• Journal of the Korea Institute of Information and Communication Engineering
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• v.5 no.1
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• pp.144-149
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• 2001

There are many types of seam tracking methods actually used in industrial spot. Lately, Non-contact sensor technics are mostly used because non-contact sensor has more advantage than contact sensor in many parts. This paper also concerned about fiber sensor a kind of non-contact sensor. X-Y robot and fiber sensor scan the seam tracking to be weld. After scanning, X-Y robot moves the first working point of being scanned and welding starts automatically. It makes an experiment on some types of Seam tracking like straight line tracking, leaned line tracking and curved line tracking to confirm how well the fibers sensor tracks the seam pass to be weld. And the seam pass that had been tracked was welded by inverter $CO_2$ voiding machine.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2000.10a
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• pp.558-561
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• 2000

There are many types of seam tracking methods actually used in industrial spot. Lately, Non-contact sensor technics are mostly used because non-contact sensor has more advantage than contact sensor in many parts. This paper also concerned about fiber sensor a kind of non-contact sensor. X-Y robot and fiber sensor scan the seam tracking to be weld. After scanning, X-Y robot moves the first working point of being scanned and welding starts automatically. It makes an experiment on some types of Seam tracking like straight line tracking, leaned line tracking and curved line tracking to confirm how well the fibers sensor tracks the seam pass to be weld. And the seam pass that had been tracked was welded by inverter CO2 welding machine.

• Journal of Sensor Science and Technology
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• v.15 no.3
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• pp.168-172
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• 2006

Potentiometric $CO_{2}$ sensors were fabricated using a NASICON ($Na_{1+x}Zr_{2}Si_{X}P_{3-X}O_{12}$, 1.8 < x < 2.4) thick film and auxiliary layers. The powder of a precursor of NASICON with high purity was synthesized by a sol-gel method. By using the NASICON paste, an electrolyte was prepared on the alumina substrate by screen printing and then sintered at $1000^{\circ}C$ for 4 h. A series of $Na_{2}CO_{3}-CaCO_{3}$ auxiliary phases were deposited on the Pt sensing electrode. The electromotive force (emf) values were linearly dependent on the logarithm of $CO_{2}$ concentration in the range between 1,000 and 10,000 ppm. The device attached with $Na_{2}CO_{3}-CaCO_{3}$ (1:2 in mol.%) showed good sensing properties in the low temperatures.

• Journal of Sensor Science and Technology
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• v.32 no.4
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• pp.207-212
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• 2023

H₂S is a toxic and harmful gas, even at concentrations as low as hundreds of parts per million; thus, developing an H₂S sensor with excellent performance in terms of high response, good selectivity, and fast response time is important. In this study, an H₂S sensor with a high response and fast response time, consisting of a sensing material (SnO₂), an electrode, a temperature sensor, and a micro-heater, was developed using micro-electro-mechanical system technology. The developed H₂S sensor with a micro-heater (circular type) has excellent H₂S detection performance at low H₂S concentrations (0-10 ppm), with quick response time (<16 s) and recovery time (<65 s). Therefore, we expect that the developed H₂S sensor will be considered a promising candidate for protecting workers and the general population and for responding to tightened regulations.

• Journal of Sensor Science and Technology
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• v.18 no.1
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• pp.72-76
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• 2009

The sensing system was designed and fabricated to investigate the ferment environment of soybeans. $NH_3$ gas was saturated after about 7 h and $CO_2$ gas was reached the peak after about 8 h in the inoculation of Bacillus subtilis. However, times that $CO_2$ gas and $NH_3$ gas were reached maximum value without Bacillus subtilis were about 15 h and 18 h, respectively. The sample that inoculated Bacillus subtils had deeper taste than one without it. We found that the peak time of $CO_2$ gas means the starting time of fermentation. If we control the operating time after the start of fermentation, it is expected to make a suitable Chungkukjang to individual preference.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07b
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• pp.805-808
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• 2002

A carbon monoxide gas sensor utilizing Pt-SiC, Pt-SnO2-SiC diode structure was fabricated. Since the operating temperature for silicon devices in limited to 200oC, sensor which employ the silicon substrate can not at high temperature. In this study, CO gas sensor operating at high temperature which utilize SiC semiconductor as a substrate was developed. Since the SiC is the semiconductor with wide band gap. the sensor at above $700^{\circ}C$. Carbon monoxide-sensing behavior of Pt-SiC, Pt-SnO2-SiC diode is systematically compared and analyzed as a function of carbon monoxide concentration and temperature by I-V and ${\Delta}$I-t method under steady-state and transient conditions.

