JP2019015634A - Dual transducer probe, measurement detection system, and measurement detection method - Google Patents

Abstract

A two-transducer probe capable of measuring the thickness of a measurement object and detecting flaws with high accuracy by reducing the propagation of ultrasonic waves between two vibrators along the surface of the measurement object. A tactile sensor, a measurement detection system, and a measurement detection method are provided. A probe according to the present invention is a dual transducer probe having a first transducer and a second transducer, and is formed into a flexible sheet as a whole. In addition, a gap 110 is provided between the first vibrator and the second vibrator. [Selection] Figure 1

Description

  The present invention relates to a dual transducer probe having two transducers, a measurement detection system, and a measurement detection method.

  The dual transducer probe performs ultrasonic measurement, for example, for measuring the thickness of a measurement object or detecting flaws. In addition, the flaw of a measured object is a crack etc. which exist in a measured object. In the two transducer probe, transmission and reception of ultrasonic waves are performed by different transducers. Ultrasonic echoes reflected by the interface of the measured object are made incident on the measured object by the ultrasonic wave generated by the transmitting side transducer. Is received by the receiving vibrator. The interface of the object to be measured is the bottom surface of the object to be measured when the thickness measurement is performed, and is a place where the defect of the object to be measured exists when detecting the defect. Note that the thickness of the measurement object is calculated by multiplying the reception time of the ultrasonic echo received by the receiving-side transducer by the material sound velocity in the measurement object.

  For this reason, in the two transducer probe, if the ultrasonic wave generated by the transmitting transducer propagates inside the two transducer probe and is received by the receiving transducer, it is reflected at the interface of the measurement object. The accuracy of detecting the ultrasonic echo is reduced. As a countermeasure, a product is commercially available in which a partition plate is provided between two transducers to reduce reception of ultrasonic waves by the receiving transducer through the inside of the dual transducer probe. Yes.

  On the other hand, the conventional probe is mainly configured to be housed in a cylindrical casing. On the other hand, Patent Document 1 discloses a single-transducer probe. However, the ultrasonic probe is formed in a flexible sheet shape so that it can be easily brought into close contact with a subject (measurement object). The proposed technology has been proposed.

Utility Model Registration No. 3191253

  However, when the two transducer probe is formed in a sheet shape, even if a physical partition plate is provided between the two transducers, ultrasonic waves are transmitted from the transmitting side to the receiving side through the upper side or the lower side of the partition plate. Propagate. For this reason, there is a problem that the noise is large, and the accuracy of thickness measurement and flaw detection is significantly reduced.

  If a physical partition plate is provided between the two transducers, the flexibility is lost even if the two transducer probe is formed in a sheet shape. For this reason, when the measurement object has a curved surface such as a pipe, it is difficult to place the sheet-like dual transducer probe along the surface of the measurement object. As a result, an air layer is easily formed between the two transducer probe and the surface of the measurement object, the propagation of ultrasonic waves is hindered, and the accuracy of thickness measurement and flaw detection of the measurement object is lowered.

  Note that the technique described in Patent Document 1 is merely a single transducer probe formed in a flexible sheet shape, and when the two transducer probe is formed in a sheet shape, The knowledge about the point which an ultrasonic wave propagates from the transmission side to the reception side is not disclosed.

  In view of such a problem, the present invention reduces the propagation of ultrasonic waves between two vibrators along the surface of the object to be measured, so that the thickness measurement and flaw detection of the object to be measured can be performed with high accuracy. It is an object of the present invention to provide a dual transducer probe, a measurement detection system, and a measurement detection method that can be performed.

  In order to solve the above problems, a representative configuration of a two-transducer probe according to the present invention is a two-transducer probe having two transducers, which is a sheet having flexibility as a whole. And an air gap is provided between the two vibrators.

