KR101250337B1 - Apparatus and method for index point and incident angle measurement of ultrasonic transducer - Google Patents

Abstract

PURPOSE: A device for measuring an incident point and a refracting angle of an ultrasonic probe and a measuring method using the same are provided to minimize the variables caused by the sensitivity difference possible to be generated before and after an inspection, thereby obtaining the reliability of an inspection result and preventing unnecessary re-inspections after the inspection. CONSTITUTION: A device for measuring an incident point and a refracting angle of an ultrasonic probe comprises a body(510), a slide bar groove(570), a probe stopper(520), a slide bar(530), a slide fixing groove(561), and an incident point display sub-window(560). The body includes a protrusion portion(575) on the top of a flat plate, thereby being moved by hanging on a correction surface of a correction testing piece. The slide bar groove is formed on the protrusion portion of the body. The probe stopper is closely adhered to the lateral surface of the wedge which has joined to the ultrasonic probe on the correction surface of the correction testing piece. The slide bar is inserted into the slide bar groove to be slid, thereby displaying a spot where scales of the wedge and scales of the correction testing piece are coincided, by marking. The slide fixing groove is joined to the slide bar with a pin(540) and fixes a position of the slide bar with a fixing knob(550). The slide fixing groove is formed inside the slide bar groove by being penetrated through the body so that a pin fixes a position of the slide bar by being joined to the slide bar. The incident point display sub-window is formed to be adjacent to the slide fixing groove, thereby marking a measured incident point of the ultrasonic probe on the slide bar.

Description

Apparatus and Method for Index Point and Incident Angle Measurement of Ultrasonic Transducer

The present invention has the largest number of test results in the calibration of an inspection system including an ultrasonic flaw detector, an ultrasonic probe, a cable, and an inspector used before the inspection in the ultrasonic flaw detection technique for nondestructively diagnosing the integrity of a nuclear power plant. The present invention relates to an apparatus for measuring an incident point and an angle of refraction of an ultrasonic probe, and a measuring method using the same, capable of more accurately performing an angle of refraction and an incident point of an ultrasonic transducer.

Ultrasonic flaw detection, which is used to check the health of industrial facilities, is a non-destructive inspection method that delivers ultrasonic energy to an inspection object and observes the waveform of ultrasonic waves reflected from the inspection object to diagnose the condition inside the material. In the ultrasonic examination, prior to the start of the examination, calibration is performed to determine the equipment settings of the ultrasonic inspection system used to suit the inspection object. And during the inspection, to make sure that the condition of the equipment is kept the same, the condition set before the inspection and the setting after the inspection are the same, and check whether the signal reflected from the reflector of the calibration specimen is the same before and after the inspection. This ensures that the continuity of the inspection system is maintained.

The first measurement performed in this calibration is the measurement of the incident point and the refraction angle of the ultrasonic probe used. The point of incidence indicates the position where the ultrasonic wave is incident from the ultrasonic probe to the object to be inspected. The angle of refraction is the angle at which the ultrasonic wave proceeds inside the object during the tilt angle ultrasonic examination. When the object to be inspected is changed according to Snell's law, the ultrasonic wave in the material changes. The angle of refraction is also changed. Since the incident point and the refraction angle correspond to the important variables for determining the position of the defect when the defect is generated in the ultrasonic scanning, the accurate measurement of the incident point and the refractive angle is an important task for determining the accuracy of the ultrasonic scanning result.

In general, calibration work requires calibration specimens in addition to the ultrasonic flaw detector and the ultrasonic probe. Figure 1 shows the IIW calibration test piece 110 proposed by the International Institute of Welding (IIW) most commonly used in ultrasonic examination.

IIW calibration specimens are the most commonly used calibration specimens for the point of incidence, angle of refraction, and time-base calibration of ultrasonic transducers, and are made of the same material as the material to be inspected. The IIW calibration test piece 110 is machined with a radius reflector 160 machined to a 100 mm radius and the center point 150 of the semicircle is marked on the outside of the calibration test piece. During calibration, ultrasonic waves are incident on this reflection source and the incident point is measured using the reflected signal. In the IIW calibration test piece 110, a circular reflector 130 and a small side hole 140 made of acrylic are processed in the calibration test piece 110 to measure the refractive angle.

