、５は送信用楔
１を伝播する超音波が受信用楔２に伝播するのを防ぐ遮
音板、６はコネクタ、７はケース、θ1 は送信用楔１に
設けられた超音波入射角度、θ2 は受信用楔２に設けら
れた超音波受信角度である。
【０００３】従来の超音波縦波斜角探触子は図３に示す
ように送信用振動子３と受信用振動子４を各々１枚有
し、送信用振動子３と受信用振動子４が超音波の伝播方
向に対して左右方向で、かつ前後方向にはズレがないよ
うに配置されている。このような超音波探触子で縦波を
被検材に斜めに伝播させて超音波縦波斜角探触子を配置
した面の表層部を超音波探傷する場合には被検材中の超
音波屈折角を約７０〜７５゜程度にする必要がある。こ
の様子を図４に示した。
【０００４】図４は、斜角探傷法の幾何学図である。図
において、１は楔、３は振動子、８は被検材、Ａは振動
子３の実際の寸法、Ｂは振動子３の見掛け上の寸法、Ｓ
は被検材８の表面、θ1 は被検材８の表面Ｓと直交する
法線Ｙ−Ｙ´に対する超音波の入射角度、θS は被検材
８の表面Ｓと直交する法線Ｙ−Ｙ´に対する超音波の屈
折角度、θは超音波の指向角度である。
【０００５】ここで屈折角度θS を仮に７５゜に設定し
た場合の楔１中の入射角度は、スネルの法則により下記
値となる。
θ1 ＝ｓｉｎ-1（ｓｉｎ７５゜×Ｃ1 ／Ｃ2 ）
≒２６．７゜ ・・・・・（１）
但し、
Ｃ1 ＝２．７４８ｋｍ／Ｓ（楔の縦波音速）
Ｃ2 ＝５．９ｋｍ／Ｓ（被検材の縦波音速）
また、被検材８の中の超音波の指向角は下式により求めることができる。
θ＝Ｋ×λ／Ｂ ・・・・・（２）
但し、Ｂ＝Ａ×ｃｏｓθS ／ｃｏｓθ1 ・・・・・（３）
つまり、このような超音波縦波斜角探触子では上記
（２），（３）式から明らかなように、屈折角度θS と
入射角度θ1 の差が大きいために大きな指向角度θが得
られ、被検材８の表層部からある程度の深部までの広範
囲を検査することが可能となる利点があるので、しばし
ば使用される。
【０００６】
【発明が解決しようとする課題】しかし、この従来の縦
波斜角探触子においては、探触子を配置した面の表層部
（例えば３〜１０ｍｍ程度）での欠陥検出能は、探触子
と欠陥の位置関係が比較的近い場合（例えば２０〜３０
ｍｍ程度）には良いが、遠くなるほど表面に近い欠陥の
検出能は低下する欠点を有することになる。すなわち、
探触子と欠陥との相対位置が遠くなるほど、超音波の指
向角範囲の大きな角度成分が必要となるが、８０゜を超
えると縦波の臨界角に近づくために楔と鋼の境界面にお
ける超音波の往復通過率が急激に低下し、欠陥検出能の
低下をまねくことになる。
【０００７】この発明は、従来の欠点を改善する目的で
なされたもので、探触子を配置した面の表層部の広範囲
にわたって欠陥検出能を十分確保できる超音波縦波斜角
探触子を提案することを目的とする。
【０００８】
【課題を解決するための手段】この発明に係る超音波縦
波斜角探触子は、超音波の伝播方向に対して前後関係の
位置で前方には送信用楔を前後に複数並べ、後方には受
信用楔を配置し、かつ上記複数の送信用楔及び受信用楔
の被検材と当接する面の反対面にそれぞれ送信用振動子
と受信用振動子を具備したものである。
【０００９】また、この発明に係る超音波縦波斜角探触
子は、超音波の伝播方向に対して前後関係の位置で前方
には送信用楔を前後に２個並べ、後方には１個の受信用
楔を配置し、かつ上記２個の送信用楔及び１個の受信用
楔の被検材と当接する面の反対面にそれぞれ送信用振動
子と受信用振動子を具備したものである。
【００１０】【作用】 この発明は、送信用振動子を前後に複数個並
べ、複数個配列された上記送信用振動子の最後方に受信
用振動子を配置することにより被検材の表層部の広範囲
に わたって欠陥検出能が確保できる。
【００１１】また、この発明は、送信用振動子を前後に
２個並べ、２個配列された上記送信用振動子の最後方に
１個の受信用振動子を配置することにより被検材の表層
部の広範囲にわたって欠陥検出能が確保できる。
【００１２】【実施例】実施例１． 図１は、この発明の一実施例を示す超音波縦波斜角探触
子の断面図である。 図１において、１は超音波の伝播方
向に対し、前後に複数個（図１では２個）並べられた送
信用楔、２は複数個並べられた送信用楔１の最後方に配
置された１個の受信用楔、３は上記送信用楔１の被検材
と当接する面の反対面にそれぞれ設けられた送信用振動
子、４は上記受信用楔１の被検材と当接する面の反対面
に設けられた受信用振動子、５は遮音板、６はコネク
タ、７はケースである。 図２はこの発明による超音波縦
波斜角探触子の鋼中での超音波ビームの概念図である。
図において、３は送信用振動子、４は受信用振動子、９
は受信用振動子３から放射される縦波超音波、１０は送
信用振動子３から放射される横波超音波、１１は受信用
振動子４で受信する縦波超音波、１２は受信用振動子４
で受信する横波超音波、θ T は超音波の送信角度、θ R
は超音波の受信角度である。
【００１３】上記のように超音波の伝播方向に対して前
後関係の位置で前方には送信用振動子３を前後に複数個
（図１，２の実施例では２個）並べ、後方には受信用振
動子４（実施例では１個の受信用振動子）を配置した構
成の超音波縦波斜角探触子において、複数個の送信用振
動子３を受信用振動子４の前方部に配置すると、受信用
