JP2006132981A - Ultrasonic wall-thickness measuring instrument and ultrasonic wall-thickness measuring method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent lowering of evaluation accuracy, with respect to a micro-change in wall thickness in the measurement of wall thickness, using ultrasonic inspection technique. <P>SOLUTION: The ultrasonic wall-thickness measuring instrument is constituted so that wall thickness variation or the like is determined in a received ultrasonic wave by using the optimum wave number signal of a repeatedly received ultrasonic wave to exaggerate wall thickness difference display on a display screen and the determination or the like of the micro-variation in wall thickness is made easy by the exaggerated display and the wall-thickness distribution display in the specimen as a whole. As a result, a measuring result can be easily determined, even by a person other than a skilled inspector, a determined mistake can be prevented and the reliability of evaluation data is also enhanced. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention measures the thickness of an object to be inspected such as a metal material (hereinafter referred to as a “subject”), and evaluates the thickness from the measurement data. The present invention relates to a thickness measuring apparatus and method.

  Nondestructive inspection methods are widely used for measuring the thickness of metal containers and metal welds. Thickness measurement is extremely important for ensuring product reliability and safety during product operation.

  For example, in the measurement of the wall thickness of a pipe through which a high-temperature fluid flows, it is indispensable to periodically confirm safety by nondestructive inspection in a gas turbine apparatus or the like in which a high pressure is applied in a high-temperature environment.

  For the wall thickness measurement, an ultrasonic flaw detection apparatus using an ultrasonic flaw detection sensor (Ultrasonic Testing Sensor: UT sensor; hereinafter referred to as a probe) is used. The ultrasonic flaw detector includes a probe, a control unit for controlling the operation of the probe, a switching unit for setting the probe in a transmission state or a reception state, and an operation for processing data acquired by the probe. And a display unit for displaying the processing results processed by the calculation unit.

  The basic principle of thickness measurement using an ultrasonic flaw detector is that an ultrasonic wave is transmitted from a probe toward a subject. Then, the ultrasonic signal transmitted from the bottom surface of the subject is reflected, and the reflected wave is received by the probe. The probe serves as both transmission and reception of an ultrasonic signal. When the ultrasonic wave reflected by the probe is received, the time when the ultrasonic wave is transmitted and the transmitted ultrasonic wave are received. The wall thickness of the subject can be calculated by obtaining the time difference from the measured time.

  In particular, it is strongly desired to improve measurement accuracy and measurement accuracy or resolution by separating wall thickness measurement accuracy from external disturbances such as scale adhesion, internal flaws, and disturbances such as material changes such as welds. In addition, in addition to these, there is an increasing demand for display technology in which the thickness measurement result is imaged and visualized to reduce determination errors and can be easily determined by non-experts.

  As one of representative techniques for achieving the above-described object, wall thickness measurement using an ultrasonic test method (hereinafter referred to as UT method) is known. FIG. 18 illustrates a pipe wall thickness measurement method by the UT method. When measuring the wall thickness of the pipe to be measured in the pipe having a relatively large diameter in FIG. 18, the operator holds the ultrasonic probe as shown in FIG. Divide the circumferential direction into 8 parts, measure the 8 positions in the circumferential direction for the specific longitudinal position of the pipe, send the measurement signal to the wall thickness measuring instrument, and use the wall thickness value obtained at the 8 places, the pipe A method (Patent Document 1) of evaluating as an average thickness value or the like at a specific longitudinal direction position is disclosed.

JP 2000-346632 A

  The thickness measurement using the conventional ultrasonic method is based on the time when the ultrasonic wave is transmitted from the ultrasonic probe using the received ultrasonic signal of the first wave obtained from the ultrasonic probe and the first wave. The time difference from the time when the received ultrasonic signal was received was obtained, and the thickness value was calculated using the sound velocity value of the subject subject itself. Further, when a scale is attached to the end face of the subject (mainly, the opposite face as viewed from the probe side), measurement errors may occur due to them. Furthermore, as described above, for example, because the thickness of the subject was evaluated by a method such as determining the representative thickness value from the measurement results of 8 locations, the determination of a minute thickness change, It was difficult to identify and evaluate the thickness distribution of the entire subject.

The ultrasonic thickness measuring apparatus according to claim 1 of the present invention for solving the above problems is
An ultrasonic probe that transmits ultrasonic waves from the ultrasonic probe to the measurement portion of the subject and receives the ultrasonic signals that are reflected back; and
Means for displaying the received ultrasound signal;
Comprising means for sequentially displaying received ultrasonic signals received repeatedly;
It is characterized by.

