• Title/Summary/Keyword: Thermocouples

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Temperature Measurement Method with Radiation Correction for Very High Temperature Gas (복사 간섭 보정을 통한 초고온 가스 온도 측정 방법)

  • Kim, Chan-Soo;Hong, Sung-Deok;Seo, Dong-Un;Kim, Yong-Wan;Lee, Won-Jae
    • Proceedings of the KSME Conference
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    • pp.2059-2063
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    • 2008
  • When a thermocouple is placed in a high temperature gas-flow stream, the measured temperature could be biased from the true gas temperature due to a large radiation heat loss from a thermocouple surface to its surroundings. In this study, two thermocouples of unequal diameters with 1/8 inch and 1/16 inch are used to correct the radiation effect. The method is called the reduced radiation error (RRE). The preliminary test results show that the radiation and the sheath conduction cannot be negligible for the gas temperature measurement. To minimize the sheath conduction effect, all the thermocouples will have a grounded junction and 1/8 inch thermocouple will be replaced with 1 mm thermocouples. In addition, the computational fluid dynamics code analysis shows that there is a negligible temperature difference between the positions where the thermocouples were installed.

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The tracking of a smoke front under a ceiling by a laser sheet and thermocouples (Laser와 열전대를 이용한 연기선단의 위치 추적 비교에 관한 연구)

  • 김명배;한용식;윤명오;김진곤
    • Fire Science and Engineering
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    • v.12 no.3
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    • pp.11-20
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    • 1998
  • A new experimental technique using a laser sheet and thermocouples is introduced to evaluate an intuitive criterion for tracking of a smoke front using thermocouples. From synchronized photos of the smoke front along with temperature signals, the intuitive criterion is shown to be acceptable. Smoke visualization by a laser sheet proves to have several advantages over the conventional techniques such as the use of smoke generators.

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Experimental Study on Transient Heating of the Glass Panel in the Infrared Heating Chamber

  • Lee, Kong-Hoon;Kim, Ook-Joong;Ha, Su-Seok
    • 한국정보디스플레이학회:학술대회논문집
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    • pp.499-502
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    • 2004
  • The temperature distribution of a glass plate heated in the infrared heating chamber has been investigated. Temperature of the glass panel is measured using a set of thermocouples and the optical pyrometer. Temperatures measured by thermocouples have good agreement with those by the pyrometer. The temperature uniformity of the panel is improved with wall reflectivity, which is one of the important factors to uniformly heat the panel

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A CMOS Compatible Micromachined Microwave Power Sensor (CMOS 공정과 호환되는 마이크로머시닝 기술을 이용한 마이크로파 전력센서)

  • 이대성;이경일;황학인;이원호;전형우;김왕섭
    • Proceedings of the IEEK Conference
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    • pp.439-442
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    • 2002
  • We present in this Paper a microwave Power sensor fabricated by a standard CMOS process and a bulk micromachining process. The sensor consists of a CPW transmission line, a resistor as a healer, and thermocouple arrays. An input microwave heater, the resistor so that the temperature rises proportionally to the microwave power and tile thermocouple arrays convert it to an electrical signal. The sensor uses air bridged 8round of CPW realized by wire bonding to reduce tile device size and cost and to improve the thermal impedance. Al/poly-Si junctions are used for the thermocouples. Poly-Si is used for tile resister and Aluminium is for transmission line. The resistor and hot junctions of the thermocouples are placed on a low stress silicon nitride diaphragm to minimize a thermal loss. The fabricated device operates properly from 1㎼ to 100㎽\ulcorner of input power. The sensitivity was measured to be ,3.2~4.7 V/W.

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Analysis of the Seebeck Effect of Textile Thermocouples Fabricated with Conductive Yarns (전도사를 이용하여 제작한 섬유형 열전대의 제백 효과에 대한 연구)

  • Rho, Soo Hyeon;Lim, Dae Young;You, Eui Sang
    • Textile Science and Engineering
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    • v.56 no.6
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    • pp.411-417
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    • 2019
  • Recently, as the wearable device industry has expanded, textile sensors have been evaluated for use in the field of monitoring human biological signals such as pulse rate, respiration rate, and body temperature. Until now, most textile products with embedded semiconductors or small metal-based sensors have been known to exhibit problems, including uncomfortable fit, low stretchability, and poor durability. To resolve these issues, we fabricated a textile thermocouple using conductive yarns and then confirmed the feasibility of this thermocouple structure as a wearable temperature sensor. The electromotive forces generated by the textile thermocouples were then measured experimentally and the Seebeck coefficient of the embroidered thermocouple was measured as 21.9 ㎶/K.

