• Journal of Sensor Science and Technology
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• v.19 no.1
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• pp.31-35
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• 2010

High temperature micro pressure sensors were fabricated by using polycrystalline 3C-SiC piezoresistors grown on oxidized SOI substrates by APCVD. These have been made by bulk micromachining under $1{\times}1mm^2$ diaphragm and Si membrane thickness of $20{\mu}m$. The pressure sensitivity of implemented pressure sensors was 0.1 mV/$V{\cdot}bar$. The nonlinearity and the hysteresis of sensors were ${\pm}0.44%{\cdot}FS$ and $0.61%{\cdot}FS$. In the temperature range of $25^{\circ}C{\sim}400^{\circ}C$ with 5 bar FS, TCS (temperature coefficient of sensitivity), TCR (temperature coefficient of resistance), and TCGF (temperature coefficient of gauge factor) of the sensor were -1867 ppm/$^{\circ}C$, -792 ppm/$^{\circ}C$, and -1042 ppm/$^{\circ}C$, respectively.

• Journal of Environmental Science International
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• v.5 no.5
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• pp.657-662
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• 1996

Meteorological and flux data measured from semiarid watersheds (Lucky Hills and Kendall) during the summer rainy and winter periods were used to study the sensitivity of the those variables used in the estimation of evapotranspiration rates. Relative sensitivity was examined to compare the importance of four meteorological and flux variables (net radiation wind speed, air temperature, and relative humidity) on Penman potential evapotranspiration (PET) estimation. The study results show that variations in Penman PET rates during the summer rainy period at both watersheds appears to be controlled by air temperature adn net radiation. During the winter period at both watersheds, wariations in Penman PET rates appears to be controlled by relative humidity and air temperature.

• Proceedings of the IEEK Conference
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• 2002.07a
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• pp.74-77
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• 2002

In this paper we present a novel temperature compensated Hall effect power IC for accurate operation of wide temperature and high current drive of the motor coil. In order to compensate the temperature dependence of Hall sensitivity with negative temperature coefficient(TC), the differential amplifier has the gain consisted of epi-layer resistor with positive TC. The material of Hall device and epi-resistor is epi-layer with the same mobility. The variation of Hall sensitivity is -38% at 150$^{\circ}C$ and 88% at - 40$^{\circ}C$. But the operating point(B$\sub$op/) and release point(B$\sub$RP/) of the Hall power IC are within ${\pm}$25%. The experimental results show very stable and accurate performance over wide temperature range of -40$^{\circ}C$ to 125$^{\circ}C$.

• Journal of Sensor Science and Technology
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• v.13 no.3
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• pp.175-181
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• 2004

A pressure sensor for high temperature was fabricated by using a SDB(Silicon-Direct-Bonding) wafer with a Si/$SiO_{2}$/ Si structure. High pressure sensitivity was shown from the sensor using a single crystal silicon of the first layer as a piezoresistive layer. It also was made feasible to use under the high temperature as of over $120^{\circ}C$, which is generally known as the critical temperature for the general silicon sensor, by isolating the piezoresistive layer dielectrically and thermally from the silicon substrate with a silicon dioxide layer of the second layer. The pressure sensor fabricated in this research showed very high sensitivity as of $183.6{\mu}V/V{\cdot}kPa$, and its characteristics also showed an excellent linearity with low hysteresis. This sensor was usable up to the high temperature range of $300^{\circ}C$.

• 제어로봇시스템학회:학술대회논문집
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• 1994.10a
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• pp.611-615
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• 1994

In this paper, the sensitivity, linearity and temperature drift characteristics of various capacitive force sensors are evaluated and compared using new experimental methods. In particular, two designs were employed to reduce temperature drift. Both types of sensor use high-sensitivity Al coated PET film, and their externals are miniaturized. The first has a layered design consisting of two dielectric substances with different temperature characteristics. The prototype of this design had a temperature drift of only 0.1% of the sensor's capacity in the 20-80.deg. C range. The second type uses both a dummy sensor ind an active sensor with the same characteristics. The temperature drift of the prototype was one-fifth the temperature drift of a single sensor.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.4
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• pp.1-12
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• 2008

The aim of this study is to investigate the sensitivity evaluation of human beings in reacting to the correlated color temperature of the optical properties of white LED lighting. For the sake of this study, white light-emitting diode modules have been fabricated their correlated color temperature have been measured, test cabinets for the sensitivity evaluation have been constructed with the white LED modules, and their sensitivity reactions on the test cabinets have been evaluated and analyzed. The sensitivity reaction has been evaluated by the semantic differential method with 15 selected questions, and the reliability and the content validity of their lighting have been analyzed to 3 factors which foe the activity as the first factor, the stability as the second one, the potency as the third one, respectively. For the data analysis on the sensitivity reaction, the dependent variable is the score of the sensitivity evaluation and the independent one is the correlated color temperature of the test module. The results of this study is as follows: In the case of the sensitive evaluation on the activity and the potency in the white LED lighting compared with the fluorescent lamp, the subjects have made higher mark on $MA_3$ with 8,300[K], and in the factor of the stability, they have made higher mark on $MA_1$ with 3,800[K].