An ultrasonic thickness measuring apparatus according to claim 2 of the present invention for solving the above-mentioned problems is provided.
In the ultrasonic thickness measuring apparatus according to claim 1,
When displaying the received ultrasonic signal, displaying the received ultrasonic signal amplitude color tone classification,
It is characterized by.

An ultrasonic thickness measuring apparatus according to claim 3 of the present invention for solving the above-described problems is provided.
In the ultrasonic thickness measuring apparatus according to claim 1 or 2,
Comprising means for displaying the thickness distribution of the entire subject by scanning the ultrasonic probe;
It is characterized by.

An ultrasonic thickness measuring apparatus according to claim 4 of the present invention for solving the above-mentioned problems is provided.
In the ultrasonic thickness measuring apparatus according to claim 2,
Comprising means for distinguishing between different color tone indications of different acoustic impedances within the subject;
It is characterized by.

The ultrasonic thickness measuring method according to claim 5 of the present invention for solving the above-mentioned problem is as follows.
A step of transmitting an ultrasonic wave from the ultrasonic probe to the subject and receiving an ultrasonic signal that is reflected and returned;
Displaying the received ultrasound signal;
Comprising a step of sequentially displaying received ultrasonic signals that are repeatedly received;
It is characterized by.

  Since the present invention is configured as described above, the following effects can be obtained.

  In wall thickness measurement using the ultrasonic flaw detection method, ultrasonic waves are transmitted from the probe to the inside of the subject, and when the ultrasonic signal is received by the probe, only the conventional reception first wave signal is used. Unlike measuring wall thickness, by using a signal that is repeatedly received, the amount of change at the thickness change point is expanded by the number of times the received signal is repeated, and the change in thickness is further increased. By displaying the color classification of the signal, it is possible to easily evaluate the presence or absence of wall thickness variation and the wall thickness, and as a result, improve the wall thickness measurement accuracy and reduce evaluation errors due to disturbances such as vertical movement of the probe itself. Accuracy data can be provided, and overall inspection accuracy can be improved, and further, safety of inspection objects can be improved.

  The best mode for carrying out an ultrasonic thickness measuring apparatus and method according to the present invention will be described below with reference to the accompanying drawings.

(First embodiment)
FIG. 1 shows the configuration of an ultrasonic thickness measuring apparatus according to Embodiment 1 of the present invention, FIG. 2 shows the detailed configuration of a signal amplitude / color tone converter 10 in the apparatus, and FIG. FIG. 9 shows a detailed configuration diagram of an ultrasonic flaw detector, with reference to a measurement situation and an example of transmission / reception ultrasonic signals using the sonic wall thickness measuring apparatus. The ultrasonic thickness measuring apparatus according to the present embodiment includes a probe 1, a signal processing unit 30, a signal amplitude / color tone converter 10, a display switch 11, and a data display unit 12. The signal processing unit 30 first outputs an electrical signal necessary for transmitting an ultrasonic signal by the probe 1 from the ultrasonic flaw detector 2 and sends the transmission / reception switch 5 to the transmission side (not shown). Switch. Next, an ultrasonic signal necessary for flaw detection on the subject 20 is transmitted to the probe 1, and the transmission / reception switch 5 is switched to the reception side (not shown) in order to receive the signal. Further, the ultrasonic flaw detector 2 receives signals as signal processing functions such as amplification of an ultrasonic transmission signal to be supplied to the probe 1 and amplification of an ultrasonic reception signal obtained from the probe 1. Filters 221, 222, and 223, and signal processors 1 231, 232, and 233 that perform processing such as amplification of these signals, and a signal switch for outputting a desired frequency signal 240. Next, the received ultrasonic signal obtained by the ultrasonic flaw detector 2 is converted into a digital signal by the A / D converter 9 to be a received ultrasonic signal 90, which is a signal amplitude / tone converter 10 and a display switcher. 11 is sent. In the signal amplitude / tone converter 10, the received ultrasound signal 90 is converted into a voltage value by the received ultrasound signal amplitude value / voltage value converter 91, and the tone value data 93 is converted using the voltage value / tone value conversion database 92. And is sent to the display switch 11.
On the other hand, in order to inspect the entire subject 20, the probe mover 6 composed of parts such as a motor and a gear for scanning (moving) the probe 1, and flaw detection control for controlling the scanning. And a probe position detector 8 for detecting the scanning (moving) position of the probe 1 and an A / D converter 9 for converting the above-mentioned ultrasonic signal into a digital signal. Yes. In the data display unit 12, the display switch 11 displays the received waveform display subjected to color conversion, the received waveform display, or the wall thickness result obtained by displaying them simultaneously.

