JP2812688B2 - Measuring method of thickness of coated object - Google Patents
Measuring method of thickness of coated objectInfo
- Publication number
- JP2812688B2 JP2812688B2 JP26064388A JP26064388A JP2812688B2 JP 2812688 B2 JP2812688 B2 JP 2812688B2 JP 26064388 A JP26064388 A JP 26064388A JP 26064388 A JP26064388 A JP 26064388A JP 2812688 B2 JP2812688 B2 JP 2812688B2
- Authority
- JP
- Japan
- Prior art keywords
- reflected wave
- signal
- thickness
- ultrasonic
- surface reflected
- 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
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- Length Measuring Devices Characterised By Use Of Acoustic Means (AREA)
Description
【発明の詳細な説明】 ［産業上の利用分野］ 本発明は、コーティングが施された被測定物の真の厚
さをコーティング上から測定するための厚さ測定方法に
関するものである。Description: FIELD OF THE INVENTION The present invention relates to a thickness measuring method for measuring the true thickness of a coated object from above the coating.
［従来の技術］ コーティングが施された鋼板等の被測定物の厚さを測
定する場合、コーティングを剥がした後に適当な厚さ測
定装置を用いて測定するのが一般的な方法である。しか
しながら、コーティングの除去及び再塗装は非常に手間
のかかる作業であるために、被測定物をコーティング付
きのままで測定できる手段が従来から色々と考えられて
いる。[Prior Art] When measuring the thickness of an object to be measured such as a coated steel plate, it is a general method to measure the thickness using a suitable thickness measuring device after peeling off the coating. However, since the removal and repainting of the coating are extremely troublesome operations, various means for measuring the object to be measured with the coating still applied have been conventionally considered.
例えば第５図に示す厚さ測定装置は超音波パルスの反
射を利用して被測定物の厚さを測定するものであり、コ
ーティング付被測定物１に密着される超音波探触子２
と、超音波探触子２からの信号により厚さを測定する厚
さ測定器３とから成っている。この装置に用いられる超
音波探触子２はいわゆる分割形と呼ばれるものであり、
円筒形のケース４内に互いに並設された超音波パルスの
送信部材５と受信部材６を有している。送信部材５と受
信部材６との間には、送信部材５から超音波パルスが受
信部材６に直接伝播しないように、音響仕切板７が設け
られており、これはケース４の開口面まで延びている。
また、ケース４内には遅延材８が充填されている。この
ような超音波探触子２は、その端面をコーティング付被
測定物１の表面に密着させることにより用いられ、送信
部材５から超音波パルスを発すると、該パルスはコーテ
ィング９と被測定物10との境界面、及び被測定物10の底
面にて反射され、これらの反射波が受信部材６により受
信され、その受信信号が厚さ測定器３に送られる。そし
て、この境界面反射波及び底面反射波の信号を利用して
厚さ測定器３内でこれらの受信時刻の差により板厚を算
出しようとするものである。For example, the thickness measuring apparatus shown in FIG. 5 measures the thickness of an object to be measured by using the reflection of an ultrasonic pulse, and the ultrasonic probe 2 which is in close contact with the object to be coated 1 having a coating.
And a thickness measuring device 3 for measuring a thickness by a signal from the ultrasonic probe 2. The ultrasonic probe 2 used in this device is a so-called split type,
An ultrasonic pulse transmitting member 5 and an ultrasonic pulse transmitting member 6 are provided side by side in a cylindrical case 4. An acoustic partition plate 7 is provided between the transmitting member 5 and the receiving member 6 so that the ultrasonic pulse does not directly propagate from the transmitting member 5 to the receiving member 6, and extends to the opening surface of the case 4. ing.
