• Title/Summary/Keyword: temperature standards

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A Study on the Temperature Environmental Test Standards (온도 환경시험 표준규격에 관한 연구)

  • Lee Kwan-Hun;Kim Joon-Won
    • Journal of Applied Reliability
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    • v.5 no.2
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    • pp.209-219
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    • 2005
  • The required standards for environmental tests for communication and electronic equipment used currently are not standards into which the Korean climate and use environment are taken into consideration. But the most used environmental testing standards of the U.S. army(MIL-STD-810) has been used without taking into consideration the Korean domestic situation and conditions by simply translating the US standards. Adherence to these standards may increase in the manufacturing costs according to excessively strict standards. Therefore, this paper will propose a new environmental test standards for temperature.

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Measurement of triple point of water temperature for improvement of the national standards and key comparison (국가표준향상과 핵심국제비교를 위한 물의 삼중점 온도 측정)

  • Yang, Inseok;Lee, Young Hee
    • Journal of Sensor Science and Technology
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    • v.30 no.5
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    • pp.349-356
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    • 2021
  • The Korea Research Institute of Standards and Science (KRISS), a National Metrology Institute of Korea, participated in the second-round of the international key comparison CCT-K7.2021 of triple point of water (TPW) cells. For the key comparison, three TPW cells, one of which had been used in the old CCT-K7 comparison, were assigned as the national standard of the TPW. The temperature difference (ΔT) between the average of the new and old national standards and ΔT between the new national standard and the transfer standard were measured. The comparison between the new and old national standards indicated a temperature increase of 69.5 µK after both the standards were corrected for the isotopic composition. The uncertainty of the national standard of the TPW temperature was 28 µK, and the uncertainty of ΔT was 14 µK. Three aspects of improvements in the new comparison compared to the old one were noted: (1) inclusion of two quartz cells in the national standard strengthens its long-term stability; (2) the standard deviation associated with the measurement of ΔT was reduced from 21 µK to 9.6 µK; (3) and the measured immersion profile of the TPW cells was much closer to the theoretically predicted dependence.

Measurement of Internal Temperature Distribution for the Evaluation of Focused Ultrasound (FUS) Stimulation Devices (집속초음파 자극기의 성능평가를 위한 팬텀 내부온도 측정)

  • Doh, Il;Joe, Daniel J.;Kim, Sung Mok;Baik, Kyung Min;Kim, Yong Tae;Park, Seung Min
    • Journal of Biomedical Engineering Research
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    • v.43 no.3
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    • pp.147-152
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    • 2022
  • This research is to measure real-time temperature distribution inside a tissue-mimicking phantom for the safety and effectiveness evaluations of focused ultrasound (FUS) device capable of linear scanning stimulation. Since the focusing area of the FUS stimulation device is smaller than diameter of conventional thermal probe and keeps moving, it is impossible to monitor temperature distribution inside the phantom. By using the phantom with a thin film temperature sensor array inserted, real-time temperature change caused by the FUS device was measured. The translation of the measured temperature peak was also tracked successfully. The present phantom had been experimentally proven to be applicable to validate the performance and safety of the therapeutic ultrasound devices.

The Effect of Temperature on Aluminum Oxide and Chilled Mirror Dew-point Hygrometers (산화 알루미늄 및 냉각거울 노점계의 온도 의존성에 관한 연구)

  • Kim, Jong Chul;Choi, Byung Il;Woo, Sang-Bong;Kim, Yong-Gyoo;Lee, Sang-Wook
    • Journal of Sensor Science and Technology
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    • v.26 no.1
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    • pp.50-55
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    • 2017
  • The measurement of absolute humidity of gases is essential in many industries. The effect of temperature on aluminum oxide and chilled mirror dew-point hygrometers is investigated. The temperature of laboratory, pipe line, and sensor is varied and the dew point is measured by two different aluminum oxide hygrometers. In all cases, the dew point of hygrometers is increased as the temperature is elevated. The reason behind this observation is due to desorption of water from the inside of pipe line and/or sensor surroundings at elevated temperature that result in the increase of the absolute humidity. Moreover, the sensor itself shows a certain degree of temperature dependency in sensing the humidity especially at low temperature. It is also studied that chilled mirror dew-point hygrometer may indicate a higher dew point than the reference at high temperature because the cooling capability of mirror is decreased at high temperature. Our study will provide evidences in the incorporation of the temperature effect as uncertainty factors in the standard calibration procedure for dew point hygrometers.

