JP7174526B2 - Dense crack depth measurement device using electrical resistance method - Google Patents

Description

The present disclosure relates to a dense crack depth measuring device and measuring device using an electrical resistance method.

Conventionally, for example, digital X-ray inspection (accuracy: ±0.3 mm) is used as a method for non-destructively measuring the depth of groove-like corrosion cracks that occur in furnace wall tubes of land-use boilers. In this digital X-ray inspection, it is necessary to secure a space between the X-ray source and the object to be inspected, and it is difficult to inspect a wide range because it takes time to adjust the position and move the X-ray source. There are certain restrictions, such as not being able to work in parallel with other construction work because it is necessary to leave the workers other than the inspector.

As a non-destructive crack depth inspection method that does not use X-rays, a crack depth measurement method using an electrical resistance method is known. For example, Patent Document 1 discloses a method of determining the crack depth from the electric resistance value of the CT test piece based on the intermittent energization of a crack length measurement current for 1 second or longer that is passed through the CT test piece. there is Further, in Patent Document 2, a probe having a plurality of contact needles and a main body having a power source connected to a predetermined contact needle among the contact needles are each provided with display illumination means so that the energized state can be confirmed. A crack depth gauge is disclosed.

JP-A-4-194741 Japanese Utility Model Laid-Open No. 4-43256

However, in both Patent Document 1 and Patent Document 2, the influence of the length of the crack and the number of cracks mixed between terminals are not considered when measuring the crack depth, and the influence of the length and number of cracks There is no disclosure of a configuration in which measurements are taken at different measurement positions to measure the crack depth in view of the above.

In view of the above circumstances, at least one embodiment of the present disclosure aims to efficiently obtain information about cracks at different measurement locations.

(1) A measuring device according to at least one embodiment of the present disclosure,
A crack depth measuring device using an electrical resistance method,
an input terminal and an output terminal for applying a power supply voltage to both sides of a crack formed on the surface of the member by contacting the surface of the member of the object to be measured;
a plurality of measurement terminal pairs configured to contact both sides of the crack;
a potentiometer for detecting a potential difference between the measurement terminals for each said measurement terminal pair;
It has

According to the above configuration (1), by providing a plurality of measurement terminal pairs and a potentiometer capable of detecting the potential difference between these measurement terminals, using the electrical resistance method, at different measurement positions on both sides of the crack Information about the crack can be obtained efficiently.

(2) In some embodiments, in the configuration of (1) above,
The plurality of measurement terminal pairs may be arranged side by side in a direction crossing a direction connecting the input terminal and the output terminal.

According to the above configuration (2), by arranging the measurement terminal pairs arranged side by side in a direction intersecting the direction connecting the input terminal and the output terminal, for example, along the length direction of the crack, The potential difference across the crack can be measured at different measurement locations along the length of the crack. Thus, for example, information regarding the maximum crack depth can be efficiently obtained.

(3) In some embodiments, in the configuration of (1) or (2) above,
At least the input terminal and the output terminal, the plurality of measurement terminal pairs, and the potentiometer may be configured to be movable along the surface of the member in a direction connecting the input terminal and the output terminal. .

According to the above configuration (3), at least the input terminal and the output terminal, the plurality of measurement terminal pairs, and the potentiometer are moved along the member surface in the direction connecting the input terminal and the output terminal, and the crack is removed. can be measured sequentially. Therefore, it is possible to greatly improve the work efficiency of measuring the potential difference of cracks in an evaluation object including a plurality of cracks.

(4) In some embodiments, in the configuration described in any one of (1) to (3) above,
The input terminal and the output terminal connected to the input terminal via a power supply are formed in a wheel shape,
The plurality of measurement terminal pairs each include a first terminal and a second terminal,
the plurality of first terminals and the plurality of second terminals are each configured radially such that the tips thereof contacting the surface of the member are arranged along the circumferential direction,
Centers of the plurality of first terminals arranged radially and one of the input terminal and the output terminal, and centers of the plurality of second terminals arranged radially and between the input terminal and the output terminal either one or the other, each connected via an axle,
The input terminal, the output terminal, the plurality of first terminals, and the plurality of second terminals may be configured to be movable along a direction connecting the input terminal and the output terminal by rotation.