The case 4 is filled with a delay material 8. Such an ultrasonic probe 2 is used by bringing its end face into close contact with the surface of the object to be coated 1, and when an ultrasonic pulse is emitted from the transmitting member 5, the pulse is applied to the coating 9 and the object to be measured. The reflected wave is reflected by the boundary surface with the object 10 and the bottom surface of the device under test 10, and these reflected waves are received by the receiving member 6, and the received signal is sent to the thickness measuring device 3. Then, using the signals of the boundary surface reflected wave and the bottom surface reflected wave, the thickness is to be calculated in the thickness measuring device 3 based on the difference between these reception times.
また、別の方法としては、底面反射波の多重反射波を
利用するいわゆるB1−B2方式がある。このB1−B2方式
は、第６図に示すように、最初に被測定物10の底面で反
射された底面反射波（第１底面反射波）と、第１底面反
射波の一部がコーティング９と被測定物10との境界面を
透過せずに反射され再び被測定物10の底面で反射された
底面反射波（第２底面反射波）との受信部材６による受
信時刻の差を測定することにより板厚を求める方法でで
ある。Further, as another method, there is a so-called B 1 -B 2 system using a multiple reflection wave of the bottom surface reflection wave. In the B 1 -B 2 method, as shown in FIG. 6, a bottom surface reflected wave (first bottom surface reflected wave) first reflected on the bottom surface of the device under test 10 and a part of the first bottom surface reflected wave are used. The difference between the time of reception by the receiving member 6 and the bottom surface reflected wave (second bottom surface reflected wave) that is reflected without passing through the boundary surface between the coating 9 and the DUT 10 and is reflected again on the bottom surface of the DUT 10 This is a method of obtaining the plate thickness by measuring.
［発明が解決しようとする問題点］ しかしながら、前述した従来の厚さ測定方法には以下
に示す問題点がある。[Problems to be Solved by the Invention] However, the conventional thickness measurement method described above has the following problems.
まず、境界面及び底面の反射波を利用する方法におい
ては、境界面反射波の信号を取り出す場合に、超音波端
触子２の音響仕切板７がコーティング付被測定物１の表
面に接しているので、境界面反射波の大部分が音響仕切
板７により遮られ、送信部材５の方に反射される。従っ
て、境界面反射波は受信部材６に僅かしか伝わらず、そ
の受信レベルは低くなり、測定誤差が生じやすいという
問題点がある。即ち、境界面反射波の信号を取り出すた
めには大幅な増幅が必要とされ、増幅による誤差を無視
できなくなる場合がある。First, in the method using the reflected waves at the boundary surface and the bottom surface, when extracting the signal of the boundary surface reflected wave, the acoustic partition plate 7 of the ultrasonic end contactor 2 comes into contact with the surface of the coated DUT 1. Therefore, most of the boundary surface reflected wave is blocked by the acoustic partition plate 7 and reflected toward the transmitting member 5. Therefore, there is a problem that the reflected wave from the boundary surface is transmitted to the receiving member 6 only slightly, and the receiving level is low, and a measurement error easily occurs. That is, in order to extract the signal of the interface reflected wave, a large amplification is required, and an error due to the amplification may not be ignored.
また、コーティング９の表面からの表面反射波も極く
僅かであるが、受信部材６に伝わり、受信される。境界
面反射波の信号を増幅した場合、この表面反射波の信号
も無視できないものとなる。特に、コーティングが薄い
場合には、表面反射波と境界面反射波の信号の受信時刻
の差が小さくなるため、表面反射波と境界面反射波の信
号の境界が不明瞭となり、表面反射波の信号のみを確実
に取り出すことは難しく、被測定物10の真の厚さを正確
に求めることは困難であった。The surface reflected wave from the surface of the coating 9 is transmitted to the receiving member 6 and received, though very slight. When the signal of the interface reflected wave is amplified, the signal of the surface reflected wave is not negligible. In particular, when the coating is thin, the difference between the reception time of the signal of the surface reflected wave and that of the signal of the interface reflected wave becomes small, so that the boundary between the signal of the surface reflected wave and the signal of the interface reflected wave becomes unclear, and It was difficult to reliably extract only the signal, and it was difficult to accurately determine the true thickness of the DUT 10.