  In the above configuration, the two transducer probe is formed into a flexible sheet as a whole. In addition, since the two transducers are separated from each other by a gap rather than a physical partition plate, the overall flexibility of the two transducer probe is not impaired. For this reason, when measuring the thickness of an object to be measured or detecting flaws using ultrasonic waves, even if the object to be measured has a curved surface such as a pipe, the two-element transducer is placed along the surface of the object to be measured. Can be made. Note that the dual transducer probe only needs to be flexible enough to be along the surface of the object to be measured. Therefore, if the vibration element is small, the element itself does not need to have flexibility.

  Furthermore, in the above configuration, since the two transducers are separated by a gap, the ultrasonic wave generated by one transducer (transmitting transducer) propagates inside the two transducer probe and the other transducer It is possible to reduce reception by the vibrator (reception-side vibrator). Therefore, the receiving-side transducer can accurately detect the ultrasonic echo reflected from the interface of the measurement object. For these reasons, it is possible to provide a sheet-like two-transducer probe capable of measuring the thickness of the measurement object and detecting a flaw with high accuracy along the surface of the measurement object.

  A sound-absorbing material that connects the back surfaces may be attached to the back surfaces of the two vibrators. Here, there is a case where the ultrasonic wave generated by the transmission-side transducer is propagated from the back surface of the transmission-side transducer to the reception-side transducer. In such a case, the accuracy of thickness measurement and flaw detection of the measurement object is lowered. Therefore, in the above configuration, the back surfaces of the two vibrators are connected by a sound absorbing material. For this reason, the ultrasonic wave propagating from the first vibrator to the second vibrator can be absorbed while the positional relationship between the first vibrator and the second vibrator is kept constant. Therefore, thickness measurement and flaw detection of the measurement object can be performed with high accuracy. The sound absorbing material is preferably a material having both sound absorbing properties and flexibility. For example, a porous material such as cork, silicon sponge, sponge rubber or the like may be used.

  A front surface layer having flexibility may be attached to the front surfaces of the two vibrators. In the conventional dual transducer probe, the contact surface with the surface of the object to be measured does not have flexibility. Therefore, a liquid such as water, oil, glycerin or the like is used as a contact medium so that an air layer is not generated on the contact surface. It is necessary to apply to the surface of the measurement object. Therefore, in the above configuration, a flexible front layer is attached to the front surfaces of the two vibrators. Since the front layer has flexibility, it can be deformed following the irregularities on the surface of the object to be measured and can be brought into close contact with the irregularities on the surface. The softness refers to a property that is softer than the flexibility and has adhesiveness that follows the unevenness of the surface of the measurement object. Therefore, an air layer is not formed between the surface of the measurement object and the front layer, and propagation of ultrasonic waves is not hindered, so that measurement of the thickness of the measurement object and flaw detection can be performed with high accuracy.

  Further, the flexible front layer has no fluidity compared to a liquid such as water, oil, glycerin, or gel, which is conventionally applied to the surface of the measurement object as a contact medium. For this reason, when the front layer is attached to the front surfaces of the two vibrators, the front layer can maintain the air gap without filling the air gap separating the two vibrators unlike the liquid or gel. Further, unlike the liquid or gel, the front layer has no trouble of being applied to the surface of the object to be measured or wiping off after the measurement, and also has good durability because it does not evaporate or flow out even when measured over a long period of time.

  A typical configuration of the measurement and detection system according to the present invention has two vibrators and is formed into a flexible sheet as a whole, and a gap is provided between the two vibrators. Then, using the dual transducer probe in which a front surface having flexibility is attached to the front surfaces of the two transducers, the above-described dual transducer probe can measure the thickness of a measurement object or detect flaws. The two vibrators include a first vibrator that transmits and receives ultrasonic waves and a second vibrator that receives ultrasonic waves, and the first vibrator has a front surface. The ultrasonic wave is incident on the measurement object through the layer, the first ultrasonic echo reflected at the first interface between the front layer and the measurement object is received, and the second vibrator is incident on the measurement object from the first vibrator. The second ultrasonic echo reflected from the second interface of the measurement object is received, and the signal processing unit receives the first ultrasonic echo. Starts counting from the received time finishes counting at the reception time of the second ultrasonic echo, on the basis of the values obtained in counts, is preferably performed thickness measurement or flaw detection test.

