JP5750066B2 - Non-destructive inspection method using guided waves - Google Patents

Description

  The present invention relates to a nondestructive inspection method using a guide wave suitable for inspecting the state of thinning or a defect generated on the outer surface and inner surface of a bent region of a pipe using a guide wave.

  Structures such as pipes used in a plant are deteriorated and deteriorated with corrosion or erosion from the inner and outer surfaces over time while being affected by the environment in use. In locations where corrosion and erosion are likely to occur, deterioration may cause accidents leading to content leakage and breakage, so operators can prevent it by conducting regular non-destructive inspections and visual inspections. And the soundness of the structure is secured.

  Conventional non-destructive inspection using ultrasonic waves is generally an ultrasonic thickness gauge, but has several problems. The ultrasonic thickness gauge is a one-point inspection in which the operator measures the thickness of the contact surface between the sensor and the subject one by one, so the inspection range is narrow, tank inspection with a large surface area, and pipe inspection with a large diameter Takes a long time, resulting in increased inspection costs. In addition, when measuring high places or low places and narrow parts of a subject placed in a pit, it is necessary to take time to prepare for the examination because some countermeasures are taken. As a result, the inspection cost increases.

  Therefore, Patent Document 1 proposes a nondestructive inspection method using a guide wave which is a kind of ultrasonic wave. Guide waves are ultrasonic waves that propagate through an object having a boundary surface between a pipe and a plate, and use a characteristic that reflects at a portion where the thickness or shape of the plate changes, that is, a portion where the cross-sectional area in the thickness direction changes. In addition, it is used in an ultrasonic inspection method in which piping and plate-like inner and outer surfaces are collectively inspected over a long distance section.

  In non-destructive inspection technology by propagating a guide wave, the single mode guide wave used in the inspection is partially reflected at the part where the shape has changed by propagating on the subject surface over a long distance, and most of the rest Propagates in a single direction in the transmission direction. By receiving and analyzing various reflected signals reflected in the process of propagation, the reflected position and the reflected size can be estimated.

  In Patent Document 1, as a non-destructive inspection method using a guide wave, a change in sound velocity of each propagation mode (S0 mode and A0 mode) of the guide wave occurs in the thinned portion using a guide wave transmission method. Measure the propagation time difference of each propagation mode, check the characteristic curve of each propagation mode, find the plate thickness that causes the propagation time difference, measure the thinning depth, and display and evaluate the inspection result as an image A method is disclosed.

  In Patent Document 2, as a nondestructive inspection apparatus and a nondestructive inspection method using a guide wave, a guide wave is propagated to a pipe, a signal of the reflected wave is received, and reception information is stored. And a method of identifying defects by comparing the received information of the same type, the same shape, and the absence of defects with reference received information inspected and stored under the same inspection conditions.

  Further, Patent Document 3 discloses a method for flaw detection by concentrating ultrasonic waves and scanning electronically at a position where a defect signal is obtained in a flaw detection method for a welded portion.

Japanese Patent No. 4094464 JP 2009-36516 A JP 2001-324484 A

  Problems remain in the nondestructive inspection methods of Patent Documents 1 to 3 using guide waves. That is, the guide wave is difficult to apply to inspection of a part having a bent region portion of the pipe. Since the straight pipe is bent by a machine in the bent area of the pipe, a tensile stress is generated and extended on the outer side, and a compressive stress is generated and contracted on the inner side. Since the effective length of the pipe is different between the outer and inner parts, the guide wave propagating through the straight pipe part is distorted, scattered, leaked, and mode changes occur in the bent area part. Making it difficult.