他方、B1−B2方式では、上述した如き境界面反射波の
取出しに伴う問題は生じないが、第７図のようにコーテ
ィング付被測定物１の底面に腐食部11が存在する場合に
は、条件によっては受信部材６から出力される信号に腐
食部11の反射波による信号f1、その多重反射波f2、及び
底面反射波信号B1が混在し、これらを区別することがで
きず、被測定物10の厚さを正確に測定することが不可能
となる。On the other hand, in the B 1 -B 2 system, the problem associated with the extraction of the reflected wave at the boundary surface as described above does not occur, but when the corroded portion 11 is present on the bottom surface of the coated DUT 1 as shown in FIG. According to the condition, the signal f 1 due to the reflected wave of the corroded portion 11, the multiple reflected wave f 2 , and the bottom surface reflected wave signal B 1 are mixed in the signal output from the receiving member 6, and these can be distinguished. Therefore, it is impossible to accurately measure the thickness of the device under test 10.
従って、本発明の目的はかかる問題点を解決すること
にある。Therefore, an object of the present invention is to solve such a problem.
［課題を解決するための手段］ 前記目的を達成するために、本発明は、コーティング
付被測定物に向けて超音波探触子の送信部材から超音波
パルスを発し、その反射波を受信部材により受信し、受
信信号のうちからコーティングと被測定物の境界面から
の境界面反射波と底面からの底面反射波の信号を取り出
し、これらの信号の時刻差により厚さを算出するコーテ
ィング付被測定物の厚さ測定方法において、超音波パル
スの送信及び受信が可能な第１の部材と少なくとも超音
波パルスの受信が可能な第２の部材とを音響仕切板を隔
てて並設した超音波探触子を用い、前記第１の部材から
超音波パルスを発し、この第１の部材により受信される
反射波の信号から境界面反射波の信号を取り出し、前記
第２の部材により受信される反射波の信号から底面反射
波の信号を取り出すものである。Means for Solving the Problems In order to achieve the above object, the present invention provides an ultrasonic probe which emits an ultrasonic pulse from a transmitting member of an ultrasonic probe toward an object to be coated and receives a reflected wave from the transmitting member. The signal of the interface reflected wave from the interface between the coating and the object to be measured and the signal of the bottom surface reflected wave from the bottom surface are extracted from the received signals, and the thickness of the coated surface is calculated based on the time difference between these signals. In the method for measuring the thickness of a measured object, an ultrasonic wave in which a first member capable of transmitting and receiving an ultrasonic pulse and at least a second member capable of receiving an ultrasonic pulse are arranged side by side with an acoustic partition plate interposed therebetween Using a probe, an ultrasonic pulse is emitted from the first member, a signal of a boundary surface reflected wave is extracted from a signal of a reflected wave received by the first member, and is received by the second member. Is it a reflected wave signal The signal of the bottom surface reflected wave is taken out from this.
［作用］ 本発明では、境界面反射波については第１の部材で受
信し、底面反射波については第２の部材で受信すること
としている。したがって、境界面反射波は、音響仕切板
により遮られるので、第２の部材には殆ど伝わらず、そ
の大部分が第１の部材に戻るため、第１の部材により受
信された境界面反射波の受信レベルは高レベルとなる。[Operation] In the present invention, the first member receives the reflected wave on the boundary surface, and the second member receives the reflected wave on the bottom surface. Therefore, since the interface reflected wave is blocked by the acoustic partition plate, it is hardly transmitted to the second member, and most of the wave returns to the first member, so that the interface reflected wave received by the first member is received. Becomes high level.
