Coating layer inspection apparatus using magnetic field

Abstract

This coating layer inspection apparatus for inspecting the thickness of a non-conductive coating layer coated on a conductive member includes: a first sensor including a first coil for applying an induced magnetic field to the conductive member on the basis of an input of a first signal and a second coil configured to obtain a second signal based on the induced magnetic field by interacting with the induced magnetic field; a second sensor, wherein the second sensor is configured to obtain first distance information related to a first distance between the second sensor and the coating layer; a detection circuit configured to obtain the second signal from the first sensor and obtain measurement values of a plurality of parameters on the basis of the second signal; a transfer device configured to transfer the first sensor and the second sensor; and a processor configured to control the transfer device and obtain, from the detection circuit, the measurement values of the plurality of parameters.

Description

Coating layer inspection device using magnetic field

[0001] The descriptions below relate to a coating layer inspection device using a magnetic field.

[0002] In order to protect a conductive member formed of a conductive material (e.g., metal), a coating layer may be formed on the surface of the conductive member. The coating layer may be formed of a non-conductive material (e.g., epoxy resin). The coating layer may protect the conductive member from physical damage and chemical damage. In order to effectively protect the conductive member, the thickness of the coating layer may be required to be maintained at a target thickness. If a portion of the coating layer is damaged, worn, etc., the thickness of the coating layer may be reduced, and the conductive member in that portion may not be protected. For example, the inner surface of a pipe may include a coating layer to protect the pipe from a fluid flowing along the hollow portion of the pipe. Inspection of the thickness of the coating layer may be required to determine the condition of the coating layer.

[0003] The above-described matter is not claimed as prior art to the present disclosure.

[0004] The thickness of the coating layer must be at least a certain thickness to effectively protect the conductive material. If a defect occurs in the coating layer, the conductive material in the defective area will not be protected, which may result in wear, corrosion, or damage to the conductive material. The thickness of the coating layer may be difficult to observe with the naked eye from the outside.

[0005] A coating layer inspection device for inspecting the thickness of a non-conductive coating layer coated on a conductive member is provided. The coating layer inspection device may include a first sensor including a first coil for applying an induced magnetic field to the conductive member based on an input of a first signal, and a second coil configured to obtain a second signal based on the induced magnetic field by interacting with the induced magnetic field. The coating layer inspection device may include a second sensor. The second sensor may be configured to obtain first distance information related to a first distance between the second sensor and the coating layer. The coating layer inspection device may include a detection circuit configured to obtain the second signal from the first sensor and obtain measurement values ​​of a plurality of parameters based on the second signal. The coating layer inspection device may include a transfer device coupled to the first sensor and the second sensor, and configured to transfer the first sensor and the second sensor. The coating layer inspection device may include a processor configured to control the transfer device and obtain the measurement values ​​of the plurality of parameters from the detection circuit. The processor may be configured to obtain the first distance information from the second sensor, obtain second distance information related to a second distance between the first sensor and the conductive member based on at least one of the measurement values ​​of the plurality of parameters, and identify a thickness of the coating layer based on the first distance information and the second distance information.

[0006] A coating layer inspection device according to one embodiment can simply and accurately determine a defect in a coating layer by identifying the thickness of the coating layer using a sensor module.

[0007] Figure 1 illustrates an example of a conductive member.

[0008] Fig. 2 is a block diagram of a coating layer inspection device according to one embodiment.

[0009] FIGS. 3A and 3B illustrate a first sensor of a coating layer inspection device according to one embodiment.

[0010] Figure 4 is a flowchart showing the operation of a coating layer inspection device according to one embodiment.

[0011] FIG. 5 is a flowchart showing an operation of a coating layer inspection device according to one embodiment to determine a defect in a coating layer.

[0012] Figure 6a shows a coating layer in a normal state.

[0013] Figure 6b illustrates an abnormal coating layer containing a defect.

[0014] Figure 7a illustrates a conductive pipe including a coating layer in a normal state.

[0015] Figure 7b illustrates a conductive pipe including an abnormal coating layer containing a defect.

[0016] Figure 7c illustrates a coating layer inspection device including a protrusion for adjusting the position of the sensor module.

[0017] Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary drawings. When designating components in each drawing, it should be noted that, where possible, identical components are given the same reference numerals, even if they appear in different drawings.

[0018] Figure 1 illustrates an example of a conductive member.

[0019] There may be various examples of forming a coating layer (20) on a conductive member (10). The conductive member (10) may include, for example, a metal material. Since the metal material has high strength, it can provide structural rigidity compared to other materials. Since the metal material has high durability, it can have high resistance to physical damage such as wear. However, if the metal material reacts with the surrounding environment and is chemically corroded, the surface of the conductive member (10) may be damaged, resulting in performance degradation such as reduced strength and durability. Since corrosion of the conductive member (10) shortens the lifespan, a coating layer (20) may be coated on the conductive member (10) to protect the surface of the conductive member (10). Coating the coating layer (20) on the conductive member (10) may be referred to as forming the coating layer (20) on the surface of the conductive member (10). For example, the coating layer (20) can be placed on the outer surface or inner surface of the conductive member (10).

[0020] Referring to Fig. 1, as an example of a conductive member (10), the conductive member (10) may include a conductive pipe (11). The conductive pipe (11) may be used to transmit a fluid such as gas, water, oil, or sewage. The conductive pipe (11) may include a hollow portion. The fluid may flow through the hollow portion of the conductive pipe (11). The conductive pipe (11) may be formed of a metal material having high strength and high durability. In order to reduce damage (e.g., corrosion) to the conductive pipe (11) due to contact between the fluid flowing along the inside of the conductive pipe (11) and the inner surface of the conductive pipe (11), a coating layer (20) may be formed on the inner surface of the conductive pipe (11). The coating layer (20) may protect the inner surface of the conductive pipe (11) from corrosion, wear, etc., improve the flow of the fluid flowing along the hollow portion, reduce friction, and reduce leakage of the fluid. For example, the coating layer (20) may include, but is not limited to, a non-conductive material such as an epoxy coating layer (20) having high strength and high chemical resistance.

[0021] The coating layer (20) may include defects. For example, when the coating layer (20) is coated, it may be coated to have a target thickness in order to protect the conductive member (10). The thickness of the coating layer (20) may be appropriately selected depending on the purpose of the conductive member (10), the type of fluid, the size of the conductive member (10), etc. After the coating layer (20) is formed, over time, the coating layer (20) may wear out or detach from the conductive member (10), thereby forming defects in the coating layer (20). Alternatively, when the coating layer (20) is coated, if the coating layer (20) is not uniformly formed, the thickness of some areas of the coating layer (20) may not have the target thickness and may have a thickness thinner than the target thickness.

