• Title/Summary/Keyword: $H_2S$ sensor

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Development of a MEMS-based H2S Sensor with a High Detection Performance and Fast Response Time

  • Dong Geon Jung;Junyeop Lee;Dong Hyuk Jung;Won Oh Lee;Byeong Seo Park;Daewoong Jung
    • 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.

H2S Micro Gas Sensor Based on a SnO2-CuO Multi-layer Thin Film

  • Kim, Sung-Eun;Choi, Woo-Chang
    • Transactions on Electrical and Electronic Materials
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    • v.13 no.1
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    • pp.27-30
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    • 2012
  • This paper proposes a micro gas sensor for measuring $H_2S$ gas. This is based on a $SnO_2$-CuO multi-layer thin film. The sensor has a silicon diaphragm, micro heater, and sensing layers. The micro heater is embedded in the sensing layer in order to increase the temperature to an operating temperature. The $SnO_2$-CuO multi layer film is prepared by the alternating deposition method and thermal oxidation which uses an electron beam evaporator and a thermal furnace. To determine the effect of the number of layers, five sets of films are prepared, each with different number of layers. The sensitivities are measured by applying $H_2S$ gas. It has a concentration of 1 ppm at an operating temperature of $270^{\circ}C$. At the same total thickness, the sensitivity of the sensor with multi sensing layers was improved, compared to the sensor with one sensing layer. The sensitivity of the sensor with five layers to 1 ppm of $H_2S$ gas is approximately 68%. This is approximately 12% more than that of a sensor with one-layer.

The H2 and H2S sensing characteristics of Pd and Pd-Rh gate MOS sensor (Pd 및 Pd-Rh 게이트 MOS센서의 수소 및 황화수소가스에 대한 검지특성)

  • Lee, Chang-Hee;Park, Chong-Ook
    • Transactions of the Korean hydrogen and new energy society
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    • v.8 no.4
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    • pp.145-154
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    • 1997
  • The $H_2$ and $H_2S$ sensing characteristics of Pd and Pd-Rh gate MOS sensor and the effect of Pd deposition condition on the hydrogen sensing performance of Pd gate MOS sensor was investigated. The increase of rf power and deposition temperature led to the decrease in the sensitivity and the initial response rate. The deposition temperature gave more effects on the decrease of the sensitivity and the initial response rate than the rf power. The sensitivity of Pd-Rh sensor gave better performance than pure Pd sensor. As the concentration of Rh in the gate increased, the sensitivity decreased. For Pd-Rh sensor, the sensitivity to $H_2$ was higher than that to $H_2S$. It was demonstrated that rf power, deposition temperature had an important role in the sensor performance.

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Polyester (PET) Fabric dyed with Lead (II) acetate-based Colorimetric Sensor for Detecting Hydrogen Sulfide (H2S) (황화수소(H2S) 감지를 위한 아세트산 납이 침염된 폴리에스터(PET) 섬유 기반의 변색성 센서)

  • Lee, Junyeop;Do, Nam Gon;Jeong, Dong Hyuk;Jung, Dong Geon;An, Hee Kyung;Kong, Seong Ho;Jung, Daewoong
    • Journal of Sensor Science and Technology
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    • v.29 no.5
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    • pp.360-364
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    • 2020
  • In this study, the colorimetric sensor, polyester (PET) fabric dyed with lead (II) acetate (Pb(C2H3O2)2), was fabricated and characterized for the detection of the hydrogen sulfide (H2S). The surface morphology of the fabric was determined using scanning electron microscope and energy-dispersive X-ray spectroscopy. The optical properties of the fabric were evaluated by measuring the variation in the blue value of an RGB sensor. The fabric showed a significant color change, high linearity (R2 : 0.98256), and fast response time (< 1.0 s) when exposed to H2S. This is because the sensor is highly porous and permeable to the gas. The fabric can not only be used as a hydrogen sulfide sensor but also be used to detect and prevent H2S influx using sticky tape on pipelines.

H2S Gas Sensing Properties of CuO Nanotubes

  • Kang, Wooseung;Park, Sunghoon
    • Applied Science and Convergence Technology
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    • v.23 no.6
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    • pp.392-397
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    • 2014
  • CuO nanotubes are synthesized using $TeO_2$ nanorod templates for application to $H_2S$ gas sensors. $TeO_2$ nanorod templates were synthesized by using the VS method through thermal evaporation. Scanning electron microscopy, transmission electron microscopy and X-ray diffraction showed that the synthesized nanotubes were monoclinic-structured polycrystalline CuO with diameter and wall thickness of approximately 100~300 nm and 5~10 nm, respectively. The CuO nanotube sensor showed responses of 136~325% for the $H_2S$ concentration of 0.1~5 ppm at room temperature. These response values are approximately twice as high as that of the CuO nanowire sensor for the same concentrations of $H_2S$ gas. Along with the investigation of the performance of the sensors, the mechanisms of $H_2S$ gas sensing of the CuO nanotubes are also discussed in this study.

