• Title/Summary/Keyword: $NO_2$ gas sensor

Search Result 180, Processing Time 0.025 seconds

Fabrication and Characteristics of Micro Platform for Micro Gas Sensor with Low Power Consumption (마이크로 가스센서의 저전력 구동을 위한 마이크로 플랫폼의 제작과 특성)

  • Jang, Woong-Jin;Park, Kwang-Bum;Kim, In-Ho;Park, Soon-Sup;Park, Hyo-Derk;Lee, In-Kyu;Park, Joon-Shik
    • Journal of Sensor Science and Technology
    • /
    • v.20 no.5
    • /
    • pp.317-321
    • /
    • 2011
  • A Micro platform for micro gas sensor consisted of micro heater, insulator, and sensing electrode on 2 ${\mu}m$ thick $SiN_x$ membrane. Three types of micro platforms were designed and fabricated with membrane sizes. Total size of micro platform was 2.6 mm by 2.6 mm. Measured power consumptions were 28 mW, 28 mW, and 32.5 mW for Type 1, Type 2, and Type 3. At this moment, temperatures of membranes on the platforms were $295^{\circ}C$, $297^{\circ}C$, and $296^{\circ}C$, respectively. Fabricated micro platform considered appropriate to apply for low power consumption micro gas sensor. Micro gas sensors were prepared by the sequence that $SnO_2$ nanopowder pastes were dropped on membrane of Type 1 platforms, dried in oven, heat-treated with micro heaters in platforms. One of the micro gas sensors was tested for gas response to 1157 ppm, 578 ppm, and 231 ppm of methane and 1.68 ppm, 0.84 ppm, and 0.42 ppm of $NO_2$.

Sensing Characteristics of $SnO_{2}$ type CO sensors for combustion exhaust gases monitoring (연소배가스 모니터링을 위한 $SnO_{2}$계 CO센서의 검지특성)

  • Kim, I.J.;Han, S.D.;Lim, H.J.;Son, Y.M.
    • Journal of Sensor Science and Technology
    • /
    • v.6 no.5
    • /
    • pp.369-375
    • /
    • 1997
  • $V_{2}O_{5}/ThO_{2}/Pd$-doped $SnO_{2}$ sensor has a good selectivity and stability to CO at high sensor temperature of about $500^{\circ}C$, and shows rapid response. In particular, many kinds of interference gases, such as $NO_{x}$, $C_{3}H_{8}$, $CH_{4}$ and $SO_{2}$ have been found to give only a slight influence on the sensor selectivity to CO gas sensitivity by doped $V_{2}O_{5}$ (3.0 wt.%). For the sensor we used well-known thick film technological route with $V_{2}O_{5}$(3.0 wt.%), Pd(1.0 wt.%) and $ThO_{2}$(l.5 wt.%) as catalytic materials. In the case of mixed $NO_{x}$-CO gases, as combustion exhaust gas, only CO detection by $SnO_{2}$ type semiconductor sensor is generally very difficult because of $NO_{x}$ interference. The developed sensors can use to measure the exhausting gas of the automobile or the boiler for the Air-to-Fuel ratio control.

  • PDF

Highly Sensitive and Fast-Responding Ethanol Sensor using Au Doped-In2O3 Hollow Spheres

  • Seong-Young Jeong
    • Journal of Sensor Science and Technology
    • /
    • v.33 no.5
    • /
    • pp.242-247
    • /
    • 2024
  • Pure and 0.3 wt% Au-doped In2O3 hollow spheres were synthesized via ultrasonic spray pyrolysis of droplets containing an In-source and sucrose in air and their gas sensing characteristics to 1 ppm ethanol, 1 ppm toluene, 1 ppm xylene, 2 ppm nitrogen dioxide (NO2), and 30 ppm carbon monoxide (CO) were measured at 400 - 450℃. The pure In2O3 hollow spheres exhibited relatively low gas responses and sluggish recovery kinetics. In contrast, the doping of Au into In2O3 hollow spheres significantly increased the gas response (S= resistance ratio) to 1 ppm ethanol (S= 20.6) at 400℃ with low cross-responses (S = 1.3-8.8) to other interference gases. Furthermore, the hollow spherical morphology of In2O3 provides a large surface area and facilitates rapid gas diffusion, resulting in fast response and recovery times. The sensor exhibited excellent performance with a low detection limit of 1.6 ppb. These findings indicate that the Au-In2O3 hollow spheres are promising candidates for advanced ethanol-sensing applications, particularly in breath-alcohol monitoring for ignition interlock devices.