また、超音波探触子の第１の部材から超音波パルスを
発すると、コーティング表面で表面反射波を生じ、この
表面反射波も第１の部材で受信されるが、この表面反射
波は、被測定物の真の厚さ測定には関与しないので、境
界面反射波と区別される必要がある。本発明では、表面
反射波も、境界面反射波と同様に、音響仕切板により遮
られることなく、第２の部材で受信するより高レベルで
受信されるので、表面反射波による信号と境界面反射波
による信号は明瞭に現れ、境界面反射波の信号は表面反
射波の信号と確実に区別して取り出すことができる。When an ultrasonic pulse is emitted from the first member of the ultrasonic probe, a surface reflected wave is generated on the coating surface, and the surface reflected wave is also received by the first member. Since it is not involved in the measurement of the true thickness of the device under test, it must be distinguished from the interface reflected wave. In the present invention, the surface reflected wave is also received at a higher level than that received by the second member without being blocked by the acoustic partition plate, similarly to the boundary surface reflected wave. The signal due to the reflected wave clearly appears, and the signal of the boundary surface reflected wave can be reliably distinguished and taken out from the signal of the surface reflected wave.
［実施例］ 以下、図面と共に本発明の好適な実施例について詳細
に説明するが、図中、同一又は相当部分には同一符号を
用いることとする。[Embodiment] Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding portions are denoted by the same reference characters.
図面の第１図は本発明の測定方法を実施するための装
置の一例を示している。符号２は従来一般に用いられて
いる分割形の超音波探触子であり、超音波パルスを発す
る送信部材（第１の部材）５と、受信を行う受信部材
（第２の部材）６とがケース４内に並設され、両者間に
は音響仕切板７が配置されている。通常、これらの部材
5,6は振動子と呼ばれるものから成り、送信及び受信の
両方の機能を有している。本発明では、送信部材５にお
いて超音波パルスの送信と受信を行うように回路構成が
なされている。尚、以下の説明では、送信部材を送受信
部材と称する。また、符号20は超音波探触子２に接続さ
れた厚さ測定器である。FIG. 1 of the drawings shows an example of an apparatus for carrying out the measuring method of the present invention. Reference numeral 2 denotes a split-type ultrasonic probe generally used in the related art, in which a transmitting member (first member) 5 for emitting an ultrasonic pulse and a receiving member (second member) 6 for receiving are provided. An acoustic partition plate 7 is arranged in the case 4 between them. Usually these components
Reference numerals 5 and 6 each include what is called a vibrator, and have functions of both transmission and reception. In the present invention, a circuit is configured so that the transmitting member 5 transmits and receives an ultrasonic pulse. In the following description, the transmitting member is referred to as a transmitting / receiving member. Reference numeral 20 denotes a thickness measuring device connected to the ultrasonic probe 2.
かかる装置を用いてコーティング付被測定物１の厚さ
を測定する場合、まず、コーティング９の表面にグリセ
リン等の接触媒質を塗布し超音波探触子２の開口面を密
着させる。When measuring the thickness of the coated object 1 using such an apparatus, first, a couplant such as glycerin is applied to the surface of the coating 9 and the opening surface of the ultrasonic probe 2 is brought into close contact.