  Since the front layer attached to the front surface of the two vibrators has flexibility, when it is pressed against the surface of the measurement object when measuring the thickness of the measurement object or detecting a flaw, the thickness depends on the applied pressure. Change. That is, the reception time of the first ultrasonic echo depends on the thickness of the front layer that changes according to the applied pressure. Therefore, in the above configuration, the counting is started from the reception time of the first ultrasonic echo depending on the thickness of the front layer, and the counting is ended at the reception time of the second ultrasonic echo. For this reason, the value obtained by counting is the time during which the ultrasonic wave propagates in the measurement object (the time for reciprocating between the first interface and the second interface of the measurement object), and is pressed against the surface of the measurement object. It does not depend on the thickness of the front layer that changes. Here, the first interface is an interface between the front layer and the measurement object, that is, the surface of the measurement object. The second interface is a place where the bottom of the measurement object or a flaw of the measurement object exists. Therefore, half the value obtained by multiplying the value obtained by counting by the material sound velocity in the measurement object is the distance from the first interface of the measurement object to the bottom surface, that is, the thickness of the measurement object, or the measurement object This is the distance from the first interface to the location where the flaw exists. Note that obtaining the distance from the first interface of the measurement object to the location where the flaw is present is equivalent to detecting the flaw. Therefore, even when the thickness of the front surface layer is changed by being pressed against the surface of the measurement object, the thickness measurement or the flaw detection of the measurement object can be performed with high accuracy.

  In order to solve the above problems, a typical configuration of the measurement detection method according to the present invention is to measure a thickness of a measurement object or a flaw using a two-transducer probe having a first transducer and a second transducer. A measurement detection method for performing detection, the step of pressing a flexible front layer attached to the front surface of each of two vibrators against the surface of the measurement object, and the measurement object from the first vibrator through the front layer And receiving the first ultrasonic echo reflected by the first interface between the front layer and the measurement object by the first vibrator, and entering the measurement object from the first vibrator, The second ultrasonic echo reflected by the second interface is received by the second transducer, and the counting is started from the reception time of the first ultrasonic echo, and the counting is finished at the reception time of the second ultrasonic echo, Based on the value obtained in step 1, measure the thickness of the measured object. Other is characterized in that it comprises a step of performing flaw detection.

  Here, since the front layer has flexibility, when it is pressed against the surface of the measurement object when measuring the thickness of the measurement object or detecting a flaw, the thickness changes according to the applied pressure. That is, the reception time of the first ultrasonic echo depends on the thickness of the front layer that changes according to the applied pressure. Therefore, in the above method, the counting is started from the reception time of the first ultrasonic echo, and the counting is ended at the reception time of the second ultrasonic echo. For this reason, the value obtained by counting is the time during which the ultrasonic wave propagates through the measurement object, and does not depend on the thickness of the front layer. Therefore, even when the thickness of the front surface layer is changed by being pressed against the surface of the measurement object, the thickness obtained or the flaw detection of the measurement object is performed with high accuracy by using the value obtained by counting. be able to.

  According to the present invention, it is possible to measure the thickness of a measurement object and detect a flaw with high accuracy by reducing propagation of ultrasonic waves between two vibrators along the surface of the measurement object. A transducer probe, a measurement detection system, and a measurement detection method can be provided.

It is a figure which shows schematic structure of the 2 transducer | vibrator probe in embodiment of this invention. It is a figure which shows the cross section of the 2 transducer | vibrator probe of a comparative example. It is a figure which shows the use condition of the two transducer probe of FIG. FIG. 2 is a functional block diagram of a measurement detection system using the dual transducer probe of FIG. 1. It is a figure which shows the change of the thickness according to the applied pressure of the front layer of the dual transducer probe of FIG. It is a flowchart which shows the process of the measurement detection system of FIG. It is an operation | movement sequence diagram of the signal processing part of the measurement detection system of FIG.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The dimensions, materials, and other specific numerical values shown in the embodiments are merely examples for facilitating understanding of the invention, and do not limit the present invention unless otherwise specified. In the present specification and drawings, elements having substantially the same function and configuration are denoted by the same reference numerals, and redundant description is omitted, and elements not directly related to the present invention are not illustrated. To do.