  That is, the guide wave propagating to the straight pipe part in a single mode is distorted in the bending area of the pipe due to the difference in the path of the bending, and the energy is concentrated outside (back side) of the bending area. Propagated by turbulent waves. On the other hand, the waves propagating to the inner side (abdominal side) of the bent region are reduced by the amount of energy concentrated outside. For this reason, the amplitude of the guide wave in the bent region part has a large difference in the sensitivity of the guide wave depending on the position inside and outside. Therefore, when detecting a defect in a bent region using a guide wave, the magnitude of the received signal of the reflected wave greatly varies depending on the position of the defect, and there is a possibility that a small signal may be overlooked, which is reliable. Defect detection becomes difficult.

  FIG. 7 is a schematic diagram showing an electronic scanning method for a pipe bending region. The guide wave sensor 5 is provided with guide wave probes 3 and 4 in the straight pipe portion of the bent pipe test body 1 in order to inspect the bent region portion 2 of the bent pipe test body 1. 18a is a measurement target portion of the back side portion of the straight tube portion that is focused and measured from the guide wave sensor 5 by the electronic scan method, and 18b is a ventral side of the straight tube portion that is focused and measured from the guide wave sensor 5 by the electronic scan method. This is a part to be measured. Reference numeral 19a denotes a measurement target portion on the back side of the bent region portion that is focused and measured from the guide wave sensor 5 by the electronic scan method, and 19b denotes a bent region portion that is focused and measured from the guide wave sensor 5 by the electronic scan method. This is a measurement target site on the ventral part. Reference numerals 2a and 2b denote boundaries between the straight pipe portion and the bent region portion of the pipe.

  8A to 8D schematically show the positional relationship between the focused part and the guide wave sensor by the electronic scanning method for the measurement target part in the pipe bending region and the signal difference depending on the position of the measurement target part. 8A and 8B, a guide wave is transmitted such that the circumferential direction is a straight tube portion before the bent region portion of the pipe, and the circumferential direction is focused on the back side portion 18a and the abdominal side portion 18b with the measurement target portion, and is focused by the electronic scanning method. Shows the received signal when the simulated reflection source is installed under the same conditions. Even if the positions in the circumferential direction are different, no change in the intensity of the reflected signal is recognized.

  In contrast, FIGS. 8C and 8D show received signals when a guide wave is transmitted so as to be focused by an electronic scanning method with the back side portion 19a and the abdominal side portion 19b being the measurement target portions in the bending region portion. . The reflected signal intensity at the back side portion 19a in the circumferential position of FIG. 8C is larger than the reflected signal intensity at the ventral side portion 19b shown in FIG. 8D. Therefore, it is necessary to correct the difference in signal sensitivity.

  With respect to this point, Patent Document 1 and Patent Document 2 take no particular measures. Further, Patent Document 3 does not mention this problem.

  The object of the present invention has been made in view of such problems, and by taking into account sensitivity correction by position in detecting defects in a bent region of a pipe, and by detecting the signal depending on the position of the bent region of the pipe. By standardizing the size, it is to provide a nondestructive inspection method using a guide wave that can be inspected without overlooking defects from inspection results.

  The present invention installs a guide wave sensor in which a plurality of guide wave ultrasonic probes are arranged in the circumferential direction on the pipe surface, and transmits a guide wave to the bending region in the axial direction of the pipe by an electronic scanning method. In a non-destructive inspection method using a guide wave that receives a reflected signal from a part focused on a measurement target part in a bending area part and inspects a defect in the bending area part, the bending area part of the pipe is defined as an axial direction. Procedures to divide in the circumferential direction and determine the intersection of the axial direction and the circumferential direction in the number of divisions as the measurement target part, the distance to the sensor that transmits the plurality of determined measurement target parts and the guide wave, and the propagation speed of the guide wave The procedure for calculating the timing of the time for transmitting the guide wave from the transmitter and the guide wave sensor for transmitting the guide wave to be focused on the measurement target site by sequentially changing the multiple measurement target sites using the electronic scan method at the calculated time. Based on the procedure for receiving the reflected wave from the measurement target part and generating the reflected signal in the inspection information data, and the comparison data of the inspection information data of the same shape and the same measurement conditions of the bent region of the pipe obtained in advance A calculation processing procedure for correcting the inspection information data of the measurement results of the plurality of measurement target parts measured in the step, and a procedure for determining the presence / absence of a defect from the signal data displayed as a result of the corrected inspection information data generated by the calculation processing. It is characterized by providing.