Fabrication of High-Performance Colorimetric Fiber-Type Sensors for Hydrogen Sulfide Detection (황화수소 가스 감지를 위한 고성능 변색성 섬유형 센서의 제작 및 개발)

  • Jeong, Dong Hyuk;Maeng, Bohee;Lee, Junyeop;Cho, Sung Been;An, Hee Kyung;Jung, Daewoong
    • Journal of Sensor Science and Technology
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    • v.31 no.3
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    • pp.168-174
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    • 2022
  • Hydrogen sulfide(H2S) gas is a high-risk gas that can cause suffocation or death in severe cases, depending on the concentration of exposure. Various studies to detect this gas are still in progress. In this study, we demonstrate a colorimetric sensor that can detect H2S gas using its direct color change. The proposed nanofiber sensor containing a dye material named Lead(II) acetate, which changes its color according to H2S gas reaction, is fabricated by electrospinning. The performance of this sensor is evaluated by measuring RGB changes, ΔE value, and gas selectivity. It has a ΔE value of 5.75 × 10-3 ΔE/s·ppm, showing improved sensitivity up to 1.4 times that of the existing H2S color change detection sensor, which is a result of the large surface area of the nanofibers. The selectivity for H2S gas is confirmed to be an excellent value of almost 70 %.

Sensitivity enhancement of H2 gas sensor using PbS quantum dots (황화납 양자점 감지막을 통해 감도가 개선된 수소센서)

  • Kim, Sae-Wan;Kim, Na-Ri;Kwon, Jin-Beom;Kim, Jae Keon;Jung, Dong Geon;Kong, Seong Ho;Jung, Daewoong
    • Journal of Sensor Science and Technology
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    • v.29 no.6
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    • pp.388-393
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    • 2020
  • In this study, a PbS quantum dots (QDs)-based H2 gas sensor with a Pd electrode was proposed. QDs have a size of several nanometers, and they can exhibit a high surface area when forming a thin film. In particular, the NH2 present in the ligand of PbS QDs and H2 gas are combined to form NH3+, subsequently the electrical characteristics of the QDs change. In addition to the resistance change owing to the reaction between Pd and H2 gas, the resistance change owing to the reaction between the NH2 of PbS QDs and H2 gas increases the current signal at the sensor output, which can produce a high output signal for the same concentration of H2 gas. Using the XRD and absorbance properties, the synthesis and particle size of the synthesized PbS QDs were analyzed. Using PbS QDs, the sensitivity was significantly improved by 44%. In addition, the proposed H2 gas sensor has high selectivity because it has low reactivity with heterogeneous gases such as C2H2, CO2, and CH4.

Development of High Sensitive Integrated Dual Sensor to Detect Harmful Exhaust Gas and Odor for the Automotive (악취분별능력을 가진 자동차용 고기능 듀얼타입 집적형 유해가스 유입차단센서 개발)

  • Chung, Wan-Young;Shim, Chang-Hyun
    • Journal of Institute of Control, Robotics and Systems
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    • v.13 no.7
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    • pp.616-623
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    • 2007
  • A dual micro gas sensor array was fabricated using nano sized $SnO_2$ thin films which had good sensitivities to CO and combustible gases, or $H_2S$ gas for air quality sensors in automobile. The already existed air quality sensor detects oxidizing gases and reducing gases, the air quality sensor(AQS), located near the fresh air inlet detected the harmful gases, the fresh air inlet door/ventilation flap was closed to reduce the amount of pollution entering the vehicle cabin through HVAC(heating, ventilating, and air conditioning) system. In this study, to make $SnO_2$ thin film AQS sensor, thin tin metal layer between 1000 and $2000{\AA}$ 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.

Characteristics and Fabrication of Dissolved Oxygen and pH Measurement System based on the Optical Sensor for Analysis of Cell Metabolic Functions (세포대사 기능 분석을 위한 광학센서 기반 용존산소와 pH 측정 시스템의 제작 및 특성 분석)

  • Jang, Jiwoon;Hwang, Insook;Lee, Jongmok;Lee, Sunmin;Kang, Sora;Kim Pak, Youngmi;Kim, Nayoung
    • Journal of Sensor Science and Technology
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    • v.25 no.1
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    • pp.51-56
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    • 2016
  • This study evaluates the performance of an optical sensor and measurement system (CMA-24) which can analyze the fluctuation of dissolved oxygen and pH simultaneously. In the optical sensor system, the fluorescent materials, Rudpp and HPTS which are sensitive to dissolved oxygen and pH, respectively, are coated on the bottom of a 24-well -plate by the sol-gel technology. The detection times of the emission light of the oxygen sensor were $4,186{\pm}13.90{\mu}s$ and $4,452{\pm}36.68{\mu}s$ for the dissolved oxygen of 17% $O_2$ and 7.6% $O_2$, respectively. On the other hand, the detection times of the pH sensor were $6,699.43{\pm}14.64{\mu}s$, $6,722.24{\pm}6.21{\mu}s$, and $6,748.52{\pm}2.63{\mu}s$ using pH 6, 7, and 8, respectively. When we determined cellular respiration levels of C2C12 myocytes with CMA-24, $O_2$/pH measurement system, the ratio of the uncoupled to coupled OCR (oxygen consumption rate) was 1.41. The results mean that this CMA-24 system shows almost the same sensitiveness as the commercial system.

Optical Voltage Sensor Using $SiO_2$ Pockels Cell ($SiO_2$ 포켈 소자를 이용한 광전압센서)

  • Shin, K.H.;Chun, J.P.;Cho, H.K.;Kim, S.K.;Kim, Y.H.;Kim, Y.S.;Park, H.S.
    • Proceedings of the KIEE Conference
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    • 1991.07a
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    • pp.846-849
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    • 1991
  • This paper reports the principle, system confiquration, test results of optical voltage sensor using quartz pockels cell. The Pockels effect of quartz material is used for designing optical voltage sensor. The quarts material has very high half-wave voltage, so, it can be applied to measure high voltage level. Experimental results show that the optical voltage sensor has excellent linear characteristics within the applied AC voltage of 1200V.

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