• Title/Summary/Keyword: Thermometry

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Measurement of combustor surface temperature using phosphor thermometry (형광체를 이용한 연소기 표면온도 측정기술)

  • Kim, Yong-Gyoo;Lee, Seok Hwan;Kim, Sunghun;Yang, Inyoung
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2017.05a
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    • pp.228-231
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    • 2017
  • The surface temperature of a combustor such as an aircraft engine is one of the important measuring factors related to the combustion performance. However, a conventional temperature measurement technique have a large measurement error due to a bad environment such as a combustion flame, vibration, and dust. In order to solve this problem, a technology has been developed which can measure the surface temperature of the combustor in real time using the wavelength change or attenuation time change according to the temperature of the phosphor. In this study, we developed a technique that can measure surface temperature of scram-jet combustor using phosphor thermometry. The calibration curve was obtained according to the temperature from $200^{\circ}C$ to $800^{\circ}C$ in the calibrated temperature chamber. So, we confirmed that phosphor thermometry can be used for measuring surface temperature of scram-jet combustor.

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Calibration by Comparison and Uncertainty Assessment of Industrial Thermometers at the Boiling Point of Nitrogen (질소의 끓는점에서의 산업용 온도계 비교 교정과 불확도 평가)

  • Yang, Inseok;Gam, Kee Sool;Joung, Wukchul;Kim, Yong-Gyoo
    • Journal of Sensor Science and Technology
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    • v.22 no.6
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    • pp.404-409
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    • 2013
  • We devised calibration procedure for industrial thermometers by a comparison method at the boiling point of nitrogen (${\sim}-196^{\circ}C$). The uncertainty of the calibration was 4 mK (k = 2). As experimentally demonstrated in this work, the effect of the atmospheric pressure on the boiling point of nitrogen can be easily detected by the thermometer. Therefore, when the boiling point of nitrogen is used for calibration of thermometer by comparison, either a reference thermometer must be used to provide the reference temperature or the effect of atmospheric pressure should be carefully considered. The use of a copper block with a large thermal mass soaked into the liquid nitrogen was proven to be more reliable, and the stability of the temperature immersed into the copper block was 1.4 mK. The temperatures at the thermometer wells, evaluated by the crossed-measurement method to compensate for the inaccuracy of the thermometers and the linear drift of the temperature of the copper block, were equivalent within 0.23 mK of standard uncertainty.

Performance Assessment on Temperature Calibration Capability of the Calibration Laboratories Using High-Precision Platinum Resistance Thermometers (고정밀 백금저항온도계를 이용한 교정기관의 온도교정능력 수행평가)

  • Gam, Kee Sool;Lee, Young Hee;Yang, Inseok
    • Journal of Sensor Science and Technology
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    • v.22 no.6
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    • pp.415-420
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    • 2013
  • Calibration capabilities for thermometer calibration by comparison method were assessed using high-precision industrial platinum resistance thermometers (IPRT). It was found in the performance assessment that out of 31 laboratories who participated, 28 laboratories resulted magnitude of En number less than 1 at every calibration points they submitted results in the range from 50 to $500^{\circ}C$. The results of about 75% of the laboratories showed the difference from the assigned values less than 1/10 of the tolerance level of the class B IPRT. This indicates that the participating calibration laboratories performed with satisfactory level that was enough to calibrate IPRTs to significant precision. The sensors used in this work were manufactured and chosen by the criteria of long-term instability less than 4 mK and hysteresis less than 8 mK in the temperature range used in this work. Furthermore, the change in the resistance of the sensors in the calibration temperature range were less than the uncertainty of the calibration, 25 mK (k=2).

Application of Magnetic Resonance Thermometry (MRT) on Fully Developed Turbulent Pipe Flow using 3T and 7T MRI (완전발달 난류 원관 유동에서의 3T 및 7T MRI를 이용한 자기공명온도계의 적용)

  • You, Hyung Woo;Baek, Seungchan;Kim, Dong-Hyun;Lee, Whal;Oh, Sukhoon;Hwang, Wontae
    • Journal of the Korean Society of Visualization
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    • v.18 no.1
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    • pp.26-37
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    • 2020
  • Magnetic resonance thermometry (MRT) is a technique capable of measuring three-dimensional mean temperature fields by utilizing temperature-dependent shifts in proton resonance frequency. In this study, experimental verification of the technique is obtained by measuring 3D temperature fields within fully developed turbulent pipe flow, using 3T and 7T MRI scanners. The effect of the proton resonance frequency (PRF) thermal constant is examined in detail.

