• Fire Science and Engineering
• /
• v.28 no.5
• /
• pp.58-63
• /
• 2014

Fire-resistance paints are supposed to become intumescent and diminish heat transfer along the steel frames in case of a fire. If unsatisfactory fire-resistance paints which do not satisfy their standard specification are used, it may result in a severe disaster. Because satisfactory fire-resistance paints are hardly discriminated from the unsatisfactory ones by a simple visual inspection, more reliable and convenient onsite evaluation methods are necessary. Here we report the preliminary study result on the fire safety testing method for fire-resistance paints using an X-ray analysis method. It was found that the existence and quantity of effective constituents in fire-resistance paints can be detected by the X-ray analysis method. X-ray fluorescence (XRF) analyses showed that P and Cl elements are much more enriched in fire-resistance paints, compared to normal paints. X-ray diffraction (XRD) analyses showed that ammonium polyphosphate is present as the main crystalline material in fire-resistance paints, but absent in normal paints. The X-ray analysis method is expected to be used for the onsite inspection of fire-resistance paints with the upcoming availability of portable XRF and XRD instruments.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2009.10a
• /
• pp.67-68
• /
• 2009

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.24 no.12
• /
• pp.1704-1710
• /
• 2020

The high-energy X-ray imaging detector used for container inspection uses a thick scintillator to effectively acquire X-rays. X-ray incident on the scintillator is generally up to 9MeV. Therefore, to effectively collect X-ray, it is necessary to use a thick scintillator. To collect the light generated by the reaction between X-ray and scintillator, an optical-sensor must be combined with the scintillator. In this study, a study on the design conditions of the detector using a CdWO4 and a small sensor is described. To calculate the collected light according to the change of the scintillator thickness and the reflectance of surface, MCNP6 and DETECT2000 were used. As a result of calculating, it was confirmed that when the reflectance of the surface was low, it was appropriate to select a scintillator with a thickness of 15 to 20-mm, but as the reflectance increased, it was confirmed that it was appropriate to select a CdWO4 with a thickness of 25 to 30-mm.

• Journal of the Korean Society for Nondestructive Testing
• /
• v.19 no.5
• /
• pp.356-362
• /
• 1999

Based on the assumption that film density increases exponentially with exposure in the industrial radiographic film. an equation representing the characteristic curves of industrial radiographic films and a new density-thickness relation are suggested. The accuracy and reliability of the suggested relation has been tested using radiographs of a carbon steel step wedge with known thickness variation by polychromatic X-ray and ${\gamma}$-ray ($Ir^{192}$). The experimental results were well agreed to the proposed relation in the range of film densities from 1.0 to 3.5 and it was more accurate than the conventional relation. It is also found that ${\gamma}$-ray is more effective in this purpose than polychromatic X-ray, which results in variation of effective linear absorption coefficient due to beam hardening effect as thickness increases. Therefore using the equation and experimentally determined parameters the quantitative evaluation of thickness variation is possible and it can be used to evaluate the depth of local corrosion of pressure vessels in plants.

• Journal of the Korea Convergence Society
• /
• v.10 no.10
• /
• pp.15-21
• /
• 2019

X-rays with shorter wavelengths than ultraviolet light have very good penetration power. It is convergence in industrial and medical fields has been used a lot. n particular, in the industrial field, various researches have been conducted on the detection of foregin body inside metal that can occur in the production process of products such as metal using x-ray, a non-destructive inspection device. Detectors are becoming increasingly popular for the popularization of DR (Digital Radiography) photography methods that digitally acquire X-ray video images. However, there are cases where foreign body detection is impossible depending on the sensor noise and sensitivity inside the detector. When producing a metal product, since the defective rate of the produced product may increase due to contamination of the foreign body, accurate detection is necessary. In this paper, we provide a correction model for X-ray images acquired in order to improve the efficiency of defect detection such as foreign body inside metal. When applied to defect detection in the production process of metal products through the proposed model, it is expected that the detection of product defects can be processed accurately and quickly.