  Here, by switching the display switch 11 to the reception ultrasonic signal side (not shown), the reception ultrasonic signal to be displayed on the data display unit 12 is, for example, a transmission ultrasonic signal at point A as shown in FIG. When 50 is transmitted to the subject 20, a first wave signal 51, a second wave signal 52, a third wave signal 53,... Of the received ultrasonic signal are sequentially received. Further, for example, when the transmission ultrasonic signal 60 is transmitted to the subject 20 at the point B, the first wave signal 61, the second wave signal 62, the third wave signal 63,. Received. Here, paying attention to the first wave signals 51 and 61 of the received ultrasonic signal, the time difference 101 corresponds to the thickness difference of the subject itself at the points A and B. Here, when attention is paid to the time difference 102, 103,... Of the received ultrasonic signal from the second wave signal 52 and 62, the thickness difference is displayed by multiplying the received ultrasonic signal by N waves. It will be. In other words, when the difference in thickness is obtained, the difference is exaggerated as the second and third waves are displayed, rather than being evaluated on the screen displayed with the thickness difference in the first wave of the received ultrasonic signal. The

  The optimum wave number of the received ultrasonic wave is determined by the S / N ratio of each of the received ultrasonic signals 51, 52, 53... The general S / N ratio is preferably about 3 or more. The optimum wave number of the received ultrasonic wave signal is determined in consideration of ease of evaluation, ease of display, and the like with the wave number that satisfies the maximum value.

  As described above, the thickness difference display is exaggerated on the display screen by judging by the wave number of the optimum repeated received ultrasound signal of the received ultrasound, and the display of the thickness difference is further exaggerated. Confirmation can be easily performed by a person other than a skilled inspector, so that a determination error can be prevented and the reliability of evaluation data is improved.

(Second Embodiment)
FIG. 1 shows a configuration of an ultrasonic thickness measuring apparatus according to Embodiment 2 of the present invention, FIG. 2 shows a detailed configuration of a signal amplitude / tone converter 10 in the apparatus, and FIG. FIG. 5 is an explanatory diagram showing the relationship between the received signal amplitude and the color tone value data, and FIG. 5 is a table showing an example of a conversion database of the ultrasonic received signal amplitude value and the color tone value data. In addition, this embodiment is a content obtained by partially improving the content described in the first embodiment described above, and the same components as those in the first embodiment are denoted by the same reference numerals, and redundant description is omitted.

The ultrasonic thickness measuring apparatus according to the present embodiment includes a probe 1, a signal processing unit 30, a signal amplitude / color tone converter 10, a display switch 11, and a data display unit 12. The signal processing unit 30 first outputs an electrical signal necessary for transmitting an ultrasonic signal by the probe 1 from the ultrasonic flaw detector 2 and sends the transmission / reception switch 5 to the transmission side (not shown). Switch. Next, an ultrasonic signal necessary for flaw detection on the subject 20 is transmitted to the probe 1, and the transmission / reception switch 5 is switched to the reception side (not shown) in order to receive the signal. Further, the ultrasonic flaw detector 2 has a signal processing function such as amplification of an ultrasonic transmission signal to be supplied to the probe 1 and amplification of an ultrasonic reception signal obtained from the probe 1. Next, the received ultrasonic signal obtained by the ultrasonic flaw detector 2 is converted into a digital signal by the A / D converter 9 to be a received ultrasonic signal 90, which is a signal amplitude / tone converter 10 and a display switcher. 11 is sent. In the signal amplitude / tone converter 10, the received ultrasound signal 90 is converted into a voltage value by the received ultrasound signal amplitude value / voltage value converter 91, and the tone value data 93 is converted using the voltage value / tone value conversion database 92. And is sent to the display switch 11.
On the other hand, in order to inspect the entire subject 20, the probe mover 6 composed of parts such as a motor and a gear for scanning (moving) the probe 1, and flaw detection control for controlling the scanning. And a probe position detector 8 for detecting the scanning (moving) position of the probe 1 and an A / D converter 9 for converting the above-mentioned ultrasonic signal into a digital signal. Yes.
In the data display unit 12, the display switch 11 displays the received waveform display subjected to color conversion, the received waveform display, or the wall thickness result obtained by displaying them simultaneously.