  FIG. 1 is a diagram showing a schematic configuration of a dual transducer probe (hereinafter, probe 100) in an embodiment of the present invention. FIG. 1A and FIG. 1B are diagrams showing an upper surface and a side surface of the probe 100, respectively. FIG.1 (c) is AA sectional drawing of Fig.1 (a). However, in FIG. 1A, the back material 102 shown in FIGS. 1B and 1C is omitted.

  The probe 100 measures the thickness of the measurement object 104 with ultrasonic waves in order to detect the thinning of the measurement object 104 (see FIG. 3B) such as a pipe. The probe 100 is formed in a sheet shape having flexibility as a whole, and has a first vibrator 106 and a second vibrator 108 as two vibrators as shown in FIG. . Further, a gap 110 is provided between the first vibrator 106 and the second vibrator 108, and the two vibrators are separated by the gap 110.

  The first vibrator 106 is a transmission-side vibrator, to which a + side electrode 114a drawn from the coaxial cable 112a is connected, and a −side electrode 116a is electrically connected via an electrode 118. The second vibrator 108 is a receiving-side vibrator, to which a positive electrode 114b drawn from the coaxial cable 112b is connected, and a negative electrode 116b is electrically connected via an electrode 118.

  As shown in FIG. 1C, a front layer 122 is attached to the front surface 120a of the first vibrator 106 and the front surface 120b of the second vibrator 108, respectively. The front surfaces 120 a and 120 b are surfaces on the side facing the measurement object 104. The front layer 122 is pressed against the surface of the measurement object 104 when measuring the thickness of the measurement object 104.

  The front layer 122 has flexibility, and when pressed against the surface of the measurement object 104, the front layer 122 follows the unevenness of the surface of the measurement object 104 and deforms to adhere to the unevenness of the surface. Note that the softness is a property that is softer than the flexibility and has an adhesion property that follows the unevenness of the surface of the measurement object 104. For this reason, an air layer is not formed between the surface of the measurement object 104 and the front layer 122, and propagation of ultrasonic waves is not hindered.

  As described above, in the probe 100, by attaching the front layer 122, conventionally, a contact medium such as water, oil, glycerin, or gel applied to the surface of the measurement object 104 becomes unnecessary. Further, unlike the liquid and gel, the front layer 122 has no fluidity. Therefore, in the probe 100, even when the front layer 122 is attached, the gap 110 that separates the first vibrator 106 and the second vibrator 108 is not filled, and the gap 110 can be maintained. . Further, unlike the liquid or gel, the front surface layer 122 has no trouble of being applied to the surface of the measurement object 104 or wiping off after the measurement, and also has durability because it does not evaporate or flow out even when measured over a long period of time. Good.

  Further, as shown in FIG. 1C, a back material 102 that connects the back surfaces 124a and 124b is attached to the back surface 124a of the first vibrator 106 and the back surface 124b of the second vibrator. The back surfaces 124 a and 124 b are surfaces that do not face the measurement object 104 (surfaces opposite to the measurement object 104). The back material 102 is made of a sound absorbing material. As the sound-absorbing material, a material having both sound-absorbing properties and flexibility is preferable. Here, a porous material such as cork, silicon sponge, sponge rubber or the like is used.

  FIG. 2 is a view showing a cross section of the probe 200 of the comparative example. The cross section of the probe 200 in the figure is shown corresponding to the AA cross section of the probe 100 shown in FIG. The probe 200 is formed in a sheet shape, and a partition plate 206 is provided between the transmitting-side vibrator 202 and the receiving-side vibrator 204. The two vibrators 202 and 204 are covered with a mold resin 208 as shown in the figure.