[0022] In order to determine whether the coating layer (20) has a defect, a coating layer inspection device for inspecting the thickness of the coating layer (20) may be used. For example, the coating layer inspection device may utilize ultrasound or a vision sensor. In the case of a coating layer inspection device utilizing ultrasound or a vision sensor, it may be difficult to measure the exact thickness of the coating layer (20) and expensive components may be required. In the case of using a sensor utilizing eddy current, since a defect in the coating layer (20) can be identified only when the coating layer (20) is formed of a conductive material, it may be difficult to identify a defect in a non-conductive coating layer (20).

[0023] A coating layer inspection device according to one embodiment (e.g., a coating layer inspection device (100) of FIG. 2) may be configured to identify a state of a non-conductive coating layer (20) coated on a conductive member (10) by using a first sensor (e.g., a first sensor (111) of FIG. 2) that uses a magnetic field and a second sensor (e.g., a second sensor (112) of FIG. 2) that measures a distance. For example, when a non-conductive coating layer (20) is formed on a conductive member (10), the coating layer inspection device (100) may obtain distance information (e.g., second distance information) about a distance between the conductive member (10) and the first sensor (111) by using the first sensor (111), and may obtain information (e.g., first distance information) about a distance between the coating layer (20) and the second sensor (112) by using the second sensor (112). The coating layer inspection device (100) can be configured to identify the thickness of the non-conductive coating layer (20) based on the first distance information and the second distance information, and to determine the state of the non-conductive coating layer (20) based on the identified thickness of the non-conductive coating layer (20).

[0024] Hereinafter, a coating layer inspection device (100) according to one embodiment is described.

[0025] Fig. 2 is a block diagram of a coating layer inspection device according to one embodiment. Figs. 3a and 3b illustrate a first sensor of the coating layer inspection device according to one embodiment.

[0026] A coating layer inspection device (100) according to one embodiment may be configured to identify the thickness of a coating layer (20) using a magnetic force current (MFC). The magnetic force current may include a current formed by an induced magnetic field (e.g., an eddy current). In the present specification, the magnetic force current may be referred to as a current formed by a magnetic field. A coating layer inspection device (100) according to one embodiment is a non-destructive coating layer inspection device (100) capable of identifying the thickness of a coating layer (20) using the magnetic force current (e.g., an eddy current), and may identify the thickness of the coating layer (20) through a simplified structure.

[0027] A coating layer inspection device (100) according to one embodiment may include a sensor module (110), a detection circuit (120), a processor (130), a transport device (140), and / or a memory (150).

[0028] According to one embodiment, the sensor module (110) may be configured to obtain distance information and provide the obtained distance information to the processor (130).

[0029] According to one embodiment, the sensor module (110) may include a first sensor (111) and a second sensor (112). Referring to FIG. 3A, the first sensor (111) may include a first coil (110a) and a second coil (110b). As illustrated in FIG. 3A, the first coil (110a) and the second coil (110b) may be wound on one core.

[0030] Referring to FIG. 3A, the first sensor (111) may be placed on a conductive member (10) on which a coating layer (20) is formed. For example, a first signal may be applied to the first coil (110a) while the sensor module (110) is positioned adjacent to the surface of the coating layer (20). As the first signal is applied to the first coil (110a), a first magnetic field (M1) may be formed. For example, when a high-frequency alternating current flows along the coil, a first magnetic field (M1), which is an alternating magnetic field, may be formed. The first magnetic field may induce a current (E) (e.g., an eddy current) on the surface of the conductive member (10). For example, since the conductive member (10) includes a conductive material (e.g., metal), an induced electromotive force may be formed on the surface of the conductive member (10), which is a conductor, and a current (E) may be formed by the induced electromotive force. The coating layer (20) may include a non-conductive material. For example, the coating layer (20) may include, but is not limited to, polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polytetrafluoroethylene (PTFE), and / or epoxy resin.

[0031] According to one embodiment, since the coating layer (20) is formed of a non-conductive material, a current can be formed on the surface of the conductive member (10). The current (E) formed on the surface of the conductive member (10) can form a second magnetic field (M2). The second magnetic field (M2) can interact with the adjacent second coil (110b). For example, the second coil (110b) can be positioned closer to the conductive member (10) and the coating layer (20) than the first coil (110a) to interact with the second magnetic field (M2). For example, when the first coil (110a) and the second coil (110b) are wound on one core, the second coil (110b) can be positioned lower than the first coil (110a). However, the present invention is not limited thereto. As illustrated in FIG. 3b, the first sensor (111) may include a first core (111-1) around which a first coil (110a) is wound and a second core (111-2) around which a second coil (110b) is wound. The second core (111-2) may be positioned closer to the conductive member (10) and the coating layer (20) than the first core (111-1). Although not illustrated, the second core (111-2) may also be positioned on the opposite side of the first core (111-1). For example, a first core (111-1) on which a first coil (110a) is wound may be positioned above a conductive member (10) and a coating layer (20), and a second core (111-2) on which a second coil (110b) is wound may be positioned below a conductive member (10) and a coating layer (20).

[0032] According to one embodiment, the second coil (110b) may be configured to obtain a second signal by a second magnetic field (M2) formed by a current (E) formed on the surface of the conductive member (10). For example, the second coil (110b) may be configured to generate a second signal by interacting with the second magnetic field (M2). The second signal generated through the second coil (110b) may include a signal regarding a current and / or voltage applied to the second coil (110b) by the second magnetic field (M2). For example, the second magnetic field (M2) formed by the current (E) may induce a current flowing along the second coil (110b). The second coil (110b) may be configured to generate a signal in the form of a sine wave regarding the current.

[0033] Referring again to FIG. 2, according to one embodiment, the detection circuit (120) may be configured to obtain a second signal via the second coil (110b) of the first sensor (111). The detection circuit (120) may be configured to obtain a plurality of parameters based on the second signal. For example, the detection circuit (120) may include a lock-in amplifier configured to detect a signal reflecting the characteristics of the current (E). For example, the detection circuit (120) may be configured to detect the amplitude and phase of an input signal relative to a periodic reference signal using a low pass filter (LPF).

