KR102558469B1 - Crack width measuring device for safety diagnosis - Google Patents

Abstract

The present invention discloses a crack width measuring device for safety diagnosis. The crack width measuring device for safety diagnosis according to the present invention includes a hollow housing with upper and lower parts open; A crack measurement unit having a measurer installed to be movable in a horizontal direction inside the lower end of the housing and displaying scales having various thicknesses spaced apart from each other so as to measure the width of cracks generated in the structure; and a magnifying glass installed on an upper portion of the housing and having a coating layer having excellent anti-fog function in a high-temperature, high-humidity atmosphere.

Description

Crack width measuring device for safety diagnosis}

The present invention relates to a crack width measuring device for safety diagnosis, and more particularly, to a crack width measuring device for safety diagnosis that can easily and accurately measure the width of a crack generated in a structure.

In general, the causes of cracks in structures such as bridges, tunnels, and buildings are caused by various causes such as drying shrinkage of structures, generation of excessive stress, or material problems.

Cracks occurring in structures are difficult to detect at an early stage due to the minute width of the cracks, and because cracks generally progress very slowly, it is easy for constructors or users to overlook them inadvertently, judging that they do not significantly affect the safety of the structure.

However, cracks occurring in structures are one of the very important factors in diagnosing the safety of a structure because any crack may cause a structural defect of the structure and eventually cause the collapse of the structure. A measuring instrument for measuring such a crack is also one of the very important devices for diagnosing the stability of a structure.

As the prior art for measuring the cracks generated in the structure as described above, equipment such as a crack strain gauge, a digital crack measurer, and a crack ruler is used. Conventional measuring devices may have a separate magnifying glass for checking micro-cracks in addition to the crack measuring device or have a magnifying glass inside in order to solve the problem of measuring minute cracks.

However, depending on the environment where the structure to measure the cracks is located, there is a problem in that the magnifying glass is fogged up and moisture must be removed frequently. In particular, in a high temperature and humidity atmosphere, the degree of moisture and the frequency of moisture removal are very high, so it is practically difficult to measure or confirm microcracks through a magnifying glass, and it is necessary to solve this problem.

1. Republic of Korea Patent Publication No. 10-2001-0002060 2. Republic of Korea Patent No. 10-1487347 3. US Patent No. 5877254 4. US Patent No. 4143181 5. US Patent No. 3935146 6. US Patent Publication No. 2009-0081292 7. Japanese Patent Laid-Open No. 10-017856 8. PCT Publication WO 2007/071700 9. PCT Publication WO 2011/080472

Therefore, the technical problem to be solved by the present invention is to provide a crack width meter for safety inspection and diagnosis of concrete structures, which can easily and accurately measure microscopic cracks generated in a structure. Since the magnifying glass is coated with an anti-fog coating, there is no need to remove moisture inside the meter. In particular, the degree of moisture and the frequency of removing moisture are very high. To provide a crack width meter for safety inspection and diagnosis of concrete structures that can measure or confirm microcracks through a magnifying glass without removing humidity separately even in a high-temperature, high-humidity atmosphere, which is a problem.

According to one aspect of the present invention, (a) a hollow housing with upper and lower ends open, (b) a crack measuring unit having a measurer installed movably in a horizontal direction inside the lower end of the housing and displaying scales having various thicknesses spaced apart from each other so as to measure the width of cracks generated in the structure, (c) a magnifying glass installed at the upper end of the housing, (d) the upper end of the housing is inserted, a first opening is formed at the center, and the inner wall is engaged with the locking groove formed on the outer wall of the upper end of the housing A crack width measuring device for safety inspection and diagnosis of a concrete structure is provided, which includes a holding part having a stumbling protrusion to grip the upper end of the housing, and (e) a terminal receiving part connected to the holding part and holding a mobile communication terminal.