With configuration (4) above, the rotatable input terminal, output terminal, and measurement terminal pair can be integrally moved along the direction connecting the input terminal and the output terminal. Specifically, the input terminal and the output terminal are always in contact with the surface of the member and apply the power supply voltage while moving the application range. On the other hand, the plurality of measurement terminal pairs change the contact points with the member surface by following the movement of the input terminal and the output terminal while switching the first terminal and the second terminal that contact the member surface by rotation. A potential difference between the measured terminals is detected by a potentiometer. With such a configuration, even if a plurality of cracks exist in the direction connecting the input terminal and the output terminal, the potential difference on both sides of each crack can be sequentially measured, so that information on cracks at different measurement positions can be efficiently obtained. can be obtained

(5) In some embodiments, in the configuration of (4) above,
A frame that mounts the power supply and the potentiometer and integrally connects the input terminal, the output terminal, and the measurement terminal pair via the axle may be further provided.

According to the configuration (5) above, by providing the frame, the input terminal, the output terminal, the power source, the measuring terminal pair, and the potentiometer can be integrally configured through the frame. Therefore, in the crack depth measuring device provided with a plurality of measuring terminal pairs, it is possible to obtain a measuring device that is easy to handle with improved portability and operability.

(6) In some embodiments, in the configuration of (4) above,
The axle may include an insulator.

According to the configuration (6) above, since the axle connecting the input terminal or the output terminal and the measurement terminal contains an insulator, the voltage applied by the input terminal and the output terminal is directly applied to the measurement terminal pair. applied to the member surface of the evaluation object without Therefore, for example, the input terminal and the output terminal are brought into contact with both sides of the crack generated in the surface of the member, and the first and second terminals of the measurement terminal pair are brought into contact with both sides of the crack. By arranging the measuring device in such a manner that the information such as the potential difference on both sides of the crack can be obtained appropriately.

(7) In some embodiments, in the configuration described in any one of (1) to (3) above,
A carrier may be further provided on which the input terminal, the output terminal, the plurality of measurement terminal pairs, and the potentiometer are transportably mounted.

With configuration (7) above, the input terminal, the output terminal, the plurality of measurement terminal pairs, and the potentiometer can be easily moved by the carrier. Therefore, for example, when there are a plurality of cracks to be measured, the potential difference on both sides of these cracks can be sequentially measured while moving the carrier. Therefore, it is possible to efficiently perform the work of measuring the depth of a plurality of cracks using the electrical resistance method.

(8) In some embodiments, in the configuration described in any one of (1) to (7) above,
A guide portion extending along the surface of the member in a direction connecting the input terminal and the output terminal and for guiding the input terminal, the output terminal, the plurality of measurement terminal pairs, and the potentiometer. may be

With configuration (8) above, the input terminal, the output terminal, the plurality of measurement terminal pairs, and the potentiometer can be guided along the guide portion.

(9) In some embodiments, in the configuration of (8) above,
A crack measuring unit may be further provided movably arranged along the guide unit and configured to measure at least one of length and number of the cracks.

With configuration (9) above, at least one of the length and the number of cracks can be measured by the crack measuring unit. In other words, in measuring the crack depth using the electrical resistance method, the crack depth is measured with high accuracy, considering the influence of at least one of the measured value of the length of the crack and the measured value of the number of cracks on the measurement accuracy. be able to. Therefore, it is not necessary to use a measuring device using radiation such as X-rays to measure the crack depth, and the inspection of the crack depth can be performed in parallel with other work, which greatly improves work efficiency. can be improved.

(10) In some embodiments, in the configuration described in any one of (1) to (9) above,
It may further include a surface treatment section arranged movably along the guide section and configured to be able to clean the surface of the member.

According to the configuration (10) above, the surface treatment section can remove stains on the surface of the member that may adversely affect potential difference measurement. Therefore, the potential difference on both sides of the crack and the depth of the crack to be measured can be measured with higher accuracy by suppressing the measurement error.