  In the nondestructive inspection method using a guide wave, the procedure for determining the presence or absence of a defect from the signal data of the display result of the corrected inspection information data generated by the arithmetic processing is such that the measurement result evaluation signal has a predetermined threshold value. If it exceeds, it is judged that there is a defect.

  Further, in the non-destructive inspection method using a guide wave, it is characterized by having a procedure for re-measuring the defect with a different inspection means when it is determined that there is a defect when the evaluation signal of the measurement result exceeds a predetermined threshold value. To do.

  Further, in the nondestructive inspection method using a guide wave, measurement results of a plurality of measurement target parts measured based on comparison data of inspection information data having the same shape and the same measurement conditions of the bent region portion of the pipe obtained in advance. In the calculation processing procedure for correcting the inspection information data, the comparison data of the inspection information data includes a procedure for preparing a test specimen having the same shape as the object to be measured, a procedure for determining measurement conditions for the test specimen having the same shape, and a test for the same shape. It is generated by the procedure of measuring the body, recording the reference data, and generating the comparison data.

  As described above, according to the present invention, in the non-destructive inspection method using a guide wave for inspecting a defect in a bent region portion, the bent region portion of the pipe is divided in the axial direction and the circumferential direction, The procedure for determining the intersection of the axial direction and the circumferential direction as the measurement target site, the distance to the determined plurality of measurement target sites and the sensor that transmits the guide wave, and the timing of the time for transmitting the guide wave from the propagation speed of the guide wave In the calculated procedure and the calculated time, the guide wave sensor transmits a guide wave to be focused on the measurement target site by sequentially changing the multiple measurement target sites using the electronic scan method, and receives the reflected waves from the multiple measurement target sites. Multiple measurements measured based on the procedure for generating the reflected signal in the inspection information data and the comparison data of the inspection information data of the same shape and the same measurement conditions of the bent area of the pipe obtained in advance A bending region, comprising a calculation processing procedure for correcting inspection information data of the measurement result of the elephant part, and a procedure for determining the presence or absence of defects from the signal data of the result display of the corrected inspection information data generated by the calculation processing Since the influence of the sensitivity of the reflected wave due to the position of the defect signal of the portion can be eliminated, it is possible to surely prevent the defect from being overlooked from the inspection result and greatly improve the reliability of the inspection.

The block diagram of the guide wave nondestructive inspection device which has a guide wave sensor by the embodiment of the present invention. The flowchart of the nondestructive inspection method using the guide wave which concerns on embodiment of this invention. The schematic diagram which shows the measurement object site | part of the piping bending area | region part which concerns on embodiment of this invention. The schematic diagram which shows the other measurement object site | part of the piping bending area | region part which concerns on embodiment of this invention. The schematic diagram which shows the other measurement object site | part of the piping bending area | region part which concerns on embodiment of this invention. The expanded view which shows the measurement result which concerns on embodiment of this invention. The expanded view which shows the measurement result which concerns on embodiment of this invention. The flowchart of the acquisition method of the reference | standard data of the piping bending area | region part which concerns on embodiment of this invention. The distribution map which shows the result of the simulation defect signal in the measuring object part concerning the embodiment of the present invention. The schematic diagram which shows the electronic scan system to the measurement object site | part of the piping bending area | region part of a prior art example. The graph which shows the difference in the signal by the position of the measurement object site | part of a prior art example. The graph which shows the difference in the signal by the position of the measurement object site | part of a prior art example. The graph which shows the difference in the signal by the position of the measurement object site | part of a prior art example. The graph which shows the difference in the signal by the position of the measurement object site | part of a prior art example.