超音波探触子２の送受信部材５は厚さ測定器20の超音
波パルス発生器21に接続されており、この超音波パルス
発生器21は原発振器22からの一定周期の矩形パルスを受
けることにより超音波パルス発生信号を発し、送受信部
材５から一定の周期で超音波パルスを送信させる。送受
信部材５から発せられた超音波パルスの一部は、まず、
コーティング９の表面で反射される。この表面反射波
は、音響仕切板７により遮られ受信部材６には殆ど伝播
されず、主に送受信部材５により受信される。また、コ
ーティング９を通過した超音波パルスの一部は、コーテ
ィング９と被測定物10との境界面で反射され、この境界
面反射波の大部分が表面反射波と同様に送受信部材５で
受信される。表面反射波及び境界面反射波を受信した送
受信部材５からの信号は厚さ測定器20の表面反射波ア
ンプ23に送られる（第２図）。表面反射波アンプ23に
おいて、オートゲインコントロール24によりオートゲイ
ンコントロール電圧（本実施例では負の一定電圧）が信
号に加えられ、第２図に示すように適当なレベルに
調整される。次いで、この調整された信号は境界面反
射波セレクタ25に入力される。境界面反射波セレクタ25
では、コーティング９の厚さに応じて第２図の如く予
め設定されたゲート信号をセレクタゲート回路26から
受け、表面反射波及び境界面反射波に対応する信号が
出力される（第２図）。そして、レベル設定回路27
で、レベル設定値（第２図）を越える信号、即ち境界
面反射波に対応する信号のみが取り出され、この信号
に基づいて板厚測定のための計時スタート信号がス
タート信号発生回路28で形成される（第２図，）。The transmitting / receiving member 5 of the ultrasonic probe 2 is connected to the ultrasonic pulse generator 21 of the thickness measuring device 20, and the ultrasonic pulse generator 21 receives a rectangular pulse of a constant period from the original oscillator 22. , An ultrasonic pulse generation signal is generated, and an ultrasonic pulse is transmitted from the transmitting / receiving member 5 at a constant cycle. Part of the ultrasonic pulse emitted from the transmitting / receiving member 5 firstly
It is reflected on the surface of the coating 9. This surface reflected wave is blocked by the acoustic partition plate 7 and hardly propagates to the receiving member 6, and is mainly received by the transmitting / receiving member 5. A part of the ultrasonic pulse that has passed through the coating 9 is reflected at the interface between the coating 9 and the device under test 10, and most of the interface reflected wave is received by the transmitting / receiving member 5 in the same manner as the surface reflected wave. Is done. The signal from the transmitting / receiving member 5 receiving the surface reflected wave and the boundary surface reflected wave is sent to the surface reflected wave amplifier 23 of the thickness measuring device 20 (FIG. 2). In the surface reflected wave amplifier 23, an auto gain control voltage (a negative constant voltage in this embodiment) is applied to the signal by the auto gain control 24, and the signal is adjusted to an appropriate level as shown in FIG. Next, the adjusted signal is input to the interface reflected wave selector 25. Interface reflected wave selector 25
Then, a gate signal preset according to the thickness of the coating 9 as shown in FIG. 2 is received from the selector gate circuit 26, and signals corresponding to the surface reflected wave and the boundary surface reflected wave are output (FIG. 2). . Then, the level setting circuit 27
Then, only the signal exceeding the level set value (FIG. 2), that is, the signal corresponding to the reflected wave at the boundary surface is taken out, and based on this signal, the time signal start signal for measuring the thickness is formed by the start signal generating circuit 28. (FIG. 2).
また、送受信部材５から発せされた超音波パルスの他
の部分は、コーティング９及び被測定物10を伝播して被
測定物10の底面で反射し、その底面反射波は受信部材６
により受信される。この受信信号は厚さ測定器20の底
面反射波アンプ29を通り、オートゲインコントロール30
により調整された後、底面反射波セレクタ31に入力され
る（第２図，）。次いで、信号は底面反射波セレ
クタ31においてセレクタゲート回路32からのゲート信号
により信号に変換され（第２図，）、レベル設
定回路33にてレベル設定値（第２図）に基づき底面反
射波に対応する信号が取り出される（第２図）。こ
の後、信号はストップ信号発生回路34で計時ストップ
信号として出力される（第２図）。Another part of the ultrasonic pulse emitted from the transmitting / receiving member 5 propagates through the coating 9 and the device under test 10 and is reflected at the bottom surface of the device under test 10.
Is received by This received signal passes through the bottom-surface reflected wave amplifier 29 of the thickness measuring device 20 and the auto gain control 30
After being adjusted by (1), it is input to the bottom surface reflected wave selector 31 (FIG. 2,). Next, the signal is converted into a signal by the gate signal from the selector gate circuit 32 in the bottom surface reflected wave selector 31 (FIG. 2), and converted into a bottom surface reflected wave by the level setting circuit 33 based on the level set value (FIG. 2). The corresponding signal is extracted (FIG. 2). Thereafter, the signal is output by the stop signal generation circuit 34 as a timing stop signal (FIG. 2).
