• 제목/요약/키워드: Temperature Difference Measurement

검색결과 446건 처리시간 0.03초

Leak Evaluation for Power Plant Valve Using Multi-Measuring Method

  • Lee, Sang-Guk;Park, Jong-Hyuck;Kim, Young-Bum
    • 비파괴검사학회지
    • /
    • 제28권6호
    • /
    • pp.469-476
    • /
    • 2008
  • Condition based maintenance(CBM) for the preventive diagnosis of important equipments related to safety or accident in power plant is essential by using the suitable methods based on actual power plant conditions. To improve the reliability and accuracy of the measured value at the minute leak situation, and also to monitor continuously internal leak condition of power plant valve, the development of a diagnosis and monitoring technique using multi-measuring method should be performed urgently. This study was conducted to estimate the feasibility of multi-measuring method using three different methods such as acoustic emission(AE) method, thermal image measurement and temperature difference$({\Delta}T)$ measurement that are applicable to internal leak diagnosis for the power plant valve. From the experimental results, it was suggested that the multi-measuring method could be an effective way to precisely diagnose and evaluate internal leak situation of valve.

광대역 CARS 분광기의 제작과 온도 측정의 정확도 분석 (Construction Broadband CARS Spectrometer and Uncertainty Analysis of Temperature Measurement)

  • 박승남
    • 한국광학회지
    • /
    • 제4권2호
    • /
    • pp.226-232
    • /
    • 1993
  • 펄스마다 전체 CARS 스펙트럼을 측정할 수 있는 광대역 CARS 분광기를 제작하였다. 이 분광기는 펌프광으로 Nd:Yag 레이저의 제2고조파를, 스독스광으로는 모드없는 광대역 스톡스 레이저를 사용하였고, 이중 회전발분광기와 이에 설치된 다채널 광검출기로 구성하여 CARS 신호를 측정한다. 측정의 장확도를 높이고 좋은 곡선맞춤 결과를 얻기 위해 검출기 시스템의 슬릿함수를 측정하였으며 이 함수의 해석적인 함수형태를 결정하였다. 이 분광기의 온도측정 정확도는 CARS 스펙트럼을 곡선맞춤하여 얻은 온도와 열전대로 측정한 온도의 차이로 평가하였다. 이 장치의 온도측정 불확정도는 300K에서 1300K까지의 온도영역에서 1.5%이었다.

  • PDF

천연가스 계량배관 내$\cdot$외의 온도차가 계량오차에 미치는 영향에 관한 연구 (A Study on Effects of Temperature Difference between the Inside and Outside the Meter-Run on Natural Gas Flow Measurement Errors)

  • 하영철;이철구;장승룡;이강진
    • 한국가스학회지
    • /
    • 제2권1호
    • /
    • pp.83-89
    • /
    • 1998
  • 단열이 되어 있지 않은 천연가스 계략배관에서 배관 내$\cdot$외의 온도차로 인한 오리피스 유량계 오차를 정성적으로 실험하였다. 고려된 주요 인자는 유속과 대기온도이며 태양복사열도 일부 고려되었다. 실험결과 유량이 극히 작고, 배관 내$\cdot$외의 온도차가 큰 하절기 유동조건에서도 그다지 큰 오차는 발생하지 않는 것으로 분석되었다.

  • PDF

외부 환경 변화에 의한 비 접촉 체온계의 오차 범위 측정 (Investigation of Standard Error Range of Non-Contact Thermometer by Environment)

  • 김정은;박상웅;최혜경
    • 대한통합의학회지
    • /
    • 제8권4호
    • /
    • pp.307-321
    • /
    • 2020
  • Purpose : A person infected by SARS-CoV2 may present various symptoms such as fever, pain in lower respiratory tract, and pneumonia. Measuring body temperature is a simple method to screen patients. However, changes in the surrounding environment may cause errors in infrared measurement. Hence, a non-contact thermometer controls this error by setting a correction value, but it is difficult to correct it for all environments. Therefore, we investigate device error values according to changes in the surrounding environment (temperature and humidity) and propose guidelines for reliable patient detection. Methods : For this study, the temperature was measured using three types of non-contact thermometers. For accurate temperature measurement, we used a water bath kept at a constant temperature. During temperature measurement, we ensured that the temperature and humidity were maintained using a thermo-hygrometer. The conditions of the surrounding environment were changed by an air conditioner, humidifier, warmer, and dehumidifier. Results : The temperature of the water bath was measured using a non-contact thermometer kept at various distances ranging from 3~10 cm. The value measured by the non-contact thermometer was then verified using a mercury thermometer, and the difference between the measured temperatures was compared. It was observed that at normal surrounding temperature (24 ℃), there was no difference between the values when the non-contact thermometer was kept at 3 cm. However, as the distance of the non-contact thermometer was increased from the water bath, the recorded temperature was significantly different compared with that of mercury thermometer. Moreover, temperature measurements were conducted at different surrounding temperatures and the results obtained significantly varied from when the thermometer was kept at 3 cm. Additionally, it was observed that the effect on temperature decreases with an increase in humidity Conclusion : In conclusion, non-contact thermometers are lower in lower temperature and dry weather in winter.