• 제어로봇시스템학회:학술대회논문집
• /
• 2002.10a
• /
• pp.87.5-87
• /
• 2002

. A high peak power demand at substations will result under This paper deals with the detection of defects at BGA solder joints in PC boards by using X-ray Imaging. . To improve a cost performance and reliability of PC boards, an inspection of BGA is required in the surface mount process. . Contents 2 We attempt to detect the characteristic of the solder bridges based on an image analysis.

• Nuclear Engineering and Technology
• /
• v.53 no.5
• /
• pp.1626-1633
• /
• 2021

In an industrial field, non-destructive testing (NDT) is commonly used to inspect industrial products. Among NDT methods using radiation sources, X-ray laminography has several advantages, such as high depth resolution and low computational costs. Moreover, an X-ray laminography system with stationary source array and compact detector is able to reduce mechanical motion artifacts and improve inspection efficiency. However, this system, called stationary inverse-geometry X-ray laminography (s-IGXL), causes truncation artifacts in reconstructed images due to limited fields-of-view (FOVs). In this study, we proposed a projection data correction (PDC) method to reduce the truncation artifacts arisen in s-IGXL images, and the performance of the proposed method was evaluated with the different number of focal spots in terms of quantitative accuracy. Comparing with conventional techniques, the PDC method showed superior performance in reducing truncation artifacts and improved the quantitative accuracy of s-IGXL images for all the number of focal spots. In conclusion, the PDC method can improve the accuracy of s-IGXL images and allow precise NDT measurements.

• Journal of Radiation Industry
• /
• v.9 no.3
• /
• pp.153-159
• /
• 2015

Reliability of printed circuit board (PCB), which is based on high integrated circuit technology, is having been important because of development of electric and self-driving car. In order to answer these demand, automated X-ray inspection (AXI) is best solution for PCB non-destructive test. PCB is consist of plastic, copper, and, lead, which have low to high Z-number materials. By using dual energy X-ray imaging, these materials can be inspected accurately and efficiently. Dual energy X-ray imaging, that have the advantage of separating materials, however, need some solution such as energy separation method and enhancing efficiency because PCB has materials that has wide range of Z-number. In this work, we found out several things by analysis of X-ray energy spectrum. Separating between lead and combination of plastic and copper is only possible with energy range not dose. On the other hand, separating between plastic and copper is only with dose not energy range. Moreover the copper filter of high energy part of dual X-ray imaging and 50 kVp of low energy part of dual X-ray imaging is best for efficiency.

• 제어로봇시스템학회:학술대회논문집
• /
• 1996.10b
• /
• pp.264-267
• /
• 1996

This paper is aimed to develop a very reliable method for automatic inspection of the solder joints on PCBS. There have been lots of previous works using vision technologies, but they can not be used for inspecting BGA, FCA or other newly used devices. Thus we adopt X-ray technologies for solder joint inspection. We put our attention on reconstructing the 3D shapes of solder joints since it gives us the most detailed information on quality of solder joints. Laminography principle is used to reject the interferences from neighboring parts or leads. To verify the effectiveness of laminography, a simulation study is performed in the case of a solder joints on double sided PCB using.

• International Commerce and Information Review
• /
• v.6 no.3
• /
• pp.183-201
• /
• 2004

Recently, Electronic commerce market is growing sharply for the expansion of internet and development of means of air transportation. Import Clearance System for express consignments, introduced in Korea, confers some benefit upon express consignments, ie. prompt clearance, simplification of the clearance procedure, exemption of necessary documents. But it has some problems such as lack of social security and trade compliance. So it requires some improvements as follows. Firstly, it has no legal background to clear all articles valued at US$100 or less carried by an express consignment operator. So customs brokers, not express consignment operators, should clear that articles. Secondly, it should be presented necessary documents including commercial invoice to prevent a wrong price declaration in entering express consignments valued at US$100 or less. Thirdly, X-ray inspectors must enhance their inspection ability. Customs must provide education programs for X-ray inspectors to improve their inspection ability. Lastly, Cargo selectivity system for express consignments have to be improved to operate effectively.