計時スタート信号と計時ストップ信号はフリップ
フロップ回路35に入力され、フリップフロップ回路35か
らは、第２図から理解されるように境界面反射波の受
信時刻から底面反射波の受信時刻までの時間に相当する
信号が出力される。これを計時・演算回路36で計時す
ると共に、被測定物10中の超音波の伝播速度に基づいて
演算処理することで、被測定物10の真の厚さが算出さ
れ、その値が測定値表示部37に表示される。The clock start signal and the clock stop signal are input to the flip-flop circuit 35, and the flip-flop circuit 35 outputs the time from the reception time of the boundary surface reflected wave to the reception time of the bottom surface reflected wave as understood from FIG. A corresponding signal is output. This is timed by a time-measurement / arithmetic circuit 36, and by calculating based on the propagation speed of the ultrasonic wave in the measured object 10, the true thickness of the measured object 10 is calculated. It is displayed on the display unit 37.
第３図は広帯域特性を有する超音波探触子を用いて本
発明による厚さ測定を行った場合における送受信部材５
での受信信号と受信部材６での受信信号の波形を示すオ
シロスコープの写真である。ここで、広帯域超音波探触
子とは、反射波のピーク数が４程度までのもので、反射
波の周波数スペクトルの帯域幅が広い探触子をいう。ま
た、第４図は、第３図と同条件で狭帯域超音波探触子を
用いた場合のオシロスコープの写真である。第３図及び
第４図を比較して分かるように、前者は表面反射波と境
界面反射波の分解能は良いが、底面反射波の応答出力の
電圧が小さく、大きな増幅を必要としているのに対し、
後者の狭帯域超音波探触子は表面反射波と境界面反射波
の分解能が悪く、底面反射波の応答出力が大きいという
特性がある。いずれの超音波探触子を用いても本発明は
実施可能であるが、それぞれ一長一短があるので、境界
面反射波と表面反射波の分解能が良好で且つ底面反射波
の大幅な増幅を不要とするためには、超音波探触子２
は、送受信部材５とその背面側のダンパー40は広帯域特
性を有するものとし、受信部材６とその背面側のダンパ
ー41は狭帯域特性を有するものとするのが好適である。FIG. 3 shows a transmitting / receiving member 5 when the thickness measurement according to the present invention is performed using an ultrasonic probe having a wide band characteristic.
6 is a photograph of an oscilloscope showing waveforms of a received signal at the receiving member and a receiving signal at the receiving member 6. Here, the broadband ultrasonic probe refers to a probe having a peak number of a reflected wave up to about 4 and having a wide bandwidth of a frequency spectrum of the reflected wave. FIG. 4 is a photograph of an oscilloscope when a narrow-band ultrasonic probe is used under the same conditions as in FIG. As can be seen by comparing FIGS. 3 and 4, the former has a good resolution of the surface reflected wave and the boundary surface reflected wave, but has a small response output voltage of the bottom surface reflected wave and requires a large amplification. On the other hand,
The latter narrow band ultrasonic probe has a characteristic that the resolution of the surface reflected wave and the boundary surface reflected wave is poor, and the response output of the bottom surface reflected wave is large. The present invention can be carried out using any of the ultrasonic probes, but each has advantages and disadvantages, so that the resolution of the boundary surface reflected wave and the surface reflected wave is good, and it is not necessary to greatly amplify the bottom surface reflected wave. To do this, use the ultrasonic probe 2
It is preferable that the transmitting / receiving member 5 and the damper 40 on the rear side have a wide band characteristic, and the receiving member 6 and the damper 41 on the rear side have a narrow band characteristic.