  An outline of a nondestructive inspection method using a guide wave in an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 shows a block diagram of a guided wave non-destructive inspection apparatus having a guided wave sensor according to an embodiment of the present invention. The guide wave nondestructive inspection device 6 includes a guide wave sensor 5 in which a plurality of transmission / reception guide wave probes 3 and 4 are arranged, a guide wave signal generator 8 for sending an electrical signal to the guide wave sensor 5, and a power amplifier. 9, a reception signal switching unit 10 that receives a signal from the guide wave sensor 5, a receiver amplifier 11, a plurality of high-speed A / D conversion units 12 that convert analog signals into digital signals, and a control unit that controls transmission and reception of signals 7.

  The personal computer 13 includes a control software 14 of the built-in guided wave nondestructive inspection device 6, a calculation / data storage unit 15 for processing a received waveform, a transmission time difference setting unit 16, and an input / output display unit 17. It is comprised, is connected to the control part 7 of the guide wave nondestructive inspection apparatus 6, and controls the guide wave nondestructive inspection apparatus 6 whole by communication.

  The guide wave sensor 5 is configured by arranging a plurality of transmission / reception guide wave probes 3 and 4 on the outer periphery of the pipe 1 in a line in the circumferential direction, and measures the bending region portion 2 of the pipe 1. Reference numeral 2a denotes a start position of the bending area 2 from the straight pipe, and 2b denotes an end position of the bending area 2.

  Ultrasound is transmitted by an electronic scanning phased array method. Since the guide wave probe 3 and the guide wave probe 4 arranged in the circumferential direction are divided and electronically controlled, the same number of guide waves is used. The probes need to have the same configuration in which the probes are connected in parallel and arranged in parallel so as to correspond one-to-one.

  Next, in the non-destructive inspection using the guide wave according to the present invention, a series of procedures in the case of performing the actual inspection by installing the guide wave non-destructive inspection apparatus on the bending pipe to be inspected will be described with reference to the flowchart of FIG. .

  First, in step S101, the measurement object is selected and the shape is grasped. Here, the bent pipe 1 will be described as an inspection target. First, the material, the diameter, the thickness, and the radius of curvature of the bent region of the bent pipe are measured and confirmed on the design drawing or on-site. Moreover, the start position 2a of the bending area part 2 and the end position 2b of the bending area part 2 are also confirmed from the straight pipe. As test measurement conditions, the measurement frequency, the type of waveform to be transmitted, and the transmission mode are determined from the parameters. In these, after starting a guide wave measurement program included in the control software of the personal computer 13, measurement conditions can be input / selected from the input / output display unit 17.

  In step 102, the guide wave sensor 5 is attached to the pipe 1. In order to measure the bending area 2 of the pipe 1, it is installed in a straight pipe section away from the start position 2 a of the bending area 2 in consideration of the dead zone area of the signal at the time of guide wave transmission / reception.

  In step S103, the measurement target site p of the bending area 2 is determined. 3A, 3B, and 3C show an example in which the bent region portion 2 is divided.

  3A to 3C are schematic diagrams showing a measurement target site p obtained by dividing the pipe bending region according to the embodiment of the present invention. FIG. 3A shows a case where the circumferential direction of the pipe is divided into 12 equal parts and the axial direction of the bent region is divided into three equal parts. The divided intersection position in the circumferential direction and the axial direction is set as a measurement target portion p for inspection. The measurement target site p was a point for focusing a beam (here, a guide wave) by a phased array method using an electronic scan method. The site to be measured in FIG. 3A is 40 points.

  FIG. 3B shows a case where the circumferential direction of the pipe is divided into 12 equal parts and the axial direction of the bent region is divided into three equal parts. The divided intersection position in the circumferential direction and the axial direction is set as a measurement target portion p for inspection. The site to be measured in FIG. 3B is 48 points.

