• Journal of Sensor Science and Technology
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• v.3 no.1
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• pp.61-67
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• 1994

In order to investigate the effects of heat treatment on the thermoelectric motive force (EMF) of type R thermocouples, the changes of EMF in the freezing points of aluminum and silver cells were measured with the immersion depth of themocouples. With the variation of heat treatment methods before use, it was found that the EMF values were different from each other, maximum $17.1{\mu}V$ at $660.323^{\circ}C$ and $18.1{\mu}V$ at $961.78^{\circ}C$. Additionally a thermocouple, which was not heat-treated fully, showed an EMF difference with the immersion depth even though it was located on the region maintained at the constant temperature. The measured differences were about maximum $7.8{\mu}V$ at the Al freezing point and $18.9{\mu}V$ at the Ag freezing point. It was recongnized that a thermocouple for the precise temperature measurement should be heat-treated carefully before service. In this report, the proper heat treatment methods for the type R thermocouple were given on the basis of the obtained experimental results.

• Journal of Sensor Science and Technology
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• v.5 no.2
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• pp.21-27
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• 1996

Thick film $TiO_{2}/WO_{3}$ butane gas sensors were fabricated by the screen printing method and their gas sensing characteristics were investigated. The sensitivity of $TiO_{2}/WO_{3}$ thick film was higher than that of pure $WO_{3}$ film to butane. The $WO_{3}$ film with 2wt.% $TiO_{2}$ showed the highest sensitivity to butane. And the optimum heat treatment temperature was $650^{\circ}C$. That film showed the highest sensitivity to butane at the operating temperature of $350^{\circ}C$. The sensitivity of the film to 20000ppm butane in air was 80% at the operating temperature of $350^{\circ}C$.

• Journal of Sensor Science and Technology
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• v.4 no.4
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• pp.62-69
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• 1995

We have developed the digital radiography system applied by the one dimensional multiwire proportional chamber. X-ray position signals were obtained from anode wires which were connected to counters through amplifiers and discriminators. The chamber was made of gas flow type and detector gas was P10. The threshold voltage which gives to the discriminator is independent on the neighboring channels. This improved the uniformity of the detector. Then the differential nonlineality is ${\pm}4%$. Increasing the gas pressure, the spatial resolution is about 1.4-mm at which the pitch of the anode wire is 2-mm. The object is scanned in vertical direction to take an image. The number of pixels in the image is $32{\times}32$.

• Journal of Sensor Science and Technology
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• v.3 no.2
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• pp.3-10
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• 1994

The use of preformed polymers and their cross-linking has been attempted in order to improve the intrinsic fragility of monolayers and Langmuir-Blodgett(LB) films. The evaluation of the characteristics of the LB multi-layer by using an AT-cut quartz crystal has been also attempted. This study reveals that the polyether pendants of 2C18VE3 lie at the air-water interface at low surface pressures and are forced down into the subphase when the monolayers are compressed. This characteristic behavoir of the pendant polyethers is very clear on aqueous poly allyl amine(PAA) and is also observeable on saturated aqueous NaCl and $CaCl_{2}$. And the characteristics of LB multi-layers could be evaluated by using AT-cut quartz crystal in situ.

• Journal of Sensor Science and Technology
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• v.3 no.2
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• pp.11-15
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• 1994

The TSEE characteristics of LiF(Mg,Cu,Na,Si)phosphor for gamma and beta rays are described. The TSEE glow curve of this phosphor showed 5 peaks in the range from $20^{\circ}C$ to $400^{\circ}C$ and its main peak appeared at $240^{\circ}C$. The sensitivity of the phospor for $^{60}Co$ gamma rays was about 450counts/mR. TSEE energy dependence for various beta radiation was nearly constant (${\pm}10%$) in the mean beta particle energy range from 0.02MeV to 0.8MeV. The efficiency of TSEE of the phosphor for beta radiation was $(2{\sim}15){\times}10^{-3}$.

• Journal of Sensor Science and Technology
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• v.4 no.4
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• pp.70-74
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• 1995

We have observed anisotropic anodisation process for porous silicon formation. The starting material was (100) silicon $n/n^{+}/n$ wafer structured by $n^{+}$-diffusion on n-type substrate and by subsequent n-epitaxial growth. After the top n-silicon epitaxial layer was etched to open the porous silicon layer(PSL) anodisation window, anodisation takes place only to $n^{+}$-buried layer. The process of porous silicon formation on (100) sample was anisotropic, which was evident from that the shapes of the reacted porous silicon layer was all squarelike regardless of the shapes of reaction windows. The experimental results show that the PSL anodisation process does not depend on chemical reaction but does on electrical conduction property, which is hole mobility depending on the crystal direction.

