• Journal of the Korean Society of Industry Convergence
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• v.27 no.1
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• pp.57-62
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• 2024

This study conducted a measurement method of high temeprature conditions using infrared termography. All objects emit infrared light, and this emissivity has a significant impact on the temperature measurements of infrared thermal imaging (IR) cameras. In order to measure the temperature more accurately with the IR camera, correction equations were derived by measuring the emissivity according to the temperature change of combustible metals in a high-temperature environment. Two combustible metals, Mg and Al, were used to measure emissivity with changing temperature. Each metal was heated, the emissivity was measured by comparing the temperature with IR camera and thermocouples so that the correlation between temperature and emissivity could be anslyzed. As a result of the experiment, the emissivity of the metals increases as the temperature increased. This can be interpreted as a result of increased radiation emission as the thermal movement of internal metal molecules increased.

• Journal of the Korea Institute of Military Science and Technology
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• v.16 no.2
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• pp.154-159
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• 2013

Alignment tolerance for EO/IR airborne camera using common optic is an important factor in stabilization accuracy and geo-pointing accuracy. Before airborne camera is mounted on the aircraft, defining alignment tolerance and verification of it is essential in production as well as research and development. In this paper we establish basic concept on the definition and elements of alignment tolerance for airborne camera and propose how to measure each of those elements. Components and the measurement sequence of alignment tolerance are as follows: 1) tolerance of alignment between EO and IR LOS. 2) tolerance of sensor alignment. 3) tolerance of position reporting accuracy. 4) tolerance of mount alignment

• 유체기계공업학회:학술대회논문집
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• 2006.08a
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• pp.487-488
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• 2006

In these days, demand of a LCD monitor is remarkably increasing with development of the LCD technology. However, there are thermal problems for improvement of efficiency for the LCD monitor. Thus, this research analyzed thermal problems such as convection and conduction heat transfer characteristics in the LCD monitor using an infrared (IR) camera. Also, the results of the outer side of the front LCD panel using the IR camera have been compared with the results of the inner side of the front panel using T-type thermocouples. The equations have been derived for the temperature distribution of the inner side of the front LCD panel by a multiple regression method including variables for ambient temperature, humidity and temperature differences between the front and back panels of the LCD monitor.

• International Journal of Highway Engineering
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• v.17 no.6
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• pp.1-9
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• 2015

PURPOSES : The objective of this study is to propose a quality control and quality assurance method for use during asphalt pavement construction using non-destructive methods, such as ground penetrating radar (GPR) and an infrared (IR) camera. METHODS : A 1.0 GHz air-coupled GPR system was used to measure the thickness and in situ density of asphalt concrete overlay during the placement and compaction of the asphalt layer in two test construction sections. The in situ density of the asphalt layer was estimated based on the dielectric constant of the asphalt concrete, which was measured as the ratio of the amplitude of the surface reflection of the asphalt mat to that of a metal plate. In addition, an IR camera was used to monitor the surface temperature of the asphalt mat to ensure its uniformity, for both conventional asphalt concrete and fiber-reinforced asphalt (FRA) concrete. RESULTS : From the GPR test, the measured in situ air void of the asphalt concrete overlay gradually decreased from 12.6% at placement to 8.1% after five roller passes for conventional asphalt concrete, and from 10.7% to 5.9% for the FRA concrete. The thickness of the asphalt concrete overlay was reduced from 7.0 cm to 6.0 cm for the conventional material, and from 9.2 cm to 6.4 cm for the FRA concrete. From the IR camera measurements, the temperature differences in the asphalt mat ranged from $10^{\circ}C$ to $30^{\circ}C$ in the two test sections. CONCLUSIONS : During asphalt concrete construction, GPR and IR tests can be applicable for monitoring the changes in in situ density, thickness, and temperature differences of the overlay, which are the most important factors for quality control. For easier and more reliable quality control of asphalt overlay construction, it is better to use the thickness measurement from the GPR.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.39 no.7
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• pp.549-555
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• 2015

A measurement technique of interfacial velocity in air-water separated flow by particle tracking velocimetry using an infrared camera (IR-PTV) was developed. As infrared light with wavelength in the range of 3-5 um could hardly penetrate water, IR-PTV can selectively visualize only the tracer particles existing in depths less than 20 um underneath the air-water interface. To validate the measurement accuracy of the IR-PTV technique, a measurement of the interfacial velocity of the air-water separated flow using Styrofoam particles floating in water was conducted. The interfacial velocity values obtained with the two different measurement techniques showed good agreement with errors less than 5%. It was found from the experimental results obtained using the developed technique that with increasing air velocity, the interfacial velocity proportionally increases, likely because of the increased interfacial stress.