Diode-Laser Absorption Sensors for measurement of combustion Gas (연소배기 가스의 계측을 위한 다이오드 레이저 센서)

  • Shin, Myung-Chul;Kim, Se-Won;Kim, Dong-Hyuck
    • Journal of the Korean Society of Combustion
    • /
    • v.11 no.3
    • /
    • pp.26-35
    • /
    • 2006
  • This work forcus on the development of gas sensor that measure the concentrations of exhaust gas using diode laser, Each diode laser for exhaust gas measurement is set to work at near-IR using both DA and WMS methods. Also use of fiber-coupled optical elements makes such a sensor rugged and easy to align. The results showed that gas concentrations of $O_2$, CO, $CO_2$, NO are accurately measured within ${\pm}2%$ error. The application of WMS method increased the beam intensity 2-3 times higher than DA method. It were experimentally compared WMS (Wavelength Modulation Spectroscopy) with DA (Direct Absorption) for the accuracy.

  • PDF

Development of a Laser Absorption NO/$NO_2$ Measuring System for Gas Turbine Exhaust Jets

  • Zhu, Y.;Yamada, H.;Hayashi, S.
    • Proceedings of the Korean Society of Propulsion Engineers Conference
    • /
    • 2004.03a
    • /
    • pp.802-806
    • /
    • 2004
  • For the protection of the local air quality and the global atmosphere, the emissions of trace species including nitric oxides (NO and NO$_2$) from gas turbines are regulated by local governments and by the International Civil Aviation Organization. In-situ measurements of such species are needed not only for the development of advanced low-emission combustion concepts but also for providing emissions data required for the sound assessment of the effects of the emissions on environment. We have been developing a laser absorption system that has a capability of simultaneous determination of NO and NO$_2$concentrations in the exhaust jets from aero gas turbines. A diode laser operating near 1.8 micrometer is used for the detection of NO while a separated visible tunable diode laser operating near 676 nanometers is used for NO$_2$. The sensitivities at elevated temperature conditions were determined for simulated gas mixtures heated up to 500K in a heated cell of a straight 0.5 m optical path. Sensitivity limits estimated as were 30 ppmv-m and 3.7 ppmv-m for NO and NO$_2$, respectively, at a typical exhaust gas temperature of 800K. Experiments using the simulated exhaust flows have proven that $CO_2$ and $H_2O$ vapor - both major combustion products - do not show any interference in the NO or NO$_2$ measurements. The measurement system has been applied to the NO/NO$_2$ measurements in NO and NO$_2$ doped real combustion gas jets issuing from a rectangular nozzle having 0.4 m optical path. The lower detection limits of the system were considerably decreased by using a multipass optical cell. A pair of off-axis parabola mirrors successfully suppressed the beam steering in the combustion gas jets by centralizing the fluctuating beam in sensor area of the detectors.

  • PDF

A study on the $NO_2$ Gas Detection Characteristics of Octa(2-ethylhexyloxy)Copper-Phthalocyanine Langmuir-Blodgett films (Octa(2-ethylhexyloxy)Copper-Phthalocyanine LB막의 $NO_2$ 가스 탐지 특성에 관한 연구)

  • 임준석;김영관;김정수
    • Electrical & Electronic Materials
    • /
    • v.10 no.5
    • /
    • pp.419-424
    • /
    • 1997
  • It is well known that the metallo-phthalocyanines (MPcs) are sensitive to toxic gaseous molecules such as NO$_2$ as well as are chemically and thermally stable. Therefore, lots of MPcs have been studied as the potential chemical sensor for NO$_2$gas using quartz crystal microbalance(QCM) or electrical conductivity. In this study, thin films of octa(2-ethylhexyloxy)copper-phthalocyanine were prepared by Langmuir-Blodgett method and characterized by using UV-VIS absorption spectroscopy and ellipsometry. Optimal transfer condition of LB films was investigated and preliminary results of current-voltage(I-V) characteristics of these films exposed to NO$_2$gas as a function of film thickness, temperature and concentration were discussed.