At this time, the crack measuring unit (b1) a movable block provided inside the housing and coupled to the measurer, (b2) a movable screw disposed inside the housing through a sidewall of the housing, coupled to the movable block and moved to move the movable block in a horizontal direction as it rotates, (b3) disposed outside the housing, but coupled to the movable screw and rotated as it rotates, a dial that rotates the movable screw, (b4) disposed to protrude from the inner wall of the lower end of the housing toward the center. (b5) a support member for supporting the lower surfaces of both ends of the measurer, (b5) disposed circularly on the outer wall of the housing along the outer circumferential surface of the dial, corresponding to the width of the crack generated in the structure; The terminal receiving part includes (e1) a main body on which the mobile communication terminal is seated, (e2) a connecting member having one end coupled to the main body, and (e3) a connecting protrusion extending downward from the other end of the connecting member, the end of which is inserted into and coupled to the first opening, and a second opening is formed at the center; arranging the camera of the mobile communication terminal in-line with the first opening to photograph cracks generated in the structure and the scale corresponding to the width of the crack; The locking protrusion is composed of an elastic body with both ends in the longitudinal direction engaged with insertion grooves formed on the inner wall of the gripper and having a protruding center; When the housing is inserted into the holding part, the central portion of the elastic body is pressed so that both longitudinal ends of the elastic body are elastically deformed in directions spaced apart from each other within the insertion groove, and the central portion of the elastic body is moved toward the inside of the insertion groove; When the housing is inserted into the holding part, the central portion of the elastic body is released from pressure, and both ends in the longitudinal direction of the elastic body are restored in a direction approaching each other inside the insertion groove, and the central portion of the elastic body protrudes outward from the insertion groove.

In addition, the magnifying glass includes a coating layer coated with a coating composition on both one side and the other side of the crack measuring unit and then cured; The coating composition includes a reaction product obtained by mixing and reacting isophorone diisocyanate, polyhexamethylene carbonate diol, trimethylolpropane, dimethylolpropionic acid, trimethylolpropane monoethoxylate methyl ether, 2-hydroxy-5-nitrobenzaldehyde of Formula 1 below, and methylethylketone.

[Formula 1]

.

In an embodiment of the present invention, by installing a magnifying glass at the upper end of the housing and having a measurer with scales having various thicknesses corresponding to the widths of cracks generated in the structure at the lower end of the housing, it is possible to easily and accurately measure fine cracks generated in the structure. In particular, since the magnifying glass is coated with an anti-fog coating, there is no need to remove moisture from the inside of the measuring instrument. To provide a crack width measuring device for safety inspection and diagnosis of concrete structures.

1 is a perspective view showing a crack width measuring device for safety inspection and diagnosis of concrete structures according to the present invention.
2 is an exploded perspective view showing a crack width measuring device for safety inspection and diagnosis of concrete structures according to the present invention.
3 is an AA plan view of FIG. 1 .
Figure 4 is a BB cross-sectional view of Figure 1;
Figure 5 is a BB cross-sectional view of Figure 1, a view showing another form of the gripping portion according to the present invention.
6 and 7 are state diagrams showing a crack width measuring device for safety inspection and diagnosis of concrete structures according to the present invention.

In order to fully understand the present invention and the advantages in operation of the present invention and the objects achieved by the practice of the present invention, reference should be made to the accompanying drawings illustrating preferred embodiments of the present invention and the contents described in the accompanying drawings.

Hereinafter, the present invention will be described in detail by describing preferred embodiments of the present invention with reference to the accompanying drawings. Like reference numerals in each figure indicate like elements.

1 is a perspective view showing a crack width measuring device for safety inspection and diagnosis of concrete structures according to the present invention, FIG. 2 is an exploded perspective view showing a crack width meter for safety inspection and diagnosis of concrete structures according to the present invention, FIG.

1 to 5, the crack width measuring instrument 100 for safety inspection and diagnosis of concrete structures according to the present invention includes a hollow housing 110 with open top and bottom, a magnifying glass 120 installed on the upper end of the housing 110, a lighting unit 130 installed inside the housing 110, a crack measuring unit 140 installed on the lower end of the housing 110, and a gripper for gripping the upper end of the housing 110. 150 and a terminal seating portion 160 connected to the gripping portion 150 and on which the mobile communication terminal P is seated.

The housing 110 according to the present embodiment is formed in a cylindrical shape with open upper and lower parts and a hollow inside. A magnifying glass 120, a lighting unit 130, and a crack measuring unit 140 are installed in the housing 110, respectively.