  In the comparative example, since the physical partition plate 206 is provided between the two vibrators 202 and 204, the flexibility is impaired even if the probe 200 is formed in a sheet shape. For this reason, as shown in FIG. 3B, when the measurement object 104 is a pipe having a curved surface, it is difficult to place the probe 200 along the surface of the measurement object 104. Therefore, in the probe 200, an air layer is easily formed between the surface of the measurement object 104, the propagation of ultrasonic waves is hindered, and the measurement accuracy of the thickness of the measurement object 104 is lowered.

  The probe 200 is formed in a sheet shape although a physical partition plate 206 is provided between the two vibrators 202 and 204. Therefore, in the probe 200, the ultrasonic waves 210 and 212 propagate from the transmitting-side transducer 202 to the receiving-side transducer 204 through the upper side or the lower side of the partition plate 206. Therefore, when the thickness of the measurement object 104 is measured using the probe 200, the noise is large and the measurement accuracy is significantly reduced.

  FIG. 3 is a diagram showing a usage state of the probe 100 of FIG. The probe 100 is formed as a sheet having flexibility as a whole. Therefore, the probe 100 can be easily bent even with the operator's finger 126 as shown in FIG. 3A, and can maintain a sheet-like state when bent.

  Therefore, in the probe 100, when the thickness of the measurement object 104 is measured using ultrasonic waves, even if the measurement object 104 has a curved surface such as a pipe as shown in FIG. , Along the surface of the measurement object 104. Therefore, in the probe 100, it is difficult to form an air layer between the surface of the measurement object 104 and the propagation of ultrasonic waves is not hindered.

  Further, since the probe 100 has a sheet shape, it can be easily installed on the surface of the measurement object 104 using a magnet 128 as shown in FIG. The probe 100 may be affixed with a double-sided tape, or may be affixed with a tape from the outside of the probe 100.

  Further, the probe 100 is different from the partition plate 206 (see FIG. 2) shown in the comparative example between the first vibrator 106 and the second vibrator 108 as shown in FIG. They are separated by a gap 110. For this reason, the probe 100 does not impair the overall flexibility, and further, the ultrasonic waves generated by the first transducer 106 propagate through the probe 100 and are transmitted by the second transducer 108. Reception can also be reduced.

  Further, in the probe 100, the back surface 124a of the first transducer 106 and the back surface 124b of the second transducer 108 are connected by a back material 102 made of a sound absorbing material. For this reason, the ultrasonic wave propagating from the first transducer 106 to the second transducer 108 can be absorbed while the positional relationship between the first transducer 106 and the second transducer 108 is kept constant.

  Therefore, according to the probe 100, it can reduce that an ultrasonic wave propagates between two vibrators along the surface of the measurement object 104. FIG. For this reason, by using the probe 100, the thickness of the measurement object 104 can be measured with high accuracy.

  FIG. 4 is a functional block diagram of a measurement detection system 130 using the probe 100 of FIG. The measurement detection system 130 includes a probe 100, a pulse generator 132, and a signal processing unit 134 as illustrated. The pulse generator 132 is electrically connected to the first vibrator 106 via the coaxial cable 112 a and applies a pulse current to the first vibrator 106.

  The signal processing unit 134 is electrically connected to the first vibrator 106 and the second vibrator 108 via the coaxial cables 112a and 112b and processes various signals. The signal processor 134 includes a first amplifier 136 and a first detector 138 connected to the first vibrator 106, a second amplifier 140 and a second detector 142 connected to the second vibrator 108, and a first And a calculation unit 144 connected to the detection unit 138 and the second detection unit 142.

  Here, the function of the first amplifier 136 will be described with reference to FIG. FIG. 5 is a diagram showing a change in thickness according to the applied pressure of the front layer 122 of the probe 100 of FIG. The left side of FIGS. 5A and 5B shows the state of the front layer 122 when the pressure applied to the front layer 122 attached to the front surface 120a of the first vibrator 106 is Pa and Pb, respectively. ing. The applied pressure Pb is larger than the applied pressure Pa. The right side of FIGS. 5A and 5B shows the waveforms of signals acquired by the first amplifier 136 via the coaxial cable 112a when the applied pressures are Pa and Pb, respectively.