• Journal of Korea Multimedia Society
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• v.14 no.4
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• pp.517-528
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• 2011

In this paper, we propose an indoor navigation system that can do walk safely to the destination for visually impaired persons. The proposed system analyzes images taken with the camera finds the ID of the marker to identify the absolute position of the pedestrian. Using the distance and angle obtained from IMU(Inertial Measurement Unit) accelerometer sensor and a gyro sensor, the system decides the relative position of a pedestrian for the previous position to determine the next direction. At the same time, we simplify a complex spatial structure in front of user by means of ultrasonic sensors and determine an avoidance direction by estimating the patterns. Then, it uses a few IR(Infrared Rays) sensors to detect stair. Our system offers position of visually impaired persons incorporating multiple sensors and helps users to arrive to destination safely.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.9
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• pp.44-51
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• 2019

Three types of samples with defects were measured by lock-in med-IR (infrared) thermography with various lock-in frequencies for different materials. The lock-in method can be used to detect defects when an external energy source is applied to the object, the non-uniformity of the incident thermal energy distribution is eliminated, and the camera's measurement cycle is synchronized with the load cycle of the incident energy source. For inspecting samples with defects, results of thermal images are analyzed when three types of materials, i.e., SM45C, STS316L, and AL6061 are tested and three lock-in frequencies, i.e., 0.08, 0.1, and 0.12 Hz are applied. In this study, the optimal lock-in frequencies were determined by comparing the results of each material and lock-in frequency measured using the mid-IR camera.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.9
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• pp.1406-1410
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• 2015

The railway catenary systems consist of a complex structure, electrical and mechanical conditions are exposed to dangerous environment due to current collection between pantograph and catenary systems. These two types of conditions for the catenary systems are critically assessed for management and are becoming increasingly more dependent on reliable inspection system. In this paper, a new measurement system which enables inspection of catenary faults was studied and implemented. The system uses wavelength band of ultraviolet (UV) and IR (Infrared) to measure the insulation of corona and temperature of catenary wire. In order to determine the sensitivity of implemented system, the performance test such as distance detection range of UV camera and temperature resolution of IR camera were conducted, respectively. The field test of development system was also conducted in metro and high-speed line using mobile type UV and IR multi-composited measurement systems.

• Journal of the Korean Society for Precision Engineering
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• v.27 no.12
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• pp.15-21
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• 2010

Recently, there is a demand for a thermal imaging microscope in the medical field as well as the semi-conductor industry Although the demand of the advanced thermal imaging microscope has been increased, it is very difficult to obtain the technology of developing a thermal camera, because it is used for defense industry. We developed the ${\times}5$ zoom microscope which has $3\;{\mu}m$ spatial resolution to research the design and fabrication of the IR (Infrared) optical system. The optical system of the IR microscope consists of four spherical lenses and four aspheric lenses. We verified individual sensitivity of each optical parameter as the first order approach to the analysis. And we also performed structure and vibration analysis. The optical elements are fabricated using Freeform 700A. The measurement results of surface roughness and form accuracy using NT 2000 and UA3P are Ra 2.36 nm and P-V $0.13\;{\mu}m$. Finally we ascertained resolution power of $3\;{\mu}m$ using USAF (United State Air Force) 1951 IR resolution test chart.

• Journal of the Korean Society for Nondestructive Testing
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• v.24 no.5
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• pp.525-531
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• 2004

In this paper, the concept of infrared thermography(IRT), the principle of measurement of IRT and how to set up the IR camera for the nondestructive testing are described in detail. Also, its utilization and non-destructive testing(NDT) diagnosis are reviewed. By performing the periodic non-touched WDT through the estimation of thermal patterns related with the temperature for the surface targeted, IRT can be applied to the early prevention of the device failure. For the diagnosis utilization, thermal imaging patterns obtained from IRT for heated blocks with internal defects were estimated through the lion-destructive method and discussed the way of IRT estimation from the analysis of characteristics between material defects and thermal imaging patterns.