• Smart Structures and Systems
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• v.19 no.3
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• pp.269-277
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• 2017

Recently, there has been significant interest in structural health monitoring for civil engineering applications. In this research, a specially designed tendon, proposed by embedding FBG sensors into the center king cable of a 7-wire strand tendon, was applied for long-term health monitoring of tensile forces on a ground anchor. To make temperature independent sensors, the effective temperature compensation of FBG sensors must be considered. The temperature sensitivity coefficient ${\beta}^{\prime}$ of the FBG sensors embedded tendon was successfully determined to be $2.0{\times}10^{-5}^{\circ}C^{-1}$ through calibrated tests in both a model rock body and a laboratory heat chamber. Furthermore, the obtained result for ${\beta}^{\prime}$ was formally verified through the ground temperature measurement test, expectedly. As a result, the ground temperature measured by a thermometer showed good agreement compared to that measured by the proposed FBG sensor, which was calibrated considering to the temperature sensitivity coefficient ${\beta}^{\prime}$. Finally, four prototype ground anchors including two tension ground anchors and two compression ground anchors made by replacing a tendon with the proposed smart tendon were installed into an actual slope at the Yeosu site. Tensile forces, after temperature compensation was taken into account using the verified temperature sensitivity coefficient ${\beta}^{\prime}$ and ground temperature obtained from the Korean Meteorological Administration (KMA) have been monitored for over one year, and the results were very consistent to those measured from the load cell, interestingly.

• Journal of the Korean GEO-environmental Society
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• v.4 no.3
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• pp.69-77
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• 2003

This study was carried out to evaluate the WASP5 model parameters and to analyze the sensitivity of parameters in Daechung Reservoir. The values predicted by the model and tendency were very similar to the observed data at Daejeon intake, so it is possible to predict water quality of the Daejeon intake region in the future. Results from the sensitivity analysis showed that Chlorophyll-a was sensitive to variations in saturated growth rate of phytoplankton, endogenous respiration rate of phytoplankton, extinction coefficient and temperature. T-N was sensitive to mineralization rate of dissolved organic nitrogen and temperature. T-P was affected by T-P load, temperature, extinction coefficient, mineralization rate of dissolved organic phosphorus and saturated growth rate of phytoplankton. BOD was influenced by deoxygenation rate and temperature, and DO was influenced by temperature. Adequate input data was applied and assessed through the model sensitivity analysis. So it is possible to distinguish the input data which need careful attention when it has application to model.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.274-274
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• 2008

This paper describes on the fabrication and characteristics of a 3C-SiC (Silicon Carbide) micro pressure sensor for harsh environment applications. The implemented micro pressure sensor used 3C-SiC thin-films heteroepitaxially grown on SOI (Si-on-insulator) structures. This sensor takes advantages of the good mechanical properties of Si as diaphragms fabricated by D-RIE technology and temperature properties of 3C-SiC piezoresistors. The fabricated pressure sensors were tasted at temperature up to $250^{\circ}C$ and indicated a sensitivity of 0.46 mV/V*bar at room temperature and 0.28 mV/V*bar at $250^{\circ}C$. The fabricated 3C-SiC/SOI pressure sensor presents a high-sensitivity and excellent temperature stability.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.11a
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• pp.456-459
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• 2002

This paper describes fabrication and characteristics of ceramic pressure sensor for working at high temperature. The proposed pressure sensor consists of a Ta-N thin-film, patterned on a Wheatstone bridge configuration, sputter deposited onto thermally oxidized Si membranes with an aluminium interconnection layer. The fabricated pressure sensor presents a low temperature coefficient of resistance, high sensitivity, low non-linearity and excellent temperature stability. The sensitivity is 1.097~1.21mV/$V{\cdot}kgf/cm^2$ in the temperature range of $25{\sim}200^{\circ}C$ and the maximum non-linearity is 0.43 %FS.