  Here, by switching the display switch 11 to the color tone value data side (not shown), the received ultrasonic signal to be displayed on the data display unit 12 is, for example, at point A as shown in FIG. The first wave signal 51, the second wave signal 52, the third wave signal 53, and so on, are sequentially received as color tone value data 510 of the first wave signal of the received ultrasonic signal, and the second wave signal. Color tone value data 520, the third wave signal color tone value data 530... Further, for example, the first wave signal 61, the second wave signal 62, the third wave signal 63,... Sequentially received at the point B are the first wave signal of the received ultrasonic signal. Color tone value data 610, second wave signal color tone value data 620, third wave signal color tone value data 630... In addition, there is a method in which the relationship between the received ultrasonic signal level and the color tone value data is stored in a database in advance as in the example shown in FIG. Here, paying attention to the tone value data 510 and 610 of the first wave signal of the received ultrasonic signal, the time difference 101 corresponds to the thickness difference of the subject itself at the points A and B. Here, when attention is paid to the time difference 102, 103,... Of the received ultrasonic signal from the tone value data 520 and 620 of the second wave signal, the thickness difference is N times the received ultrasonic signal. Will be displayed. In other words, when the difference in thickness is obtained, the difference is exaggerated as the second wave and the third wave are evaluated rather than being evaluated on the screen displayed with the thickness difference in the first wave of the received ultrasonic signal. The

  As described above, the thickness difference display is exaggerated on the display screen by judging the thickness variation etc. mainly using the color tone data of the wave number signal of the optimum received ultrasonic wave of the received ultrasonic wave, Further, since the display is exaggerated, it is easy for a person other than a skilled inspector to confirm the difference in thickness, and therefore, a determination error can be prevented and the reliability of the evaluation data is improved.

(Third embodiment)
FIG. 1 shows the configuration of an ultrasonic thickness measuring apparatus according to Embodiment 3 of the present invention, FIG. 2 shows the detailed configuration of the signal amplitude / color tone converter 10 in the apparatus, and FIG. FIG. 5 is an explanatory diagram showing the relationship between the signal amplitude and the color tone value data, FIG. 5 is a table showing an example of a conversion database between the ultrasonic wave reception signal amplitude value and the color tone value data, and FIG. Are continuously scanned, and the thickness distribution of the entire subject 20 is displayed in color tone. This embodiment is a content obtained by partially improving the contents described in the first embodiment and the second embodiment described above, and the same reference numerals are given to components having the same configurations as those in the first and second embodiments. In addition, overlapping explanation is omitted.

The ultrasonic thickness measuring apparatus according to the present embodiment includes a probe 1, a signal processing unit 30, a signal amplitude / color tone converter 10, a display switch 11, and a data display unit 12. The signal processing unit 30 first outputs an electrical signal necessary for transmitting an ultrasonic signal by the probe 1 from the ultrasonic flaw detector 2 and sends the transmission / reception switch 5 to the transmission side (not shown). Switch. Next, an ultrasonic signal necessary for flaw detection on the subject 20 is transmitted to the probe 1, and the transmission / reception switch 5 is switched to the reception side (not shown) in order to receive the signal. Further, the ultrasonic flaw detector 2 receives signals as signal processing functions such as amplification of an ultrasonic transmission signal to be supplied to the probe 1 and amplification of an ultrasonic reception signal obtained from the probe 1. Filters 221, 222, and 223, and signal processors 1 231, 232, and 233 that perform processing such as amplification of these signals, and a signal switch for outputting a desired frequency signal 240. Next, the ultrasonic signal obtained by the ultrasonic flaw detector 2 is converted into a digital signal by the A / D converter 9 to be a received ultrasonic signal 90, which is a signal amplitude / color tone converter 10 and a display switcher 11. Sent to. In the signal amplitude / tone converter 10, the received ultrasound signal 90 is converted into a voltage value by the received ultrasound signal amplitude value / voltage value converter 91, and the tone value data 93 is converted using the voltage value / tone value conversion database 92. And is sent to the display switch 11.
On the other hand, in order to inspect the entire subject 20, the probe mover 6 composed of parts such as a motor and a gear for scanning (moving) the probe 1, and flaw detection control for controlling the scanning. And a probe position detector 8 for detecting the scanning (moving) position of the probe 1 and an A / D converter 9 for converting the above-mentioned ultrasonic signal into a digital signal. Yes. In the data display unit 12, the display switch 11 displays the received waveform display subjected to color conversion, the received waveform display, or the wall thickness result obtained by displaying them simultaneously.

