• 센서학회지
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• 제22권6호
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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.

• 센서학회지
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• 제21권2호
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• pp.109-113
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• 2012

We propose an improved interpolating equation to express temperature-resistance characteristics for modern industrial platinum resistance thermometers (PRTs). Callendar-van Dusen equation which has been widely used for platinum resistance thermometer fails to fully describe temperature characteristics of high quality PRTs and leaves systematic residual when the calibration point include temperatures above $300^{\circ}C$. Expanding Callendar-van Dusen to higher-order polynomial drastically improves the uncertainty of the fitting even with reduced degrees of freedom of the fitting. We found that in the fourth-order polynomial fitting, the third-order and fourth-order coefficients have a strong correlation. Using the correlation, we suggest an improved interpolating equation in the form of fourth-order polynomial, but with three fitting parameters. Applying this interpolating equation reduced the uncertainty of the fitting to 32 % of that resulted from the traditional Callendar-van Dusen. This improvement was better than that from a simple third-order polynomial despite that the degrees of the freedom of the fitting was the same.

• 센서학회지
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• 제22권6호
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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).

• Journal of Biosystems Engineering
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• 제40권4호
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• pp.368-372
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• 2015

Purpose: The purpose of this study is to verify the feasibility of using an infrared sensor to measure the body temperature of a sow. We first conducted experiments on three pigs by using three infrared sensors and one indoor temperature sensor. Methods: The three infrared sensors were installed inside our model house and were used to take temperature measurements per second of the backs of the pigs. While feeding, the temperatures of the backs of the pigs were measured at distances of 10 cm, 20 cm, and 30 cm from the infrared sensors. Results: We concluded that the relation between the temperature of the pigs' backs and the indoor temperature was y =0.549x + 18.459 at a measuring distance of 30 cm. The relation was y = 0.645x + 15.461 for a distance of 20 cm and y = 0.760x + 11.913 for a distance of 10 cm. We found high correlation between the indoor temperature and the temperature of the pigs' backs. Conclusions: It is possible to use an infrared thermometer to monitor the temperature of pigs' backs. This system seems to be feasible and effective in monitoring pig temperature. The use of an infrared thermometer will also make daily monitoring easy. In later experiments, the possibility of developing a system that can determine if an error can be corrected by using infrared sensor is explored by considering humidity variables.

• 한국분무공학회지
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• 제21권4호
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• pp.184-194
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• 2016

Many industrial processes require reliable temperature measurements in harsh environments with high temperature, dust, humidity, and pressure. However, commercially-available conventional temperature measurement devices are not suitable for use in such conditions. This study thus proposes a reliable, durable two-color radiation thermometer (RT) for harsh environments that was developed by selecting the appropriate components, designing a suitable mechanical structure, and compensating environmental factors such as absorption by particles and gases. The two-color RT has a simple, compactly-designed probe with a well-structured data acquisition system combined with efficient LabVIEW-based code. As a result, the RT can measure the temperature in real time, ranging from 300 to $900^{\circ}C$ in extremely harsh environments, such as that above the burden zone of a blast furnace. The error in the temperature measurements taken with the proposed two-color RT compared to that obtained using K-type thermocouple readouts was within 6.1 to $1.4^{\circ}C$ at a temperature range from 200 to $700^{\circ}C$. The effects of absorption by gases including $CO_2$, CO and $H_2O$ and the scattering by fine particles were calculated to find the transmittance of the two wavelength bands of operation through the path between the measured burden surface and the two-color probe. This method is applied to determine the transmittance of the short and long wavelength bands to be 0.31 and 0.51, respectively. Accordingly, the signals that were measured were corrected, and the true burden surface temperature was calculated. The proposed two-color RT and the correction method can be applied to measure temperatures in harsh environments where light-absorbing gases and scattering particles exist and optical components can be contaminated.

• 센서학회지
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• 제18권4호
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• pp.322-326
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• 2009

To estimate the measurement uncertainty for industrial platinum resistance thermometers(IPRTs) made with 3-wire connection, the immersion temperature profile was investigated using a liquid bath. Two types of IPRTs having lead wires made of silver and nickel were constructed and the immersion profiles were measured at temperatures from -50 $^{\circ}C$ to 250 $^{\circ}C$ using 3-wire and 4-wire method. As immersion depth and temperature increased, the resistances measured by 3-wire method increased linearly but not for 4-wire method. To calibrate a 3-wire IPRT, the immersion effect must be accounted for. We propose a linear equation to assess correctly the measurement uncertainty.

• 월간산업보건
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• 통권11호
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• pp.7-12
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• 1989

A case of Occupational Mercury Poisoning Chung Yill Park, Chee Kyung Chung, Kwang Mook Lee and Seung Han Lee Catholic Industrial Medical Center,Catholic University Medical College, Seoul, Korea. The diagnosis of occupational mercury poisoning will depend on the exposure history, clininal symptoms and sings, laboratory findings and other informations such as laboratory results of other workers who have been worked under the same working condition. We diagnosed a 15 year-old male patient, who had been worked for 12 days at mercuny thermometer workshop, as occupational mercury poisoning by putting the above mentioned diagnostic bases together and reported here with brief rewiew of literature.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2009년 추계학술발표대회
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• pp.226-234
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• 2009

The purpose of this study was to investigate the melting phenomenon of filler wire in detail and to obtain the precise temperature distribution of filler wire during GTA welding under the ultra-high welding speed condition in order to develop the ultra-high-speed GTA welding process with the pulse-heated hot-wire system by using three kinds of materials. The melting phenomenon of filler wire was observed using a high-speed camera and the temperature distribution of filler wire was measured using a radiation thermometer. From the above result, the adequate welding conditions of each material to make the GTA welding process with the ultra-high welding speed could be obtained. The ultra-high-speed GTA welding process needed the adequate wire current in order to obtain the adequate temperature distribution and the adequate melting position of filler wire. Moreover, the temperature distributions of three kinds of filler wire could be estimated by using the proposed simple estimation method.

• 한국정밀공학회지
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• 제26권11호
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• pp.41-46
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• 2009

We present experimental data on the time response behavior of industrial platinum resistance thermometers (IPRT) to help with the selection of proper sensors in industry and research laboratories. Time constants of IPRTs were measured using a method specified in ASTM standards. Two different sensors of different protecting sheath diameters were tested in air, water and silicon oil at temperatures from $0^{\circ}C$ to $200^{\circ}C$. The time constant was the smallest in water and the highest in air. As the test temperature increased, time constants tended to decrease at all heat conducting media. For different diameters of sheath of IPRT at the same temperature, it was found that the IPRT of larger diameter showed higher time constant in air, but the opposite dependence was observed in water and oil. From the measured results, it was suggested that the sensor diameter and heat conducting medium should be considered if one wants to select proper thermometer to measure the dynamic temperature change in industry and research area.

• 한국축산시설환경학회지
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• 제20권3호
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• pp.91-96
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• 2014

The temperature of a pig is the most key point in determining, it's health status. We wanted to monitor the body temperature of pig to find out if any changes would occur, we used 3 minipigs (about 20 kg) who were feed using a feeding system while being confined in a pig house. The infrared testings were taken from a height of 30 cm above the pigs backs over a period of 28 days. We were able to conclude that the results between the back and indoor temperature were y = 0.5487x + 18.459. These values were compared with the values found after infrared sensor results were taken. We found an error range of $0.004{\sim}1.82^{\circ}C$ and an average of $0.58^{\circ}C$. In conclusion, using an infrared thermometer made monitoring of pigs back possible. This system seems to be feasible and effective in monitoring pig temperature.