(11) In some embodiments, in the configuration described in any one of (1) to (3) above,
A relay switch may be further provided for switching, among the plurality of measurement terminal pairs, the measurement terminal pair used for measuring the potential difference between both ends of the crack to be measured.

According to the above configuration (11), among the plurality of measurement terminal pairs, the measurement terminal used for the potential difference measurement can be switched by the relay switch according to the characteristics of the crack to be measured. As a result, in one measurement operation, it is possible to measure the potential difference between both ends of the crack appropriately corresponding to various cracks, thereby shortening the operation time.

(12) In some embodiments, in the configuration described in any one of (1) to (11) above,
The measurement object may include a furnace wall tube.

According to the above configuration (12), the depth of the crack generated on the surface of the furnace wall tube can be efficiently obtained using the electrical resistance method. As a result, it is not necessary to use a measuring device using radiation such as X-rays to measure the crack depth of the furnace wall pipe, and inspection of the crack depth can be performed in parallel with other work. , the work efficiency can be greatly improved.

According to at least one embodiment of the present disclosure, a metrology device is provided that can efficiently obtain information about cracks at different measurement locations.

It is a figure showing roughly composition of a crack depth measuring device concerning one embodiment of this indication. It is the schematic for demonstrating the measuring principle of the crack depth using an electrical resistance method. It is a schematic diagram for explaining the principle of measuring the crack depth using the electrical resistance method, (a) is a plan view seen from above the crack 14, (b) is a view seen from the crack length L1 direction. . FIG. 3 is a view similar to FIG. 2, showing a case where the crack length is shorter than in FIG. 2; FIG. 4 is a view similar to FIG. 3 and shows a case where the crack length is shorter than in FIG. 3; FIG. 4 is a perspective view showing a state in which an input terminal, an output terminal, and a pair of measurement terminals are arranged in series to measure a potential difference; The input terminal, output terminal and measuring terminal pair are arranged in series to measure the potential difference, (a) shows one crack between the measuring terminals, (b) shows two cracks between the measuring terminals, ( c) shows a state in which one crack exists between the measuring terminals and between the measuring terminal and the input terminal. FIG. 4 is a perspective view showing a state in which an input terminal, an output terminal, and a pair of measurement terminals are arranged in parallel to measure a potential difference; The input terminal, the output terminal, and the measurement terminal pair are arranged in parallel to measure the potential difference, (a) shows one crack between the measurement terminals, (b) shows two cracks between the measurement terminals, ( c) shows a state in which one crack exists between the measuring terminals and the outside of the measuring terminal pair. FIG. 4 is a diagram showing a relationship between an estimated crack depth value and an actual measurement value obtained by a crack depth measuring method according to an embodiment of the present disclosure; It is a figure which shows the relationship between the number of cracks contained between measurement terminals, and a potential difference. It is a figure which shows the structure of the measuring device which concerns on other embodiment, (a) is a top view, (b) is a side view. It is a perspective view showing composition of a measuring device concerning other embodiments.

Several embodiments of the present disclosure will now be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of the components described as embodiments or shown in the drawings are not intended to limit the scope of the present invention, and are merely illustrative examples. do not have.
For example, expressions denoting relative or absolute arrangements such as "in a direction", "along a direction", "parallel", "perpendicular", "center", "concentric" or "coaxial" are strictly not only represents such an arrangement, but also represents a state of relative displacement with a tolerance or an angle or distance to the extent that the same function can be obtained.
Further, for example, expressions representing shapes such as a square shape and a cylindrical shape not only represent shapes such as a square shape and a cylindrical shape in a geometrically strict sense, but also within the range where the same effect can be obtained, such as uneven parts and Shapes including chamfers and the like are also represented.
On the other hand, the expressions "comprising", "comprising", "having", "including", or "having" one component are not exclusive expressions excluding the presence of other components.