Effect of Passive Temperature Therapy of the Femoral Muscles on the Countermovement Jump Performance

  • Lee, Jintaek;Panday, Siddhartha Bikram;Byun, Kyungseok;Lee, Jusung;Hwang, Jinny;Moon, Jeheon
    • 한국운동역학회지
    • /
    • 제29권4호
    • /
    • pp.227-235
    • /
    • 2019
  • Objective: The purpose of this study was to evaluate the effect of passive-acute temperature therapy of the femoral muscle and dynamic warm-up on the countermovement jump performance. Method: Twenty male track and field athletes from national team underwent three treatments applied on the femoral muscles; cold temperature treatment, thermal treatment and dynamic warm-up. The variables extracted at 2 time points (pre-measurement and post measurement) were the temperature of the left and right femoral muscle, displacement & velocity of centre of mass, peak power out, range of motion and moment & power of the knee joint. Results: There was a statistically significant difference in the temperature of the femoral muscle according to measurement time which was high in the order of thermal treatment, dynamic treatment and cold treatment. The jump height was the highest in the dynamic warm-up with no statistically significant difference for the range of motion of the knee joint. The peak power out at dynamic warm-up and the power of the knee joint were statistically significant according to the treatment and measurement time. Conclusion: Local cold and thermal treatment of femoral muscles at ambient temperature did not improve jump performance, while dynamic warm-up was considered to be effective for maintaining the performance of the activities that require strong muscular power.

이마 체온의 진단정확도 (Diagnostic Accuracy of Temporal Artery Temperatures Measurements)

  • 박유미;정원제;오현;김윤경;김은영;김미경;신희연
    • 임상간호연구
    • /
    • 제24권2호
    • /
    • pp.227-234
    • /
    • 2018
  • Purpose: This study compared the temporal artery temperature (TAT) measured by infrared temporal artery thermometers to the axillary temperature (AT) measured by standard mercury-in-glass thermometers, and evaluated accuracy of the TAT measurement for clinical practice. Methods: A total of 247 adult inpatients in general wards in a tertiary medical center located in Seoul participated in the study. The TAT was measured within one minute after the AT measurement. Data were analyzed using descriptive statistics, paired t-test, Pearson correlation coefficient, linear regression, and the Bland-Altman plot. Results: There was a significant difference in mean temperature between AT and TAT, $36.89^{\circ}C$ (SD=0.70) versus $37.35^{\circ}C$ (SD=0.72). The Bland-Altman plots demonstrated the difference between the AT and TAT as -1.29 to +0.33. The specificity and sensitivity of the TAT in detecting fever were high. The positive predictive values were 57.5% and 71.0% when the AT were higher than $38.0^{\circ}C$ and the TAT fever cutoff levels were $38.0^{\circ}C$ and $38.3^{\circ}C$ respectively. Conclusion: TAT and AT were highly correlated and agreeable, indicating that TAT is as accurate as AT. The findings suggested that TAT measurement can be used in clinical practice. For accurate communication between medical personnel, medical institutions need to provide guidelines for temperature measurement, especially for the use of thermometer and measurement sites.

산업용 무선온도측정 시스템 개발 (Development of industrial wireless temperature System)

  • 류정탁;차부상;김연보;문병현
    • 한국산업정보학회논문지
    • /
    • 제14권1호
    • /
    • pp.90-94
    • /
    • 2009
  • 본 연구에서는 산업현장에서 직접적으로 활용할 수 있는 시스템에 중심을 둔다. 따라서 본 논문은 산업 실내 환경에 적합한 무선 기반의 원격 측정 시스템 설계에 관한 기초 연구로서 비교적 간단한 실내 온도 측정 시스템을 설계하고 제작하였다. 또한 실내 환경에서의 응용 가능성을 검토하기 위해 측정거리에 따른 특성 분석과 안테나 변경에 따른 성능 차이에 대해 논한다.