  Here, by switching the display switch 11 to the color tone value data side (not shown), the received ultrasonic signal to be displayed on the data display unit 12 is, for example, at point A as shown in FIG. The first wave signal 51, the second wave signal 52, the third wave signal 53, and so on, are sequentially received as color tone value data 510 of the first wave signal of the received ultrasonic signal, and the second wave signal. Color tone value data 520, the third wave signal color tone value data 530... Further, for example, the first wave signal 61, the second wave signal 62, the third wave signal 63,... Sequentially received at the point B are the first wave signal of the received ultrasonic signal. Color tone value data 610, second wave signal color tone value data 620, third wave signal color tone value data 630... In addition, there is a method in which the relationship between the received ultrasonic signal level and the color tone value data is stored in a database in advance as in the example shown in FIG. Here, paying attention to the tone value data 510 and 610 of the first wave signal of the received ultrasonic signal, the time difference 101 corresponds to the thickness difference of the subject itself at the points A and B. Here, when attention is paid to the time difference 102, 103,... Of the received ultrasonic signal from the tone value data 520 and 620 of the second wave signal, the thickness difference is N times the received ultrasonic signal. Will be displayed. In other words, the difference is exaggerated as the second wave and the third wave, rather than evaluating on the screen displayed by the thickness difference in the first wave of the received ultrasonic signal when obtaining the wall thickness difference. Is displayed. As described above, the probe 1 is not limited to the points A and B, and the probe 1 is continuously scanned over the entire measurement target portion of the subject 20 to sequentially collect data, and further sequentially convert the color of the signal to change the display. Each received ultrasonic signal and color tone data are recorded and stored in the device 11 (not shown), and the whole and necessary parts are enlarged / reduced on the data display unit as necessary.

  As described above, the thickness difference display is exaggerated on the display screen by judging the thickness variation etc. mainly using the color tone data of the wave number signal of the optimum received ultrasonic wave of the received ultrasonic wave, Furthermore, the exaggerated display and the thickness distribution display of the entire subject 20 make it easy to determine minute thickness fluctuations, and as a result, even a person other than a skilled inspector can easily determine the measurement result. Therefore, determination errors can be prevented and the reliability of the evaluation data is improved.

Furthermore, as another effect, in the case where the probe 1 fluctuates up and down at the time of measurement, for example, when the probe is lifted from the subject, the first wave and the second wave of the received ultrasonic signal. ... and the color data obtained by color-tone-converting the received ultrasonic signal, the interval value between the first wave and the second wave of the received ultrasonic signal or the color data, and the second wave and the third wave. Are equal interval values, and the time difference values 101, 102,... Corresponding to the thickness difference between the point A and the point B using the first wave reception signal described above. Thus, unlike the display in which the thickness value fluctuates, it is possible to determine the difference from the vertical fluctuation of the probe 1.

(Fourth embodiment)
12 shows the configuration of the ultrasonic thickness measuring apparatus according to the fourth embodiment of the present invention, FIG. 13 shows the detailed configuration of the signal amplitude / tone converter 100 in the apparatus, and FIG. 14 shows the ultrasonic reception. FIG. 15 is an explanatory diagram showing the relationship between the signal amplitude and the tone value data, FIG. 15 is an explanatory diagram of reflection and transmission at different acoustic impedance boundaries, and FIG. 16 is the presence or absence of inversion of the reflected signal at different acoustic impedance boundaries. FIG. 17 is a diagram showing an example of acoustic impedance values of various materials, and FIG. 9 is a diagram showing a detailed configuration of the ultrasonic flaw detector 2. In addition, this embodiment is a content obtained by partially improving the content described in the first embodiment described above, and the same components as those in the first, second, and third embodiments are denoted by the same reference numerals, and duplicated. The description to be omitted is omitted.

The ultrasonic thickness measuring apparatus according to the present embodiment includes a probe 1, a signal processing unit 30, a signal amplitude / color tone converter 100, a display switch 11, and a data display unit 12. The signal processing unit 30 first outputs an electrical signal necessary for transmitting an ultrasonic signal by the probe 1 from the ultrasonic flaw detector 2 and sends the transmission / reception switch 5 to the transmission side (not shown). Switch. Next, an ultrasonic signal necessary for flaw detection on the subject 20 is transmitted to the probe 1, and the transmission / reception switch 5 is switched to the reception side (not shown) in order to receive the signal. Further, the ultrasonic flaw detector 2 receives signals as signal processing functions such as amplification of an ultrasonic transmission signal to be supplied to the probe 1 and amplification of an ultrasonic reception signal obtained from the probe 1. 221, 222 and 223 of the filter 1, 232, 232 and 233 of the signal processor 1 that performs processing such as amplification of these signals, and a signal switch for outputting a target frequency signal 240. Next, the ultrasonic signal obtained by the ultrasonic flaw detector 2 is converted into a digital signal by the A / D converter 9 to be a received ultrasonic signal 90, which is a signal amplitude / color tone converter 100 and a display switcher 11. Sent to. In the signal amplitude / tone converter 100, the received ultrasonic signal 90 is converted into a voltage value by the received ultrasonic signal amplitude value / voltage value converter 91 via the signal rising direction determiner 89, and the voltage value / tone value is changed. It becomes color tone value data 93 using the conversion database 92 and is sent to the display switch 11.
The received ultrasonic signal is converted into a digital signal by the A / D converter 9 and sent to the signal amplitude / tone converter 100 and the display switch 11. On the other hand, in order to inspect the entire subject 20, the probe mover 6 composed of parts such as a motor and a gear for scanning (moving) the probe 1, and flaw detection control for controlling the scanning. And a probe position detector 8 for detecting the scanning (moving) position of the probe 1 and an A / D converter 9 for converting the above-mentioned ultrasonic signal into a digital signal. Yes. In the data display unit 12, the display switch 11 displays the received waveform display subjected to color conversion, the received waveform display, or the wall thickness result obtained by displaying them simultaneously.