FIG. 1 is a diagram schematically showing the configuration of a crack depth measuring device 1 according to an embodiment of the present disclosure.
As shown in FIG. 1, a measuring device 1 according to at least one embodiment of the present disclosure is a measuring device 1 for crack depth D using an electrical resistance method, and is applied to a member surface 12 of an object 10 to be measured. An input terminal 2 and an output terminal 4 for applying a power supply voltage to both sides of a crack 14 formed in the member surface 12 by contact, and a plurality of measurement terminal pairs 6, 6 configured to be able to contact both sides of the crack 14. and a potentiometer 8 for detecting the potential difference V between the measuring terminals 6 for each measuring terminal pair 6,6.

First, the principle of measuring the crack depth D using the electrical resistance method will be described. Since the principle is well known in the art, the details thereof will not be described in detail, and only the points related to the present disclosure will be described.
FIG. 2 is a schematic diagram for explaining the principle of measuring the crack depth D using the electrical resistance method, and is a diagram viewed from a direction orthogonal to the length L1 direction of the crack 14. FIG. FIG. 3 is a schematic diagram for explaining the principle of measuring the crack depth D using the electrical resistance method, (a) is a plan view from above the crack 14, (b) is the length L1 of the crack 14 It is the figure seen from the direction. In addition, FIG. 2 shows, for example, a part of the pipe viewed from the pipe axial direction A as the evaluation object 10 for which the depth D1 of the crack 14 is to be evaluated.
As shown in FIGS. 2 and 3, for example, when obtaining the depth D of a crack 14 generated in the direction perpendicular to the pipe axis direction A, the depth of the evaluation object 10 corresponding to one side of the crack 14 in the pipe axis direction A is The input terminal 2 of the power supply voltage is brought into contact with the member surface 12 , and the output terminal 4 of the power supply voltage is brought into contact with the member surface 12 on the other side of the crack 14 . Then, when a voltage is applied between the input terminal 2 and the output terminal 4, a constant voltage is applied from the input terminal 2 to the output terminal 4 along a route that passes below the crack 14 (where the distance from the member surface 12 is deeper than the depth of the crack 14). current flows (see, for example, FIG. 3(b)). Then, by bringing the pair of measuring terminals 6, 6 connected to the potentiometer 8 into contact with one side and the other side of the crack 14, respectively, the potential difference V on both sides (the one side and the other side) of the crack 14 is measured. is measured by the potentiometer 8 . Since the potential difference V and the crack 14 are represented by a linear relationship, the depth D of the crack 14 can be obtained by measuring the potential difference V.

Here, as a result of intensive research by the present inventors, in measuring the depth of cracks 14 using the electrical resistance method, measurement errors may occur depending on the length L of cracks 14 (for example, L1 or L2 above) and the number of cracks 14. It became clear.
FIG. 4 is a view similar to FIG. 2 and shows the case where the length L2 of the crack 14 is shorter than the crack length L1 shown in FIG. 2 (L1>L2). FIG. 5 is similar to FIG. 3 and shows the case where the length L2 of the crack 14 is shorter than the crack length L1 shown in FIG.
As shown in FIGS. 4 and 5, when the length L of the crack 14 is short, a current path bypassing the side of the crack 14 (see, for example, FIGS. 5(a) and 5(b)) is generated. Therefore, the potential difference V, that is, the electrical resistance value is observed to be low (R=V/I). Therefore, if the crack depth D is estimated based only on the potential difference V measured by the potentiometer 8 without considering the crack length L, the ratio of the measurement error from the measured value of the crack depth D will increase. . On the other hand, when the crack depth D is estimated by considering the crack length L in the potential difference V measured by the potentiometer 8, the ratio of the error is greatly reduced, and the measurement error from the measured value of the crack depth D is For example, it has been clarified that it is generally within the range of ±0.3 mm, which is about the same as digital X-ray inspection (see, for example, FIG. 10).