The magnifying glass 120 according to the present embodiment enlarges and shows the width of the crack generated in the structure and the scale 142 displayed on the measurer 141 of the crack measuring unit 140 to be described later.

The magnifying glass 120 may be installed inside the upper end of the housing 110 or coupled to the upper end of the housing 110 . Also, if necessary, the magnifying glass 120 may be movably installed in the height direction of the housing 110 to enlarge the width of the crack and the scale 142 of the measuring ruler 141.

The lighting unit 130 according to the present embodiment makes it possible to easily measure cracks in a structure in a dark place. The lighting unit 130 includes a lighting lamp 130 installed inside the housing 110, a switch (not shown) installed on an outer wall of the housing 110 to turn the lighting lamp 130 on and off, and a power source (not shown) installed inside the housing 110 and electrically connected to the switch and the lighting lamp 130 to supply power to the lighting lamp 130.

In this embodiment, the lighting 130 may use a light bulb, LED, etc., and may be installed inclined downward from the inner sidewall of the housing 110 to uniformly illuminate the crack measuring unit 140. In addition, a portable battery or a rechargeable battery capable of being charged by connecting a power cable may be used as the power source according to the present embodiment.

The crack measurement unit 140 according to the present embodiment serves to measure the width of a crack generated in a structure.

4 and 5, the crack measurement unit 140 includes a probe 141 movably installed inside the lower end of the housing 110 in a horizontal direction, and a probe moving unit 143 that is connected to the probe 141 and moves the probe 141 horizontally inside the housing 110.

The measurer 141 has a thin plate shape. On the surface of the measurer 141, scales 142 having a thickness corresponding to the width of the crack are spaced apart from each other so that the width of the crack generated in the structure can be measured on an actual scale.

The scales 142 displayed on the measuring ruler 141 have various thicknesses to easily measure the crack width. For example, the scales 142 displayed on the measuring ruler 141 may have a thickness difference of 0.1 mm from a minimum thickness of 0.1 to a maximum thickness of 2 mm, but the scope of the present invention is not limited by the minimum thickness and maximum thickness and the difference in thickness.

On the other hand, since the scale 142 displayed on the measuring ruler 141 and cracks generated in the structure are magnified by the magnifying glass 120, the measuring ruler 141 is placed close to the surface of the structure to prevent distortion by the magnifying glass 120. It is preferable.

In this embodiment, in order to measure the width of the crack, the housing 110 is brought into close contact with the cracked structure, and then the measuring ruler 141 is moved relative to the housing 110 in a horizontal direction to match the thickness scale 142 corresponding to the width of the crack. To this end, in this embodiment, a measurer moving unit 143 for moving the measurer 141 in a horizontal direction is provided.

The measuring ruler moving unit 143 includes a moving block 144 coupled to the measuring ruler 141, a moving screw 145 penetrating the sidewall of the housing 110 and coupled to the moving block 144, and a dial 146 coupled to the moving screw 145 and disposed outside the housing 110.

The moving block 144 is disposed inside the housing 110 and coupled to the measurer 141 . In addition, the moving block 144 may be formed integrally with the measuring element 141, and when the moving block 144 and the measuring element 141 are integrally formed, the moving screw 145 is inserted into the housing 110. After being inserted into the housing 110 in the opposite direction, the moving block 144 may be coupled to the moving screw 145 and disposed inside the housing 110.

In this embodiment, the moving block 144 may have various shapes such as a rectangular parallelepiped and a cylinder. The moving block 144 may be made of acrylic or glass material through which light can be transmitted.

The moving screw 145 passes through the sidewall of the housing 110, is disposed inside the lower end of the housing 110, and is coupled to the moving block 144. One end of the moving screw 145 may be disposed inside the housing 110 by penetrating one side wall of the housing 110 . Also, the other end of the moving screw 145 may be coupled to and supported by a bearing member (not shown) installed on one side wall of the housing 110 . In addition, both ends of the movable screw 145 may be coupled to and supported by bearing members (not shown) installed on opposite sides of the housing 110 .

The dial 146 is coupled to the other end of the moving screw 145 disposed outside the housing 110 . When the user rotates the dial 146, the moving screw 145 is also rotated in conjunction with it.

