Ultrasonic measurement device and ultrasonic measurement method

Abstract

To provide an ultrasonic measurement device and an ultrasonic measurement method which can increase the SN ratio over the entire measurement possible range while having the large measurement possible range of the thickness of a concrete structure.SOLUTION: An ultrasonic measurement device includes a signal processing device 16 which performs processing by acquiring a plurality of waveform signals corresponding to the combination of a position of a transmission vertical probe 11 in the lateral direction of the front surface of a concrete wall 2 and a position of a reception vertical probe 12. The signal processing device 16 generates the first amplitude distribution data to a shallow part of the concrete wall 2 by performing processing by acquiring a plurality of waveform signals in a case where an interval between the probes 11, 12 in the vertical direction of the front surface of the concrete wall 2 is a set value L1, generates the second amplitude distribution data to a deep part of the concrete wall 2 by performing processing by acquiring the plurality of waveform signals in a case where an interval between the probes 11, 12 is a set value L2 (L2>L1), and calculates the thickness of the concrete wall 2 by using them.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an ultrasonic measurement device and an ultrasonic measurement method for measuring the thickness of a concrete structure. [Background technology]

[0002] Ultrasonic measurement is one of the non-destructive measurements, and is used to measure the thickness of an object to be inspected. Patent Document 1 discloses a two-probe method using a vertical transmitting probe and a vertical receiving probe. In this method, ultrasonic waves are transmitted to the inside of the object to be inspected using a vertical transmitting probe arranged on the surface of the object to be inspected. A vertical receiving probe arranged on the surface of the object to be inspected receives a reflected wave (bottom echo) reflected on the bottom surface of the object to be inspected and converts it into a waveform signal (change in amplitude over time). Then, the reception time of the bottom echo (i.e., the propagation time of the ultrasonic wave) is extracted from the waveform signal, and the thickness of the object to be inspected is calculated based on this.

[0003] In recent years, a technique called Full Matrix Capture (FMC) / Total Focusing Method (TFM) or Synthetic Aperture Focusing Technique (SAFT) has been attracting attention. When this method is adopted together with the above-mentioned two-probe method, the position of the transmitting vertical probe and the position of the receiving vertical element in the first direction along the surface of the object to be inspected are changed, and multiple waveform signals corresponding to the combination of the position of the transmitting vertical probe and the position of the receiving vertical element are obtained. Then, for each position inside the object to be inspected, the amplitudes of the multiple waveform signals corresponding to that position are extracted and summed based on the propagation time of the ultrasonic wave when it is assumed that the ultrasonic wave is reflected at that position, and amplitude distribution data indicating the distribution of the summed amplitudes is generated. Then, the position of the bottom echo is extracted from the amplitude distribution data, and the thickness of the object to be inspected is calculated based on this. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 09-061144 Summary of the Invention [Problem to be solved by the invention]

[0005] When ultrasonic measurement is used to measure the thickness of a concrete structure, scattered waves (scattering noise) are generated by the aggregates in the concrete structure, and the S / N ratio of the bottom echo to this scattered noise decreases. By adopting the above-mentioned two-probe method or a method called FMC / TFM or SAFT, it is possible to suppress the decrease in S / N ratio. However, for example, if the concrete structure is thick and the change in thickness due to thinning is large, if the measurable range of the concrete structure's thickness is made large, it becomes difficult to increase the S / N ratio over the entire measurable range. This will be described in detail below.

[0006] The distance between the vertical transmitting probe and the vertical receiving probe in a second direction along the surface of the concrete structure and perpendicular to the first direction is generally fixed and as small as possible. As a result, the sensitive area where the directivity angle of the vertical transmitting probe and the directivity angle of the vertical receiving probe overlap in the cross section of the concrete structure (specifically, the cross section parallel to the depth direction of the concrete structure and the second direction) spreads over the entire depth direction of the concrete structure. Therefore, it is possible to widen the measurable range of the thickness of the concrete structure.