振動子４より前方にある欠陥を検出する場合には必ず超
音波の送信角度θ T が受信角度θ R に対して小さくな
る。その結果、送信用楔１から被検材８への超音波の入
射効率が向上し、送信角度θ T と受信角度θ R が同一な
場合に比べて縦波超音波９の往復通過率が向上すること
になる。特にこの特性は受信用振動子４と 欠陥との相対
位置が遠くて、かつ送信用振動子３を配置した被検材８
表面に近い欠陥ほど顕著な差として現れ、欠陥信号を大
きなレベルで検出できる。
【００１４】また、縦波斜角探触子の特徴として次の次
の利点を備える。すなわち送信用振動子３のほぼ直下に
存在する欠陥に対しては横波超音波１０が有効に作用
し、これも欠陥信号を大きなレベルで検出できることに
なり、大幅にＳ／Ｎ比を向上させることが可能となる。
【００１５】この発明による超音波縦波斜角探触子は超
音波の伝播方向に対して平行な方向に探触子または、試
験体を走査しない探傷方式、すなわち自動探傷装置用と
してかなり有効性を示すものである。
【００１６】なお、超音波の伝播方向に対して前後関係
の位置に振動子を配置している探触子として実開昭５２
−１１５２７２号公報、特開昭５６−６７７５０号公報
及び特開昭５４−１４１１８８号公報に示されたものが
あるが、これらは、この発明のように超音波の伝播方向
に対して前後関係の位置で前方には送信用振動子を前後
に複数個並べ、後方には受信用振動子を配置することに
より被検材表層部の広範囲にわたって高いＳ／Ｎ比を確
保できるものではない。
【００１７】【発明の効果】 この発明は、超音波の伝播方向に対して
前後関係の位置で前方には送信用振動子を前後に複数個
並べ、後方には受信用振動子を配置することにより被検
材表層部の広範囲にわたって高いＳ／Ｎ比を確保するこ
とができる。
【００１８】また、この発明は、超音波の伝播方向に対
して前後関係の位置で前方には送信用振動子を前後に２
個並べ、後方には１個の受信用振動子を配置することに
より上記同様の効果を有する。 Description: BACKGROUND OF THE INVENTION 1. Field of the Invention
The present invention relates to an ultrasonic longitudinal wave oblique probe for an ultrasonic flaw detector which mainly detects a surface layer portion defect such as a square billet. 2. Description of the Related Art FIG. 3 is a document of No. 2 of the Japan Non-Destructive Inspection Association, No. 2, published in September 1982, for example. 2931
Is a diagram showing a "creeping wave and its Applications (1)" shown in ultrasonic longitudinal wave angle probe, FIGS. 3 (a)
Is a perspective view, FIG. 3 (b) is a side sectional view, FIG. 3 (c) is a rear cross-sectional view. In the figure, 1 is a transmission wedge, 2 is a reception wedge, 3 is a transmission vibrator attached to the transmission wedge 1, 4 is a reception vibrator attached to the reception wedge 2, and 5 is a transmission wedge. sound insulating plate ultrasound is prevented from propagating to the receiving wedge 2 propagating 1, 6 connectors 7 case, theta 1 ultrasonic incident angle provided in the transmission wedges 1, theta 2 is received wedge 2 is an ultrasonic wave receiving angle provided in the second ultrasonic wave receiving device. As shown in FIG. 3 , a conventional ultrasonic longitudinal wave oblique probe has one transmitting vibrator 3 and one receiving vibrator 4, and the transmitting vibrator 3 and the receiving vibrator 4 Are arranged in the left-right direction with