Statistical Analysis on the Temperature Dependence and Long-Term Change of Relative Humidity Sensors (상대습도계의 온도 의존성과 경년변화의 통계적 분석)

  • Kim, Jong Chul;Choi, Byung Il;Woo, Sangbong;Yang, Inseok
    • Journal of Sensor Science and Technology
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    • v.21 no.6
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    • pp.420-424
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    • 2012
  • We have investigated temperature dependence and long-term change of humidity measurement from 32 relative humidity sensors. The readings of the humidity sensors depended not only the reference humidity, but also temperature of the chamber. Approximately, the temperature dependence of the humidity sensor in average was 0.05 %R.H./$^{\circ}C$ in the temperature range from $5^{\circ}C$ to $55^{\circ}C$. For humidity sensors that have an internal temperature compensation circuit, the resulting temperature dependence was weaker by 20%. It should be also noted that for the humidity sensors used in this work underwent ${\pm}3$ %R.H. change per year for level of confidence of 95%. The users of relative humidity sensors may refer this value as a minimum change when they set the calibration interval of the humidity sensors.

Effects on Heat Treatment Methods in Indium-Tin-Oxide Films by DC Magnetron Sputter of Powder Target

  • Kim, H.H.;Shin, J.H.;Baek, J.Y.;Shin, S.H.;Park, K.J.
    • Transactions on Electrical and Electronic Materials
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    • v.2 no.1
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    • pp.22-26
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    • 2001
  • ITO (Indium-tin-oxide) thin films were deposited on glass substrates by a dc magnetron sputtering system using ITO powder target. The methods of heat treatment are important factor to obtain high quality ITO films with low electrical resistivity and good optical transmittance. Therefore, both methods of the substrate temperature and post-deposition annealing temperature have been compared on the film structural, electrical and optical properties. A preferred orientations shifts from (411) to (222) peak at annealing temperature of 200$\^{C}$. Minimum resistivity of ITO film is approximately 8.7$\times$10$\^$-4/ Ωcm at substrate temperature of 450$\^{C}$. Optical transmittances at post annealing temperature above 200$\^{C}$ are 90%. As a result, the minimum value of annealing temperature that is required for the recrystallization of as-deposited ITo thin films is 200$\^{C}$.

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A Study on the Temperature Environmental Test Standards (온도 환경시험 표준규격에 관한 연구)

  • Lee Kwan-Hun;Kim Joon-Won
    • Proceedings of the Korean Reliability Society Conference
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    • 2005.06a
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    • pp.421-430
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    • 2005
  • The required standards for environmental tests for communication and electronic equipment used currently are not standards into which the Korean climate and use environment are taken into consideration. But the most used environmental testing standards of the U.S. army(MIL-STD-810) has been used without taking into consideration the Korean domestic situation and conditions by simply translating the US standards. Adherence to these standards may increase in the manufacturing costs according to excessively strict standards. Therefore, this paper will propose a new environmental test standards for temperature.

  • PDF

Electron Density and Electron Temperature in Atmospheric Pressure Microplasma

  • Tran, T.H.;Kim, J.H.;Seong, D.J.;Jeong, J.R.;You, S.J.
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.08a
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    • pp.152-152
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    • 2012
  • In this work we measured electron temperature and electron density of a microplasma by optical emission spectroscopy. The plasma is generated from a small discharge gap of a microwave parallel stripline resonator (MPSR) in Helium at atmospheric pressure. The microwave power supplied for this plasma source from 0.5 to 5 watts at a frequency close to 800 MHz. The electron temperature and electron density were estimated through Collisional-radiative model combined with Corona-equilibrium model. The results show that the electron density and temperature of this plasma in the case small discharge gap width are higher than that in larger gap width. The diagnostic techniques and associated challenges will be presented and discussed.

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