[0034] According to one embodiment, the detection circuit (120) may be configured to identify the characteristics indicated by the second signal due to the impedance change in the second coil (110b). The detection circuit (120) may utilize a process of finding solutions for each boundary condition in Maxwell's equations to interpret the second signal based on the current (E) formed on the surface of the conductive member (10), and in particular, may utilize signal analysis using the finite element method in consideration of the geometric shape and material properties of the conductive member (10) to be analyzed. For example, as a signal analysis that analyzes an electromagnetic field and is used for current modeling, an analytical method and a numerical method may be utilized, and a finite difference method (FDM), a finite element method (FEM), a boundary element method (BEM), a volume integral method (VIM), etc. may be utilized.

[0035] According to one embodiment, measurement values ​​of a plurality of parameters acquired through the detection circuit (120) may be provided to the processor (130). The detection circuit (120) may be configured to acquire a second signal from the second sensor (112) and provide measurement values ​​of a plurality of parameters acquired based on the second signal to the processor (130).

[0036] According to one embodiment, the plurality of parameters may include a first parameter and a second parameter. For example, the first parameter may include a voltage difference between the first signal and the second signal, and a phase difference between the first signal and the second signal, as a primary sensing parameter obtained through the detection circuit (120). For example, the second parameter may include a resistance of the second coil (110b) and an impedance of the second coil (110b) calculated based on the first parameter. However, the present invention is not limited thereto. For example, the voltage difference may be expressed as an amplitude due to a potential difference.

[0037] According to one embodiment, the processor (130) can obtain measurement values ​​of a plurality of parameters obtained from the detection circuit (120). The processor (130) can represent the measurement values ​​for each of the plurality of parameters in a graph.

[0038] According to one embodiment, the processor (130) may be configured to obtain second distance information corresponding to a second distance between the first sensor (111) and the conductive member (10) based on at least one of a plurality of parameters. The processor (130) may obtain the second distance information based on at least one of a plurality of parameters received from the detection circuit (120). Depending on the distance between the first sensor (111) and the conductive member (10), the characteristics of the second signal obtained from the second coil (110b) may vary. For example, the memory (150) may store information indicating the distance between the conductive member (10) and the first sensor (111), each corresponding to a measurement value of the plurality of parameters. The information stored in the memory (150) may be related to the measurement values ​​of the plurality of parameters corresponding to the distance between the conductive member (10) and the first sensor (111). For example, the information stored in the memory (150) may include information related to the distance between the conductive member (10) and the first sensor (111) corresponding to the phase difference a value when the phase difference between the first signal and the second signal is a value. The information stored in the memory (150) may be information corrected according to the type, characteristics, material, use, and shape of the conductive member (10).

[0039] According to one embodiment, the processor (130) may obtain second distance information based on the information stored in the memory (150). For example, the processor (130) may select at least one measurement value among measurement values ​​of a plurality of parameters and obtain second distance information corresponding to the selected measurement value. For example, the processor (130) may obtain a b value corresponding to the impedance of the second coil (110b), and obtain information related to the distance between the conductive member (10) and the first sensor (111) corresponding to the impedance b value from the information stored in the memory (150), thereby obtaining the second distance information. Since the second distance information is based on the current (E) formed on the surface of the conductive member (10), it may be independent of the thickness of the coating layer (20). If the coating layer (20) includes a conductive material, the coating layer (20) affects the current (E), the first magnetic field (M1), and the second magnetic field (M2), so the second distance information may be distorted. According to one embodiment, the coating layer (20) on the conductive member (10) may be referred to as a non-conductive coating layer including a non-conductive material.

[0040] According to one embodiment, the second sensor (112) may be configured to obtain first distance information related to a first distance between the coating layer (20) and the second sensor (112). For example, the second sensor (112) may be a distance sensor configured to measure a distance to an object.

[0041] For example, the second sensor (112) may include an ultrasonic sensor. The ultrasonic sensor can measure the distance to an object using ultrasonic waves. Ultrasonic waves travel at the speed of sound in air, and the second sensor (112) can calculate the distance by measuring the time it takes for the ultrasonic waves to reflect off the object and return. A signal generated by the second sensor (112) by the reflection of the ultrasonic waves may be referred to as the third signal.

[0042] For example, the second sensor (112) may include an infrared sensor. The infrared sensor can measure the distance to an object using infrared light. Infrared light emits heat, and the second sensor (112) can detect infrared energy emitted from the object to calculate the distance. A signal generated by the second sensor (112) by detecting infrared energy may be referred to as the third signal.

[0043] For example, the second sensor (112) may include a time of flight (TOF) sensor. The TOF sensor can measure the distance to an object using a laser or light. The second sensor (112) can calculate the distance by emitting light and measuring the time it takes for the emitted light to reflect off the object and return. A signal generated from the second sensor (112) by the reflection of light may be referred to as the third signal.

[0044] For example, the second sensor (112) may include a lidar sensor. The lidar sensor can measure the distance to an object using a laser. In addition, examples of the second sensor (112) may vary. It should be noted that the second sensor (112) is used to measure the first distance between the coating layer (20) coated on the conductive member (10) and the second sensor (112). Since the coating layer (20) is coated on the conductive member (10), the second sensor (112) may measure the first distance from the coating layer (20) to the second sensor (112), rather than measuring the distance from the conductive member (10) to the second sensor (112). The second sensor (112) may be configured to obtain first distance information related to the first distance and provide the first distance information to the processor (130).

[0045] According to one embodiment, the transport device (140) may be configured to transport the sensor module (110). The transport device (140) may include a body (141) and a motor (142). The body (141) and the motor (142) will be described later. The transport device (140) may be coupled to the sensor module (110) and configured to transport the sensor module (110) along at least a portion of the surface of the coating layer (20). The sensor module (110) may be transported along at least a portion of the coating layer (20) while being coupled to the transport device (140). The transport device (140) may adjust the distance between the sensor module (110) and the coating layer (20). For example, the transport device (140) may move the sensor module (110) closer to or farther away from the coating layer (20). The processor (130) may be configured to control a thickness inspection operation of the coating layer (20). Instructions stored in the memory (150) may be configured to cause the operation of the coating layer inspection device (100) when executed by the processor (130). Any function or operation described in the present disclosure may be processed by one processor (130) or a combination of processors (130).