respect to the propagation direction of the ultrasonic wave, and are not displaced in the front-rear direction. When ultrasonic waves are transmitted obliquely to the test material with such an ultrasonic probe and the surface layer portion of the surface on which the ultrasonic longitudinal wave oblique probe is arranged is subjected to ultrasonic flaw detection, the ultrasonic wave in the test material is used. The ultrasonic refraction angle needs to be about 70-75 °. This state is shown in FIG. FIG. 4 is a geometric diagram of the oblique flaw detection method. In the drawing, 1 is a wedge, 3 is a vibrator, 8 is a test material , A is the actual size of the vibrator 3, B is the apparent size of the vibrator 3, S
The surface of the test material 8, the ultrasonic incident angle of theta 1 with respect to the normal Y-Y'perpendicular to the surface S of the material being tested 8, theta S is normal Y which is perpendicular to the surface S of the material being tested 8 The refraction angle of the ultrasonic wave with respect to −Y ′, θ is the directivity angle of the ultrasonic wave. Here, when the refraction angle θ S is set to 75 °, the incident angle in the wedge 1 has the following value according to Snell's law. θ 1 = sin -1 (sin 75 ゜ C 1 / C 2 ) {26.7} (1) where C 1 = 2.748 km / S (longitudinal sound speed of wedge) C 2 = 5 .9 km / S (longitudinal wave sound velocity of the test material) The directivity angle of the ultrasonic wave in the test material 8 can be obtained by the following equation. θ = K × λ / B (2) where B = A × cos θ S / cos θ 1 (3) That is, in such an ultrasonic longitudinal wave oblique angle probe, As is clear from the equations (2) and (3), a large directivity angle θ is obtained due to a large difference between the refraction angle θ S and the incident angle θ 1 , and a large angle from the surface layer of the test material 8 to a certain depth is obtained. It is often used because it has the advantage of allowing a large area to be examined. [0006] However, in this conventional longitudinal wave oblique probe, the ability to detect a defect in the surface layer (for example, about 3 to 10 mm) of the surface on which the probe is arranged is low. When the positional relationship between the probe and the defect is relatively close (for example, 20 to 30).