  Since the front layer 122 has flexibility, when the thickness of the measurement object 104 is measured and the front layer 122 is pressed against the surface 146 of the measurement object 104, the thickness changes according to the applied pressure. The surface 146 of the measurement object 104 is a first interface between the front layer 122 and the measurement object 104.

  The front layer 122 has a thickness La in a state where the pressure Pa shown in FIG. When a pulse current is applied to the first vibrator 106 in this state, the first vibrator 106 generates an ultrasonic wave. The first amplifier 136 first acquires the transmission pulse T accompanying the generation of ultrasonic waves.

  The ultrasonic wave generated by the first transducer 106 is incident on the front layer 122 from the front surface 120 a of the first transducer 106, is reflected by the surface 146 of the measurement object 104, and becomes the first ultrasonic echo S. Then, the first transducer 106 receives the first ultrasonic echo S. That is, the first transducer 106 not only transmits an ultrasonic wave as a transmission-side transducer but also receives the first ultrasonic echo S.

  The first transducer 106 is deformed by the reached ultrasonic wave and changes its resistance. The first amplifier 136 receives a change in the resistance of the first transducer 106, acquires a signal indicating the first ultrasonic echo S in FIG. 5A, and amplifies it. Here, the time ta required for the first amplifier 136 to acquire the signal indicating the first ultrasonic echo S after acquiring the transmission pulse T depends on the thickness La of the front layer 122. That is, the time ta is a time during which the ultrasonic wave is propagating in the front layer 122, and is a time for reciprocating between the front surface 120a of the first transducer 106 and the surface 146 of the measurement object 104. Therefore, the thickness La of the front layer 122 is a value obtained by multiplying the time ta by the material sound velocity of the front layer 122 and halving it.

  On the other hand, when the pressure Pb larger than the pressure Pa is received, the front layer 122 has a thickness Lb as shown in FIG. 5B and is smaller than the thickness La shown in FIG. For this reason, when the first transducer 106 generates an ultrasonic wave in this state, the time tb required from the first amplifier 136 to acquire the transmission pulse T to the acquisition of the signal indicating the first ultrasonic echo S is As shown in FIG. 5B, the time ta becomes smaller. When calculating the thickness Lb of the front layer 122, the time tb may be multiplied by the material sound velocity of the front layer 122 to halve it.

  However, when measuring the thickness of the measurement object 104, calculating the thickness of the front surface layer 122 that changes in accordance with the applied pressure each time is nothing but increasing the measurement effort. Therefore, the measurement detection system 130 employs a measurement detection method that does not depend on the thickness of the front surface layer 122 that is changed by being pressed against the surface 146 of the measurement object 104. Hereinafter, the case where the thickness is measured by the measurement detection system 130 and the measurement detection method according to the present embodiment will be described with reference to FIGS.

  FIG. 6 is a flowchart showing processing of the measurement detection system 130 of FIG. FIG. 7 is an operation sequence diagram of the signal processing unit 134 of the measurement detection system 130 of FIG. A, B, C, D, and E in FIG. 7 are diagrams for explaining functions of the first amplifier 136, the first detection unit 138, the second amplifier 140, the second detection unit 142, and the calculation unit 144, respectively.

  First, in the measurement detection system 130, the probe 100 is installed on the measurement object 104 using, for example, the magnet 128 shown in FIG. 3B (step S100). As described above, the probe 100 is formed in a sheet shape having flexibility as a whole with the first vibrator 106 and the second vibrator 108 separated by the gap 110. Therefore, in step S100, the probe 100 can be placed along the surface 146 (see FIG. 5) of the measurement object 104 even if the measurement object 104 has a curved surface.