[0007] When the sensitive region is set as described above, the amplitude of the scattered noise tends to decrease as the reflection position deepens (in other words, as the propagation time becomes longer) as long as the reflection position is within a predetermined depth (for example, 0.4 m). However, once the reflection position exceeds the predetermined depth, the amplitude tends to be constant regardless of the reflection position (in other words, regardless of the propagation time). This is because the number of overlapping scattered waves increases because the propagation paths are different but the propagation times are the same. On the other hand, the amplitude of the bottom echo tends to decrease as the reflection position deepens, regardless of whether the reflection position exceeds the predetermined depth. Therefore, the signal-to-noise ratio decreases in the deeper parts of the concrete structure (in other words, in the parts beyond the predetermined depth).

[0008] An object of the present invention is to provide an ultrasonic measuring device and an ultrasonic measuring method that can widen the measurable range of the thickness of a concrete structure while improving the signal-to-noise ratio over the entire measurable range. [Means for solving the problem]

[0009] In order to achieve the above-mentioned object, a representative embodiment of the present invention is an ultrasonic measurement device comprising: a transmitting vertical probe arranged on a surface of a concrete structure and transmitting ultrasonic waves; a receiving vertical probe arranged on the surface of the concrete structure and receiving reflected waves and converting them into waveform signals; a moving device that changes the position of the transmitting vertical probe and the position of the receiving vertical probe in a first direction along the surface of the concrete structure; and a signal processing device that acquires and processes a plurality of waveform signals corresponding to combinations of the positions of the transmitting vertical probe and the receiving vertical probe, wherein the moving device moves the transmitting vertical probe in a second direction along the surface of the concrete structure and perpendicular to the first direction. The distance between the vertical transmitting probe and the vertical receiving probe is made changeable, and the signal processing device acquires and processes the plurality of waveform signals when the distance between the vertical transmitting probe and the vertical receiving probe in the second direction is set to a set value L1 to generate first amplitude distribution data for a shallow portion of the concrete structure, acquires and processes the plurality of waveform signals when the distance between the vertical transmitting probe and the vertical receiving probe in the second direction is set to a set value L2 that is larger than the set value L1 to generate second amplitude distribution data for a deep portion of the concrete structure, and calculates a thickness of the concrete structure using the first amplitude distribution data and the second amplitude distribution data. Effect of the Invention

[0010] According to the present invention, the measurable range of the thickness of a concrete structure can be increased, while the S / N ratio can be increased over the entire measurable range. [Brief description of the drawings]

[0011] [Figure 1] 1 is a schematic diagram illustrating a configuration of an ultrasonic measurement device according to an embodiment of the present invention. [Diagram 2] FIG. 2 is an XZ plane view showing an example of an ultrasonic propagation path inside a concrete wall in one embodiment of the present invention. [Diagram 3]FIG. 2 is a YZ plane view showing a sensitive region together with the interval between a transmitting vertical probe and a receiving vertical probe in one embodiment of the present invention. [Figure 4] 4 is a flowchart showing the operation of the ultrasonic measurement device in one embodiment of the present invention. [Diagram 5] FIG. 4 is a diagram showing first amplitude distribution data for a shallow portion of a concrete wall in one embodiment of the present invention. [Figure 6] FIG. 11 is a diagram showing second amplitude distribution data for a deep portion of a concrete wall in one embodiment of the present invention. [Figure 7] 6 is a flowchart showing the operation of an ultrasonic measurement device in a first modified example of the present invention. [Figure 8] FIG. 11 is a diagram illustrating a part of composite data in a first modified example of the present invention. [Figure 9] FIG. 13 is a schematic diagram illustrating a configuration of a moving device according to a second modified example of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] An embodiment of the present invention will be described with reference to the drawings.

[0013] FIG. 1 is a schematic diagram showing the configuration of an ultrasonic measurement device according to this embodiment.