[0046] According to one embodiment, the memory (150) can store information related to the conductive member (10). For example, the memory (150) can store size information of the conductive member (10), material information of the conductive member (10), material information of the coating layer (20), manufacturer information of the conductive member (10), specification information of the conductive member (10), etc. According to one embodiment, the memory (150) can store distance information between the first sensor (111) and the conductive member (10) corresponding to each of the measurement values ​​of a plurality of parameters. Using the above information, the distance between the first sensor (111) and the conductive member (10) can be measured according to the measurement values ​​of the plurality of parameters.

[0047] Figure 4 is a flowchart showing the operation of a coating layer inspection device according to one embodiment.

[0048] The operations described in FIG. 4 may be referred to as operations caused by the coating layer inspection device (100) when instructions stored in the memory (150) are executed by the processor (130).

[0049] Referring to FIG. 4, in operation 401, the processor (130) may be configured to obtain first distance information from the second sensor (112).

[0050] According to one embodiment, the second sensor (112) may be configured to generate first distance information and provide the generated first distance information to the processor (130). The processor (130) may be configured to obtain the first distance information from the second sensor (112). The first distance may be referred to as a distance between the second sensor (112) and the coating layer (20). According to one embodiment, since the coating layer (20) is formed on the conductive member (10), the first distance information generated by the second sensor (112) may represent a distance between the coating layer (20) and the second sensor (112).

[0051] Since the second sensor (112) measures the distance to the object, the ultrasonic waves, infrared rays, lasers, and / or light emitted from the second sensor (112) cannot reach the surface of the conductive member (10) substantially shielded by the coating layer (20), but can only reach the coating layer (20). Therefore, the first distance may not represent the distance between the conductive member (10) and the second sensor (112), but rather the first distance between the coating layer (20) disposed on the conductive member (10) and the second sensor (112).

[0052] In operation 403, the processor (130) may be configured to obtain measurement values ​​of a plurality of parameters from the detection circuit (120).

[0053] According to one embodiment, the detection circuit (120) may be configured to detect a plurality of parameters within the second signal. For example, the detection circuit (120) may include a lock-in amplifier configured to detect a signal reflecting the characteristics of a current (E) (e.g., eddy current) caused by a defect in a noisy environment. The detection circuit (120) may mix a reference signal having the same frequency as the measurement signal (e.g., the second signal) with the second signal, and pass the mixed signal through a low-pass filter to extract only the desired frequency components. The detection circuit (120) may amplify the extracted signal to a level that is easy to measure.

[0054] In one embodiment, the plurality of parameters may include a first parameter and a second parameter. For example, the first parameter may include a difference between the voltage of the first signal and the voltage of the second signal and a difference between the phase of the first signal and the phase of the second signal. For example, the difference in voltage may be referred to as an amplitude, which is a potential difference. The second parameter may be obtained through calculation from the first parameter. For example, the second parameter may include a resistance of the second coil (110b) and an impedance of the second coil (110b).

[0055] For example, the voltage of the first signal provided to the first coil (110a) may be different from the voltage of the second signal received by the second coil (110b). The second magnetic field (M2) formed by the induced electromotive force phenomenon may induce a voltage applied to the second coil (110b), and the voltage of the second signal may be lower than the voltage of the first signal. The difference in voltage may generate an amplitude, which is a potential difference. The detection circuit (120) may obtain the voltage difference between the voltage of the first signal and the voltage of the second signal by detecting the difference in voltage.

[0056] For example, the detection circuit (120) can identify the difference between the phase of the first signal and the phase of the second signal. Due to reactance, a delay of the second signal may occur with respect to the first signal, and the delay may cause a phase difference. By detecting the phase difference, the detection circuit (120) can obtain the phase difference between the first signal and the second signal.

[0057] According to one embodiment, the resistance and reactance of the second coil (110b) can be obtained based on the difference in voltage and the difference in phase that can be obtained through the detection circuit (120). For example, the detection circuit (120) can obtain the electrical parameters of resistance and reactance through an impedance plane for the second coil (110b). The impedance plane can be referred to as a plane in which the reactance and resistance of the circuit are expressed as measured values ​​or vectors on two axes that are perpendicular to each other. The processor (130) can obtain the second parameter that can be obtained secondarily based on the first parameter that can be obtained primarily from the detection circuit (120). For example, the processor (130) can obtain the resistance and reactance based on the voltage and phase. According to one embodiment, the processor (130) can obtain measurement values ​​of a plurality of parameters, including a first parameter and a second parameter, from the detection circuit (120).

[0058] In operation 405, the processor (130) may be configured to obtain second distance information based on at least one of the measurement values.

[0059] According to one embodiment, the processor (130) may select at least one of the measurement values ​​of a plurality of parameters received from the detection circuit (120). For example, the processor (130) may select one parameter that best represents the second distance between the first sensor (111) and the coating layer (20) within the frequency of the first signal and / or the second signal.

[0060] For example, among the multiple parameters acquired through the detection circuit (120), if the difference between the voltage of the first signal and the voltage of the second signal is clear, the processor (130) may be configured to select the difference in voltage.

[0061] For another example, a parameter may be specified that is selected based on the frequency. In one embodiment, the processor (130) may be configured to select one of a plurality of parameters based on the frequency band of the first signal applied to the first coil (110a). For example, when the frequency band of the first signal is in the range of about 400 kHz to about 500 kHz, the processor (130) may be configured to select the phase difference between the first signal and the second signal from among the plurality of parameters. If the frequency of the first signal is too low, it may be difficult to identify the second distance. In one embodiment, the frequency of the first signal may be about 400 kHz to about 500 KHz. The processor (130) may be configured to, in response to identifying the first signal on the frequency band, select the phase difference between the first signal and the second signal, and identify second distance information between the first sensor (111) and the conductive member (10) based on the phase difference.

[0062] According to one embodiment, the processor (130) may obtain second distance information based on the selected measurement value. For example, the processor (130) may obtain the second distance information using information stored in the memory (150). If the processor (130) selects a phase difference among a plurality of parameters, the processor (130) may identify a measurement value x for the phase difference and read second distance information corresponding to the measurement value x for the phase difference stored in the memory (150). However, the present invention is not limited thereto. If the processor (130) selects an impedance among a plurality of parameters, the processor (130) may identify a measurement value y for the impedance and read second distance information corresponding to the measurement value y for the impedance stored in the memory (150).

[0063] In operation 407, the processor (130) may be configured to identify the thickness of the coating layer (20) based on the first distance information and the second distance information.