In addition, the crack measuring unit 140 may further include a support member 147 disposed to protrude from the inner wall of the lower end of the housing 110 toward the center. The support member 147 supports the lower surfaces of both ends of the measuring element 141 .

Therefore, when the user rotates the dial 146, the moving screw 145 coupled to the dial 146 is rotated, and accordingly, the moving block 144 moves in the horizontal direction along the longitudinal direction of the moving screw 145 inside the housing 110, and the measuring ruler 141 coupled to the moving block 144 is also moved horizontally along with the moving block 144 inside the housing 110. At this time, both ends of the lower surface of the measurer 141 are supported by the support member 147 .

Meanwhile, the crack measuring unit 140 according to the present embodiment may further include a plurality of dimension lines 148 disposed in a circular shape along the outer circumferential surface of the dial 146 on the outer wall of the housing 110 . Each of the plurality of dimension lines 148 represents the thickness of each of the plurality of graduations 142 . When the dial 146 is rotated to move the measuring ruler 141 horizontally and the thickness of the scale 142 and the width of the crack are matched, the user can check the thickness of the scale 142 corresponding to the width of the crack through the dimension line 148. Meanwhile, a reference line may be provided on the inner wall of the housing 110, and the width of the crack may be checked through the dimension line 148 when the reference line and the crack and the scale 142 coincide.

The gripping part 150 according to the present embodiment is formed in a cylindrical shape with an open bottom and a hollow inside so that the upper end of the housing 110 can be inserted.

When the upper end of the housing 110 is inserted into the gripping part 150 , the housing 110 may be engaged with the gripping part 150 . To this end, a locking groove 111 is formed on the outer wall of the upper end of the housing 110 along the circumferential direction, and a locking protrusion 152 engaged with the locking groove 111 formed on the housing 110 is formed on the inner wall of the gripping part 150.

In addition, a first opening 151 is formed at the center of the upper end of the gripping part 150, and even when the housing 110 is inserted into the gripping part 150, the user can see the cracks generated in the structure, the scale 142 of the measuring ruler 141, and the reference line through the first opening 151.

As shown in FIG. 4 , the protrusion 152 is integrally formed on the inner wall of the gripping part 150 and may protrude from the inner wall of the gripping part 150 toward the center.

In addition, as shown in FIG. 5, the protrusion 152 may be composed of an elastic body 152a having both ends in the longitudinal direction engaged with insertion grooves 153a formed on the inner wall of the gripping part 150 and having a protruding center.

When the housing 110 is inserted into the gripping portion 150, the central portion of the elastic body 152a is pressed so that both ends in the longitudinal direction of the elastic body 152a are elastically deformed in a direction spaced apart from each other inside the insertion groove 153a. The central portion of the elastic body 152a is moved toward the inside of the insertion groove 153a. On the other hand, when the housing 110 is inserted into the gripping part 150, the central portion of the elastic body 152a is released, and both ends in the longitudinal direction of the elastic body 152a are restored in a direction approaching each other inside the insertion groove 153a, and the central portion of the elastic body 152a protrudes outward from the insertion groove 153a.

The terminal seating portion 160 according to the present embodiment is connected to the gripping portion 150 and the mobile communication terminal P is seated thereon.

Specifically, the terminal seating portion 160 includes a main body portion 161 on which the mobile communication terminal P is seated, a connecting member 162 having one end coupled to the main body portion 161, and a coupling protrusion 163 formed to extend downward from the other end of the connecting member 162 and inserted into and coupled to the first opening 151 at the end thereof and having a second opening 164 formed at the center thereof.

In a state where the mobile communication terminal P is seated on the main body part 161, the camera of the mobile communication terminal P is arranged inline with the second opening 164 and the first opening 151 to take a picture of the crack generated in the structure and the scale 142 corresponding to the width of the crack.

An operation of measuring the width of a crack generated in a structure using the crack width measuring device 100 for safety inspection and diagnosis of a concrete structure according to the present invention configured as described above will be described as follows.

6 and 7 are state diagrams showing a crack width measuring device for safety inspection and diagnosis of concrete structures according to the present invention.

The width of cracks generated in a structure can have various sizes.