[0014] The ultrasonic measuring device of this embodiment measures the thickness of a concrete wall 2 erected on a floor 1. The ultrasonic measuring device of this embodiment includes a vertical transmitting probe 11 and a vertical receiving probe 12 arranged on the surface of the concrete wall 2, a moving device 13 that changes the position of the vertical transmitting probe 11 and the vertical receiving probe 12 in the lateral direction (X direction) along the surface of the concrete wall 2, a moving control device 14 that controls the moving device 13, an ultrasonic flaw detector 15 that inputs and outputs signals between the vertical transmitting probe 11 and the vertical receiving probe 12, a signal processing device 16 connected to the moving control device 14 and the ultrasonic flaw detector 15 via wiring, and a display device 17 connected to the signal processing device 16 via wiring. The display device 17 is, for example, a display.

[0015] The moving device 13 comprises a pair of running bodies 18A, 18B that run on the floor 1 in response to commands from the moving control device 14, a pair of arms 19A, 19B that are provided between the running bodies 18A, 18B and extend laterally (X direction) on the surface of the concrete wall 2, a slider mechanism (not shown) that moves the transmitting vertical probe 11 along the arm 19A in response to commands from the moving control device 14, and a slider mechanism (not shown) that moves the receiving vertical probe 12 along the arm 19B in response to commands from the moving control device 14.

[0016] The movement device 13 has a movement sensor (not shown) that detects state quantities related to the movement of the moving bodies 18A, 18B, a movement sensor (not shown) that detects the amount of movement of the transmitting vertical probe 11 by the slider mechanism, and a movement sensor (not shown) that detects the amount of movement of the receiving vertical probe 12 by the slider mechanism, and outputs detection signals from the movement sensor and the movement sensor to the movement control device 14.

[0017] Although not shown, the movement control device 14 has a processor that executes control according to a program, and a memory that stores programs and data. The movement control device 14 has a movement control unit 20 and a position calculation unit 21 as functional components. The movement control unit 20 outputs a command to the movement device 13 to control the position of the vertical transmitting probe 11 and the vertical receiving probe 12 in the lateral direction (X direction) of the surface of the concrete wall 2. The position calculation unit 21 calculates the position of the vertical transmitting probe 11 and the vertical receiving probe 12 in the lateral direction (X direction) of the surface of the concrete wall 2 based on the detection signals of the travel sensor and the movement sensor, and outputs the position to the signal processing device 16.

[0018] The ultrasonic flaw detector 15 has a pulser 22 and a receiver 23. The pulser 22 applies a voltage to the piezoelectric element of the vertical transmitting probe 11 each time at least one of the positions of the vertical transmitting probe 11 and the vertical receiving probe 12 is changed, causing the piezoelectric element to transmit ultrasonic waves to the concrete wall 2. The piezoelectric element of the vertical receiving probe 12 receives the reflected wave from the concrete wall 2, converts it into a waveform signal, and outputs it to the receiver 23. The receiver 23 digitally converts the waveform signal and outputs it to the signal processing device 16. The waveform signal indicates the change over time in the amplitude (intensity) of the reflected wave received by the vertical receiving probe 12, based on the timing of transmission of the ultrasonic waves by the vertical transmitting probe 11.

[0019] Although not shown, the signal processing device 16 has a processor that executes control according to a program and a memory that stores the program and data. The signal processing device 16 has, as its functional configuration, a storage unit 24, an amplitude distribution data generating unit 25, and a thickness calculating unit 26.

[0020] The memory unit 24 of the signal processing device 16 records the combination of the position of the transmitting vertical probe 11 and the position of the receiving vertical probe 12 and the corresponding waveform signal. k-1 , P k The transmitting vertical probe 11 is placed at position P1, and the receiving vertical probe 12 is placed at positions P1, P2, ..., P k-1 , P k , and the corresponding waveform signal W 11 , W 12 , …, W 1(k-1) , W 1k After that, the transmitting vertical probe 11 is placed at position P2, and the receiving vertical probe 12 is placed at positions P1, P2, ..., P k-1 , P k , and the corresponding waveform signal W 21 , W 22 , …, W 2(k-1) , W 2kFurthermore, while changing the combination of the position of the transmitting vertical probe 11 and the position of the receiving vertical probe 12, waveform signals are acquired and recorded.