以上のように、本発明の方法によれば、分解形超音波
探触子の送信側の第１の部材により境界面反射波を受信
することとしたので、境界面反射波の受信レベルは高
く、その信号を確実に取り出すことができる。したがっ
て、境界面反射波と底面反射波とから、コーティングを
含まない被測定物の真の厚さを正確に測定することがで
きる。また、B1−B2方式でみられるような被測定物の腐
食による測定誤差も生じ得ない。さらに、従来において
は、受信部材で受信される各種反射波の信号を分離して
取り出すために、コーティング、被測定物および遅延材
の厚さや、それぞれの超音波伝播速度等に応じて超音波
探触子の種類を選ぶ必要があったが、本発明の方法によ
れば、境界面反射波を第１の部材で受信し、底面反射波
を第２の部材（受信部材）で受信することとしたので、
信号の取り出しが容易化され、１種類の超音波探触子で
多種の被測定物に対応することが可能である。As described above, according to the method of the present invention, the interface-reflected wave is received by the first member on the transmitting side of the decomposed ultrasonic probe, so that the reception level of the interface-reflected wave is high. , The signal can be reliably taken out. Therefore, the true thickness of the object not including the coating can be accurately measured from the boundary surface reflected wave and the bottom surface reflected wave. In addition, a measurement error due to corrosion of an object to be measured as seen in the B 1 -B 2 method cannot occur. Furthermore, conventionally, in order to separate and extract various reflected wave signals received by the receiving member, an ultrasonic probe is used in accordance with the thickness of the coating, the object to be measured, and the delay member, and the ultrasonic propagation speed of each. According to the method of the present invention, it is necessary to select the type of the stylus. However, according to the method of the present invention, the first member receives the boundary surface reflected wave and the second member (the receiving member) receives the bottom surface reflected wave. Because
Signal extraction is facilitated, and one type of ultrasonic probe can cope with various types of objects to be measured.
［発明の効果］ 本発明の方法によれば、超音波パルスの送信及び受信
が可能な第１の部材と少なくとも超音波パルスの受信が
可能な第２の部材とを音響仕切板を隔てて並設した超音
波探触子を用い、前記第１の部材から超音波パルスを発
し、この第１の部材により受信される反射波の信号から
境界面反射波の信号を取り出し、前記第２の部材により
受信される反射波の信号から底面反射波の信号を取り出
すので、境界面反射波の受信レベルが高く、表面反射波
とも容易に区別することができるので、境界面反射波の
信号を確実に取り出すことができる。したがって、境界
面反射波と底面反射波とから、コーティングを含まない
被測定物の真の厚さを正確に測定することができる。According to the method of the present invention, a first member capable of transmitting and receiving ultrasonic pulses and a second member capable of receiving at least ultrasonic pulses are arranged side by side with an acoustic partition plate interposed therebetween. Using the ultrasonic probe provided, an ultrasonic pulse is emitted from the first member, a signal of a boundary surface reflected wave is extracted from a signal of a reflected wave received by the first member, and the second member is Since the signal of the bottom surface reflected wave is extracted from the signal of the reflected wave received by the device, the reception level of the boundary surface reflected wave is high, and it can be easily distinguished from the surface reflected wave. Can be taken out. Therefore, the true thickness of the object not including the coating can be accurately measured from the boundary surface reflected wave and the bottom surface reflected wave.
