• Title/Summary/Keyword: Temperature Accuracy

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Variable Temperature Cryostat for Cryogenic Temperature Sensor Calibration

  • Kim, Myung Su;Choi, Yeon Suk;Kim, Dong Lak
    • Progress in Superconductivity and Cryogenics
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    • v.14 no.4
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    • pp.46-49
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    • 2012
  • The selection of the temperature sensor in the cryogenic system depends on the temperature range, shape and accuracy. The accuracy of the temperature sensor is essential to improve the reliability of experiment. We have developed the variable temperature cryostat using a two-stage cryocooler. In order to reduce heat load, thermal shield is installed at the first stage with MLI (Multiple layer insulation). We have also developed the sensor holder calibrating more than twenty sensors at the same time for saving time and money. The system can calibrate sensor at variable temperature by controlling electric heater. In this paper, we present design and fabrication of variable temperature cryostat and representative result of Cernox sensor calibration.

Reliability and Accuracy of Infrared Temperature: A Systematic Review (적외선 체온의 진단 정확도 평가 연구: 체계적 문헌고찰)

  • Park, Seong-Hi
    • Korean Journal of Adult Nursing
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    • v.26 no.6
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    • pp.668-680
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    • 2014
  • Purpose: The aim of this study was to investigate the accuracy of infrared temperature measurements compared to axillary temperature in order to detect fever in patients. Methods: Studies published between 1946 and 2012 from periodicals indexed in Ovid Medline, Embase, CINAHL, Cochrane, KoreaMed, NDSL, KERIS and other databases were selected using the following key words: "infrared thermometer". QUADAS-II was utilized to assess the internal validity of the diagnostic studies. Selected studies were analyzed through a meta-analysis using MetaDisc 1.4. Results: Twenty-one diagnostic studies with high methodological quality were included representing 3,623 subjects in total. Results of the meta-analysis showed that the pooled sensitivity, specificity, and area under the curve (AUC) of infrared tympanic thermometers were 0.73 (95% CI 0.70~0.75), 0.92 (95% CI 0.91~0.92), and 0.90, respectively. For axillary temperature readings, the pooled sensitivity was 0.67 (95% CI 0.62~0.73), the pooled specificity was 0.87 (95% CI 0.85~0.90), and the AUC was 0.80. Conclusion: Infrared tympanic temperature can predict axillary temperature in normothermic and in febrile patients with an acceptable level of diagnostic accuracy. However, further research is necessary to substantiate this finding in patients with hyperthermia.

Accuracy improvement of FBG temperature sensor system for usage in electric power systems (전력 시스템 보호를 위한 광섬유 격자 온도센서의 정밀도 개선)

  • Lee, Hyun-Wook;Lee, Jun-Ho;Song, Min-Ho
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2005.05a
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    • pp.421-425
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    • 2005
  • A distributed FBG temperature sensor system was constructed for the use in protection of electric power system. A F-P wavelength tunable filter is used converting temperature-induced wavelength variations to temporal peak locations. We used Gaussian line-fitted algorithm to alleviate the error caused by quantization and electrical noises. The experimental results showed much better accuracy than the raw peak-detection scheme.

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The Development of Linearized Digital Temperature Monitor Based on EPROM (EPROM을 이용한 선형디지탈 체온 모니터의 개발)

  • 고한우;이건기
    • Journal of Biomedical Engineering Research
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    • v.4 no.1
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    • pp.21-28
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    • 1983
  • The opjective of this research is to derelop the linearijed digital temperature monitor based on EPROM. The advantages associated with this proposod monitor as Compared with the conventional temperature montor is very high accuracy in wide range The accuracy of this monitor was evaluated by the experimental system which was consisted of the water-bath controller. mercury thermometor, and YSI-400 series probes.

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Accuracy evaluation of near-surface air temperature from ERA-Interim reanalysis and satellite-based data according to elevation