A conventional technique for measuring the incident point and the refraction angle will be described with reference to FIGS. 2 and 3.

In the general calibration, the first measurement is the incident point measurement, which measures the exact position of the ultrasonic wave generated in the ultrasonic probe's body. Since the incidence point is the reference point for estimating the defects detected with the ultrasonic probe, when the incidence angle is used incorrectly, the measurement of the position of the defect is accompanied by an error. Most of the vertical transducers 210 that vertically inject the ultrasonic wave into the inspection object regard the center point of the piezoelectric element as the incident point of the ultrasonic probe, but in the square flaw that injects the ultrasonic wave at an inclination angle, the wedge 220 having a specific angle with the ultrasonic probe Used in combination. In the case of a square ultrasonic transducer coupled with the wedge, the incidence point is deviated from the center point of the transducer due to the wedge 220.

First, in order to measure the incidence point, the ultrasonic probe 210 is connected to the ultrasonic flaw detector 350 through the cable 360, and the transducer coupled with the ultrasonic probe 210 and the wedge 220 is semicircle of the IIW calibration test piece 110. The surface of the reflector 160 is in contact with the center point 150. At this position, while the ultrasonic probe 210 is moved back and forth, the reflection signal 340 from which the ultrasonic wave is reflected from the semi-circular reflector 160 is observed through the screen 310 of the ultrasonic flaw detector.

3 is a configuration of a flaw detection screen generally shown in the ultrasonic flaw detector 350. The horizontal axis 320 of the ultrasonic screen 310 indicates the distance or time that the ultrasonic wave has progressed in the material, and the vertical axis 330 indicates the magnitude of the reflected signal. The reflected signal 340 has the largest magnitude when the incident point of the ultrasonic probe is at the center of the semi-circular reflector 160 of the IIW calibration test piece 110. Therefore, the ultrasonic transducer 210 is fixed at the position where the amplitude of the signal is the highest. At this time, by measuring the position where the center 150 of the reflector reflector of the IIW block 110 is displayed on the body of the ultrasonic probe 210, the measurement of the incident point is completed. At this time, the display line shown on the body corresponds to the incidence point of the ultrasonic probe 210 under the current ultrasonic scanning conditions. In addition, the incidence point indicated in the future refraction angle measurement and the actual test is used as a reference point of the test.

Since the refraction angle is measured using the circular reflector 130 or the side hole 140 instead of the position where the incidence point is measured in the IIW calibration test piece 110, the refraction angle is performed at the refraction angle measurement points 180 and 190. When the nominal refractive angle of the ultrasonic probe 210 is 60 degrees or less, the measurement is performed at the low angle of refraction angle measurement point 180 and the refraction angle of 60 degrees or more is measured at the high angle of refraction angle measurement point 190. In order to measure the refraction angle, the ultrasonic probe 210 is placed at the refraction angle measuring points 180 and 190 and the transducer is moved to the left and right while the ultrasonic probe 210 is positioned at the maximum point in the ultrasonic flaw detector 310 in the same manner as in the incident point measurement. Stops moving. At this time, reading the scales 180 and 190 of the IIW calibration test piece 110 coinciding with the scale of the ultrasonic probe 210 indicated by the incident point, the refraction angle measurement is completed.

Until now, in the incidence point and refraction angle measurement, the inspector grabbed the ultrasonic transducer 210 and manually moved back and forth on the ultrasonic transducer contact surface to measure the position where the maximum amplitude appeared. However, the problem with this method is that the tester cannot measure at the same position of the IIW calibration test piece 110 each time the measurement is made.

This problem will be described with reference to FIG. 4. Looking at the contact surface of the ultrasonic probe 210 in the IIW calibration test piece 110, the ultrasonic probe 210 is positioned as shown in Figure 4 (a). However, the most ideal and good amplitude position can be obtained when the ultrasonic transducer 210 is reflected perpendicularly to the semi-circular reflector exactly at the center of the test piece and the reflected ultrasonic wave is also reflected vertically to obtain the largest amplitude. .