  Here, by switching the display switch 11 to the reception ultrasonic signal side (not shown), the reception ultrasonic signal to be displayed on the data display unit 12 is, for example, at the point A as shown in FIG. The first wave signal 51, the second wave signal 52, the third wave signal 53,. Further, for example, at the point B, the first wave signal 61, the second wave signal 62, the third wave signal 63,. Here, for example, when there is a deposit (not shown) such as a scale different from the material of the subject on the bottom surface (opposite surface of the probe 1) of the subject, the sound of the subject 1 and the scale is detected. Since the impedance is different, reflection occurs at the boundary portion, and as a result, the first wave signal 81, the second wave signal 82, the third wave signal 83,. . As shown in FIG. 15, the reception ultrasonic signal by the scale differs in the rising direction of the reception ultrasonic signal depending on the combination of acoustic impedances. In the example of FIG. 14, the rising direction of the received ultrasonic signal from the subject end face is toward the plus (+) side (upward on the paper surface), while the rising direction of the received ultrasonic signal due to the scale is minus (−). To the side (downward on the page). Here, the received ultrasonic signal input to the signal amplitude / tone converter 100 is determined to be a plus side or a minus side by the signal rising direction determiner 89, and the information is sent to the voltage value / tone value conversion database 95. Thus, when selecting the color tone value data to be displayed based on the relationship between the received ultrasonic signal amplitude value and the corresponding color tone value, the rising direction of the signal is also displayed with the color tone value data distinguished.

  The above description will be described in detail with reference to FIGS. 15, 16, and 17 in terms of the acoustic impedance inherent to the material. A transmission ultrasonic signal 450 is transmitted to the material A 410, and the material A and the material B 430 are transmitted. At the boundary 420, a part of the transmission ultrasonic signal 450 is reflected as a reflected ultrasonic signal 452, and a part of the transmission ultrasonic signal 450 is transmitted as a transmitted ultrasonic signal 451. In general, the ratio of reflection at the boundary 420 is said to be such that the greater the difference between the acoustic impedance values of the two, the greater the signal amplitude of the reflected ultrasound. The relationship is shown in Equation (1).

Here, X is the reflected ultrasonic signal 452, Y is the transmitted ultrasonic signal 450, Z1 is the acoustic impedance value of the material A, and Z2 is the acoustic impedance value of the material B, where the phase of the reflected ultrasonic signal 452 is Is the relationship between the acoustic impedance value Z2 of the material B and the acoustic impedance value Z1 of the material A in equation (1). When Z2> Z1, there is no inversion, and when Z2 <Z1, there is inversion. It becomes. Therefore, it is possible to determine whether or not the reflected ultrasonic signal is inverted by storing the relationship as a database in advance and referring to the data.

  As another example of distinguishing the tone data of the rising edge of the received ultrasonic signal described above, there is a method of fixing the color in the rising direction of the received signal and displaying the signal amplitude value by the density of the fixed color or the like. is there. For example, specifically, the positive signal in the rising direction of the signal can be selected by a combination that is easy to identify and recognize, such as red for the negative signal and blue for the negative signal.

  As described above, it is easier to judge the difference between the wall thickness fluctuation and the signal due to the acoustic impedance fluctuation such as deposits such as scales. The reliability of the evaluation data can be improved. Further, it is also possible to separate the scale thickness and the variation thereof from the wall thickness and the variation and evaluate each thickness.