지능형 전력제어모듈을 위한 온도 모니터링 시스템 (Temperature Monitoring System of Power MOSFET for IPCM)

  • 최낙권;김기현;김형우;서길수;김남균
    • 대한전기학회논문지:전기물성ㆍ응용부문C
    • /
    • 제55권1호
    • /
    • pp.20-25
    • /
    • 2006
  • We suggest a novel temperature detection method utilized in temperature monitoring system. Suggested method detects temperature variation by using $R_{ds(on)}$ characteristics of MOSFET, while conventional methods are using extra devices such as a temperature sensor or an over-temperature detection transistor. For voltage detection between drain and source, 10 bits resolution ADC is needed. Therefore possible measurement signal range is about ten mV. If detected temperature's voltage exceed protection temperature's voltage then controller generates OT (Over Temperature) signal to stop MOSFET's trigger signal. Whole process of measurement is controlled by software. Experimental results show that the developed temperature monitoring system can provide the suitable temperature monitoring method and difference between detected and data sheet value of the suggested system is about $3\%$.

Measurement of electron density of atmospheric pressure Ar plasma jet by using Michelson interferometer

  • Lim, Jun-Sup;Hong, Young June;Choi, Eun Ha
    • 한국진공학회:학술대회논문집
    • /
    • 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
    • /
    • pp.195.1-195.1
    • /
    • 2016
  • Currently, as Plasma application is expanded to the industrial and medical industrial, low temperature plasma applications became important. Especially in medical and biology, many researchers have studied about generated radical species in atmospheric pressure low temperature plasma directly adapted to human body. Therefore, so measurement their plasma parameter is very important work and is widely studied all around world. One of the plasma parameters is electron density and it is closely relative to radical production through the plasma source. some kinds of method to measuring the electron density are Thomson scattering spectroscopy and Millimeter-wave transmission measurement. But most methods have very expensive cost and complex configuration to composed of experiment system. We selected Michelson interferometer system which is very cheap and simple to setting up, so we tried to measuring electron density by laser interferometer with laser beam chopping module for measurement of temporal phase difference in plasma jet. To measuring electron density at atmospheric pressure Ar plasma jet, we obtained the temporal phase shift signal of interferometer. Phase difference of interferometer can occur because of change by refractive index of electron density in plasma jet. The electron density was able to estimate with this phase difference values by using physical formula about refractive index change of external electromagnetic wave in plasma. Our guiding laser used Helium-Neon laser of the centered wavelength of 632 nm. We installed chopper module which can make a 4kHz pulse laser signal at the laser front side. In this experiment, we obtained more exact synchronized phase difference between with and without plasma jet than reported data at last year. Especially, we found the phase difference between time range of discharge current. Electron density is changed from Townsend discharge's electron bombardment, so we observed the phase difference phenomenon and calculated the temporal electron density by using phase shift. In our result, we suggest that the electron density have approximately range between 1014~ 1015 cm-3 in atmospheric pressure Ar plasma jet.

  • PDF

Sensor Nodes Localization for Temperature Distribution Measurement System

  • Ohyama, Shinji;Alasiry, Ali Husein;Takayama, Junya;Kobayashi, Akira
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 제어로봇시스템학회 2005년도 ICCAS
    • /
    • pp.1781-1786
    • /
    • 2005
  • In sensor network systems, all the nodes are interconnected and the positional information of each sensor is essential. To measure the temperature, position detection and communication functions are required. Many sensor nodes are distributed to a measurement field, and these sensors have three main functions: they measure the distance to the other nodes, the data of which are used to determine the position of each node; they communicate with other nodes; and they measure the temperature of each node. A novel range measurement method using the difference between light and sound propagation speed is proposed. The experimental results show the temperature distribution as measured with the aid of the determined positions. The positions of every node were calculated with a PC program. Eight nodes were manufactured and their fundamental functions were tested. The results of the range measurement method, which takes relatively accurate measurements, contribute significantly to the accuracy of the position determination. Future studies will focus on 3-D position determination and on the architecture of appropriate sensors and actuators.

  • PDF