[0064] According to one embodiment, the processor (130) can identify the thickness of the coating layer (20) by using first distance information related to a first distance between the second sensor (112) and the coating layer (20) and second distance information related to a second distance between the first sensor (111) and the conductive member (10). For example, the thickness of the coating layer (20) can be identified based on a difference between the first distance information and the second distance information.

[0065] If the position of the first sensor (111) and the position of the second sensor (112) are substantially the same, the difference between the first distance information and the second distance information may indicate the thickness of the coating layer (20). The position of the first sensor (111) and the position of the second sensor (112) may be determined according to the positions of the end of the first sensor (111) and the end of the second sensor (112). The fact that the position of the first sensor (111) and the position of the second sensor (112) are substantially the same may be referred to as a state in which the position of the end of the first sensor (111) and the position of the end of the second sensor (112) are located at substantially the same positions. In this case, since the difference between the first distance and the second distance may be determined as the thickness of the coating layer (20), the processor (130) may identify the difference between the first distance information and the second distance information as the thickness of the coating layer (20).

[0066] If the positions of the first sensor (111) and the second sensor (112) are not substantially the same, the processor (130) can identify the thickness of the coating layer (20) by compensating for the difference between the positions. The processor (130) can add or subtract the first distance information or the second distance information by the difference between the positions. For example, if the position of the end of the first sensor (111) protrudes a certain distance toward the coating layer (20) more than the position of the end of the second sensor (112), the processor (130) can add the certain distance to the second distance information obtained through the first sensor (111) or subtract the certain distance from the first distance information obtained through the second sensor (112). The processor (130) can identify the thickness of the coating layer (20) by compensating for the difference between the position of the first sensor (111) and the position of the second sensor (112) based on the difference between the first distance information and the second distance information.

[0067] According to one embodiment, a coating layer inspection device (100) can simply and accurately identify the thickness of a coating layer (20) using a first sensor (111) and a second sensor (112). The first sensor (111) can identify a second distance between the first sensor (111) and the conductive member (10) based on a current (E) formed on the conductive member (10) covered by the coating layer (20), and the second sensor (112) can identify a first distance between the coating layer (20) and the second sensor (112). The processor (130) can identify the thickness of the coating layer (20) based on first distance information related to the first distance and second distance information related to the second distance. Through the thickness of the coating layer (20), the coating layer inspection device (100) can identify whether the coating layer (20) is formed uniformly or whether a defect exists.

[0068] According to one embodiment, since the transport device (140) transports the sensor module (110) along the coating layer (20), the sensor module (110) can generate first distance information and second distance information while being transported. The processor (130) can identify the thickness of the entire coating layer (20) using the first distance information and the second distance information acquired at different locations. The processor (130) can control the transport device (140) so that the first sensor (111) and the second sensor (112) can sense at specific locations. Through the first distance information and the second distance information sensed at specific locations, the processor (130) can know at which location in the coating layer (20) the distance information is sensed, and thus the thickness of the coating layer (20) at the specific location can be identified.

[0069] FIG. 5 is a flowchart illustrating an operation of a coating layer inspection device according to one embodiment to determine a defect in a coating layer. FIG. 6a illustrates a coating layer in a normal state. FIG. 6b illustrates a coating layer in an abnormal state containing a defect.

[0070] The operations described in FIG. 5 may be referred to as operations caused by the coating layer inspection device (100) when instructions stored in the memory (150) are executed by the processor (130).

[0071] Referring to FIG. 5, in operation 501, the processor (130) may be configured to identify the thickness of the coating layer (20).

[0072] Action 501 may correspond to action 407 of FIG. 4. The descriptions of action 407 may be substantially identically applied to action 501.

[0073] In operation 503, the processor (130) may be configured to compare the thickness of the coating layer (20) with a reference thickness.

[0074] According to one embodiment, the processor (130) may compare the thickness of the identified coating layer (20) with a reference thickness to determine whether the coating layer (20) is defective. The reference thickness may be a thickness of the coating layer (20) in a normal state and may be referenced as a thickness of the target coating layer (20) to protect the conductive member (10). The reference thickness may be pre-specified, and information related to the reference thickness may be stored in the memory (150). The processor (130) may compare the thickness of the identified coating layer (20) in operation 501 with the reference thickness stored in the memory (150). Since the sensor module (110) is transported by the transport device (140), the processor (130) may identify the thickness of the entire coating layer (20) and compare the thickness of the entire coating layer (20) with the reference thickness.

[0075] In operation 505, the processor (130) may be configured to identify the state of the coating layer (20) based on the comparison result.

[0076] According to one embodiment, the processor (130) may determine that a defect exists in the coating layer (20) when a difference between the reference thickness and the thickness of the coating layer (20) exceeds a threshold value. The normal state of the coating layer (20) may be referred to as a state in which no defect exists, and the abnormal state of the coating layer (20) may be referred to as a state in which a defect exists.

[0077] Referring to FIG. 6A, when there is no defect in the coating layer (20), the first distance information and the second distance information may be substantially constant. For example, when there is no defect in the coating layer (20), the thickness of the coating layer (20) may be substantially constant overall. As described above, the processor (130) may identify the thickness of the coating layer (20) based on the difference between the first distance information and the second distance information. In the example illustrated in FIG. 6A, the processor (130) may identify the first distance between the first sensor (111) and the conductive member (10) based on the first distance information, and may identify the second distance between the second sensor (112) and the coating layer (20) based on the second distance information. Since the positions of the first sensor (111) and the second sensor (112) are substantially the same, the processor (130) can identify the thickness of the coating layer (20) based on the difference between the first distance and the second distance. For example, if the first distance is D1 and the second distance is D2, the thickness of the coating layer (20) can be calculated as D2 - D1. The processor (130) can compare the thickness of the coating layer (20) with a reference thickness. If there is no defect in the coating layer (20), the thickness of the coating layer (20) is constant, and the difference between the thickness of the coating layer (20) and the reference thickness as a whole can be less than or equal to a threshold value. The processor (130) can be configured to determine the normal state of the coating layer (20) based on identifying the difference less than or equal to the threshold value.

[0078] Referring to FIG. 6B, a defect (601) may exist in the coating layer (20). For example, as a portion of the coating layer (20) is worn or damaged, a thin region of the coating layer (20) may occur. In the region where the defect (601) of the coating layer (20) exists, since the thickness of the coating layer (20) is formed thin, the difference between the first distance and the second distance may be reduced. For example, the difference between the thickness of the coating layer (20) calculated as D2 - D1 and the reference thickness may exceed a threshold value. The processor (130) may be configured to determine a defect (601) of the coating layer (20) based on identifying the difference exceeding the threshold value. When the processor (130) controls the transport device (140), the position information of the first sensor (111) and the second sensor (112) can be identified, and based on the position information, the position of the coating layer (20) in which the defect (601) is determined can be identified.