As shown in FIG. 6, the lower surface of the housing 110 is brought into close contact with the cracked structure. At this time, only the housing 110 in which the crack measuring unit 140, the magnifying glass 120, and the lighting lamp 130 are combined can be attached to the structure, but the housing 110 in which the crack measuring unit 140, the magnifying glass 120, and the lighting lamp 130 are combined is gripped with the gripping unit 150 and the lower surface of the housing 110 is in close contact with the structure in a state in which the mobile communication terminal P is seated on the terminal seating unit 160. can make it

And, as shown in FIG. 7, the dial 146 is rotated to move the measuring ruler 141 in the horizontal direction so that the crack and the scale 142 having a thickness corresponding to the width of the crack are matched. In addition, the width of the crack can be confirmed by checking the dimension line 148 disposed around the dial 146.

As such, according to one aspect of the present invention, (a) a hollow housing with upper and lower parts open, (b) a crack measuring unit having a measurer installed horizontally movably inside the lower end of the housing and displaying scales having various thicknesses spaced apart from each other so as to measure the width of cracks generated in the structure, (c) a magnifying glass installed at the upper end of the housing, (d) the upper end of the housing is inserted, a first opening is formed at the center, and a locking groove formed on the inner wall of the upper end of the housing A crack width measuring device for safety inspection and diagnosis of concrete structures is provided, which includes a gripping part for gripping the upper end of the housing with a hooking protrusion formed thereon, and (e) a terminal seating part connected to the gripping part and holding a mobile communication terminal.

At this time, the crack measuring unit (b1) a movable block provided inside the housing and coupled to the measurer, (b2) a movable screw disposed inside the housing through a sidewall of the housing, coupled to the movable block and moved to move the movable block in a horizontal direction as it rotates, (b3) disposed outside the housing, but coupled to the movable screw and rotated as it rotates, a dial that rotates the movable screw, (b4) disposed to protrude from the inner wall of the lower end of the housing toward the center. (b5) a support member for supporting the lower surfaces of both ends of the measurer, (b5) disposed circularly on the outer wall of the housing along the outer circumferential surface of the dial, corresponding to the width of the crack generated in the structure;

The terminal receiving part includes (e1) a main body on which the mobile communication terminal is seated, (e2) a connecting member having one end coupled to the main body, and (e3) a connecting protrusion extending downward from the other end of the connecting member, the end of which is inserted into and coupled to the first opening, and a second opening is formed at the center;

arranging the camera of the mobile communication terminal in-line with the first opening to photograph cracks generated in the structure and the scale corresponding to the width of the crack;

The locking protrusion is composed of an elastic body with both ends in the longitudinal direction engaged with insertion grooves formed on the inner wall of the gripper and having a protruding center;

When the housing is inserted into the holding part, the central portion of the elastic body is pressed so that both longitudinal ends of the elastic body are elastically deformed in directions spaced apart from each other within the insertion groove, and the central portion of the elastic body is moved toward the inside of the insertion groove;

When the housing is inserted into the holding part, the central portion of the elastic body is released from pressure, and both ends in the longitudinal direction of the elastic body are restored in a direction approaching each other inside the insertion groove, and the central portion of the elastic body protrudes outward from the insertion groove.

In addition, the magnifying glass includes a coating layer coated with a coating composition on both one side and the other side of the crack measuring unit and then cured;

The coating composition includes a reaction product obtained by mixing and reacting isophorone diisocyanate, polyhexamethylene carbonate diol, trimethylolpropane, dimethylolpropionic acid, trimethylolpropane monoethoxylate methyl ether, 2-hydroxy-5-nitrobenzaldehyde and methylethylketone.

In one embodiment, the coating composition in the present invention is isophorone diisocyanate 20-21% by weight, polyhexamethylene carbonate diol 28-29% by weight, trimethylolpropane 2-3% by weight, dimethylolpropionic acid 3-4% by weight, trimethylolpropane monoethoxylate methyl ether 8-9% by weight, 2-hydroxy-5-nitrobenzaldehyde 2-3% by weight and methyl ethyl ketone It includes reaction products obtained by mixing and then reacting 34-36% by weight.