However, as shown in (b) and (c) of FIG. 4, when the ultrasonic transducer is shifted from the direction of the IIW block, the path of the ultrasonic wave is different so that the magnitude of the amplitude is reduced. If the inspector who performs the calibration does not perform the same condition before and after the test, and if the position or direction of the ultrasonic probe is not constant in the calibration performed before and after the test, the result of the calibration before and after the test cannot be obtained. Reliability cannot be recognized for the test results that have been performed for a long time.

The angle of refraction measured by the above is also used in the arithmetic formula for the evaluation of the size of the defect found during the inspection. A method of evaluating the quantitative size of defects will be described with reference to FIG. 4.

When the refractive angle of the ultrasonic transducer 210 is θ, the thickness of the inspection object is t, and the distance on which the ultrasonic wave is reflected is w, the depth of the defect is calculated as d = tw · cosθ, and the distance s from the transducer incident point to the defect s. Is calculated by s = w · sinθ.

Therefore, since the depth and distance of the defect are calculated using the refraction angle θ, the measurement of the incident point and the refraction angle corresponds to the important calibration work in the ultrasonic examination.

As such, the position and direction of the ultrasonic probe cannot be kept constant during the measurement of the incident point and the refraction angle of the ultrasonic probe in the calibration work of the ultrasonic probe, so that the repeatability and precision of the measured value cannot be secured. This is necessary.

Accordingly, the present invention has been invented to solve the conventional problems as described above, so that the ultrasonic probe can move at a certain position of the calibration test piece in the measurement of the incident point and the refraction angle, and maintain the direction of the ultrasonic wave relative to the reflector of the calibration test piece vertically. The present invention provides an incidence point and refraction angle measuring device and a measuring method using the same, which can minimize the measurement error even when the inspector has changed the inspector even if the inspector changes. There is this.

The present invention is an apparatus for measuring the incident point and the refraction angle during the calibration operation of the ultrasonic probe using the calibration test piece in the ultrasonic inspection,

In order to minimize the play of the probe on the body made of transparent material, the vertical test surface is combined with the incident point and the refraction angle measuring device and the ultrasonic probe so that the body can be seated at the edge of the mother surface of the calibration test piece. It provides an incidence point and refraction angle measuring device which is mounted on the calibration surface of and configured to obtain a uniformly sized reflected wave from the reflector of the calibration specimen by moving the ultrasonic transducer in a fixed position and direction with respect to the reflector when the ultrasonic transducer moves back and forth. It is characterized by.

The incident point and refraction angle measuring device of the present invention is characterized in that an auxiliary window is provided in the measuring device used for measuring the incident point so as to check the position of the incident point and display the incident point.

The incidence point and refraction angle measuring device of the present invention is characterized in that the slide bar is provided to facilitate the measurement of the incidence point through the incidence point display window on the side, and the slide bar is configured to indicate the incidence point of the ultrasonic probe and display the incidence point. have.

The incidence point and refraction angle measuring device of the present invention is characterized in that the ultrasonic transducer support stages are installed on the side and the front side to minimize the movement of the ultrasonic probe to be measured.

The present invention is to accurately perform the measurement of the incident point and the refraction angle which will have a decisive influence on the inspection result in the calibration work that is essential in the ultrasonic inspection of the industrial facilities and power generation facilities.

In the present invention, in order to minimize the position and direction change error of the ultrasonic transducer generated during the measurement of the incident point and the refraction angle, a guide was made to move constantly in a specific position and direction, and additional devices for measuring the incident point and the refraction angle were added. .

By applying the present invention, even in the same inspector, it is possible to improve the measurement accuracy of the incident point and the refraction angle that change every measurement time point, so that the measurement accuracy of the incident point and the refraction angle can be improved so that the same measurement result can be derived even if the inspector is changed. Can be.

In addition, the sensitivity of the ultrasound system is usually set before the ultrasound examination and the device is used to check the homogeneity of the inspection system in comparison with the sensitivity performed before the examination under the same conditions. By minimizing the variable due to the difference in sensitivity that the inspector can make during the measurement, the problem that the reliability of the test result cannot be secured can be eliminated. Therefore, unnecessary re-testing can be eliminated after the test.