  Next, when the pulse generator 132 applies a pulse current to the first transducer 106, the first transducer 106 transmits an ultrasonic wave (step S102). When the ultrasonic wave is transmitted, the first amplifier 136 acquires a transmission pulse T shown in A of FIG.

  Subsequently, the first transducer 106 receives the first ultrasonic echo S in which the ultrasonic wave incident on the front surface layer 122 is reflected by the surface 146 of the measurement object 104 (step S104). When the first ultrasonic echo S is received, the first transducer 106 is deformed and the resistance changes. As shown in FIG. 7A, the first amplifier 136 receives a change in the resistance of the first transducer 106, acquires a signal indicating the first ultrasonic echo S, and amplifies it.

  As shown in B of FIG. 7, the first detection unit 138 detects a signal indicating the amplified first ultrasonic echo S, and transmits the reception time TS when the signal is detected to the calculation unit 144. Thereby, the calculating part 144 acquires reception time TS, as shown to E of FIG.

  In addition, the ultrasonic wave incident on the measurement object 104 from the first vibrator 106 is reflected by the surface 146 of the measurement object 104 to be not only the first ultrasonic echo S but also propagated in the measurement object 104 and measured. Reflecting on the bottom surface 148 (see FIG. 5), which is the second interface of the object 104, becomes the second ultrasonic echo B.

  This second ultrasonic echo B is received by the second transducer 108, which is the transducer on the receiving side (step S106). When the second ultrasonic echo B is received, the second transducer 108 is deformed and the resistance changes. As shown in FIG. 7C, the second amplifier 140 receives a change in the resistance of the second transducer 108, acquires a signal indicating the second ultrasonic echo B, and amplifies it.

  As shown in D of FIG. 7, the second detection unit 142 detects a signal indicating the amplified second ultrasonic echo B, and transmits a reception time TB at which this signal is detected to the calculation unit 144. Thereby, the calculating part 144 acquires reception time TB as shown to E of FIG.

  Next, the calculation unit 144 starts counting from the reception time TS of the first ultrasonic echo S, and ends counting at the reception time TB of the second ultrasonic echo B (step S108). The value obtained by this count is a time tc shown in E of FIG. Subsequently, the calculation unit 144 measures the thickness of the measurement object 104 based on the time tc (step S110). The time tc is a time during which the ultrasonic wave propagates in the measurement object 104, that is, a time for reciprocating between the surface 146 and the bottom surface 148 of the measurement object 104, and does not depend on the thickness of the front layer 122. Therefore, the calculation unit 144 can calculate the thickness of the measurement object 104 by halving a value obtained by multiplying the time tc by the material sound velocity in the measurement object 104 in step S110.

  Therefore, according to the measurement detection system 130 and the measurement detection method using the probe 100 according to the present embodiment, when measuring the thickness of the measurement object 104, it is pressed against the surface 146 of the measurement object 104 and the front layer 122 is pressed. Even when the thickness changes, the thickness of the measurement object 104 can be measured with high accuracy.

  The front layer 122 needs to be thin so that the ultrasonic waves generated by the first transducer 106 are not attenuated while the first ultrasonic echo S and the transmission pulse are distinguished. That is, the thickness of the front layer 122 is selected in consideration of such conditions. Then, by applying the front layer 122 having the selected thickness to the probe 100, the measurement detection system 130 and the measurement detection method described above can be realized.

  In the above embodiment, the case where the thickness of the measurement object 104 is measured by the measurement detection system 130 and the measurement detection method is exemplified, but the present invention is not limited to this, and a flaw such as a crack existing in the measurement object 104 is detected. Also good. In this case, the ultrasonic wave propagating through the measurement object 104 is reflected at the second interface of the measurement object 104, that is, at a place where a flaw exists in the measurement object 104, thereby becoming the second ultrasonic echo B.

  In addition, the time tc shown in E of FIG. 7 obtained by the calculation unit 144 in step S108 is a time during which the ultrasonic wave propagates through the measurement object 104 when the flaw of the measurement object 104 is detected, that is, It is time to reciprocate between the surface 146 that is the first interface and the point where the flaw exists that is the second interface.