[0079] A coating layer inspection device (100) according to one embodiment may include an indicator (610) for providing status information of a coating layer (20). The indicator (610) may be configured to provide information indicating whether the coating layer (20) is in a normal state or whether a defect (601) exists. When the processor (130) identifies a coating layer (20) in a normal state, the indicator (610) may control the indicator (610) to provide information indicating that the state of the coating layer (20) is normal. For example, the indicator (610) may include a display configured to display text such as “the coating layer is normal” or a visual object that can intuitively recognize the normal state, and / or a speaker configured to emit an audible notification.

[0080] When the processor (130) identifies a defect (601) in the coating layer (20), the indicator (610) can control the indicator (610) to provide information indicating that the state of the coating layer (20) is abnormal. For example, the indicator (610) can include a display configured to display text such as “There is a defect in the coating layer” or a visual object that can intuitively recognize the abnormal state, and / or a speaker configured to emit an audible notification.

[0081] Figure 7a illustrates a conductive pipe comprising a coating layer in a normal state. Figure 7b illustrates a conductive pipe comprising a coating layer in an abnormal state containing a defect. Figure 7c illustrates a coating layer inspection device comprising a protrusion for adjusting the position of a sensor module.

[0082] Referring to FIG. 7a, as described above, a conductive member (e.g., conductive member (10) of FIG. 1) may include a conductive pipe (11). The conductive pipe (11) may include a cavity through which a fluid flows. A coating layer (20) may be coated on an inner surface forming the cavity of the conductive pipe (11).

[0083] According to one embodiment, in order to identify the thickness of the coating layer (20) coated on the inner surface of the conductive pipe (11), the transport device (140) and the sensor module (110) may be placed within the hollow portion of the conductive pipe (11). The sensor module (110) may identify the first distance information and the second distance information by the transport device (140) rotating along the inner surface.

[0084] According to one embodiment, the transport device (140) may include a body (141) and a motor (142). The body (141) may be disposed within a hollow space. For example, the body (141) may be implemented in a cylindrical shape having a diameter smaller than the diameter of the hollow space. The body (141) may include a mounting portion (141a) on which the first sensor (111) and the second sensor (112) are mounted. The mounting portion (141a) may have a shape that is sunken toward the inside of the body (141). The first sensor (111) and the second sensor (112) may be disposed on the mounting portion (141a).

[0085] In one embodiment, the motor (142) may be configured to rotate the body (141). For example, the motor (142) may be connected to the center of the body (141) and configured to rotate the body (141) 360 degrees about the center. When the body (141) rotates, the posture of the body (141) may change. The posture of the body (141) may be defined according to the direction in which the mounting portion (141a) faces. For example, the posture of the body (141) may change from a first posture in which the mounting portion (141a) faces a first direction to a second posture in which the mounting portion (141a) faces a second direction. Since the posture of the body (141) changes based on the rotation of the motor (142), the second direction may be different from the first direction.

[0086] According to one embodiment, the processor (130) can identify the first thickness of the coating layer (20) in the first posture of the body (141). For example, in the first posture of the body (141), the first sensor (111) and the second sensor (112) can face a first direction. With the first sensor (111) and the second sensor (112) facing the first direction, the processor (130) can obtain first distance information and second distance information, and identify the first thickness of the coating layer (20) based on a difference between the first distance information and the second distance information. After identifying the first thickness, the processor (130) can control the motor (142) to change the posture of the body (141) from the first posture to the second posture. In the second posture of the body (141), the first sensor (111) and the second sensor (112) may face a second direction different from the first direction. In a state where the first sensor (111) and the second sensor (112) face the second direction, the processor (130) may obtain first distance information and second distance information, and identify the second thickness of the coating layer (20) based on the difference between the first distance information and the second distance information. By repeating the above operation, the processor (130) may rotate the motor (142) 360 degrees and identify the thickness of the coating layer (20) at each designated angle. The designated angle may be an angle between the first direction and the second direction.

[0087] According to one embodiment, the processor (130) can identify the thickness of the coating layer (20) and determine a defect in the coating layer (20). For example, the thickness of the coating layer (20) can be compared with a reference thickness, and the state (normal state or abnormal state) of the coating layer (20) can be determined based on the result of the comparison. According to one embodiment, the processor (130) can identify the position of the thickness of the coating layer (20) according to the amount of rotation. If the difference between the thickness of the coating layer (20) and the reference thickness at a specific position exceeds a threshold value, the processor (130) can determine a defect in the coating layer (20).

[0088] Referring to FIG. 7A, the processor (130) can rotate the body (141) by controlling the motor (142). As the body (141) rotates, the position toward which the mounting portion (141a) faces can change. That is, the posture of the body (141) can change. For example, 701 of FIG. 7A illustrates the body (141) in a first posture. In the first posture, the processor (130) can identify the first thickness of the coating layer (20) based on the first distance information and the second distance information. 702 of FIG. 7A illustrates the body (141) in a second posture. After identifying the first thickness, the processor (130) can control the motor (142) to change the body (141) to the second posture and identify the second thickness of the coating layer (20). As the above operation is performed repeatedly, the body (141) can be rotated 360 degrees and configured to measure the thickness of the coating layer (20) formed on the inner surface of the conductive pipe (11).

[0089] As illustrated in FIG. 7A, when the coating layer (20) is in a normal state, the first thickness and the second thickness may exhibit a difference below a threshold value from the reference thickness. The processor (130) may be configured to determine the normal state of the coating layer (20) based on identifying a difference below the threshold value.