  • Ryu, Jae-Hyun;Han, Kyung-Soo;Park, Eun-Bin
    • Korean Journal of Remote Sensing
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    • v.29 no.6
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    • pp.595-600
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    • 2013
  • In order to spatially interpolate the near-surface temperature (Ta) values, satellite and reanalysis methods were used from previous studies. Accuracy of reanalysis Ta was generally better than that of satellite-based Ta, but spatial resolution of reanalysis Ta was large to use at local scale studies. Our purpose is to evaluate accuracy of reanalysis Ta and satellite-based Ta according to elevation from April 2011 to March 2012 in Northeast Asia that includes various topographic features. In this study, we used reanalysis data that is ERA-Interim produced by European Centre for Medium-Range Weather Forecasts (ECMWF), and estimated satellite-based Ta using Digital Elevation Meter (DEM), Normalized Difference Vegetation Index (NDVI), difference between brightness temperature of $11{\mu}m$ and $12{\mu}m$, and Land Surface Temperature (LST) data. The DEM data was used as auxiliary data, and observed Ta at 470 meteorological stations was used in order to evaluate accuracy. We confirmed that the accuracy of satellite-based Ta was less accurate than that of ERA-Interim Ta for total data. Results of analyzing according to elevation that was divided nine cases, ERA-Interim Ta showed higher accurate than satellite-based Ta at the low elevation (less than 500 m). However, satellite-based Ta was more accurate than ERA-Interim Ta at the higher elevation from 500 to 3500 m. Also, the width of the upper and lower quartile appeared largely from 2500 to 3500 m. It is clear from these results that ERA-Interim Ta do not consider elevation because of large spatial resolution. Therefore, satellite-based Ta was more effective than ERA-Interim Ta in the regions that is range from 500 m to 3500 m, and satellite-based Ta was recommended at a region of above 2500 m.

Generation of Land Surface Temperature Orthophoto and Temperature Accuracy Analysis by Land Covers Based on Thermal Infrared Sensor Mounted on Unmanned Aerial Vehicle (무인항공기에 탑재된 열적외선 센서 기반의 지표면 온도 정사영상 제작 및 피복별 온도 정확도 분석)

  • Park, Jin Hwan;Lee, Ki Rim;Lee, Won Hee;Han, You Kyung
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.36 no.4
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    • pp.263-270
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    • 2018
  • Land surface temperature is known to be an important factor in understanding the interactions of the ground-atmosphere. However, because of the large spatio-temporal variability, regular observation is rarely made. The existing land surface temperature is observed using satellite images, but due to the nature of satellite, it has the limit of long revisit period and low accuracy. In this study, in order to confirm the possibility of replacing land surface temperature observation using satellite imagery, images acquired by TIR (Thermal Infrared) sensor mounted on UAV (Unmanned Aerial Vehicle) are used. The acquired images were transformed from JPEG (Joint Photographic Experts Group) to TIFF (Tagged Image File Format) format and orthophoto was then generated. The DN (Digital Number) value of orthophoto was used to calculate the actual land surface temperature. In order to evaluate the accuracy of the calculated land surface temperature, the land surface temperature was compared with the land surface temperature directly observed with an infrared thermometer at the same time. When comparing the observed land surface temperatures in two ways, the accuracy of all the land covers was below the measure accuracy of the TIR sensor. Therefore, the possibility of replacing the satellite image, which is a conventional land surface temperature observation method, is confirmed by using the TIR sensor mounted on UAV.

Comparative Analysis of Models used to Predict the Temperature Decreases in the Steel Making Process using Soft Computing Techniques (철강 생산 공정에서 Soft Computing 기술을 이용한 온도하락 예측 모형의 비교 연구)

  • Kim, Jong-Han;Seong, Deok-Hyun
    • Journal of Institute of Control, Robotics and Systems
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    • v.13 no.2
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    • pp.173-178
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    • 2007
  • This paper is to establish an appropriate model for predicting the temperature decreases in the batch transferred from the refining process to the caster in steel-making companies. Mathematical modeling of the temperature decreases between the processes is difficult, since the reaction mechanism by which the temperature changes in a molten steel batch is dynamic, uncertain and complex. Three soft computing techniques are examined using the same data, namely the multiple regression, fuzzy regression, and neural net (NN) models. To compare the accuracy of these three models, a limited number of input variables are selected from those variables significantly affecting the temperature decrease. The results show that the difference in accuracy between the three models is not statistically significant. Nonetheless, the NN model is recommended because of its adaptive ability and robustness. The method presented in this paper allows the temperature decrease to be predicted without requiring any precise metallurgical knowledge.