Hereinafter, the present invention will be described in more detail through examples and the like, but the scope and contents of the present invention are reduced or limited by the examples below and cannot be interpreted. In addition, based on the disclosure of the present invention including the following examples, it is clear that a person skilled in the art can easily practice the present invention for which no experimental results are specifically presented, and such variations and modifications are included in the appended claims.

In addition, the experimental results presented below are only representative experimental results of the above examples and comparative examples, and each effect of various embodiments of the present invention that is not explicitly presented below will be described in detail in the corresponding section.

Example

Example 1

21.1 g of isophorone diisocyanate (IPDI), 28.2 g of polyhexamethylene carbonate diol (Mw 2,000), 2.1 g of trimethylolpropane, 3.2 g of dimethylolpropionic acid, 8.1 g of trimethylol propane monoethoxylate methyl ether (M _n 1,220), 2.3 g of 2-hydroxy-5-nitrobenzaldehyde, and 35 g of methyl ethyl ketone were mixed together. The mixture was heated to 70° C. and 0.01 g of tin catalyst was added. The mixture was then reacted for 3 hours in a nitrogen environment.

After the reaction was over, the resulting polyurethane prepolymer mixture was cooled to 40°C. 40.3 g of the polyurethane prepolymer mixture was then dispersed in 51.2 g of water and 7.0 g of an aqueous betaine surfactant solution using a high shear disperser. While dispersing using a high shear disperser, 0.25 g of hydrazine-monohydrate and 0.58 g of 1,6-hexanediamine were also added together to obtain an aqueous polyurethane dispersion having about 27% solids by weight of the dispersion.

The resulting polyurethane comprised polyethylene oxide side chains at about 10% by weight of the polyurethane solids and neutralized amines at about 10% by weight of the polyurethane solids. The viscosity of the aqueous polyurethane dispersion was measured to be 34 centipoise (cps) at 25°C. A glass magnifying glass was dip coated in an aqueous polyurethane dispersion at a draw rate of 12 inches/min. Dip-coated magnifiers were dried at room temperature for 30 minutes. Drying as above gave a non-tacky coating.

The coated magnifying glass was then cured at 90° C. for 2 hours. The coating thickness of the resulting coated magnifying glass was about 14.2 μm.

Comparative Example 1

The experiment was conducted by preparing a coating composition in the same manner as in Example 1, except that 2-hydroxy-5-nitrobenzaldehyde was not included.

The resulting polyurethane comprised polyethylene oxide side chains at about 10% by weight of the polyurethane solids and neutralized amines at about 10% by weight of the polyurethane solids. The viscosity of the aqueous polyurethane dispersion was measured to be 34 centipoise (cps) at 25°C. A glass magnifying glass was dip coated in an aqueous polyurethane dispersion at a draw rate of 12 inches/min. Dip-coated magnifiers were dried at room temperature for 30 minutes. Drying as above gave a non-tacky coating.

The coated magnifying glass was then cured at 90° C. for 2 hours. The coating thickness of the resulting coated magnifying glass was about 14.2 μm.

Test Example 1: Initial anti-fog test

The polyurethane coated magnifying glass is not treated or modified in any other way, i.e. the coated magnifying glass is placed at a standard height above the water source in such a way that the coated magnifying glass is exposed to water vapor from the water source at 50° C. for 3 minutes before immersing the coated magnifying glass in water. If fogging does not appear on the polyurethane-coated magnifying glass during this period, the coating composition passes the initial anti-fogging test. Otherwise, if fogging appears on the coated magnifying glass, then the coating composition fails the initial antifogging test.

Anti-fog test conducted after immersion for 1 hour: The coated polyurethane magnifying glass is immersed in water at room temperature for 1 hour. After allowing the coated magnifying glass to recover from immersion for 12 hours, the magnifying glass is placed at a standard height above the water source by exposing the coated magnifying glass to water vapor from a water source at 50° C. for at least 8 seconds according to the EN166/EN168 anti-fog performance specification. If fogging does not appear on the polyurethane-coated magnifying glass during this period, the coating composition passes the anti-fogging test. Otherwise, if fogging appears on the coated magnifying glass, then the coating composition fails the anti-fogging test.