FIG. 6 is a perspective view showing a state in which the input terminal 2, the output terminal 4, and the measuring terminal pair 6, 6 are arranged in series and the potential difference V is measured. FIG. 7 shows a state in which the input terminal 2, the output terminal 4 and the measuring terminal pair 6, 6 are arranged in series to measure the potential difference V. (a) shows one crack between the measuring terminals 6, 6, ( b) shows a state in which two cracks exist between the measuring terminals 6 and 6, and (c) shows a state in which one crack exists between the measuring terminals 6 and 6 and between the measuring terminal 6 and the input terminal 2 respectively.
As shown in FIGS. 6 and 7, when the number of cracks 14 existing between the input/output terminals 2, 4 and the measurement terminals 6, 6 of the power supply voltage increases (for example, FIGS. 7(a) and 7(b) ), the electrical resistance increases, so the potential difference V measured by the potentiometer 8 increases. Therefore, the measurement accuracy of the crack depth D may be affected (see FIG. 11, for example).
Therefore, the inventors have found that it is effective to consider the length L and the number of cracks 14 in order to reduce the measurement error as described above.
The width of each crack 14 may be, for example, approximately 2.5 mm. Also, at least one of the length L or the number of cracks 14, the potential difference V between one side and the other side of the crack 14 in the direction orthogonal to the length L direction of the crack 14, and the depth D of the crack 14 The evaluation formula showing the correlation is obtained by measuring in advance according to the length L of the crack 14, the number of cracks 14 included between the measurement terminal pairs 6, 6, or the material used as the evaluation object 10. You may
The input terminal 2, the output terminal 4 and the measurement terminals 6, 6 may be provided, for example, as a portable probe mounted on a carrier 24 (for example, FIGS. 2, 10(a) and 10(b)). )reference). Note that the center position of the measurement terminal pair 6, 6 is located in the direction connecting the input/output terminal pair 2, 4 from the line along the length L direction of the crack 14 passing through the center position of the input/output terminal pair 2, 4, for example , ±10%. Also, the distance between the measurement terminals 6,6 may be, for example, 0.7 to 1.5 times the distance between the input/output terminal pair 2,4.

According to the above configuration, by providing the plurality of measuring terminal pairs 6, 6 and the potentiometer 8 capable of detecting the potential difference V between these measuring terminals 6, the electric resistance method can be used to Information about the crack 14 can be efficiently obtained at different measurement locations. Information about the crack 14 may include, for example, the length L, width, number of cracks 14, potential difference V between both sides of the crack 14, depth D, and various other information.

In some embodiments, for example, as shown in FIG. 1, the plurality of measurement terminal pairs 6, 6 are arranged in a direction connecting the input terminal 2 and the output terminal 4 (a non-limiting example shown in FIG. 1). Then, for example, they may be arranged side by side in a direction intersecting with the tube axis direction A). In that case, for example, the plurality of measurement terminal pairs 6, 6 may be arranged side by side in a direction perpendicular to the tube axis direction A.

According to the above configuration, the pair of measurement terminals 6, 6 arranged in a direction crossing the direction connecting the input terminal 2 and the output terminal 4 are arranged along the length direction of the crack 14, for example. Thereby, the potential difference V on both sides of the crack 14 can be measured at a plurality of different measurement positions along the length of the crack 14 . Therefore, for example, information regarding the maximum depth of the crack 14 can be efficiently obtained.
Note that the plurality of measurement terminal pairs may be configured such that the plurality of first terminals and the plurality of second terminals are arranged in an arc when viewed from a direction perpendicular to the length direction of the crack. . In this way, when measuring, for example, a crack 14 generated on the surface of a pipe as a measurement object, all the measurement terminals 6 can be arranged so as to contact the surface of the pipe, which is the measurement object 10. can be done.