• Journal of Sensor Science and Technology
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• v.3 no.2
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• pp.65-73
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• 1994

TO:F($SnO_{2}:F$) thin films were prepared by RF magnetron sputtering system. The dependence of their structural, electrical, and optical properties on deposition conditions such as substrate temperature, working pressure and power was studied. The optimum conditions of TO:F thin film are $SnF_{2}$ content of 15wt.% in target, RF power of 150W, substrate temperature of $150^{\circ}C$ and working pressure of 2mmTr. The resistivity and transmittance at 550nm in visible spectrum of the TO:F film deposited at optimum condition are $9{\times}10^{-4}{\Omega}{\cdot}cm$ and above 85%, respectively. For the films deposited from the target without $SnF_{2}$ and with 15wt.% $SnF_{2}$, the optical bandgaps calculated from the transmittance curves are 3.84 and 3.9eV, respectively. X-ray diffraction patterns showed that TO and TO:F films had tetragonal rutile structure with (101), (200) direction.

• Journal of Sensor Science and Technology
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• v.25 no.4
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• pp.235-242
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• 2016

A system for measuring the electrodermal activity (EDA) signal occurring at the sweat glands in the left palm and left finger of the human body was implemented in this study. The EDA measurement system (EDAMS) consisted of an algometer, a biopotential measurement system (BPMS), and a PC. Two experiments were performed to evaluate the function and clinical applicability of EDAMS. First, an experiment was carried out on the linearity of the voltage and the pressure that comprised the output signals of the algometer used for applying a pressure stimulus. Second, the amplitude of the EDA signal acquired from the electrode attached to the left palm or finger was measured while increasing the pressure stimulus of the algometer. When the pressure stimulus of the algometer applied to the left scapula was increased, the amplitude of the EDA signal increased. The amplitude of the EDA signal at the left palm was observed to be greater than that at the left finger. The amplitude of the EDA signal was observed to increase in a relatively linear relation with the intensity of the pressure stimuli. In addition, the latency of the EDA signal acquired from the electrode attached to the left palm or finger was measured while increasing the pressure stimulus of the algometer. When the pressure stimulus of the algometer applied to the left scapula was increased, the latency of the EDA signal decreased. The latency of the EDA signal at the palm was observed to be less than that at the finger. The latency of the EDA signal was observed to decrease nonlinearly with the pressure stimuli.

• Journal of Sensor Science and Technology
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• v.21 no.6
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• pp.395-401
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• 2012

The bond strength of three types of $TiO_2$ coatings onto fluorine-doped $SnO_2$ (FTO) glass was investigated with the aid of a tape test according to ASTM D 3359-95. Transmittance was then measured using an UV-vis spectrophotometer in the wavelength range of 300 nm to 800 nm to evaluate the extent of adhesion of $TiO_2$ nanorods/nanoparticles on FTO glass. A sharp interface between the coating layer and the substrate was observed for single $TiO_2$ coating ($TiO_2$ nanorods/FTO glass), which may be detrimental to the bonding strength. In multicoating sample ($TiO_2$ nanorod/$TiO_2$ nanoparticle/$TiO_2$ nanoparticle/FTO glass), the tape test was not performed due to severe peeling-off prior to the test. On the other hand, the dual coating sample ($TiO_2$ nanorod/$TiO_2$ nanoparticle/FTO glass) showed minimum variation of transmittance (4%) after the test, suggesting that the topcoat adheres well with the FTO substrate due to the presence of the $TiO_2$ nanoparticle buffer layer. The use of a $TiO_2$ nanorod electrode layer with good adhesion may be attributed to the excellent dye sensitized solar cell performance.

• Journal of Sensor Science and Technology
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• v.18 no.1
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• pp.77-85
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• 2009

We propose a new image pixel architecture which has OFD(Over Flow Device) node by improving conventional 3TR pixel structure. Newly designed pixel consists of photo diode which is verified with HSPICE simulation, PMOS reset transistor, several NMOS and several PMOS transistors. Photodiode signals from each PMOS and NMOS are detected by Reset PMOS. These output signals give enough chances to detect wide operation coverage because OFD node has overflow photocurrent. According to various light intensity, we analyzed characteristic of the output voltage with a SPICE tool. Proposed pixel output has specific value which can detect possible from $0.1{\mu}W/cm^2$ to $10W/cm^2$ light intensity. It has wide-dynamic range of 160 dB.