Test Example 2: Initial haze test

Haze (%) of coated magnifiers is measured using Haze-Gard Plus available from BYK Gardner USA (Columbia, MD). Measuring haze using Haze-Guard Plus quantifies the amount of scattered light that appears as a result of light transmission through a coated magnifying glass. The initial haze (%) is measured immediately after curing of the polyurethane coating on the substrate magnifying glass, and immediately before any other coated magnifying glass is modified or treated in any other way, i.e., before the coated magnifying glass is immersed in water, or before the magnifying glass is used in the drop-down method.

Haze test performed after immersion for 1 hour: After immersing the coated magnifying glass in water at room temperature for 1 hour, immediately measure the haze (%) of the coated magnifying glass using Haze-Guard Plus. A haze of about 1% or greater is visible on the surface of the coated magnifying glass substrate. Conversely, a haze of less than about 1% is not visible in a coated magnifying glass. In the haze test performed after immersion, if the magnifying glass is transparent and the haze is not visible in the coated magnifying glass, it passes the test.

Test Example 3: Fall-type wear test

The coated magnifying glass is mounted on an HP-1160 Gardner Falling Sand Apparatus available from Paul N. Gardner Company (Pompano Beach, Fla., USA). According to EN166/168 specifications, three (3) kilograms of ASTM 20-30 are dropped through an HP-1160 device onto a coated magnifying glass. After washing the coated magnifying glass with soap and water to remove residual sand from the coated magnifying glass, the Haze-Guard Plus is used to measure the haze (%) of the coated magnifying glass. In the examples described herein, "haze increase" is referred to after the fall-off abrasion test. The "haze increase" is the arithmetic difference between the haze (%) measurement value measured after the fall-off test and the initial haze (%) measurement value, that is, the haze increase = [(haze after the fall-off test (%)) - (Initial haze (%))].

Test Example 4: High humidity and high temperature atmosphere test

Ten anti-fogging coated magnifying glasses prepared in Example 1 and Comparative Example 1 were prepared, respectively, and a high humidity test was performed on them as follows.

Prior to first testing, the magnifying glasses were placed in an environment regulated to a relative humidity of 40% to 50% and a temperature of 20-25° C. for 6 hours. Then, the magnifying glasses were placed in an atmosphere with a humidity of 70 to 80% and a temperature of 50-60° C. for 48 hours. Thereafter, the visual acuity scale located 5 m away was viewed through a test magnifying glass, and the observer evaluated visual acuity according to time and the following criteria.

0. No fogging, no visual distortion (visual acuity = 10/10),

1. Fog and/or visual distortions that allow >6/10 visual acuity;

2. Fog and/or visual distortions that allow for < 6/10 visual acuity.

In practical terms, to obtain a score of 0 or 1, a wearer with 10/10 visual acuity could discern the direction of the letter "E" on line 6/10 of a Snellen eye chart from 5 m away through a magnifying glass placed in front of their eyes.

The test allowed the wearer to simulate everyday life conditions, such as when the wearer tilts their face toward a teacup/coffee cup or toward a pot filled with boiling water. If the magnifiers obtained a score of 0 or 1, the magnifiers were placed under a Waldmann lamp to dry completely before a new vapor test was performed. This test was repeated for each pair of magnifiers until each magnifying glass scored 2, meaning it failed the vapor test.

Test result

In the case of the anti-fog coated magnifying glass obtained in Example 1 and Comparative Example 1 above, the haze was about 0.30% in the initial haze test, about 0.21% after immersion in water for 1 hour, and the haze increase after the drop-down abrasion test was about 12.8%, and passed the adhesion test, the initial anti-fog test, and the anti-fog test conducted after immersion for 1 hour without significant differences.

However, in the test under high-temperature steam, the anti-fog coated magnifying glass obtained in Example 1 and Comparative Example 1 showed a great difference. The magnifying glass manufactured in Comparative Example 1 showed a failure result in the high-humidity and high-temperature test repeated 7 to 12 times, whereas the magnifying glass manufactured in Example 1 showed no visual distortion even in the high-humidity and high-temperature test repeated up to 30 times. It was confirmed that it did not show.

Those skilled in the art will be able to easily understand and reproduce the present invention based on the contents described in this specification, and if necessary for understanding and reproducing the present invention, even if necessary for matters not described in the specification, Korean Patent Nos. 10-1487347 and 10-1961392 It is obvious that you can easily learn by referring to known literature.