第１図は本発明による厚さ測定方法を実施するための厚
さ測定装置の一例を示す概略説明図、第２図は第１図に
おける各出力信号の波形を示す波形説明図、第３図は広
帯域特性を有する超音波探触子を用いた場合における送
受信部材と受信部材での受信信号の波形を示すオシロス
コープの写真、第４図は狭帯域特性を有する超音波探触
子を用いた場合における送受信部材と受信部材での受信
信号の波形を示すオシロスコープの写真、第５図は従来
一般の厚さ測定装置を示す概略説明図、第６図及び第７
図はB1−B2方式による厚さ測定を示す概略説明図であ
る。図中、 １……コーティング付被測定物 ２……超音波探触子、3,20……厚さ測定器 ５……送受信部材（第１の部材） ６……受信部材（第２の部材） ９……コーティング、10……被測定物FIG. 1 is a schematic explanatory view showing an example of a thickness measuring apparatus for carrying out the thickness measuring method according to the present invention, FIG. 2 is a waveform explanatory view showing the waveform of each output signal in FIG. 1, and FIG. Is a photograph of an oscilloscope showing the waveforms of the signals received and transmitted by the transmitting and receiving members and the receiving member when an ultrasonic probe having a wide band characteristic is used, and FIG. 4 is a case where an ultrasonic probe having a narrow band characteristic is used. FIG. 5 is a photograph of an oscilloscope showing waveforms of received signals at a transmitting / receiving member and a receiving member in FIG. 5, FIG. 5 is a schematic explanatory view showing a conventional general thickness measuring apparatus, and FIGS.
The figure is a schematic explanatory view showing thickness measurement by the B 1 -B 2 method. In the drawing, 1 ... the object to be coated 2 ... the ultrasonic probe, 3,20 ... the thickness measuring device 5 ... the transmitting / receiving member (first member) 6 ... the receiving member (second member) 9) Coating, 10 ... DUT
Claims (1)
触子の送信部材から超音波パルスを発し、その反射波を
受信部材により受信し、受信信号のうちからコーティン
グと被測定物の境界面からの境界面反射波と底面からの
底面反射波の信号を取り出し、これらの信号の時刻差に
より厚さを算出するコーティング付被測定物の厚さ測定
方法において、超音波パルスの送信及び受信が可能な第
１の部材と少なくとも超音波パルスの受信が可能な第２
の部材とを音響仕切板を隔てて並設した超音波探触子を
用い、前記第１の部材から超音波パルスを発し、この第
１の部材により受信される反射波の信号から境界面反射
波の信号を取り出し、前記第２の部材により受信される
反射波の信号から底面反射波の信号を取り出すことを特
徴とするコーティング付被測定物の厚さ測定方法。An ultrasonic pulse is emitted from a transmitting member of an ultrasonic probe toward an object to be coated with a coating, and a reflected wave is received by a receiving member. Transmission and reception of ultrasonic pulses in a method of measuring the thickness of an object to be coated, in which a signal of a boundary surface reflected wave from a surface and a signal of a bottom surface reflected wave from a bottom surface are taken out and a thickness is calculated based on a time difference between these signals. And a second member capable of receiving at least an ultrasonic pulse
An ultrasonic pulse is emitted from the first member using an ultrasonic probe in which the members are arranged side by side with an acoustic partition plate interposed therebetween, and an interface reflection is performed based on a signal of a reflected wave received by the first member. A method of measuring a thickness of a coated object to be measured, wherein a signal of a wave is extracted, and a signal of a bottom surface reflected wave is extracted from a signal of a reflected wave received by the second member.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP26064388A JP2812688B2 (en) | 1988-10-18 | 1988-10-18 | Measuring method of thickness of coated object |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP26064388A JP2812688B2 (en) | 1988-10-18 | 1988-10-18 | Measuring method of thickness of coated object |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH02108908A JPH02108908A (en) | 1990-04-20 |
| JP2812688B2 true JP2812688B2 (en) | 1998-10-22 |
Family
ID=17350768
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP26064388A Expired - Lifetime JP2812688B2 (en) | 1988-10-18 | 1988-10-18 | Measuring method of thickness of coated object |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2812688B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5271274A (en) * | 1991-08-14 | 1993-12-21 | The Board Of Trustees Of The Leland Stanford Junior University | Thin film process monitoring techniques using acoustic waves |
-
1988
- 1988-10-18 JP JP26064388A patent/JP2812688B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH02108908A (en) | 1990-04-20 |
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