1 is a configuration of a calibration test piece for measuring the general incident point and the refraction angle
2 is an explanatory diagram of measurement of normal incidence point and refraction angle using a calibration test piece;
3 is an explanatory diagram for determining the maximum amplitude of an ultrasonic signal at the time of incidence point and refraction angle measurement.
4 is an explanatory diagram of a method for positioning a defect using an incident point and a refractive angle result.
5 is an explanatory view of the influence of the position and direction of the ultrasonic probe in the calibration test piece.
6 is an exploded view of an incident point and a refraction angle measuring device according to the present invention.
7 is an assembly point of the incident point and the refraction angle measuring device according to the present invention.
8 is an exemplary view of the apparatus for measuring the incident point and the refraction angle invented according to the present invention seated on a calibration test piece for measurement.
9 and 10 are explanatory diagrams of measurement using the incident point and the refraction angle measuring device invented according to the present invention.

Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

6 is an exploded view of the incident point and refractive angle measuring device according to the present invention, Figure 7 is an assembly view of the incident point and refractive angle measuring device according to the present invention, Figure 8 is a device for measuring the incident point and refractive angle invented according to the present invention Is an illustration seated on a calibration specimen for measurement. As shown therein,

The measured ultrasonic signal output through the ultrasonic flaw detector is maximum when the wedge 220 and the ultrasonic probe 210 which are set and displayed for the incident point and the refraction angle are combined and moved on the calibration surface of the calibration test piece 110. In the device for measuring the incident point and the refraction angle correction value of the ultrasonic transducer 210 by finding a matching indication scale of the wedge 220 and the calibration test piece 110 at the position,

The ultrasonic probe 210 to be calibrated provides a jig capable of guiding a calibration operation to be performed in a predetermined direction and at a predetermined position on the calibration surface 120 of the calibration test piece 110.

A measuring unit body 510 which is formed at the upper end of the flat plate 575 so as to be seated on the calibration surface of the calibration test piece 110 and moved;

A slide bar groove 570 formed in the protrusion 575 of the measuring device body 510;

A probe stopper 520 for blocking and contacting the end of the slide bar groove 570 to be in contact with the side of the wedge 220 coupled with the ultrasonic probe 210 on the calibration surface of the calibration test piece 110;

The display scale of the wedge 220 and the calibration test piece 110 at a position where a maximum signal is measured in an ultrasonic flaw detector inserted slidably into the slide bar groove 570 to display a measurement signal of the ultrasonic probe 210. A slide bar 530 for marking and displaying a position at which a display scale of the coincides;

The pin 540 is coupled to the slide bar 530 to penetrate the measuring device body 510 in the slide bar groove 570 to fix the position of the slide bar 530 with the fixing knob 550. Slide fixed groove 561 and;

It is formed adjacent to the slide fixing groove 561 is characterized in that it comprises an incident point display auxiliary window 560 for marking the measurement position of the incident point of the ultrasonic transducer 210 on the slide bar (530).

The body 510 of the incidence point and refraction angle measuring device according to the present invention is composed of a transparent material so that the situation of the ultrasonic probe to be measured can be easily read so that the scale recorded on the calibration test piece 110 can be read. In the case of non-transparent materials, a transparent window or an open viewing window is formed at a corresponding position, that is, an area with a scale mark of the calibration test piece 110 to read the scale of the calibration test piece 110 and the scale of the wedge 220. Configure it to be.

The body 510 of the measuring device has a "F" shape, and thus the body is mounted on the calibration surface 120 of the calibration test piece 110 to produce a linear motion. In addition, when the ultrasonic transducer 210 is seated on the measuring device, the transducer stopper 520 is provided at the front end to allow the incident point and the refraction angle measuring device and the ultrasonic probe 210 to move on the calibration surface 120 integrally.

That is, the ultrasonic transducer 210 coupled to the wedge 220 is positioned on the upper surface of the calibration surface 120, and the incident point and refraction angle measuring device of the present invention is mounted on the calibration surface 120 so that the transducer stopper 520 is mounted. Into the inside of the wedge 220 is in close contact with the hand to find a measuring position while moving together.