mm), but the further the distance, the lower the ability to detect defects near the surface. That is,
As the relative position between the probe and the defects are distant, at a large angle component but is required, the wedge and the boundary surface of the steel to approach the critical angle of the longitudinal wave exceeds 80 degrees of directional angle range of the ultrasonic The reciprocation rate of the ultrasonic wave is sharply reduced, which leads to a decrease in defect detection ability. SUMMARY OF THE INVENTION The present invention has been made for the purpose of remedying the conventional disadvantage, and an ultrasonic longitudinal wave oblique angle capable of sufficiently securing defect detection capability over a wide area of a surface layer on a surface on which a probe is arranged. The purpose is to propose a probe. [0008] An ultrasonic longitudinal wave oblique probe according to the present invention has a relationship with the propagation direction of ultrasonic waves.
At the position, a plurality of transmission wedges are arranged in front and back, and
A plurality of transmitting wedges and receiving wedges for arranging credit wedges;
Transmitter transducers on the surface opposite to the surface that comes into contact with the test material
And a receiving vibrator. Also, an ultrasonic longitudinal wave oblique angle probe according to the present invention is provided.
The child is in front of and behind the propagation direction of the ultrasonic wave.
, Two transmission wedges are arranged in front and back, and one reception wedge is
Wedges are arranged, and the two transmitting wedges and one receiving wedge
Vibration for transmission on the opposite surface of the wedge that comes into contact with the test material
And a transducer for receiving. [0010] SUMMARY OF THE INVENTION This invention plurality parallel for transmission transducer back and forth
In addition, receive at the end of the above-mentioned transmitting transducers
By placing a transducer for the test, the surface
Defect detectability can be secured over. Further , according to the present invention, the transmitting vibrator can be moved back and forth.
At the end of the two transmitting transducers where two are arranged and two are arranged
By placing one receiving transducer, the surface layer of the test material
The defect detection ability can be secured over a wide range of the part. [ Embodiment 1] FIG. 1 is an ultrasonic longitudinal wave oblique angle probe showing one embodiment of the present invention.
It is sectional drawing of a child. In FIG. 1, reference numeral 1 denotes an ultrasonic wave propagation method.
A plurality of (two in FIG. 1)
The credit wedge 2 is arranged at the end of the transmission wedge 1 in which a plurality of transmission wedges are arranged.
One receiving wedge placed, 3 is the test material of the transmitting wedge 1
Transmission vibration provided on the opposite side of the surface that comes into contact with
The reference numeral 4 denotes a surface opposite to the surface of the receiving wedge 1 in contact with the test material.
, 5 is a sound insulating plate, 6 is a connector
And 7 is a case. FIG. 2 shows an ultrasonic longitudinal wave according to the present invention.
It is a conceptual diagram of the ultrasonic beam in steel of a wave angle probe.
In the figure, 3 is a transmitting oscillator, 4 is a receiving oscillator, 9
Is a longitudinal ultrasonic wave radiated from the receiving transducer 3;
Transverse ultrasonic waves radiated from the credit transducer 3, 11 for reception
Longitudinal wave ultrasonic wave received by the vibrator 4, 12 is the receiving vibrator 4
Is the shear wave ultrasonic wave received at θ T is the transmission angle of the ultrasonic wave, θ R
Is the reception angle of the ultrasonic wave. As described above, the direction of propagation of the ultrasonic wave is
A plurality of transmitting transducers 3 are arranged forward and backward in the rear relation position.
(Two in the embodiment of FIGS. 1 and 2).
Structure in which the moving element 4 (one receiving transducer in the embodiment) is arranged
In the ultrasonic longitudinal wave angle probe, the
When the moving element 3 is arranged in front of the receiving transducer 4,
When detecting a defect in front of the vibrator 4,
The transmission angle θ T of the sound wave becomes smaller than the reception angle θ R
You. As a result, the transmission of ultrasonic waves from the transmission wedge 1 to the test material 8 is performed.
The transmission angle θ T and the reception angle θ R are the same.