In some embodiments, at least an input terminal 2 and an output terminal 4, a plurality of measurement terminal pairs 6, 6, and a potentiometer 8, for example, as shown in FIGS. 10(a) and 10(b). , along the member surface 12 in the direction connecting the input terminal 2 and the output terminal 4 (for example, the tube axis direction A). As a movement system, for example, a monorail system, a crawler system, a wheel system, a walking system, or the like can be applied. With this configuration, at least the input terminal 2 and the output terminal 4, the plurality of measuring terminal pairs 6, 6, and the potentiometer 8 are connected along the member surface 12 in the direction connecting the input terminal 2 and the output terminal 4. , the potential difference V on both sides of the crack 14 can be measured sequentially. Therefore, it is possible to significantly improve the working efficiency of potential difference measurement of the cracks 14 in the measurement object 10 including a plurality of cracks 14 .
When the surface to be measured of the measurement object 10 extends in the vertical direction (for example, a surface other than a horizontal surface such as a vertical surface or an inclined surface), the movement method may be, for example, an adsorption method (using a vacuum) or a magnetic method. etc. may be applied. Furthermore, the movement of the measuring device may be assisted by using a configuration in which a cable or the like connected to the measuring device 1 is wound by a winding drum.

In some embodiments, for example, as shown in FIG. 10, a carrier 24 is provided as a terminal holding section on which the input terminal 2 and the output terminal 4, the plurality of measuring terminal pairs 6, 6 and the potentiometer 8 are transportably mounted. You may have more. The carrier 24 may have a mechanism that can move up and down (that is, in a direction in which the distance to the measurement object 10 can be changed). Electrical resistance may be measured. With this configuration, the input terminal 2, the output terminal 4, the plurality of measuring terminal pairs 6, 6, and the potentiometer 8 can be easily moved by the carrier 24. FIG. Therefore, for example, when there are a plurality of cracks 14 to be measured, the potential difference V on both sides of these cracks 14 can be sequentially measured while moving the carrier 24 . Therefore, the work of measuring the depth D of the plurality of cracks 14 can be efficiently performed using the electrical resistance method. Note that the carrier 24 may also be configured to mount the power source 16 .

In some embodiments, for example, as shown in FIG. 10, the input terminal 2, the output terminal 4, and the plurality of measurement terminals extend along the member surface 12 in the direction connecting the input terminal 2 and the output terminal 4. A guide part 26 for guiding the pair 6, 6 and the potentiometer 8 may also be provided. With this configuration, the input terminal 2, the output terminal 4, the plurality of measuring terminal pairs 6, 6, and the potentiometer 8 can be guided along the guide portion 26. FIG.

In some embodiments, for example, as shown in FIG. 10, a crack measuring portion 28 is movably disposed along the guide portion 26 and configured to measure at least one of the length and number of cracks 14. may further comprise Crack metrology unit 28 may be configured to determine the length of a flaw (eg, crack 14) by, for example, laser scattering techniques. The carrier 24, the crack measuring section 28, or the surface treatment section 30 may be configured to be movable to any position on the guide section 26 and positioned by a positioning mechanism or the like, for example. With the configuration including the crack measuring unit 28 in this way, at least one of the length L and the number of the cracks 14 can be measured by the crack measuring unit 28 . That is, in the measurement of the crack depth D using the electrical resistance method, considering the influence of at least one of the measured value of the length of the crack 14 and the measured value of the number of cracks 14 on the measurement accuracy, the crack depth D can be measured with high accuracy. can be measured to Therefore, it is not necessary to use a measuring device using radiation such as X-rays to measure the crack depth D, and the crack depth D can be inspected in parallel with other work, improving work efficiency. can be greatly improved.

In some embodiments, for example, as shown in FIG. 10 , the measuring device 1 further includes a surface treatment section 30 arranged movably along the guide section 26 and configured to clean the member surface 12 . may be
The surface treatment unit 30 is a pretreatment unit ( function as a pretreatment device). Therefore, the surface treatment section 30 can be arranged at the front in the moving direction along the guide section 26 in the measuring device 1 . Such a surface treatment section 30 can be configured including, for example, a high-pressure water nozzle or a blaster.
According to the configuration including the surface treatment section 30 in this manner, the surface treatment section 30 can previously remove dirt on the member surface 12 that may adversely affect the potential difference measurement. Therefore, the potential difference V on both sides of the crack 14 and the depth D of the crack to be measured can be measured with higher accuracy by suppressing measurement errors.