[0021] The amplitude distribution data generating unit 25 of the signal processing device 16 extracts and sums the amplitudes of multiple waveform signals corresponding to each position inside the concrete wall 2, based on the propagation time of the ultrasonic wave when it is assumed that the ultrasonic wave is reflected at that position, and generates amplitude distribution data indicating the distribution of the summed amplitudes. The details will be described below.

[0022] As shown in FIG. 2, the transmitting vertical probe 11 is positioned at position P m and the receiving vertical probe 12 is disposed at position P n Assume that the ultrasonic wave from the transmitting vertical probe 11 is reflected at a position p and received by the receiving vertical probe 12. m coordinates in the XZ coordinate system (x m ,z m ) and the position P of the receiving vertical probe 12 is defined as n coordinates in the XZ coordinate system (x n ,z n ) and position p is defined by the coordinates (r, φ) in the polar coordinate system.

[0023] The propagation distance r of the ultrasonic wave from the transmitting vertical probe 11 to the position p m is given by the following formula (1). The propagation distance r of the ultrasonic wave from the position p to the vertical receiving probe 12 is n is given by the following equation (2). Therefore, the propagation time τ of the ultrasonic wave from the transmitting vertical probe 11 to the receiving vertical probe 12 is mn is given by the following equation (3), where c is the speed of sound in the concrete wall.

[0024]

number

[0025]

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[0026]

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[0027] The amplitude (added value) S at position p inside the concrete wall 2 is given by the following formula (4). That is, for each waveform signal, the amplitude at the propagation time corresponding to position p inside the concrete wall 2 is extracted and added up. In this way, amplitude distribution data is generated.

[0028]

number

[0029] The thickness calculation unit 26 of the signal processing device 16 extracts the position of the bottom echo from the amplitude distribution data, and calculates the thickness of the concrete wall 2 based on this.

[0030] 3(a), it is preferable to set the distance between the vertical transmitting probe 11 and the vertical receiving probe 12 in the vertical direction (Y direction) along the surface of the concrete wall 2 and perpendicular to the horizontal direction (X direction) to a set value L1 that is as small as possible. As a result, a sensitive area E1 where the beam angle θ of the vertical transmitting probe 11 and the beam angle θ of the vertical receiving probe 12 overlap in the cross section of the concrete wall 2 (specifically, the YZ plane) spreads over the entire depth direction of the concrete wall 2. This makes it possible to increase the measurable range of the thickness of the concrete wall 2.

[0031] When the sensitive region E1 is set as described above, the scattering noise generated by the aggregates in the concrete wall 2 tends to decrease in amplitude as the reflection position deepens (in other words, as the propagation time becomes longer) if the reflection position is up to the boundary depth d (for example, 0.4 m). However, when the reflection position exceeds the boundary depth d, the amplitude tends to be constant regardless of the reflection position (in other words, regardless of the propagation time). This is because the number of overlapping scattered waves increases because the propagation paths are different but the propagation times are the same. Therefore, in the amplitude distribution data for the deep part of the concrete wall 2 (in other words, the part beyond the boundary depth d), the amplitude of the scattering noise cannot be suppressed, and the signal-to-noise ratio decreases.

[0032] Therefore, the moving device 13 of this embodiment is provided with a mechanism for adjusting the interval between the arms 19A, 19B in response to a command from the moving control device 14. This makes it possible to change the interval between the transmitting vertical probe 11 and the receiving vertical probe 12 in the vertical direction (Y direction) of the surface of the concrete wall 2. As shown in FIG. 3(b), the interval between the transmitting vertical probe 11 and the receiving vertical probe in the vertical direction (Y direction) of the surface of the concrete wall 2 can be changed from a set value L1 to a set value L2 (where L2>L1), thereby making it possible to change from the sensitive region E2 to the sensitive region E2. It is preferable that the sensitive region E2 exists only in the deep part of the concrete wall 2, and does not exist in the shallow part (in other words, the part below the boundary depth d). Therefore, it is preferable that the set value L2 is calculated and set by the following formula (5).

[0033]

number

[0034] When the sensitive region E2 is set as described above, it is possible to suppress the amplitude of the scattering noise in the amplitude distribution data for the deep part of the concrete wall 2. This is because the number of overlapping scattered waves is reduced since the propagation paths are different but the propagation times are the same.