Experimental verification and improvement of heat transfer tube local wall temperature measurement method

  • Jiabao Liu;Xiaxin Cao;Peixun Yang
    • Nuclear Engineering and Technology
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    • v.55 no.12
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    • pp.4317-4328
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    • 2023
  • To ensure the measuring accuracy of the wall temperature, the outer wall temperature measurement values by using three kinds of thermocouple welding methods were analyzed and evaluated in the paper, including single-point flush-mounted in the wall groove method, single-point insert-mounted in the wall groove, and outer surface direct welding method, based on the application of a tube-in-tube condensing heat exchanger. And the impacts of silver, tin, and thermal resistance adhesive as filling materials on wall temperature measurement were also investigated, and the results were compared to that obtained without filling materials. The results showed that the wall temperatures measured by the three welding methods were lower than the theoretically calculated value. And the wall temperature measured by the outer surface direct welding method was lowest under the same experimental conditions. The wall temperatures measured by single-point flush-mounted and insert-mounted in the wall groove methods were also affected by different welding filling materials. It was found that the greater the thermal resistance of filling materials, the smaller the heat loss. By analyzing the reasons for the low measured value of wall temperature, a new wall temperature measurement method was developed to improve the accuracy of the current measurement method. Meanwhile, the outer wall temperature measurement experiments of vertical and horizontal heat transfer tubes were carried out to validate and calibrate the improved outer wall temperature measurement method. The results showed that the average outer wall temperature deviation measured by the improved wall temperature measurement method ranged from - 0.82% to +2.29% for vertical tubes and - 4.75% to - 1.44% for horizontal tubes, and the improved measurement method had good measurement accuracy.

Accuracy, Precision, and Validity of Fever Detection using Non-invasive Temperature Measurement in Adult Coronary Care Unit Patients with Pulmonary Catheters (폐동맥관을 부착하고 있는 심장수술 환자에 대한 비침습적 체온측정 방법의 정확도, 정밀도 및 발열감별 타당도)

  • Joo, Ga-Eul;Sohng, Kyeong-Yae
    • Journal of Korean Academy of Nursing
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    • v.42 no.3
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    • pp.424-433
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    • 2012
  • Purpose: To investigate the accuracy, precision and validity of fever detection of tympanic membrane (TM), temporal artery (TA) and axillary temperature (AT) compared with pulmonary artery temperature (PA). Methods: Repeated-measures design was conducted for one year on 83 adult cardiac care unit patients with pulmonary artery catheters after open heart surgery. Sequential temperature measurements were taken three times at 20-minute intervals. Accuracy, precision, repeatability, and validity of fever detection were analyzed. Results: Mean pulmonary artery temperature was $37.04^{\circ}C$ (SD $0.70^{\circ}C$). The mean (SD) offsets from PA, with the mean reflecting accuracy and SD reflecting precision, were $-1.31^{\circ}C$ ($0.75^{\circ}C$) for TA, $-0.20^{\circ}C$ ($0.24^{\circ}C$) for TM, and $-0.97^{\circ}C$ ($0.64^{\circ}C$) for AT. Percentage of pairs with differences within ${\pm}0.5^{\circ}C$ was 9.6% for TA, 19.7% for AT, and 91.6% for TM. Repeated measurements with all three methods had mean SD values within $0.04^{\circ}C$. Sensitivity, specificity, and positive and negative predictive values of tympanic measurements were 0.76, 1.0, and 1.0, and 0.90, respectively. Conclusion: Results show that TM best reflects PA, and is most consistent, accurate, and precise. AT tends to underestimate PA, and TA is least accurate and precise. Therefore tympanic membrane measurement is a reliable alternative to other non-invasive methods of measuring temperatures.

An Improvement of Expendable Bathythermograph Measurement Mechanism for Anti-Submarine Warfare (대잠용 수온측정계 측정 메커니즘 개선)

  • Shin, Sang-Sik;Cho, Hwan Hwi;Park, Seung Soo
    • Journal of Korean Society for Quality Management
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    • v.42 no.3
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    • pp.301-310
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    • 2014
  • Purpose: The purpose of this study is to improve a mechanism of expendable bathythermograph measurement by balancing wire resistances between plus wire part and minus wire part and by removing effects of sea water resistance between XBT(Expendable Bathythermograph) and temperature recorder. Methods: The problems are exactly found out through the analysis of XBT and temperature recorder circuit. A process of XBT manufacturing that balances wire resistances between plus wire part and minus wire part is added. Results: The results of this study are as follows; the complicated test process such as temperature accuracy test with a cistern is substituted with a simple process of XBT manufacturing such as balancing wire resistances between plus wire part and minus wire part. Then, the temperature accuracy tolerance of XBT is improved up to ${\pm}0.1^{\circ}C$. Conclusion: Consequently, balancing wire resistances and removing effects of sea water resistance improve temperature accuracy of XBT and reduce expensive and harassing process of XBT manufacturing.