In some embodiments, for example, as shown in FIG. 13, an input terminal 2 and an output terminal 4 connected to the input terminal 2 via a power supply 16 are each formed in a wheel shape, and a plurality of measurement terminal pairs are provided. 6 and 6 each include a first terminal 6A and a second terminal 6B, and each of the plurality of first terminals 6A and the plurality of second terminals 6B has a tip that contacts the member surface 12 along the circumferential direction. The center of the plurality of radially arranged first terminals 6A, one of the input terminal 2 and the output terminal 4, and the plurality of radially arranged second terminals 6B and the other of the input terminal 2 and the output terminal 4 are connected via axles 20, respectively, and the input terminal 2, the output terminal 4, the plurality of first terminals 6A and the plurality of second terminals 6B are connected to each other. may be configured to be movable along the direction connecting the input terminal 2 and the output terminal 4.

According to the above configuration, the rotatable input terminal 2, output terminal 4, and measuring terminal pair 6, 6 can be integrally moved along the direction connecting the input terminal 2 and the output terminal 4. can. Specifically, the input terminal 2 and the output terminal 4 are always in contact with the member surface 12 and apply the power supply voltage while moving the application range. On the other hand, the plurality of measurement terminal pairs 6, 6 follow the movement of the input terminal 2 and the output terminal 4 while switching between the first terminal 6A and the second terminal 6B in contact with the member surface 12 by rotation. are changed, and the potential difference V between the changed measuring terminals 6 is detected by the potentiometer 8 . With such a configuration, even when a plurality of cracks 14 exist in the direction connecting the input terminal 2 and the output terminal 4, the potential difference V on both sides of each crack 14 can be sequentially measured. Information about the crack 14 can be efficiently obtained.

In some embodiments, for example, as shown in FIG. A connecting frame 22 may be further provided. With this configuration, by providing the frame 22, the input terminal 2, the output terminal 4, the power source 16, the measuring terminal pair 6, 6, and the potentiometer 8 can be integrally configured through the frame 22. . Therefore, in the crack depth measuring device 1 provided with a plurality of measuring terminal pairs 6, 6, it is possible to obtain the measuring device 1 that is easy to handle with improved portability and operability.

In some embodiments, axle 20 may include insulation. In this way, since the axle 20 connecting the input terminal 2 or the output terminal 4 and the measuring terminal 6 contains an insulator, the voltage applied by the input terminal 2 and the output terminal 4 is reduced to the measuring terminal pair 6, 6 is applied to the member surface 12 of the measurement object 10 . Therefore, for example, the input terminal 2 and the output terminal 4 are brought into contact with both sides of the crack 14 generated in the member surface 12 , and the first terminal 6 A and the second terminal 6 A of the measuring terminal pair 6 , 6 are placed on both sides of the crack 14 . Information such as the potential difference on both sides of the crack 14 can be obtained appropriately by arranging the measuring device 1 so that the terminals 6B are in contact with each other. Alternatively, the entire axle 20 may be made of an insulator.

In some embodiments, in the configuration described in any one of (1) to (3) above,
A relay switch 32 may be further provided for switching, among the plurality of measurement terminal pairs 6, 6, the measurement terminal pair 6, 6 used for measuring the potential difference across the crack 14 to be measured. Such a relay switch 32 can be used to avoid interference between terminals during measurement. According to the configuration including the relay switch 32 in this manner, the relay switch 32 switches the measuring terminal 6 used for potential difference measurement among the plurality of measuring terminal pairs 6, 6 according to the characteristics of the crack 14 to be measured. be able to. As a result, in a single measurement operation, the potential difference between both ends of the crack 14 can be measured appropriately corresponding to various cracks 14, so that the operation time can be shortened.
In some embodiments, instead of using all the terminals described above, the terminals to be used may be selected according to the measurement results of the crack measuring section 28 .

In some embodiments, the measurement object 10 may include a furnace wall tube 10A. By doing so, the depth of the crack 14 generated on the surface of the furnace wall tube 10A can be efficiently obtained using the electric resistance method. As a result, it is not necessary to use a measuring device using radiation such as X-rays to measure the crack depth of the furnace wall pipe 10A, and inspection of the crack depth can be performed in parallel with other work. Therefore, work efficiency can be greatly improved.