  FIG. 3C shows a case where the circumferential direction of the pipe is divided into 16 equal parts and the axial direction of the bent region is divided into 4 equal parts. The divided intersection position in the circumferential direction and the axial direction is set as a measurement target portion p for inspection. The site to be measured in FIG. 3C is 80 points. The interval of division is determined by the pipe diameter, wall thickness, radius of curvature, frequency, and the like.

  In step S104, a guide wave transmission delay time is calculated. The guide wave to be focused on the measurement target part of the bent region 2 by the electronic scanning method is the position of the measurement target part p determined in step S103, the guide wave probe 3 of the guide wave sensor 5, the guide wave probe 4, and the like. The distance is determined from the position of. The time to reach the measurement target part is calculated from the distance and the sound velocity of the guide wave propagating to the pipe. The arrival time is calculated for each measurement target part determined in step S103. The transmission guide wave can be focused at the position of the measurement target site by giving a time difference to the guide wave probe 3 and the guide wave probe 4 of the guide wave sensor 5 and transmitting the calculated delay time.

  In step S105, the main measurement is started. For measurement, a guide wave measurement program built in the guide wave nondestructive inspection apparatus 6 and the personal computer 13 is started up, and measurement condition parameters are input and selected from the input / output display unit 17. The basic conditions are stored in advance and set manually or automatically, and have a function that can be changed later. Measurement conditions include measurement frequency, measurement gain, transmission waveform, transmission mode, applied voltage, noise cut filter, and the like. There are other transmission waveform generation, trigger signal timing, etc., but details are omitted.

  When there is a discontinuous part such as a defect in the pipe 1, a reflected wave is generated, and the reflected wave is received by the guide wave sensor 5 as a reflected signal. The received signal is amplified by the receiver amplifier 11, sent to the high-speed A / D converter 12, converted into a digital signal, sent to the controller 7 and the personal computer 13, and each of the guide wave probes 3, 4 Is generated by performing a superposition calculation process of the received signal from the signal, and used as inspection information data as a received waveform. The amplitude value of the signal at the position of the measurement target part is obtained, and the measurement target part and the amplitude value are stored in the storage unit 15 as a database.

  In step S106, the measurement is repeated until the measurement of the measurement target region is completed.

  In step S107, the display of the measurement result is represented, for example, in a development view obtained by dividing the curved pipe as shown in FIGS. 4A and 4B from the database of the measurement target part and the amplitude value stored from the examination information data. The amplitude value is displayed in a map with shades of color depending on the magnitude. The horizontal axis is the angle in the circumferential direction, and the vertical axis is the distance from the beginning of the bent region of the pipe. The amplitude value obtained here is data before correction that does not consider the influence of the sensitivity difference due to the propagation behavior peculiar to the guide wave in the bent region of the pipe.

  In step S108, a pipe having the same shape as the pipe to be measured is measured in advance under the same conditions and stored in the database as comparison data. The measurement target region and the amplitude value data obtained in S105 are compared with corresponding comparison data selected from the database. The data obtained in S105 has a one-to-one correspondence with the sensitivity correction distribution data shown in FIGS. 4A and 4B.

  By correcting the measured data with the sensitivity correction value of the comparison data, it is possible to cancel and correct the influence of the sensitivity difference due to the propagation behavior peculiar to the guide wave in the bent region of the pipe.

  In step S109, the result of correcting the sensitivity difference in the bent region of the pipe is displayed in the same manner as in FIGS. 4A and 4B. Moreover, you may display as a distribution map by the shading of the color in the area | region divided | segmented by the piping bent shape.

  In step S110, a threshold is set from the amplitude value data after sensitivity correction obtained in step S109, and a portion where data equal to or greater than the threshold is obtained is determined as a defect. About the measurement object site | part determined with the defect, it re-measures and confirms by another test | inspection by step S111. Since the amplitude value of the threshold varies depending on the size of the defect, a lower limit value of the allowable size of the defect is set in advance.