The reciprocation rate of longitudinal ultrasonic wave 9 is improved compared to the case
become. In particular, this characteristic indicates the relative distance between the receiving oscillator 4 and the defect.
Test material 8 that is far away and on which transmitting oscillator 3 is arranged
Defects closer to the surface show up as a noticeable difference, increasing the defect signal.
Can be detected at the optimal level. Further, the following features of the longitudinal wave oblique probe are as follows.
With the advantages of That is, almost immediately below the transmitting transducer 3
Shear wave ultrasonic wave 10 works effectively for existing defects
This also means that defect signals can be detected at a large level.
Thus, it is possible to greatly improve the S / N ratio. The ultrasonic longitudinal wave oblique probe according to the present invention is super
Set the probe or sample in a direction parallel to the sound wave
Inspection method that does not scan the specimen, that is, for automatic inspection equipment
It shows considerable effectiveness. [0016] The order of the ultrasonic wave propagation
As a probe with a transducer at the position of
-115272, JP-A-56-67750
And Japanese Patent Application Laid-Open No. 54-141188.
However, these are the propagation directions of the ultrasonic wave as in the present invention.
The transmitting oscillator is located in front of the transmitter
Are arranged in a row, and a receiving transducer is
High S / N ratio over a wide range of surface layer of test material
It cannot be maintained. [0017] [Effect of the Invention] The present invention, with respect to the propagation direction of the ultrasonic
In front of the front-back position, a plurality of transmitting transducers
The test is performed by arranging the receiving transducers
Ensure a high S / N ratio over a wide area of the surface layer
Can be. Also, the present invention relates to a method for controlling the propagation direction of ultrasonic waves.
And the transmitting transducer is placed in front of the front and back
And one receiving transducer at the back.
It has the same effect as above.
【図面の簡単な説明】
【図１】 この発明の実施例を示す超音波縦波斜角探触
子の断面図である。
【図２】 この発明における超音波ビームの概念図であ
る。
【図３】 従来の超音波縦波斜角探触子を示す斜視図と
断面図である。
【図４】 斜角探傷法の幾何学図である。
【符号の説明】
１ 送信用楔、２ 受信用楔、３ 送信用振動子、４
受信用振動子。BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an ultrasonic longitudinal wave oblique probe showing an embodiment of the present invention.
It is sectional drawing of a child . FIG. 2 is a conceptual diagram of an ultrasonic beam according to the present invention. FIG. 3 is a perspective view showing a conventional ultrasonic longitudinal wave oblique probe;
It is sectional drawing. FIG. 4 is a geometric diagram of the oblique flaw detection method. [Description of Signs] 1 wedge for transmission, 2 wedge for reception, 3 oscillator for transmission, 4
Transducer for reception.
Claims (1)
子において、超音波の伝播方向に対して前後関係の位置
で前方には送信用楔を前後に複数並べ、後方には受信用
楔を配置し、かつ上記複数の送信用楔及び受信用楔の被
検材と当接する面の反対面にそれぞれ送信用振動子と受
信用振動子を具備したことを特徴とする超音波縦波斜角
探触子。２．被検材の表層部近傍を探傷する超音波縦波斜角探触
子において、超音波の伝播方向に対して前後関係の位置
で前方には送信用楔を前後に２個並べ、後方には１個の
受信用楔を配置し、かつ上記２個の送信用楔及び１個の
受信用楔の被検材と当接する面の反対面にそれぞれ送信
用振動子と受信用振動子を具備したことを特徴とする超
音波縦波斜角探触子 。(57) [Claims] Position of the ultrasonic longitudinal wave oblique probe for flaw detection near the surface layer of the test material
In front, a plurality of transmission wedges are arranged in front and behind, and reception
A wedge is arranged, and the plurality of transmission wedges and reception wedges are covered with the wedge.