(Fifth embodiment)
FIG. 10 shows a configuration of an ultrasonic thickness measuring apparatus according to the fifth embodiment of the present invention, and FIG. 11 shows a detailed configuration diagram of the ultrasonic flaw detector. The ultrasonic thickness measuring apparatus according to the present embodiment includes a probe 1, a signal processing unit 300, a signal calculation processing unit 1000, and a data display unit 12. First, the signal processing unit 300 outputs an electrical signal necessary for transmitting an ultrasonic signal by the probe 1 from the ultrasonic flaw detector 200, and sends the transmission / reception switch 5 to the transmission side (not shown). Switch. Next, an ultrasonic signal necessary for flaw detection on the subject 20 is transmitted to the probe 1, and the transmission / reception switch 5 is switched to the reception side (not shown) in order to receive the signal. Furthermore, the ultrasonic flaw detector 200 receives signal processing functions such as amplification of an ultrasonic transmission signal to be supplied to the probe 1 and signal processing functions such as amplification of an ultrasonic reception signal obtained from the probe 1. Filters 221, 222, and 223, and signal processors 1 232, 232, and 233 that perform processing such as amplification of these signals are included. Next, the received ultrasonic signal obtained by the ultrasonic flaw detector 200 is received by the A / D converter 1 910, the A / D converter 2 920, the A / D converter 3 930. It is converted into an independent digital signal in the frequency band. Then, it is a device that performs calculations using the characteristics at each frequency and displays the wall thickness results.

  Here, for example, in the case of a thickness measurement location including a weld metal part or a partial material change of the subject, when a narrow-band probe is used, a phenomenon peculiar to the reception ultrasonic frequency, for example, a decrease in reception sensitivity, An error factor in the wall thickness evaluation may occur due to a frequency-specific phenomenon such as a change in the received signal amplitude value and a change in reflection from the bottom surface of the object (wall thickness measurement surface). Also, depending on the frequency of the narrow band, the bottom echo itself that is the basis of the thickness measurement may not be obtained due to attenuation. In this case, the flaw detection is usually performed again with a probe having a different frequency. These were time consuming and required preparation of multiple probes. On the other hand, by using a probe having a wide frequency band and calculating using various parameters based on a plurality of received signals of each frequency as described above, the above-mentioned error factors can be eliminated and various types of signals can be calculated. A result corresponding to the thickness measurement by frequency is obtained. Specifically, in the signal calculation processing unit, the wall thickness measurement for each frequency, the wall thickness average value of the measurement result at each frequency, and each frequency waveform are added in the time domain, and the wall thickness measurement and It also has the signal amplitude / tone conversion and display switching functions described in the previous section. Therefore, a single probe with a wide frequency band and signal calculation yield the same results as multiple flaw detection with multiple narrow band probes, shortening the flaw detection time, and transmitting materials that are difficult to transmit ultrasonic waves Wall thickness can be measured.

In the ultrasonic thickness measurement apparatus and method, when performing thickness measurement, determination, and evaluation using the received ultrasonic signal, the optimum received ultrasonic wave number signal of the received ultrasonic wave and the optimum received wave number signal are converted into color tone data. By judging the thickness variation using the converted data, the thickness difference display is exaggerated on the display screen, and the exaggerated display and the thickness distribution display of the entire subject are displayed. As a result, it is easy to judge measurement results even by a person other than a skilled inspector, thus preventing judgment errors and improving the reliability of evaluation data. improves.

It is a block diagram of the ultrasonic thickness measuring apparatus of 1st, 2nd and 3rd embodiment which concerns on this invention. It is a detailed block diagram of the signal amplitude / tone converter of 1st, 2nd and 3rd embodiment which concerns on this invention. It is an example of the ultrasonic transmission and reception signal of 1st Embodiment which concerns on this invention. It is an explanatory example showing the relationship between the ultrasonic wave reception signal amplitude and the tone value data of the second and third embodiments according to the present invention. It is an example of the received ultrasonic signal amplitude value and color tone value conversion database of the second and third embodiments according to the present invention. It is an example of thickness distribution color tone display of the whole subject of the 3rd embodiment concerning the present invention. It is an example of the color tone display of 1st, 2nd and 3rd embodiment which concerns on this invention. It is a color tone display example of the emphasis process of the fourth embodiment according to the present invention. It is a detailed block diagram of the ultrasonic flaw detector of 1st, 2nd, 3rd and 4th embodiment which concerns on this invention. It is a block diagram of the ultrasonic thickness measuring apparatus of 5th Embodiment which concerns on this invention. It is a detailed block diagram of the ultrasonic flaw detector of 5th Embodiment which concerns on this invention. It is a block diagram of the ultrasonic thickness measuring apparatus of 4th Embodiment which concerns on this invention. It is a detailed block diagram of the signal amplitude / tone converter of 4th Embodiment which concerns on this invention. It is an explanatory example showing the relationship between the ultrasonic reception signal and the tone value data based on the ultrasonic reception signal amplitude and scale according to the fourth embodiment of the present invention. It is explanatory drawing of reflection and permeation | transmission in the different acoustic impedance boundary part of 4th Embodiment which concerns on this invention. It is the example of a database which showed the presence or absence of inversion of the reflected signal in the different acoustic impedance boundary part of 4th Embodiment which concerns on this invention. It is an example of the acoustic impedance value of the various materials of 4th Embodiment which concerns on this invention. It is the conventional ultrasonic thickness measurement schematic.