  FIG. 5 shows a flowchart of a method for recording the reference data of the bent pipe that is measured and stored in advance. In general, the main measurement and the procedure in FIG. 2 are the same.

  In step 201 and step 202, after investigating the shape of the target pipe to be inspected, a pipe specimen having the same shape such as the pipe material, the diameter, the wall thickness, and the curvature radius of the bent region is prepared. The measurement conditions may be set in a slightly wider range than the value including the measurement conditions in consideration of the measurement, such as the frequency, the type of waveform to be transmitted, and the transmission mode.

  In step S203, the guide wave sensor 5 is attached to the pipe 1. In order to measure the bend area 2 of the pipe 1, in consideration of the dead zone area of the signal at the time of guide wave transmission / reception, a straight pipe section away from the start portion 2a of the bend area is set to the same distance as the main measurement. Is desirable.

  In step S204, the measurement target part of the pipe bending region part is determined by determining the number to be divided in the circumferential direction and the axial direction, and the intersection position is set as the measurement target part. For example, there is a method in which the circumferential direction is divided by an angle and the axial direction is divided by an angle of curvature of a bent region portion. It is better to subdivide as much as possible for the purpose of obtaining basic data. Next, the simulated reflection source is installed at the measurement site. In this method, a simulated reflection source such as a magnet is installed at one location on the measurement target site, and measurement is performed in order.

  In step S205, the guide wave transmission delay time is calculated by calculation based on the sound velocity of the guide wave propagating from the distance between each measurement target region and the guide wave probe.

  In step S206, the measurement of the reference data is performed by transmitting a guide wave by the electronic scan phased array method using the delay time obtained in step S205 and the measurement conditions set in step S202, and determining in step S204. When a simulated reflection source is installed at the focused measurement target site, the reflected wave is received as a reflected signal by the guide wave sensor 5 in the presence or absence of the simulated reflection source. 6. The personal computer 13 performs arithmetic processing to obtain inspection information data as a received waveform.

  In storing the measurement result in step S207, the received signal and the received waveform after the arithmetic processing are stored in the storage unit as inspection information data. Further, by performing a difference calculation process on the measurement result when there is no simulated reflection source and the measurement result when there is a simulated reflection source, a reflected signal of a reflected wave from the net simulated reflection source can be obtained.

  FIG. 6 shows a distribution diagram in which a simulated reflection source is installed at a measurement target site in the bent region and the reflected signal from the simulated reflection source is expressed by an amplitude value. Here, the horizontal axis indicates the circumferential position of the pipe, and the vertical axis indicates the axial distance of the bent region. The 0 ° position in the circumferential direction represents the back side of the bent region. The signal sensitivity is highest in the central portion on the back side, and the signal sensitivity is lowest in the central portion on the ventral side at 180 ° in the circumferential direction. Furthermore, since the sensitivity distribution of the pipe bending area is obtained from the relationship between the signal intensity of the reflected signal from the simulated reflection source and the position of the measurement target part, each type of bent pipe is stored as a reference data in a database. And used as comparison data in S107.

  In step S208 and step S209, repeated measurement is performed under different measurement conditions, and the obtained reference data is stored in the storage unit 15 each time.

  As described above, in the present invention, the noise signal that has undergone mode conversion by total reflection is detected by focusing the guide wave on the bent region of the pipe and using the sensitivity correction distribution in consideration of the influence of the distortion of the guide wave propagation caused by the bend. And, even if the signal from the defect overlaps in the detected area, the noise signal and the signal from the defect can be distinguished, so the technology that maintains the measurement performance of the guide wave sensor and the reliability of the inspection result It can be combined with improvement.