Transmitter oscillators and receivers are provided on the opposite sides of the
An ultrasonic longitudinal wave bevel probe comprising a credit oscillator . 2. Ultrasonic longitudinal wave oblique angle detection for flaw detection near the surface layer of test material
Position of the ultrasonic wave
In front, two transmission wedges are arranged in front and back, and one
A receiving wedge is arranged, and the two transmitting wedges and one
Transmission to the opposite side of the receiving wedge opposite to the surface that comes into contact with the test material
Characterized by comprising a resonator for reception and a resonator for reception
Sonic longitudinal wave bevel probe .
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7042749A JP2661580B2 (en) | 1995-03-02 | 1995-03-02 | Ultrasonic longitudinal wave bevel probe |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7042749A JP2661580B2 (en) | 1995-03-02 | 1995-03-02 | Ultrasonic longitudinal wave bevel probe |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0894595A JPH0894595A (en) | 1996-04-12 |
| JP2661580B2 true JP2661580B2 (en) | 1997-10-08 |
Family
ID=12644668
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP7042749A Expired - Lifetime JP2661580B2 (en) | 1995-03-02 | 1995-03-02 | Ultrasonic longitudinal wave bevel probe |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2661580B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP7023406B1 (en) * | 2021-09-02 | 2022-02-21 | 三菱重工パワー検査株式会社 | Ultrasonic probe and ultrasonic flaw detection method |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS54141188A (en) * | 1978-04-25 | 1979-11-02 | Hitachi Shipbuilding Eng Co | Method of ultrasonic flaw detection |
| JPS5667750A (en) * | 1979-11-08 | 1981-06-08 | Kawasaki Steel Corp | Automatic ultrasonic flaw detecting method |
| JPS59133457A (en) * | 1983-01-20 | 1984-07-31 | Mitsubishi Electric Corp | Ultrasonic flaw detector for steel plate |
| JPH0521011U (en) * | 1991-09-02 | 1993-03-19 | 日本建鐵株式会社 | Horizontal material roll prevention structure |
-
1995
- 1995-03-02 JP JP7042749A patent/JP2661580B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0894595A (en) | 1996-04-12 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP3635453B2 (en) | Ultrasonic shear wave oblique angle flaw detection method and apparatus | |
| JP2661580B2 (en) | Ultrasonic longitudinal wave bevel probe | |
| JP3140157B2 (en) | Ultrasonic flaw detection method for planar defects | |
| JP2001228126A (en) | Ultrasonic flaw detector | |
| JP4527238B2 (en) | Ultrasonic rail flaw detector | |
| JPH0521011Y2 (en) | ||
| KR101139592B1 (en) | longitudinal wave transducer wedge to maintain couplant layer and longitudinal wave transducer using the same | |
| JP2001221784A (en) | Ultrasonic angle beam probe | |
| JP7074488B2 (en) | Ultrasonic probe | |
| JP2978708B2 (en) | Composite angle beam probe | |
| JPH07260747A (en) | Ultrasonic flaw detection method and apparatus | |
| JP3176495B2 (en) | Bevel probe for ultrasonic inspection of socket weld joint | |
| JPS63186143A (en) | ultrasonic probe | |
| JP4171130B2 (en) | Ultrasonic rail flaw detector | |
| JPH11316216A (en) | Ultrasonic probe | |
| JPH10111281A (en) | Ultrasonic flaw detection method and ultrasonic probe | |
| JP2585658B2 (en) | Ultrasonic probe | |
| KR101558921B1 (en) | Dual type ultrasonic sensor for adjusting focal length | |
| JPH095304A (en) | Ultrasonic flaw detection method in welded part between straight pipe and elbow | |
| KR101558922B1 (en) | Split-type ultrasonic sensor with adjustable beam size | |
| JP3619732B2 (en) | Ultrasonic flaw detection apparatus and ultrasonic flaw detection method | |
| JPH0521502B2 (en) | ||
| JP2883051B2 (en) | Ultrasonic critical angle flaw detector | |
| JPH08220079A (en) | Ultrasonic probe | |
| JPH02208557A (en) | Array type skew probe |