In addition, when the ultrasonic probe 210 is combined with a measuring device to measure the incident point, the ultrasonic probe 210 checks the incident point indicated on the calibration test piece 110 and displays the incident point on the slide bar 530 body. The pin 540 and the fixing knob 550 are fastened to install the auxiliary window 560 so as to slide the slide bar 530 to display the incident point at the identified position and to fix it at the corresponding position.

The slide bar 530 may move back and forth through the slide bar groove 570 processed in the body of the measuring device, and when the incident point is measured, the slide bar 530 is fixed using the fixing knob 550.

The method of measuring the incident point and the flexural angle of the ultrasonic probe using the incident point and the refraction angle measuring device according to the present invention,

After the incident point and the refraction angle measuring device is seated on the calibration surface, the ultrasonic transducer 210 coupled to the wedge 220 is placed on the center of the calibration surface 120 of the calibration test piece 100 and the incident point and refraction angle measuring device An incidence point measuring process of finding a position at which the maximum signal is detected by detecting an ultrasonic signal through an ultrasonic flaw detector while driving the ultrasonic probe 210 while moving from side to side while being in close contact with the transducer stopper of the ultrasonic wave detector;

At the position where the maximum signal is detected in the incident point measurement process, the slide bar of the incident point and the refraction angle measuring device is moved to the coincidence point position of the wedge 220 and the calibration test piece 110 to fix the position of the slide bar. An incident point marking process of manually marking the corresponding position on the slide bar;

After the incidence point marking is completed, the ultrasonic transducer 210 is seated and moved by mounting the ultrasonic transducer 210 coupled to the incidence point and refraction angle measuring device and the wedge 220 on the calibration surface for measuring the refraction angle of the calibration test piece 110. Drive to find the position where the maximum signal of the ultrasonic pulse detected by the ultrasonic flaw detector is detected, and measure the refraction angle by reading the refraction angle indication scale of the calibration test piece 110 corresponding to the indication of the incident point marked on the slide bar at the corresponding position. Characterized in that it is made to perform the refractive angle measurement process.

An embodiment will be described with reference to FIGS. 9 and 10. The transducer 210 to be measured and the wedge 220 are fastened, and the ultrasonic transducer 210 is brought into close contact with the transducer stopper 520 and is in contact with the calibration surface 120 of the calibration test piece 110. In this case, the ultrasonic probe is positioned at the center of the calibration surface 120 and the direction is perpendicular to the calibration reflection surface 160.

In this state, the probe and the measuring device are stopped at the position where the maximum signal appears while observing the flaw screen 310 of the ultrasonic flaw detector 350 while moving the ultrasonic probe 210 and the measuring device together. In the stopped state, the slide bar knob 550 is pushed to the incident point indicated on the calibration test piece 110 to stop when the slide bar 530 coincides with the incident point.

The slide bar fixing knob 550 is fixed to prevent the slide bar 530 from moving and the incident point 580 is displayed on the vertical portion of the slide bar 530 by using a writing instrument to complete the incident point measurement.

When the incident point measurement is completed, the measuring device 510 and the probe 210 are seated at the refraction angle measurement positions 180 and 190 in order to measure the refraction angle of the ultrasonic wave. In the refraction angle measurement, the screen 310 of the ultrasonic flaw detector 350 is observed while moving the measuring device 510 and the ultrasonic probe 210 back and forth at the refraction angle measurement positions 180 and 190 where the refraction angle is displayed in the same manner as the incident point measurement. Observe the maximum signal of the ultrasonic pulse.

The measuring device and the ultrasonic transducer 210 are stopped at the position where the maximum pulse appears, and the refraction angle measurement point 590 where the scale 580 of the previously measured incident point coincides with the scale at the refraction angle measurement positions 180 and 190 of the calibration test piece. The refraction angle measurement is completed by reading the scale of.