As such, the present invention is not limited to the described embodiments, and it is obvious to those skilled in the art that various modifications and variations can be made without departing from the spirit and scope of the present invention. Therefore, it should be said that such modifications or variations fall within the scope of the present invention.

100: crack width meter 110: housing
111: locking groove 120: magnifying glass
130: lighting 140: crack measurement unit
141: measurer 142: scale
143: measurer moving unit 144: moving block
145: moving screw 146: dial
147: support member 148: dimension line
150: holding part 151: first opening
152: stumbling block 152a: elastic body
153a: insertion groove 160: terminal seating portion
161: body part 162: connection member
163: coupling protrusion 164: second opening

Claims (2)

(a) a hollow housing with upper and lower portions open, (b) a crack measuring unit having a measurer installed to be movable in a horizontal direction inside the lower end of the housing and displaying scales having various thicknesses spaced apart from each other so as to measure the width of cracks generated in the structure, (c) a magnifying glass installed at the upper end of the housing, (d) the upper end of the housing is inserted, but a first opening is formed in the center, and a locking protrusion is formed on the inner wall to be engaged with the locking groove formed on the outer wall of the upper end of the housing. A crack width measuring device for safety inspection and diagnosis of a concrete structure comprising a gripping part for gripping the upper end, and (e) a terminal seating part connected to the gripping part and in which a mobile communication terminal is seated;
The crack measuring unit (b1) a moving block provided inside the housing and coupled to the measurer, (b2) a moving screw disposed inside the housing through a sidewall of the housing, coupled to the moving block and moving the moving block in a horizontal direction as it is rotated, (b3) disposed outside the housing, but coupled to the moving screw and rotating the moving screw as it rotates, (b4) disposed to protrude from the inner wall of the lower end of the housing toward the center, A support member for supporting the lower surfaces of both ends of the measurer, (b5) disposed in a circular shape along the outer circumferential surface of the dial on the outer wall of the housing, allowing the thickness of the scale corresponding to the width of the crack generated in the structure to be confirmed. Including a plurality of dimension lines;
The terminal receiving part includes (e1) a main body on which the mobile communication terminal is seated, (e2) a connecting member having one end coupled to the main body, and (e3) a connecting protrusion extending downward from the other end of the connecting member, the end of which is inserted into and coupled to the first opening, and a second opening is formed at the center;
arranging the camera of the mobile communication terminal in-line with the first opening to photograph cracks generated in the structure and the scale corresponding to the width of the crack;
The locking protrusion is composed of an elastic body with both ends in the longitudinal direction engaged with insertion grooves formed on the inner wall of the gripper and having a protruding center;
When the housing is inserted into the holding part, the central portion of the elastic body is pressed so that both longitudinal ends of the elastic body are elastically deformed in directions spaced apart from each other within the insertion groove, and the central portion of the elastic body is moved toward the inside of the insertion groove;
When the housing is inserted into the holding part, the central portion of the elastic body is released from pressure, and both ends in the longitudinal direction of the elastic body are restored in a mutually approaching direction inside the insertion groove, and the central portion of the elastic body protrudes outward from the insertion groove;
The magnifying glass includes a coating layer coated with a coating composition on both one side and the other side of the crack measurement unit and then cured;
The coating composition includes a reaction product obtained by mixing and reacting isophorone diisocyanate, polyhexamethylene carbonate diol, trimethylolpropane, dimethylolpropionic acid, trimethylolpropane monoethoxylate methyl ether, 2-hydroxy-5-nitrobenzaldehyde and methylethylketone;
The coating composition contains 20-21% by weight of isophorone diisocyanate, 28-29% by weight of polyhexamethylene carbonate diol, 2-3% by weight of trimethylolpropane, 3-4% by weight of dimethylolpropionic acid, 8-9% by weight of trimethylolpropane monoethoxylate methyl ether, 2-3% by weight of 2-hydroxy-5-nitrobenzaldehyde and 34-36% by weight of methyl ethyl ketone. A crack width measuring instrument for safety inspection and diagnosis of concrete structures, characterized in that it comprises a reaction product obtained by reacting after mixing. delete