• Electrical & Electronic Materials
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• v.9 no.5
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• pp.455-462
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• 1996

Automobile Fuel Shortage Detecting Sensor, in this paper, was fabricated by using heat dissipation coefficient difference between gasoline and air condition the NTC thermistor of Mn-Ni Co system with the composition ratio of Mn$_{3}$O$_{4}$ : 9wt%, NiO : 28wt%, and CO$_{3}$O$_{4}$ : 61wt%. The condition of sensor operation is that, for turn-on characteristics, the time of arriving at 135mA must be less than 180 second when the DC voltage of 11V is applied in the air condition of -10.deg. C and that, for turn-off characteristics, the saturation current must be less than 60mA when the DC voltage of 15V is applied in the gasoline condition of 60.deg. C. It is known, from the experimental results, that the resistance range and B-constant for the Automobile Fuel Shortage Detecting Sensor with dimension of 5*3*0.9mm were 850-1150.ohm. and 1150-1250.deg. C, respectively and the resistance range and B-constant were agree with that of sensor operation condition. When Bi$_{2}$O$_{3}$ of 0-0.5wt% was added to Mn$_{3}$O$_{4}$ : 9wt%, NiO : 28wt%, and CO$_{3}$O$_{4}$ : 61wt% composition, the resistivity and B-value were 380-430(.ohm.-cm) and 1930 - 2030, respectively. Particularly, for Bi$_{3}$O$_{3}$ of 0.25-0.5wt%, the sintering density of over 90% and the operation characteristics necessary to Automobile Fuel Shortage Detecting Sensor were obtained. The difference of heat dissipation coefficient gasoline and air condition was 15 times.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.05a
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• pp.549-550
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• 2010

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.9
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• pp.1641-1647
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• 2006

A dual micro gas sensor way for detecting reducing gas and bad order was fabricated using nano sized $SnO_2$ thin film fabrication method. To make nano-sized thin gas sensitive $SnO_2$ thin rilm, thin tin metal layer $2500{\AA}$ thick was oxidized between 600 and $800^{\circ}C$ by thermal oxidation. The gas sensing layers such as $SnO_2,\;SnO_2(+Pt)\;and\;SnO_2(+CuO)$ were patterned by metal shadow mask for simple fabrication process on the silicon substrate. The micro gas sensors with $SnO_2(Pt)$ and $SnO_2(+CuO)$ showed good selectivity to CO gas among reducing gases and good sensitivity to $H_2S$ that is main component of bad odor, separately.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.3
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• pp.624-629
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• 2018

The current study was conducted to develop a portable composite gas detector allowing the detection of both $CO_2$ and $CH_4$ gases by means of the Non Dispersive Infra-Red (NDIR) method. The gas detector is configured to radiate infrared waves using infrared lamps, where the wavelength of the infrared light is reduced due to absorption throughout the chamber, and this reduction (absorption) is detected by the absorption detector, before being converted and amplified to a 3.5V~6V electrical signal, providing as accurate a measurement as possible. The conventional singe sensor method measures the relative measurement by absorbing only specified wavelengths of infrared radiation, which in the case of gas detection leads to problems with accuracy due to the lack of a reference sensor when detecting light with a wavelength of only $4.26{\mu}m$. The dual sensor employed in this study provides a comparative measurement between the reference value derived from the wavelength of $3.91{\mu}m$, which is not influenced by other gas sources, and the measurement value derived from the wavelength of $4.26{\mu}m$, in order to reduce the errors and enhance the reliability, thereby allowing low power consumption for portable devices and multi-gas detection for both $CO_2$ and $CH_4$ gases. The portable composite gas detector developed herein provides a measurement rage of 0ppm~5,000ppm for $CO_2$ gas, and 0.5%vol for $CH_4$, which allows the determination of whether the $CO_2$ and $CH_4$ contents in indoor air are less than 1,000ppm or not. The current study established that the composite gas detector can be interlinked with firefighting appliances through portable devices or home automation, and is anticipated to be very effective in fire prevention.