110: normal ultrasonic calibration test piece 120: ultrasonic transducer contact surface
130: circular reflector 140: side ball
150: incident point measuring position (100mm radius center point) 160-100mm radius reflector
170: bottom 180: low refractive angle measurement position
190: high refractive angle measurement position 210: ultrasonic transducer
220: wedge 230: ultrasonic transducer incident point scale
310: flaw detector screen 320: time axis / distance axis
330: amplitude axis 340: maximum amplitude ultrasonic signal
350: ultrasonic flaw detector 360: cable
410: inspection target 420: defect
430: ultrasonic beam 440: center line
510: Jig for measuring the point of incidence, angle of refraction 520: Probe stopper
530: slider bar 540: pin
550: fixed knob 560: incident point display auxiliary window
570: slider bar groove 575: protrusion
580: incident point 590: refraction angle measurement point

Claims (4)

In the device for measuring the incident point and the refraction angle of the ultrasonic transducer 210 using the calibration test piece 110,
A measuring unit body 510 which is formed at the upper end of the flat plate 575 so as to be seated on the calibration surface of the calibration test piece 110 and moved;
A slide bar groove 570 formed in the protrusion 575 of the measuring device body 510;
A probe stopper 520 for blocking and contacting the end of the slide bar groove 570 to be in contact with the side of the wedge 220 coupled with the ultrasonic probe 210 on the calibration surface of the calibration test piece 110;
The display scale of the wedge 220 and the calibration test piece 110 at a position where a maximum signal is measured in an ultrasonic flaw detector inserted slidably into the slide bar groove 570 to display a measurement signal of the ultrasonic probe 210. A slide bar 530 for marking and displaying a position at which a display scale of the coincides;
The pin 540 is coupled to the slide bar 530 to penetrate the measuring device body 510 in the slide bar groove 570 to fix the position of the slide bar 530 with the fixing knob 550. Slide fixed groove 561 and;
The ultrasonic probe is formed adjacent to the slide fixing groove 561 and comprises an incident point display auxiliary window 560 for marking the measurement position of the incident point of the ultrasonic probe 210 on the slide bar 530. Incident point and refraction angle measuring device of. The method of claim 1, wherein the measuring device body 510,
The incident point and the refraction angle measuring apparatus of the ultrasonic probe, characterized in that made of a transparent material made to read the incident point display scale and the refraction angle display scale displayed on the calibration test piece (110). The method of claim 1, wherein the measuring device body 510,
Device for measuring the incident point and the refraction angle of the ultrasonic probe, characterized in that the transparent window or an open viewing window is formed in a corresponding position area to read the incident point display scale and the refraction angle display scale displayed on the calibration test piece 110 . In the method of measuring the incident point and the flexural angle of the ultrasonic probe using the incident point and the refraction angle measuring device,
After the incident point and the refraction angle measuring device is seated on the calibration surface, the ultrasonic transducer 210 coupled to the wedge 220 is placed on the center of the calibration surface 120 of the calibration test piece 100 and the incident point and refraction angle measuring device An incidence point measuring process of finding a position at which the maximum signal is detected by detecting an ultrasonic signal through an ultrasonic flaw detector while driving the ultrasonic probe 210 while moving from side to side while being in close contact with the transducer stopper of the ultrasonic wave detector;
At the position where the maximum signal is detected in the incident point measurement process, the slide bar of the incident point and the refraction angle measuring device is moved to the coincidence point position of the wedge 220 and the calibration test piece 110 to fix the position of the slide bar. An incident point marking process of manually marking the corresponding position on the slide bar;
After the incidence point marking is completed, the ultrasonic transducer 210 is seated and moved by mounting the ultrasonic transducer 210 coupled to the incidence point and refraction angle measuring device and the wedge 220 on the calibration surface for measuring the refraction angle of the calibration test piece 110. Drive to find the position where the maximum signal of the ultrasonic pulse detected by the ultrasonic flaw detector is detected, and measure the refraction angle by reading the refraction angle indication scale of the calibration test piece 110 corresponding to the indication of the incident point marked on the slide bar at the corresponding position. An incident point and a refraction angle measuring method using an ultrasonic probe measuring device, characterized in that to perform a refraction angle measuring process.

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