[0035] From the above viewpoint, the ultrasonic measuring device of this embodiment generates the first amplitude distribution data for the shallow part of the concrete wall 2 and the second amplitude distribution data for the deep part of the concrete wall 2 by different methods, and uses them to calculate the thickness of the concrete wall 2. The details will be described with reference to Fig. 4. Fig. 4 is a flowchart showing the operation of the ultrasonic measuring device of this embodiment.

[0036] In step S1, the movement control device 14 controls the movement device 13 to set the distance between the vertical transmitting probe 11 and the vertical receiving probe 12 in the longitudinal direction (Y direction) of the surface of the concrete wall 2 to a set value L1. Then, the process proceeds to step S2, where the movement control device 14 controls the movement device 13 to sequentially change the combination of the positions of the vertical transmitting probe 11 and the vertical receiving probe 12 in the lateral direction (X direction) of the surface of the concrete wall 2. As a result, the signal processing device 16 acquires a plurality of waveform signals when the distance between the vertical transmitting probe 11 and the vertical receiving probe 12 is set to the set value L1.

[0037] Then, the process proceeds to step S3, where the signal processing device 16 generates first amplitude distribution data for the shallow portion of the concrete wall 2 based on the plurality of waveform signals acquired in the above-mentioned step S2. In detail, for each position in the shallow portion of the concrete wall 2, the amplitudes of the plurality of waveform signals corresponding to that position are extracted and summed based on the propagation time of the ultrasonic wave when it is assumed that the ultrasonic wave is reflected at that position, and first amplitude distribution data (the dashed line portion in FIG. 5(a) and FIG. 5(b)) indicating the distribution of the summed amplitudes is generated.

[0038] For convenience, Fig. 5(a) shows amplitude distribution data for shallow and deep parts of the concrete wall 2, generated based on a plurality of waveform signals when the distance between the transmitting vertical probe 11 and the receiving vertical probe 12 is set to a set value L1, and the amplitude is shown as brightness. Fig. 5(b) shows the change in amplitude at the position of the dotted line in Fig. 5(a). In this embodiment, it is not necessary to generate amplitude distribution data for deep parts of the concrete wall 2 based on a plurality of waveform signals when the distance between the transmitting vertical probe 11 and the receiving vertical probe 12 is set to a set value L1.

[0039] In step S4, the movement control device 14 controls the movement device 13 to set the distance between the vertical transmitting probe 11 and the vertical receiving probe 12 in the longitudinal direction (Y direction) of the surface of the concrete wall 2 to a set value L2. Then, the process proceeds to step S5, in which the movement control device 14 controls the movement device 13 to sequentially change the combination of the positions of the vertical transmitting probe 11 and the vertical receiving probe 12 in the lateral direction (X direction) of the surface of the concrete wall 2. As a result, the signal processing device 16 acquires a plurality of waveform signals when the distance between the vertical transmitting probe 11 and the vertical receiving probe 12 is set to the set value L2.

[0040] Then, the process proceeds to step S6, where the signal processing device 16 generates second amplitude distribution data for the deep portion of the concrete wall 2 based on the plurality of waveform signals acquired in the above-mentioned step S5. In detail, for each position within the deep portion of the concrete wall 2, based on the propagation time of the ultrasonic wave when it is assumed that the ultrasonic wave is reflected at that position, the amplitudes of the plurality of waveform signals corresponding to that position are extracted and summed, and second amplitude distribution data (the dashed line portion in FIG. 6(a) and FIG. 6(b)) showing the distribution of the summed amplitudes is generated.

[0041] For convenience, Fig. 6(a) shows amplitude distribution data for the deep and shallow parts of the concrete wall 2, generated based on a plurality of waveform signals when the distance between the transmitting vertical probe 11 and the receiving vertical probe 12 is set to a set value L2, and the amplitude is shown as brightness. Fig. 6(b) shows the change in amplitude at the position of the dotted line in Fig. 6(a). In this embodiment, it is not necessary to generate amplitude distribution data for the shallow part of the concrete wall 2 based on a plurality of waveform signals when the distance between the transmitting vertical probe 11 and the receiving vertical probe 12 is set to a set value L2.

