• Journal of IKEEE
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• v.8 no.1 s.14
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• pp.117-120
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• 2004

We demonstrate a fiber-optic sensor scheme, capable of the simultaneous measurement of strain and temperature using a single fiber Bragg grating written in an erbium: ytterbium-doped fiber. This novel and compact fiber grating based sensor scheme can be used for synchronous measurement of strain and temperature over ranges of $1100\;{\mu}{\varepsilon}$ and $50-180\;^{\circ}C$ with rms errors of $55.8\;{\mu}{\varepsilon}$ and $3^{\circ}C$, respectively. The simple and low-cost sensor approach has a considerable potential, particularly for wide-range strain sensing applications in which high resolution is not required.

• Journal of the Korean Society for Nondestructive Testing
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• v.25 no.5
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• pp.356-361
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• 2005

A temperature-compensating double fiber Bragg grating(FBG) sensor having two different FBGs in one fiber line was proposed for real time measurement of mechanical normal strain in structures. Measurement of mechanical strains of the aluminum beam surface by the double FBG sensor was performed under various thermal conditions, and the results were compared with those of electrical resistance strain gage. The FBG sensor fabricated in this study was able to measure accurately the mechanical strains without containing any thermal strain component.

• Journal of Biosystems Engineering
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• v.36 no.2
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• pp.122-129
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• 2011

This study was performed to develop a wireless system for measuring agricultural atmospheric factors using ubiquitous sensor network(USN). In the study, temperature, humidity and light intensity were selected and evaluated as major agricultural atmospheric factors. An USN system was designed and implemented by using Zigbex I and II (mote sensor nodes of MICA series) provided by Hanback Electronics, Korea. The system was tested in a greenhouse and an orchard. The experiment results showed that the suggested USN measuring system would be very effective on comprehensive measurement of the selected factors on the basis of time, day, spatial sequence with reasonable costs.

• Journal of Sensor Science and Technology
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• v.26 no.2
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• pp.141-147
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• 2017

A pressure sensor in pulse measurement system is a core component for precisely measuring the pulse waveform of radial artery. A pulse sensor signal that measures the pulse wave in contact with the skin is affected by the temperature difference between the ambient temperature and skin surface. In this study, we found experimentally that the signal changes of the pressure sensors and a temperature sensor were caused by the temperature of the wrist surface while the pressure sensor was contacted on the skin surface for measuring pulse wave. To observe the signal change of the pulse sensor caused by temperature increase on sensor surface, Peltier device that can be kept at a set temperature was used. As the temperature of Peltier device was kept at $35^{\circ}C$ (the maximum wrist temperature), the device was put on the pulse sensor surface. The temperature and pressure signals were obtained simultaneously from a temperature sensor and six pressure sensors embedded in the pulse sensor. As a result of signal analysis, the sensor pressure was decreased during temperature increase of pulse sensor surface. In addition, the signal difference ratio of pressure and temperature sensors with respect to thickness of cover layer in pulse sensor was increased exponentially. Therefore, the signal of pressure sensor was modified by the compensation equation derived by the temperature sensor signal. We suggested that the thickness of cover layer in pulse sensor should be designed considering the skin surface temperature.

• Proceedings of the KIEE Conference
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• 2003.11c
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• pp.916-919
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• 2003

In this paper, we deal with a development of measurement system to apply the leakage rates test of primary containment in nuclear power plant. The measurement test about leakage rates in primary containment is one sort of test to prove safety of nuclear power plant. The parameters which are measured to calculate leakage rates are drybulb temperature, dew point temperature(or relative humidity), absolute pressure and flow. Overall, the measurement system consists of sensor module for data acquisition of the parameters, transfer module for wireless data communication and control module to control system and to calculate leakage rates. Because existing measurement systems are difficult to set in field, we pursued convenience of use, we applied wireless data communication and individual form module using battery. We also changed for the better in confidence. Recently, we are developing a drybulb temperature and a dew point temperature sensor module. We describe about function of developed measurement system, its standard and an plan for verification of measurement system.