Development of Multichannel On-line Thermometry System (다 채널 직결 온도측정 시스템의 설계 및 제작)

  • Shin, Sei-One;Shin, Hyun-Jin;Kim, Myung-Se;Kim, Sung-Kyu
    • Journal of Yeungnam Medical Science
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    • v.16 no.2
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    • pp.193-199
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    • 1999
  • Background: Measurement of body temperature is an important parameter in patient management in many clinical conditions. Failure to reach minimal acceptable body temperature standards has been associated with physiological derangements and has necessitated the application of additional therapy. The authors developed a new, simple, accurate thermometry system, which could be used to undertake precise temperature measurement for various clinical conditions. Materials and Methods: A new thermometry system using a specially designed temperature detecting and display system was developed. This system contains a temperature detecting sensor(LM 35CZ), which enables multiple serial checking of heat, data collection and processing computer, and 3-dimensional display system. It provides real time volumetric visualization of temperature distribution of a defined volume and stores and prints the data. Results: With this system, temperature can be measured at multiple interesting sites simultaneously, demonstrated as a 3-dimensional temperature distribution and stored. In well-controlled, systematic experiments a significant correlation has been observed between standard temperature and temperature using this system at various measuring points. Conclusion: This thermometry system is a real-time measurement system, which can demonstrate 3-dimensional heat distribution in experimental phantom and human body and can be used for diagnosing abnormal clinical conditions. In addition, this system reduces the nursing staff work load, providing them more time for long term care to patients.

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Using Leaf Temperature for Irrigation Scheduling in Greenhouse (온실작물의 관개계획의 수립을 위한 엽온의 활용)

  • 이남호;이훈선
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.43 no.6
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    • pp.103-112
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    • 2001
  • The development of infrared thermometry has led many researchers to use plant temperatures, and specifically the temperature of the crop canopy in the field, for estimating the water stress of a crop. The purpose of this study was to evaluate the role of leaf temperature in irrigation scheduling. An experiment was carried out in a greenhouse with chinese cabbage. Leaf temperature was measured with infrared thermometry and evapotranspiration of the crop was measured by lysimeters. Influence of the difference between leaf temperature and air temperature on crop evapotranspiration was evaluated under varying water stress condition. A further objective was to evaluate the effect of other climatic variables on the relationship between evapotranspiration and temperature difference between leaf and air. A statistical model for estimating evapotranspiration using the temperature difference, relative humidity. and radiation was developed and tested. Crop water stress index was calculated using vapour pressure deficit and the temperature difference. Relations between the crop water stress index and crop evapotranspiration was tested. The index was closely related with evapotranspiration.

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State-of-the-art progress of gaseous radiochemical method for detecting of ionizing radiation

  • Lebedev, S.G.;Yants, V.E.
    • Nuclear Engineering and Technology
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    • v.53 no.7
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    • pp.2075-2083
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    • 2021
  • The article provides a review of the research results obtained during of more than 20 years concerning using the gaseous radiochemical method (GRCM) for detecting of ionizing radiation. This method based on threshold nuclear reactions with production of radioactive noble gas which does not interact with the materials of gaseous tract. The applications of GRCM in the diagnostics of neutrinos, neutrons, charged particles, thermonuclear plasma thermometry, and the study of the structure and dynamics of astrophysical objects, position-sensitive dosimetry of neutron targets with accelerator driving, spatial distribution of the fast neutron flux density in a nuclear reactor allowing the transformation of longitudinal coordinate of neutron flux distribution into a temporal distribution of the radiochemical gas decay counting rate ("barcode" semblance) and measurement of bombarding particles spectra are described. Experimental testing of the described technologies was made on the neutron target driven with the linear proton accelerator of Institute for Nuclear Research of Russian Academy of Sciences (INR RAS).