[0042] In step 7, the signal processing device 16 extracts the position of the bottom echo from the first amplitude distribution data or the second amplitude distribution data for each position in the lateral direction (X direction) on the surface of the concrete wall 2, and calculates the thickness of the concrete wall 2 based on the extracted position. Then, the thickness of the concrete wall 2 is displayed on the display device 17.

[0043] Therefore, in this embodiment, the measurable range of the thickness of the concrete wall 2 can be increased, while the S / N ratio can be increased over the entire measurable range.

[0044] Although not particularly described in the above embodiment, the signal processing device 16 may correct one of the first amplitude distribution data and the second amplitude distribution data. Such a modification will be described with reference to Fig. 7 and Fig. 8. Fig. 7 is a flowchart showing the operation of the ultrasonic measuring device in this modification.

[0045] In steps S1 and S2, the signal processing device 16 acquires a plurality of waveform signals when the distance between the transmitting vertical probe 11 and the receiving vertical probe 12 is set to a set value L1. In step S3, the signal processing device 16 generates first amplitude distribution data for a shallow portion of the concrete wall 2 based on the plurality of waveform signals acquired in step S2. In addition, in step S8, the signal processing device 16 generates third amplitude distribution data for a part of the deep portion of the concrete wall 2 (for example, a range from depth d to (d+Δd)) based on the plurality of waveform signals acquired in step S2.

[0046] In steps S4 and S5, the signal processing device 16 acquires a plurality of waveform signals when the distance between the transmitting vertical probe 11 and the receiving vertical probe 12 is set to a set value L2. In step S6, the signal processing device 16 generates second amplitude distribution data for a deep portion of the concrete wall 2 based on the plurality of waveform signals acquired in step S5. In addition, in step S9, the signal processing device 16 extracts fourth amplitude distribution data for a part of the deep portion of the concrete wall 2 described above from the second amplitude distribution data generated in step S6.

[0047] In step S10, the signal processing device 16 calculates the amplitude average value of the third amplitude distribution data, calculates the amplitude average value of the fourth amplitude distribution data, and calculates the ratio between them. Then, the first amplitude distribution data or the second amplitude distribution data is corrected using the above-mentioned ratio so that the measurement sensitivity of the first amplitude distribution data and the second amplitude distribution data is the same. Then, the first amplitude distribution data and the second amplitude distribution data are synthesized to generate amplitude distribution data (see FIG. 8), and the thickness of the concrete wall is calculated using this. Then, the thickness of the concrete wall and the synthesized amplitude distribution data (for example, an amplitude distribution image showing the amplitude by brightness, etc.) are displayed on the display device 17.

[0048] In the above embodiment, the moving device 13 is described as including a pair of traveling bodies 18A, 18B, a pair of arms 19A, 19B provided between the traveling bodies 18A, 18B, a slider mechanism for moving the vertical transmitting probe 11 along the arm 19A, a slider mechanism for moving the vertical receiving probe 12 along the arm 19B, and a mechanism for adjusting the distance between the arms 19A, 19B, but is not limited to this. For example, as in a modified example shown in Fig. 8, the moving device 13 may be composed of a traveling body 18A supporting the vertical transmitting probe 11, and a traveling body 18B separated from the traveling body 18A and supporting the vertical receiving probe 12.

