• Korean Journal of Optics and Photonics
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• v.29 no.1
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• pp.28-31
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• 2018

In this paper, we have proposed and demonstrated a variable optical attenuator (VOA) incorporating a dual-fiber collimator and a bimetallic actuator. The optical attenuation between input and output single-mode fibers was tuned by tilting the angle of a reflection mirror fixed on the bimetal. The bimetal was heated or cooled by a thermoelectric cooler (TEC) and then moved the reflection mirror, due to bending and unreeling. The desired optical attenuation can be obtained through adjusting the electrical input into the TEC. The fabricated device showed 0.5 dB of insertion loss, 0.2 dB of maximum polarization-dependent loss, and 40 dB of dynamic range. The response time was measured to be about 5 s.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2012.04a
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• pp.412-415
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• 2012

본 논문에서는 냉온정수기 등의 온수조의 온도 조절 및 온도과승방지를 위해 주로 사용되는 바이메탈 서모스탯 외부 표면의 오손에 따른 화재 위험성에 대하여 실험, 분석하였다. 실험 분석결과, 서모스탯 표면의 극간 간격에 관계없이 절연물 표면의 오염에 의해 절연물 표면에 누설전류가 흘러 탄화되면서 화재로 이어지는 것을 확인할 수 있었다. 바이메탈 서모스탯의 외부 오염에 의한 화재 예방을 위하여 불연성 재질의 서모스탯으로 하거나 외부 물기 등의 영향을 받지 않는 구조로 개선할 필요가 있음을 확인할 수 있었으며, 제품자체의 안전뿐만 아니라 사용 환경 등을 고려한 안전설계가 요구된다. 연구결과는 관련 규정의 개선과 바이메탈 서모스탯과 관련된 화재원인 규명에 도움이 될 것으로 기대된다.

• 전기의세계
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• v.96 no.8
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• pp.29-34
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• 1960

• Journal of Korean Institute of Fire Investigation
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• v.11 no.1
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• pp.63-73
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• 2007

In this paper, we discussed the hazard of ignition on the bimetal type thermostat molded by phenol resin with case study and accelerated aging test. We experimented three type thermostats molded by phenol resin which are used on hot/cold water dispenser. On the case study, the thermostat was origin of 6re and dry tracking occurred around it's moveable contactor. On the accelerated aging test, the more thermostat was switched, the more damaged it become. One of the A-type thermostats that is similar type on the case study fired around moveable contactor. We therefore confirmed that the tracking around the moveable contactor of bimetal type thermostat molded by phenol resin could be origin of fire and it is available to reduce of fire that using noncombustible material for molding of bimetal type thermostat.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.22 no.1
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• pp.131-137
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• 2013

Gas springs have been widely used in motor vehicles as well as in most areas of industry. Instead of coil springs, these gas springs are easily operated to extrusion process or compression process the doors because $N_2$ gas with high pressure and oil are charged in tube. Gas spring sustain the constant elasticity change rate in the high reaction force and long stroke, and they have compact design, appearance and an excellent assembling ability to be mounted easily with any applicatory products. By means of these aspects, gas springs have been widely used in stead of coil springs in the over all industries. In this study, using acommonly used program, ANSYS, the basic research about the heat transfer and equivalent stress change of bimetal.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.24 no.11
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• pp.799-805
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• 2012

In this study, structural thermal analyses for steam trap valve considering contact boundary condition have been conducted for high temperature and pressure conditions using nonlinear finite element method. Full steam trap model also including regulator and housing structures is considered in order to accurately simulate the complex valve mechanism and investigate thermal stress levels, and structural behaviors of core structural parts. It is typically shown that the present computational approach can give very useful results for design engineers so that the operating performance and structural safety of the steam trap valve can be verified in the design process.

• Journal of Korean Institute of Fire Investigation
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• v.6 no.1
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• pp.37-41
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• 2005

본 실험은 화재현장에서 발견된 소훼된 전기다리미 내부 바이메탈 스위치 접점이 꺼짐 상태로 식별되는 경우와 다리미에 접촉된 바닥재가 소실 상태로 발견되는 경우의 과열 출화흔을 확인키 위해 조건별 A, B, C로 구분하여 실험한 결과 사용중인 전기 다리미를 면셔츠 위에 1시간 정도 방치한 정도로는 자체 과열 발화할 가능성은 희박한 것으로 판단되었고, 내부 안정장치(바이메탈 스위치, 온도휴즈 등)를 제거하여 자체과열 시킨 다리미의 경우 외부 화염으로 소훼시킨 다리미에 비해 발열선 주변과 발열판 바닥이 심하게 용융된 특징점을 발견하였으나, 실험의 조건상 바닥재 탄화소실정도에 대한 과열 특징점은 명확히 구분치 못하였다.

• Fire Science and Engineering
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• v.31 no.3
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• pp.73-78
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• 2017

In this paper, the fire risk using a bimetal type thermometer for construction installation is presented. Because construction equipment is used widely in the field and the site is exposed to explosions and fire by combustible gas or fume, strong restrictions on the structure and usage are applied. Moreover, the risk of fire increases as precise temperature measurements are poorly conducted via an inner temperature sensor inside construction furnace. Therefore, this paper presents the results of structural analysis of a bimetal temperature sensor which is used widely in construction installation and temperature measurement experiments relative to the material property of the target object. The results revealed the relatively precise temperature of the liquid object, whereas those of the gas and solid object showed a lower temperature compared to the real temperature. This shows that bimetal-type temperature sensor is more suitable for measuring a liquid state object than measuring a gas or solid state object.

• Journal of the Korean Society for Nondestructive Testing
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• v.3 no.2
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• pp.13-27
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• 1984

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.4 no.4
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• pp.34-38
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• 2005

This is a widespread requirement for low cost lightweight thermal imaging sensors for both military and civilian applications. Today, a large number of uncooled infrared detector developments are under progress due to the availability of silicon technology that enables realization of low cost IR sensor. System prices are continuing to drop, and swelling production volume will soon drive process substantially lower. The feasibility of micromechanical optical and infrared (IR) detection using microcantilevers is demonstrated. Microcantilevers provide a simple Structurefor developing single- and multi-element sensors for visible and infrared radiation that are smaller, more sensitive and lower in cost than quantum or thermal detectors. Microcantilevers coated with a heat absorbing layer undergo bending due to the differential stress originating from the bimetallic effect. This paper reports a micromachined silicon uncooled thermal imager intended for applications in automated process control. This paper presents the design, fabrication, and the behavior of cantilever for thermomechanical sensing.