[0090] For example, 703 of FIG. 7B illustrates a body (141) in a first posture. In the first posture, the processor (130) can identify a first thickness of the coating layer (20) based on the first distance information and the second distance information. 704 of FIG. 7B illustrates a body (141) in a second posture. After identifying the first thickness, the processor (130) can control the motor (142) to change the body (141) to the second posture and identify a second thickness of the coating layer (20). As illustrated in FIG. 7B, when the coating layer (20) is in an abnormal state including a defect, the first thickness and the second thickness may represent a difference between the referent thickness and a threshold value exceeding the referent thickness. Referring to 603 of FIG. 7B, the first thickness identified in the first posture of the body (141) may represent a difference between the referent thickness and a threshold value exceeding the referent thickness. Referring to 704 of FIG. 7B, the second thickness identified in the second posture of the body (141) may indicate a difference between the reference thickness and a threshold value or less. The processor (130) may be configured to determine a defect in the coating layer (20) based on identifying a difference exceeding the threshold value in the first posture. Since the defect in the coating layer (20) is identified in the first posture of the body (141), the processor (130) may identify the location of the defect based on the first posture of the first body (141). As described above, the coating layer inspection device (e.g., the coating layer inspection device (100) of FIG. 2) may be configured to provide information indicating a normal or abnormal state by using an indicator (e.g., the indicator (610) of FIG. 6A).

[0091] According to one embodiment, the processor (130) may be configured to control the motor (142) to control the rotational direction of the body (141). For example, the processor (130) may control the motor (142) to rotate the body (141) in a first rotational direction (e.g., counterclockwise) to inspect the thickness of the coating layer (20). The body (141) may be rotated in the first rotational direction by the motor (142). As the body (141) is rotated in the first rotational direction, the first sensor (111) and the second sensor (112) may generate first distance information and second distance information for the thickness of the coating layer (20) along the first rotational direction.

[0092] According to one embodiment, after the body (141) is rotated 360 degrees along the first rotation direction, the processor (130) can control the motor (142) to rotate the body (141) in a second rotation direction (e.g., clockwise) opposite to the first rotation direction. The body (141) can be rotated in the second rotation direction by the motor (142). As the body (141) is rotated in the second rotation direction, the first sensor (111) and the second sensor (112) can generate first distance information and second distance information for the thickness of the coating layer (20) along the second rotation direction.

[0093] According to one embodiment, the processor (130) can identify the thickness of the coating layer (20) by synthesizing the first distance information and the second distance information obtained when the body (141) is rotated in the first rotational direction and the first distance information and the second distance information obtained when the body (141) is rotated in the second rotational direction. That is, the processor (130) can reduce the error rate by identifying the thickness of the coating layer (20) after rotating the body (141) twice by 360 degrees in different directions. That is, the body (141) can be rotated 360 degrees along the first rotational direction and 360 degrees along the second rotational direction. If there is a large difference between the first distance information and the second distance information obtained when the body (141) is rotated in the first rotation direction and the first distance information and the second distance information obtained when the body (141) is rotated in the second rotation direction (for example, if the difference exceeds a threshold value), the processor (130) may determine that there is an error in the obtained first distance information or the second distance information, and may re-acquire the first distance information and the second distance information while rotating the body (141) in the first rotation direction and the second rotation direction again. Based on identifying that the difference between the first distance information and the second distance information obtained when the body (141) is rotated in the first rotation direction and the first distance information and the second distance information obtained when the body (141) is rotated in the second rotation direction is less than or equal to the threshold value, the control of the motor (142) may be stopped, and the thickness of the coating layer (20) may be identified based on the first distance information and the second distance information. By the above operation, the coating layer inspection device (100) can accurately identify the thickness of the coating layer (20) without error.

[0094] Referring to FIG. 7c, the body (141) may include a protrusion (141b) for adjusting the position of the sensor module (110). The protrusion (141b) may protrude from the mounting portion (141a) to lift the sensor module (110). The protrusion (141b) may come into contact with the sensor module (110). When the protrusion (141b) protrudes from the mounting portion (141a), the distance between the coating layer (20) and the sensor module (110) may be reduced. For example, if the distance between the coating layer (20) or the conductive member (10) and the sensor module (110) is too far, it may be difficult to identify the first distance information and the second distance information.

[0095] According to one embodiment, the processor (130) may control the protrusion (141b) to protrude from the mounting portion (141a) based on the intensity of the second signal by the second magnetic field (M2). For example, the processor (130) may control the protrusion (141b) to protrude based on identifying that the intensity of the second signal acquired through the second coil (110b) is below a threshold value. As the protrusion (141b) protrudes, the first sensor (111) may come closer to the conductive member (10), and the intensity of the second signal may increase. As the intensity of the second signal increases, the accuracy of the second distance information acquired based on the second signal may increase.

[0096] According to one embodiment, the processor (130) may control the protrusion (141b) to protrude from the mounting portion (141a) based on the intensity of the third signal of the second sensor (112) for obtaining the first distance information. The third signal is a signal generated by the second sensor (112) and may be referred to as a signal representing the first distance information. For example, the processor (130) may control the protrusion (141b) to protrude from the mounting portion (141a) based on identifying that the intensity of the third signal of the second sensor (112) is below a threshold value. As the protrusion (141b) protrudes, the second sensor (112) may come closer to the coating layer (20), and the intensity of the third signal of the second sensor (112) may increase. As the intensity of the third signal of the second sensor (112) increases, the accuracy of the first distance information acquired by the second sensor (112) can increase.

[0097] According to one embodiment, the processor (130) may be configured to adjust the length by which the protrusion (141b) protrudes from the mounting portion (141a) based on at least one of the intensity of the second signal or the intensity of the third signal. For example, when the intensity of the second signal or the intensity of the third signal is below a threshold value, the processor (130) may increase the length by which the protrusion (141b) protrudes from the mounting portion (141a). For example, when the intensity of the second signal or the intensity of the third signal exceeds a threshold value, the processor (130) may decrease the length by which the protrusion (141b) protrudes from the mounting portion (141a). When the intensity of the second signal or the intensity of the third signal is too strong or too weak, the processor (130) may control the protrusion length of the protrusion (141b) so that an appropriate signal intensity is detected.

[0098] A coating layer inspection device for inspecting the thickness of a non-conductive coating layer coated on a conductive member according to one embodiment may include a first sensor including a first coil for applying an induced magnetic field to the conductive member based on an input of a first signal, and a second coil configured to obtain a second signal based on the induced magnetic field by interacting with the induced magnetic field; a second sensor, the second sensor configured to obtain first distance information related to a first distance between the second sensor and the coating layer; a detection circuit configured to obtain the second signal from the first sensor and obtain measurement values ​​of a plurality of parameters based on the second signal; a transfer device coupled to the first sensor and the second sensor and configured to transfer the first sensor and the second sensor; and a processor configured to control the transfer device and obtain the measurement values ​​of the plurality of parameters from the detection circuit. The processor may be configured to obtain the first distance information from the second sensor, obtain second distance information related to a second distance between the first sensor and the conductive member based on at least one of the measured values ​​of the plurality of parameters, and identify a thickness of the coating layer based on the first distance information and the second distance information.