Explanation of symbols

1, probe 2, ultrasonic flaw detector 3, data recording system 5, transmission / reception switch 6, probe mover 7, flaw controller 8, probe position detector 9, A / D converter 10, Signal amplitude / color tone converter 11, display switcher 12, data display unit 20, subject 30, signal processing unit 50, transmission ultrasonic signal 51 at point A, received first wave signal 52 at point A, point A Received second wave signal 53 at point A, received third wave signal 54 at point A, received fourth wave signal 60 at point A, transmitted ultrasonic signal 61 at point B, received first wave signal at point B 62, received second wave signal 63 at point B, received third wave signal 64 at point B, received fourth wave signal 81 at point B, received first wave signal 82 by scale, received second wave by scale Signal 83, received third wave signal 84 based on scale, received fourth wave signal 89 based on scale, signal rising direction determiner 90, received Sound wave signal 91, signal amplitude value / voltage value converter 92, voltage value / color value conversion database 93, color value data 95, voltage value / color value conversion database 100, signal amplitude / color value converter 101, first wave reception Time difference value 102 corresponding to the wall thickness difference between point A and point B using the signal, time difference value 103 corresponding to the wall thickness difference between point A and point B using the second wave reception signal, third wave reception Time difference value 104 corresponding to the wall thickness difference between point A and B using the signal, time difference value 200 corresponding to the wall thickness difference between point A and B using the fourth wave received signal, ultrasonic flaw detector 210, transmission / reception signal buffer 221, reception filter 1
222, reception filter 2
223, reception filter 3
231, signal processor 1
232, signal processor 2
233, signal processor 3
240, signal switcher 300, signal processor 410, material A
420, boundary portion 430, material B
450, transmitted ultrasonic signal 451, transmitted ultrasonic signal 452, reflected ultrasonic signal 500, time value 510 corresponding to the thickness at point A, color tone value data 520 of received first wave signal at point A, point A Color tone value data 530 of the received second wave signal at, color tone value data 540 of the received third wave signal at point A, color tone value data 600 of the received fourth wave signal at point A, and thickness at point B Corresponding time value 610, color tone value data 620 of the received first wave signal at point B, color tone value data 630 of the received second wave signal at point B, color tone value data 640 of the received third wave signal at point B , Color tone value data 810 of the received fourth wave signal at point B, color tone value data 820 of the received first wave signal based on the scale, color tone value data 830 of the received second wave signal based on the scale, and the received third wave signal based on the scale Tone value data 840, reception by scale Tonal value data 910 of the four-wave signal, A / D converter 1
920, A / D converter 2
930, A / D converter 3
1000, signal arithmetic processing unit

Claims (5)

An ultrasonic probe that transmits ultrasonic waves from the ultrasonic probe to the measurement portion of the subject and receives the ultrasonic signals that are reflected back; and
Means for displaying the received ultrasound signal;
It comprises means for sequentially displaying received ultrasonic signals that are repeatedly received,
Ultrasonic wall thickness measuring device. In the ultrasonic thickness measuring apparatus according to claim 1,
When displaying the received ultrasonic signal, the received ultrasonic signal amplitude is displayed in color tone classification,
Ultrasonic wall thickness measuring device. In the ultrasonic thickness measuring apparatus according to claim 1 or 2,
It comprises means for displaying the thickness distribution of the entire subject by scanning the ultrasonic probe,
Ultrasonic wall thickness measuring device. In the ultrasonic thickness measuring apparatus according to claim 2,
It is characterized by comprising means for distinguishing the color classification display of different parts of the acoustic impedance inside the subject,
Ultrasonic wall thickness measuring device. A step of transmitting an ultrasonic wave from the ultrasonic probe to the subject and receiving an ultrasonic signal that is reflected and returned;
Displaying the received ultrasound signal;
It comprises a step of sequentially displaying received ultrasonic signals that are repeatedly received,
Ultrasonic wall thickness measurement method.

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