  • PDF

A study on the $NO_2$ Gas Detection Characteristics of Octa(2-ethylhexyloxy)copper-phthalocyanine LB Films (Octa(2-ethylhexyloxy)copper-phthalocyanine LB막의 $NO_2$ 가스 탐지 특성에 관한연구)

  • Yim, Jun-Seok;Kim, Young-Kwan;Kim, Jung-Soo
    • Proceedings of the KIEE Conference
    • /
    • 1996.07c
    • /
    • pp.1716-1718
    • /
    • 1996
  • It is well known that the metallophthalocyanine (MPcs) are sensitive to toxic gaseous molecules such as $NO_2$ and also chemically and thermally stable. Therefore, lots of MPcs are studied for the potential chemical sensor for $NO_2$ gas using quartz crystal microbalance(QCM) or electrical conductivity. In this study, thin films of octa(2-ethylhexyloxy) copper-phthalocyanine were prepared by Langmuir-Blodgett method and characterized by using UV-VIS spectrascopy and ellipsometry. Transfer condition, film characterization, and preliminary results of current-voltage(I-V) characteristics of these films exposed to $NO_2$ gas as a function of film thickness will be discussed.

  • PDF

A study on the NO$_2$ Gas Detection Characteristics of Octa(2-ethylhexyloxy)copper-phthalocyanine LB films (Octa(2-ethylhexyloxy)copper-phnthalocyanine LB막의 NO$_2$ 가스 탐지 특성에 관한 연구)

  • 임준석;김영관;김정수
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 1996.05a
    • /
    • pp.162-165
    • /
    • 1996
  • It is well shown that the metallophthalocyanine (MPcs) are sensitive to tonic gaseous molecules such as NO$_2$ and also chemically and thermally stable. Therefore, lots of MPcs are studied for the potential chemical sensor for NO$_2$ gas using quartz crystal microbalance(QCM) or electrical conductivity. In this study, thin films of octa(2-ethylhexyloxy) copper-phthalocyaninc ware prepared by Langmuir-Blodgett method and characterized by using UV-VIS spectrascopy and cllipsometry. Transfer condition, film characterization, and preliminary results of current-voltage(I-V) characteristics of these films exposed to NO$_2$ gas as a function of film thickness will be discusscd.

  • PDF

A study on the NO$_2$Gas Detection chracteristics of the Octa (2-ethylhexyloxy) copper-phthalocyanine LB film (Octa (2-ethyls expel oxy) copper-phthalocyanine LB막의 NO$_2$가스 탐지 특성에 관한 연구)

  • 임준석;김영관;김정수
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 1996.11a
    • /
    • pp.121-124
    • /
    • 1996
  • It is well known that the metallo- phthalocyanine (MPcs) are sensitive to toxic gaseous molecules such as NO$_2$and also chemically and thermally stable. Therefore, lots of MPcs have been studied for the potential chemical sensor for NO$_2$gas using quartz crystal microbalance(QCM) or electrical conductivity. In this study, thin films of octa(2-ethylhexyloxy) copper-phthalocyanine were prepared by Langmuir -Blodgett method and characterized by using UV-VIS spectroscopy and ellipsometry. Transfer condition, and characterization of LB films were investigated and preliminary results of current-voltage(I-V) characteristics of these films exposed to NO$_2$gas as a function of film thickness, temperature and temperature were discussed.

  • PDF

A Study on Micro Gas Sensor Utilizing WO$_3$ Thin Films Fabricated by Sputtering Method (스퍼터링법으로 제작한 WO$_3$ 박막을 이용한 NO$_2$ 마이크로 가스센서에 관한 연구)

  • 김창교;이영환;노일호;유홍진;유광수;기창진
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.4 no.3
    • /
    • pp.139-144
    • /
    • 2003
  • A flat type micro gas sensor was fabricated on the p-type silicon wafer with low stress Si$_3$N$_4$, whose thickness is 2 ${\mu}{\textrm}{m}$, using MEMS technology. WO$_3$ thin film as a sensing material for detection of NO$_2$ gas was deposited using a tungsten target by sputtering method, followed by thermal oxidation at several temperatures (40$0^{\circ}C$-$600^{\circ}C$) for one hour. NO$_2$ sensitivities were investigated for the WO$_3$ thin films with different annealing temperatures. The highest sensitivity was obtained for the samples annealed at $600^{\circ}C$ when it was operated at 20$0^{\circ}C$. The results of XRD analysis showed the annealed samples had polycrystalline phase mixed with triclinic and orthorhombic structures. The sample exhibits higher sensitivity when the system has less triclinic structure. The sensitivities, $R_{gas}/R_{air},$ operating at 20$0^{\circ}C$ to 5 ppm NO$_2$ of the sample annealed at $600^{\circ}C$ were approximately 90.

  • PDF