[0099] According to one embodiment, the processor may be configured to identify the thickness of the coating layer based on a difference between the first distance information and the second distance information, compare the identified thickness of the coating layer with a specified reference thickness, and identify a state of the coating layer based on a result of the comparison.

[0100] According to one embodiment, the conductive member may include a conductive pipe including a hollow portion, and the transport device may include a mounting portion on which the first sensor and the second sensor are mounted, a body disposed within the hollow portion, and a motor configured to rotate the body. The body may be configured to be rotated by the motor while being disposed within the hollow portion of the conductive pipe.

[0101] In one embodiment, the processor may be configured to control the motor to identify a first thickness of the coating layer in a first posture of the body in which the mounting portion faces a first direction, change the posture of the body to a second posture of the body in which the mounting portion faces a second direction different from the first direction, and identify a second thickness of the coating layer in the second posture of the body.

[0102] In one embodiment, the body may further include a protrusion configured to adjust the first distance and the second distance by being in contact with the first sensor and the second sensor and being configured to protrude from the mounting portion. The processor may be configured to control the protrusion so that the protrusion protrudes from the mounting portion based on at least one of the intensity of the second signal or the intensity of a third signal generated by the second sensor and representing the first distance information.

[0103] The devices described above may be implemented as hardware components, software components, and / or a combination of hardware components and software components. For example, the devices and components described in the embodiments may be implemented using one or more general-purpose computers or special-purpose computers, such as, for example, a processor, a controller, an arithmetic logic unit (ALU), a digital signal processor, a microcomputer, a field programmable gate array (FPGA), a programmable logic unit (PLU), a microprocessor, or any other device capable of executing instructions and responding to them. The processing device may execute an operating system (OS) and one or more software applications running on the operating system. The processing device may also access, store, manipulate, process, and generate data in response to the execution of the software. For ease of understanding, the processing device is sometimes described as being used alone; however, one of ordinary skill in the art will recognize that the processing device may include multiple processing elements and / or multiple types of processing elements. For example, a processing unit may include multiple processors, or a processor and a controller. Other processing configurations, such as parallel processors, are also possible.

[0104] Software may include a computer program, code, instructions, or a combination of one or more of these, which may configure a processing device to perform a desired operation or may, independently or collectively, command the processing device. The software and / or data may be permanently or temporarily embodied in any type of machine, component, physical device, virtual equipment, computer storage medium or device, or transmitted signal wave, for interpretation by the processing device or for providing instructions or data to the processing device. The software may also be distributed over networked computer systems and stored or executed in a distributed manner. The software and data may be stored on one or more computer-readable recording media.

[0105] The method according to the embodiment may be implemented in the form of program commands that can be executed through various computer means and recorded on a computer-readable medium. The computer-readable medium may include program commands, data files, data structures, etc., alone or in combination. The program commands recorded on the medium may be those specially designed and configured for the embodiment or may be those known and available to those skilled in the art of computer software. Examples of the computer-readable recording medium include magnetic media such as hard disks, floppy disks, and magnetic tapes, optical media such as CD-ROMs and DVDs, magneto-optical media such as floptical disks, and hardware devices specially configured to store and execute program commands, such as ROMs, RAMs, and flash memories. Examples of the program commands include not only machine language codes generated by a compiler, but also high-level language codes that can be executed by a computer using an interpreter, etc. The hardware devices described above may be configured to operate as one or more software modules to perform the operations of the embodiment, and vice versa.

[0106] Although the embodiments described above have been described by way of limited examples and drawings, those skilled in the art will appreciate that various modifications and variations can be made based on the above teachings. For example, appropriate results can still be achieved even if the described techniques are performed in a different order than described, and / or components of the described systems, structures, devices, circuits, etc. are combined or combined in a different manner than described, or are replaced or substituted with other components or equivalents.

[0107] Therefore, other implementations, other embodiments, and equivalents to the claims also fall within the scope of the claims described below.

Claims

1. In a coating layer inspection device for inspecting the thickness of a non-conductive coating layer coated on a conductive member, A first sensor comprising a first coil for applying an induced magnetic field to the conductive member based on an input of a first signal, and a second coil configured to obtain a second signal based on the induced magnetic field by interacting with the induced magnetic field; A second sensor, wherein the second sensor is configured to obtain first distance information related to a first distance between the second sensor and the coating layer; A detection circuit configured to obtain the second signal from the first sensor and obtain measurement values ​​of a plurality of parameters based on the second signal; A transport device coupled to the first sensor and the second sensor and configured to transport the first sensor and the second sensor; and A processor configured to control the transport device and obtain the measurement values ​​of the plurality of parameters from the detection circuit, The above processor, Obtaining the first distance information from the second sensor, Based on at least one of the measured values ​​of the plurality of parameters, second distance information related to a second distance between the first sensor and the conductive member is obtained, Based on the first distance information and the second distance information, configured to identify the thickness of the coating layer, Coating layer inspection device.

2. In paragraph 1, The above processor, Based on the difference between the first distance information and the second distance information, the thickness of the coating layer is identified, Comparing the thickness of the identified coating layer with a specified reference thickness, Based on the above comparison results, configured to identify the state of the coating layer, Coating layer inspection device.

3. In paragraph 1, The above conductive member is, Contains a conductive pipe including a hollow portion, The above transport device, A body including a mounting portion on which the first sensor and the second sensor are mounted, and disposed within the hollow; and comprising a motor configured to rotate the above body, The above body, configured to be rotated by the motor while being placed within the hollow portion of the conductive pipe; Coating layer inspection device.

4. In paragraph 3, The above processor, In a first posture of the body in which the mounting portion faces the first direction, the first thickness of the coating layer is identified, Controlling the motor to change the posture of the body to a second posture of the body in which the mounting portion faces a second direction different from the first direction, In the second posture of the above body, configured to identify the second thickness of the above coating layer, Coating layer inspection device.

5. In paragraph 3, The above body, It further includes a protrusion configured to be in contact with the first sensor and the second sensor and to protrude from the mounting portion, thereby adjusting the first distance and the second distance. The above processor, Controlling the protrusion so that the protrusion protrudes from the mounting portion based on at least one of the intensity of the second signal or the intensity of a third signal generated by the second sensor and representing the first distance information; Coating layer inspection device.

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