• Journal of Mechanical Science and Technology
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• v.17 no.1
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• pp.139-145
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• 2003

Diode laser sensor is conducted to measure the gas temperature in the liquid-gas 2-phase counter flow flame. C$\_$10/H/ sub 22/ and city gas were used as liquid fuel and gas fuel, respectively. Two vibrational overtones of H$_2$O were selected and measurements were carried out in the spray flame region stabilized the above gaseous premixed flame. The path-averaged temperature measurement using diode laser absorption method succeeded in the liquid fuel combustion environment regardless of droplets of wide range diameter. The path-averaged temperature measured in the post flame of liquid-gas 2-phase counter flow flame showed qualitative reliable results. The successful demonstration of time series temperature measurement in the liquid-gas 2-phase counter flow flame gave us motivation of trying to establish the effective control system in practical combustion system. These results demonstrated the ability of real-time feedback from combustor inside using the non-intrusive measurement as well as the possibility of application to practical combustion system. Failure case due to influence of spray flame was also discussed.

• Proceedings of the KSME Conference
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• 2003.11a
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• pp.1198-1205
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• 2003

Most domestic fossil power plant have exceeded 100,000 hours of operation with the severe operating condition. Among the critical components of fossil power plant, high temperature steam pipe system have had a many problems and damage from unstable displacement behavior because of frequent start up and shut down. In order to prevent the serious damage and failure of the critical pipe system in fossil power plant, 3-dimensional displacement measurement system were developed for the on-line monitoring system. 3-D Measurement system was developed with using the LVDT type sensor and rotary encoder type sensor, this system was installed and operated on the real power plant successfully. In the future time, network system of on-line diagnosis for critical pipe will be designed.

• Journal of Sensor Science and Technology
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• v.19 no.1
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• pp.36-42
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• 2010

This paper describes a multi channel measurement system which can measure the cellular respiration level in a solution containing cells by using a Clark-type sensor with the solution temperature control unit. The Clark-type sensor can measure the cellular respiration level in the solution because it can measure the reduction current depending on the dissolved oxygen level in the solution. This measurement system was maintained the temperature within ${\pm}0.1^{\circ}C$ of the setting temperature value by on/off control method in order to measure the precise cellular respiration level. The measurement system showed that the applied voltage to the working electrode was very stable(-0.8 V$\pm$ 0.0071 V) by using proportional control method. From the current measurement, the response time and the linearity correlation coefficient were 25 sec and 0.94, respectively, which are very close to the results of the commercial product. Using this system and the fabricated Clarktype sensor, the average ratio of the uncoupled OCR(oxygen consumption rate) to the coupled OCR was 1.35 and this is almost the same as that obtained from a commercial systems.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1996.06c
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• pp.1126-1135
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• 1996

This study was conducted to select the sensors for measuring temperature, relative humidity, and air velocity among the major environmental factors affecting the pig productivity as a part of the study for the optimum production system model development of pig-housing. The study results are summarized as the follows : Two sensors , HMP233L and HANI, were tested for measuring temperature and relative humidity , Test results were analyzed by the statistical methods. And the sensor, HMP233L was selected as a proper sensor for temperature sand relative humidity measurement . An air velocity sensor was tested. Test results showed that its accuracy was low and incongruent for the air velocity measurement when it was lower than 4m/s.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1993.10a
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• pp.393-402
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• 1993

Two field test installations are discussed. In the first one a new ammonia sensor and an accurate ventilation rate sensor are combined. They are installed in the exhaust chimney in a ventilated pig house. The relative humidity and the room temperature are measured as well. In the second one, an in situ NH$_3$longrightarrowNO converter with subsequent NOx analyser is also being added for accurate ammonia measurement . In this way , the continuous measurement of the total NH$_3$emission can be obtained , the performance of the NH$_3$ sensor can be evaluated, and the ammonia reduction techniques can be tested. The outputs of measurement are fed into a data acquisition system then to a PC in the laboratory. There has been realised the first test installation with which research on the new ammonia sensor is carried out. The primary research results are presented.