  The above-described effects of the present invention can identify the noise of the pseudo signal at the end subjected to mode conversion by total reflection, and can extract the reflected signal from the defect, thereby preventing the inspection result from being overlooked and improving the reliability of the inspection. This specific method is to generate data measured by the same measurement system at two or more locations as inspection information data, and perform arithmetic processing and comparison of the obtained plurality of data.

  As described above, according to the non-destructive inspection method using the guide wave of the present embodiment, it is possible to prevent the oversight of the defect by correcting the size of the defect in the bent region portion of the pipe by the sensitivity correction distribution. The reliability of inspection can be improved.

  According to the present invention, a non-destructive inspection of a cylindrical structure can be performed, so that it can be applied to many fields.

1: Curved piping test body 2: Curved region of piping 3: Guide wave probe 4: Guide wave probe 5: Guide wave sensor 6: Guide wave nondestructive inspection device 7: Control unit 8: Signal generation unit 13 : Personal computer 14: Guide wave control software 15: Calculation / storage unit 16: Transmission time difference setting unit 17: Input / display unit Y 1: Reflected signal Y 2 from the measurement target part of the simulated reflection source on the back side of the straight tube unit: Reflected signal X1 from the measurement target portion of the simulated reflection source on the ventral side of the straight tube portion Reflected signal X2 from the measurement target portion of the simulated reflection source on the back side of the bent region portion: on the ventral portion of the bent region portion Reflection signal from the measurement target part of the simulated reflection source

Claims (4)

A guide wave sensor in which a plurality of guide wave ultrasonic probes are arranged in the circumferential direction is installed on the pipe surface, and a guide wave is transmitted to the bending area in the axial direction of the pipe by an electronic scanning method. In a nondestructive inspection method using a guide wave that receives a reflected signal from a part focused on a measurement target part and inspects a defect in a bent region part,
Dividing the bent region of the pipe in the axial direction and the circumferential direction, and determining the intersection of the axial direction and the circumferential direction in the number of divisions as a measurement target site;
A procedure for calculating the timing of transmitting a guide wave from the determined distance to the plurality of measurement target parts and a sensor for transmitting the guide wave and the propagation speed of the guide wave;
At the calculated time, the guide wave sensor transmits a guide wave to be focused on the measurement target part by sequentially changing the plurality of measurement target parts by an electronic scan method, and receives and reflects the reflected waves from the plurality of measurement target parts. A procedure for generating signals into test information data;
An arithmetic processing procedure for correcting inspection information data of measurement results of a plurality of measurement target parts measured based on comparison data of inspection information data of the same shape and the same measurement conditions of the bent region portion of the pipe obtained in advance,
A nondestructive inspection method using a guide wave, comprising: a step of determining the presence or absence of a defect from signal data of a result display of inspection information data after correction generated by the arithmetic processing.   2. The nondestructive inspection method using a guide wave according to claim 1, wherein the procedure for determining the presence / absence of a defect from the signal data of the result display of the corrected inspection information data generated by the arithmetic processing is an evaluation of a measurement result. A nondestructive inspection method using a guide wave, wherein a defect is determined to be present when a signal exceeds a predetermined threshold.   In the nondestructive inspection method using the guide wave according to claim 2, a procedure for re-measuring the defect with a different inspection means when it is determined that there is a defect when the evaluation signal of the measurement result exceeds a predetermined threshold value. A nondestructive inspection method using a guide wave characterized by comprising: In the nondestructive inspection method using the guide wave according to any one of claims 1 to 3, in the comparison data of the inspection information data of the same shape and the same measurement condition of the bent region portion of the pipe obtained in advance. The comparison data of the test information data in the calculation processing procedure for correcting the test information data of the measurement results of the plurality of measurement target parts measured based on
A procedure for preparing a specimen having the same shape as the object to be measured;
A procedure for determining measurement conditions for the same shape test specimen;
A nondestructive inspection method using a guide wave, characterized in that it is generated by a procedure of measuring the same shape specimen and recording reference data and generating comparison data.

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