Phase transition features of binary Co-C eutectic temperature fixed-point (이원계 Co-C 공정계 온도 고정점의 특성)

  • Kim, Yong-Gyoo;Yang, In-Seok;Gam, Kee-Sool
    • Journal of Sensor Science and Technology
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    • v.14 no.6
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    • pp.381-386
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    • 2005
  • A Co-C eutectic cell for thermocouple calibration was manufactured and tested to investigate its phase transition characteristics using Type B thermocouples. It was observed that the freezing plateaus were flatter than those of melting, but the melting points were closer to the true transition temperature than the freezing points. The expanded uncertainty of melting temperature was calculated not to exceed $0.2^{\circ}C$ (k = 2). Based on the observed results, the melting process is recommended for the calibration of thermocouples.

Multi-junction thermocouple for temperature gradient measurements (온도구배 측정용 다중접점 열전대)

  • Kim, Yong-Gyoo;Gam, Kee-Sool
    • Journal of Sensor Science and Technology
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    • v.4 no.2
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    • pp.3-6
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    • 1995
  • Type K thermocouples having multi-junction for measuring the temperature gradient of the furnace were fabricated. The obtained results on the temperature gradient of the electric furnace maintained at $800^{\circ}C$ were consistent with those for the reference grade type S thermocouple, which was carefully calibrated, within the permitted error limit of the type K thermocouple. It was suggested that noble metal multi-junction thermocouples be suitable for more accurate temperature gradient measurements.

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Measurement Technique of Cutting Temperatures Using Implanted Thermocouples in Ball End-Milling (볼 엔드밀링에서 열전대를 이용한 절삭온도 측정법)

  • Lee, Deuk-U
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.24 no.7
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    • pp.1748-1752
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    • 2000
  • In this paper, the measurement technique of cutting temperatures of shear zone using implanted thermocouples is proposed in ball end milling. K-type thermocouple implanted in the hole of workpieces is directly cut in order to measure temperatures of the shear zone in cutting process. Experiments are performed for a nickel based superalloy(Inconel 718) using a ball nose end mill. The results show that the cutting temperature in shear zone is about 3200C at the cutting speed of 90m/min with dry.

Characteristics variation of thermal time constant of thermocouples by the structure changes (열전대 구조변화에 의한 열시정수 특성 변화)

  • Gam, Kee-Sool
    • Journal of Sensor Science and Technology
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    • v.18 no.2
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    • pp.103-109
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    • 2009
  • Thermal time constant measurement system was designed and fabricated to measure the thermal time constant, which shows a dynamic property of the thermocouple. Type K thermocouple samples were fabricated with variable shape each other and the thermal time constants of thermocouples were measured using the home-made thermal time constant measurement system. Thermal time constants of 12 type K thermocouple samples were distributed from 0.03 s to 8.2 s. It showed experimentally that the thermal time constant of thermocouple was increased linearly for the increase of the sheath diameter of thermocouple.

Visualization of Temperature Distribution Deep Inside the Agar Gel Tissue Phantom Heated Using Moxibustion and 1064 nm Infrared Laser (쑥뜸과 1064 nm 파장의 근적외선 레이저로 가열된 아가젤 조직 팬텀 심부의 온도분포 가시화)

  • Cho, Ji-Yong;Kim, Jung-Kyung
    • Journal of the Korean Society of Visualization
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    • v.8 no.4
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    • pp.54-59
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    • 2010
  • A laser moxibustion therapy device having effect similar to that of traditional moxibustion is being developed using 1064 nm infrared laser. The therapy device allows direct interaction of laser light with the tissue rendering temperature distribution both on the skin surface and deep under the skin. We made a device that could measure temperature of deep under the surface of agar gel tissue phantom using thermocouples. A thermal imaging camera was used to verify results from the temperature measurement device. We compared the characteristics of heat transfer inside the tissue phantom during moxibustion and laser irradiation. The temperature distribution measured by thermocouples was found to be similar to that of distribution given by thermal imaging camera.