[0049] In the above embodiment, the measurement target is described as the concrete wall 2 by way of example. However, the measurement target is not limited to this, and may be a concrete structure other than the concrete wall 2. [Explanation of symbols]

[0050] 2. Concrete Wall 11 Transmitting vertical probe 12 Receiving vertical probe 13. Mobile Devices 16 Signal Processing Device

Claims

1. a transmitting vertical probe arranged on the surface of the concrete structure and transmitting ultrasonic waves; a receiving vertical probe disposed on the surface of the concrete structure, for receiving the reflected wave and converting it into a waveform signal; a moving device that changes a position of the transmitting vertical probe and a position of the receiving vertical probe in a first direction along the surface of the concrete structure; and a signal processing device that acquires and processes a plurality of waveform signals corresponding to combinations of positions of the transmitting vertical probe and the receiving vertical probe, the moving device is capable of changing a distance between the transmitting vertical probe and the receiving vertical probe in a second direction along the surface of the concrete structure and perpendicular to the first direction; The signal processing device includes: acquiring and processing the plurality of waveform signals when a distance between the transmitting vertical probe and the receiving vertical probe in the second direction is set to a set value L1, thereby generating first amplitude distribution data for a shallow portion of the concrete structure; acquiring and processing the plurality of waveform signals when a distance between the transmitting vertical probe and the receiving vertical probe in the second direction is set to a set value L2 that is greater than the set value L1, thereby generating second amplitude distribution data for a deep portion of the concrete structure; 2. An ultrasonic measuring device comprising: a measuring section for measuring a thickness of the concrete structure by using the first amplitude distribution data and the second amplitude distribution data.

2. 2. The ultrasonic measuring device according to claim 1, When the boundary depth between the shallow portion and the deep portion of the concrete structure is d and the directivity angle of the transmitting vertical probe and the directivity angle of the receiving vertical probe are θ, The ultrasonic measuring device is characterized in that the set value L2 is calculated and set using the formula 2×d×tan(θ / 2).

3. 2. The ultrasonic measuring device according to claim 1, acquiring and processing the plurality of waveform signals when a distance between the transmitting vertical probe and the receiving vertical probe in the second direction is set to the set value L1, thereby generating third amplitude distribution data for a portion of the deep portion of the concrete structure; extracting fourth amplitude distribution data for the part of the deep portion of the concrete structure from the second amplitude distribution data; an ultrasonic measuring device comprising: a first amplitude distribution data unit that corrects the first amplitude distribution data unit or the second amplitude distribution data unit using a ratio between an amplitude average value of the third amplitude distribution data unit and an amplitude average value of the fourth amplitude distribution data unit.

4. 1. An ultrasonic measurement method for obtaining a plurality of waveform signals corresponding to combinations of positions of a vertical transmitting probe and a vertical receiving probe, the method comprising: transmitting ultrasonic waves from the vertical transmitting probe while changing positions of a vertical receiving probe in a first direction along a surface of a concrete structure; and receiving reflected waves from the vertical receiving probe and converting the reflected waves into waveform signals. acquiring and processing the plurality of waveform signals when a distance between the transmitting vertical probe and the receiving vertical probe in a second direction along the surface of the concrete structure and perpendicular to the first direction is set to a set value L1, thereby generating first amplitude distribution data for a shallow portion of the concrete structure; acquiring and processing the plurality of waveform signals when a distance between the transmitting vertical probe and the receiving vertical probe in the second direction is set to a set value L2 that is greater than the set value L1, thereby generating second amplitude distribution data for a deep portion of the concrete structure; an ultrasonic measuring method comprising: calculating a thickness of the concrete structure by using the first amplitude distribution data and the second amplitude distribution data.

5. The ultrasonic measurement method according to claim 4, When the boundary depth between the shallow portion and the deep portion of the concrete structure is d and the directivity angle of the transmitting vertical probe and the directivity angle of the receiving vertical probe are θ, The ultrasonic measuring method is characterized in that the set value L2 is calculated and set using the formula 2×d×tan(θ / 2).

6. The ultrasonic measurement method according to claim 4, acquiring and processing the plurality of waveform signals when a distance between the transmitting vertical probe and the receiving vertical probe in the second direction is set to the set value L1, thereby generating third amplitude distribution data for a portion of the deep portion of the concrete structure; extracting fourth amplitude distribution data for the part of the deep portion of the concrete structure from the second amplitude distribution data; an ultrasonic measuring method comprising: correcting the first amplitude distribution data or the second amplitude distribution data using a ratio between an amplitude average value of the third amplitude distribution data and an amplitude average value of the fourth amplitude distribution data.

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