In some embodiments, the measurement device 1 automatically measures the crack 14 length L or the crack depth D of the surface of the measurement object 10 by including any of the configurations described above or any combination thereof. It may also be configured for measurement (automated measuring device for crack length or crack depth). By doing so, the working efficiency of the crack length L or crack depth D inspection can be further improved.

According to the configuration described above, it is possible to efficiently acquire information about the crack 14 at different measurement positions.

The present invention is not limited to the above-described embodiments, and includes modifications of the above-described embodiments and modes in which these modes are combined as appropriate.

1 Measuring device (crack depth measuring device)
2 Input terminal 4 Output terminal 6 Measurement terminal (measurement terminal pair)
6A measurement terminal (first terminal)
6B measurement terminal (second terminal)
8 Potentiometer 10 Measurement object (pipe/furnace wall tube)
12 Member surface 14 Crack 16 Power supply 20 Axle (insulator)
22 frame 24 carrier 26 guide part (rail)
28 Crack measurement unit 30 Surface treatment unit 32 Relay switch A Tube axis direction D Crack depths L1, L2 Crack length

Claims (10)

A crack depth measuring device using an electrical resistance method,
an input terminal and an output terminal for applying a power supply voltage to both sides of a crack formed on the surface of the member by contacting the surface of the member of the object to be measured;
a plurality of measurement terminal pairs configured to contact both sides of the crack;
a potentiometer for detecting a potential difference between the measurement terminals for each said measurement terminal pair;
a guide portion extending in a direction connecting the input terminal and the output terminal along the surface of the member and guiding the input terminal and the output terminal, the plurality of measurement terminal pairs, and the potentiometer;
A carrier mounted with the input terminal, the output terminal, the plurality of measurement terminal pairs, and the potentiometer is connected to the carrier and arranged movably along the guide section to measure the length and number of the cracks. a crack measurement unit configured as
with
A measuring device configured to determine the crack depth based on the potential difference measured by the potentiometer and the length and number of cracks measured by the crack measuring unit. 2. The measurement apparatus according to claim 1, wherein the plurality of measurement terminal pairs are arranged in a direction crossing a direction connecting the input terminal and the output terminal. At least the input terminal and the output terminal, the plurality of measurement terminal pairs, and the potentiometer are configured to be movable along the surface of the member in a direction connecting the input terminal and the output terminal. The measuring device according to claim 1 or 2, characterized by: The input terminal and the output terminal connected to the input terminal via a power supply are formed in a wheel shape,
The plurality of measurement terminal pairs each include a first terminal and a second terminal,
the plurality of first terminals and the plurality of second terminals are each configured radially such that the tips thereof contacting the surface of the member are arranged along the circumferential direction,
Centers of the plurality of first terminals arranged radially and one of the input terminal and the output terminal, and centers of the plurality of second terminals arranged radially and between the input terminal and the output terminal either one or the other, each connected via an axle,
The input terminal, the output terminal, the plurality of first terminals, and the plurality of second terminals are configured to be movable along a direction connecting the input terminal and the output terminal by rotation. The measuring device according to any one of claims 1 to 3. 5. The measurement according to claim 4, further comprising a frame that mounts the power supply and the potentiometer and integrally connects the input terminal, the output terminal and the measurement terminal pair via the axle. Device. 5. The metrology device of claim 4, wherein said axle includes an insulator. 7. The measuring apparatus according to any one of claims 1 to 6, further comprising a carrier on which the input terminal, the output terminal, the plurality of measurement terminal pairs, and the potentiometer are transportably mounted. The measuring device according to any one of claims 1 to 7, further comprising a surface treatment section arranged movably along the guide section and configured to be able to clean the surface of the member. 4. The method according to any one of claims 1 to 3, further comprising a relay switch for switching, among the plurality of measurement terminal pairs, the measurement terminal pair used for measuring the potential difference across the crack to be measured. measuring device. 10. The measuring device according to any one of claims 1 to 9, wherein the object to be measured includes a furnace wall tube.

Images