  For this reason, the calculation unit 144 halves the value obtained by multiplying the time tc by the material sound velocity in the measurement object 104 in step S110, thereby calculating the distance from the surface 146 of the measurement object 104 to the location where the flaw exists. As a result, flaws can be detected.

  Therefore, according to the measurement detection system 130 and the measurement detection method using the probe 100 of this embodiment, when detecting a flaw on the measurement object 104, the thickness of the front layer 122 is pressed against the surface 146 of the measurement object 104. Even when is changed, it is possible to detect the flaw of the measurement object 104 with high accuracy. Note that the measurement detection system 130 not only detects flaws, but also repeats the processes in steps S102 to S110 while shifting the position where the probe 100 is installed on the measurement object 104, so that flaws on the measurement object 104 occur. An existing range (for example, crack length and shape) can also be detected.

  As mentioned above, although preferred embodiment of this invention was described referring an accompanying drawing, it cannot be overemphasized that this invention is not limited to this example. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. Understood.

  The present invention can be used as a dual transducer probe having two transducers, a measurement detection system, and a measurement detection method.

DESCRIPTION OF SYMBOLS 100 ... Two transducer probe, 102 ... Back material, 104 ... Measurement object, 106 ... 1st transducer, 108 ... 2nd transducer, 110 ... Gap, 112a, 112b ... Coaxial cable, 114a, 114b ... + side Electrode, 116a, 116b ...- side electrode, 118 ... electrode, 120a, 120b ... front, 122 ... front layer, 124a, 124b ... back, 126 ... operator's finger, 128 ... magnet, 130 ... measurement detection system, 132 ... Pulse generator, 134 ... signal processing unit, 136 ... first amplifier, 138 ... first detection unit, 140 ... second amplifier, 142 ... second detection unit, 144 ... calculation unit, 146 ... surface of measurement object, 148 ... measurement Bottom of the object

Claims (5)

A dual transducer probe having two transducers,
It is formed into a flexible sheet as a whole,
A dual transducer probe, wherein a gap is provided between the two transducers.   The dual transducer probe according to claim 1, wherein a sound-absorbing material that connects the back surfaces is attached to the back surfaces of the two transducers.   The dual transducer probe according to claim 1 or 2, wherein a front surface layer having flexibility is attached to a front surface of the two transducers. It has two vibrators and is formed into a flexible sheet as a whole. There is a gap between the two vibrators, and the front face of the two vibrators is flexible. Using a dual transducer probe with a front layer having
The dual transducer probe is connected to a signal processing unit for measuring a thickness of a measurement object or detecting a flaw,
The two vibrators include a first vibrator that transmits and receives ultrasonic waves, and a second vibrator that receives ultrasonic waves,
The first transducer receives ultrasonic waves incident on the measurement object via the front layer and reflected by a first interface between the front layer and the measurement object,
The second transducer receives a second ultrasonic echo incident on the measurement object from the first transducer and reflected by the second interface of the measurement object,
The signal processing unit starts counting from the reception time of the first ultrasonic echo, ends counting at the reception time of the second ultrasonic echo, and based on the value obtained by the count, A measurement detection system characterized by measuring wall thickness or detecting flaws. A measurement detection method for measuring a thickness of a measurement object or detecting a flaw using a two-vibrator probe having a first transducer and a second transducer,
Pressing a flexible front layer attached to the front of each of the two transducers against the surface of the workpiece;
An ultrasonic wave is incident on the measurement object from the first vibrator through the front layer, and the first ultrasonic echo reflected at the first interface between the front layer and the measurement object is received by the first vibrator. Steps,
Receiving the second ultrasonic echo incident on the measurement object from the first vibrator and reflected by the second interface of the measurement object by the second vibrator;
Counting starts from the reception time of the first ultrasonic echo, ends counting at the reception time of the second ultrasonic echo, and measures the thickness of the measurement object or detects flaws based on the value obtained by the count And a step of performing measurement.

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