• Asian Journal of Atmospheric Environment
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• 제11권4호
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• pp.300-312
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• 2017

To improve the understanding of secondary organic aerosol (SOA) formation from the photo-oxidation of anthropogenic and biogenic precursors at the regional background station on Baengnyeong Island, Korea, gas phase and aerosol chemistries were investigated using the Proton Transfer Reaction Time of Flight Mass Spectrometer (PTR-ToF-MS) and the Aerodyne High Resolution Time of Flight Aerosol Mass Spectrometer (HR-ToF-AMS), respectively. HR-ToF-AMS measured fine particles ($PM_1$; diameter of particle matter less than $1{\mu}m$) at a 6-minute time resolution from February to November 2012, while PTR-ToF-MS was deployed during an intensive period from September 21 to 29, 2012. The one-minute time-resolution and high mass resolution (up to $4000m{\Delta}m^{-1}$) data from the PTR-ToF-MS provided the basis for calculations of the concentrations of anthropogenic and biogenic volatile organic compounds (BVOCs) including oxygenated VOCs (OVOCs). The dominant BVOCs from the site are isoprene (0.23 ppb), dimethyl sulphide (DMS, 0.20 ppb), and monoterpenes (0.38 ppb). Toluene (0.45 ppb) and benzene (0.32 ppb) accounted for the majority of anthropogenic VOCs (AVOCs). OVOCs including acetone (3.98 ppb), acetaldehyde (2.67 ppb), acetic acid (1.68 ppb), and formic acid (2.24 ppb) were measured. The OVOCs comprise approximately 75% of total measured VOCs, suggesting the occurrence of strong oxidation processes and/or long-range transported at the site. A strong photochemical aging and oxidation of the atmospheric pollutants were also observed in aerosol measured by HR-ToF-AMS, whereby a high $f_{44}:f_{43}$ value is shown for organic aerosols (OAs); however, relatively low $f_{44}:f_{43}$ values were observed when high concentrations of BVOCs and AVOCs were available, providing evidence of the formation of SOA from VOC precursors at the site. Overall, the results of this study revealed several different SOA formation mechanisms, and new particle formation and particle growth events were identified using the powerful tools scanning mobility particle sizer (SMPS), PTR-ToF-MS, and HR-ToF-AMS.

• 품질경영학회지
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• 제44권1호
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• pp.77-94
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• 2016

Purpose: This paper reviews Type 1 Gage study, Gage R&R study, and procedure of ISO 22514-7 for assessing a measurement system, and discusses some relationships between the measurement capability indices. Methods: The gage capability index $C_g$ of Type 1 Gage study, precision-to-tolerance ratio PTR of Gage R&R study, and measurement performance ratio $Q_{MS}$ and $Q_{MP}$ of ISO 22514-7 are considered in this paper. Results: This paper derives the relationships between $C_g$ and $Q_{MS}$, PTR and $Q_{MP}$, and $Q_{MS}$ and $Q_{MP}$, respectively, and discusses the acceptance conditions for each procedures. Conclusion: The measurement capability analysis is the first step for the quality improvement of the manufacturing processes. Therefore the result of this study provides a helpful guidelines for assessing the measurement system, enabling proper evaluation of manufacturing processes.

• 한국도시환경학회지
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• 제18권4호
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• pp.503-509
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• 2018

본 연구에서는 양자전이 비행시간질량분석기(PTR-ToF-MS)를 이용하여 반도체 공정의 작업환경(PHOTO, FPD, OLED, WET 공정)에서 VOCs를 실시간으로 모니터링하였다. 작업환경에서 평균 VOCs 농도는 PHOTO 6.5 ppm, FPH 6.4 ppm, WET 2.0 ppm, OLED 1.3 ppm이었다. VOCs 중 methyl ethyl ketone이 2.8 ppm (69%), acetaldehyde가 0.5 ppm (13.2%)로 나타났다. 반도체 공정 특성에 따라 다양한 VOCs 가 작업환경에서 관측되었다. 관측된 VOCs 농도는 작업환경기준보다 낮지만, 이러한 VOCs를 지속적으로 모니터링하여 효과적으로 관리해 나갈 필요가 있다.

• 한국분무공학회지
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• 제19권3호
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• pp.142-148
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• 2014

In this study, characteristics of gaseous pollutants and particulate matter were investigated on the condition of DPF regeneration and normal DPF condition. THC, CO, $CO_2$, NOx, and $CH_4$ were analyzed by MEXA-7200H and CVS-7100 respectively. Particulate Matter (PM) was measured by difference in weight of Membrane filter. Particle Number (PN) was measured by CPC analyzer. And Sulfate, Nitrate, Organic were measured by Aerosol Mass Spectrometer (AMS). As a result, gaseous pollutants and particulate matter were detected in higher concentration during DPF regeneration than normal DPF condition. And the PN increased by 94%, the fuel consumption was reduced by 29% on DPF generation process. Sulfate, Nitrate and Organic were undetectable level during normal DPF condition. But the highest concentration of Sulfate, Nitrate and Organic were measured as $100{\mu}g/m^3$, $20{\mu}g/m^3$ and $15{\mu}g/m^3$ respectively on DPF regeneration condition. VOCs concentrations (Benzene, Toluene, Ethylbenzene, Xylene) were analyzed by using PTR-MS. Benzene and Toluene emission have little or no change depending on DPF regeneration. But the Ethylbenzene and Xylene have comparatively low emissions on DPF regeneration.

• 환경분석과 독성보건
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• 제21권4호
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• pp.264-280
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• 2018

In this study, volatile organic compounds (VOCs) were measured using a proton transfer reaction-time of flight-mass spectrometer (PTR-ToF-MS) at the Seoul Metropolitan Area Intensive Monitoring Station (SIMS) in Korea during the summer season of 2018. The results revealed that oxygenated VOCs (OVOCs) contributed a large fraction (83.6%) of the total VOCs, with methanol being the most abundant constituent (38.6%). The VOCs measured at SIMS were strongly influenced by local conditions. Non-volatile organic compounds (NVOCs), such as pinene, increased due to northeasterly wind direction in the morning, and OVOCs and anthropogenic VOCS (AVOCs) increased with northwesterly wind direction during the daytime. This was the result of the eastward location of Bukhansan National Park and the westward location of urban area from the SIMS location. The VOCs included abundant oxidized forms of VOCs, which can affect the generation of fine dust through various response pathways in the atmosphere. The real-time measurement technique using PTR-ToF-MS suggested in this study is expected to contribute to an improved scientific understanding of high-concentration fine dust events because the high temporal resolution makes it possible to analyze the variations of VOCs reflected in dynamic events.

• 한국농림기상학회지
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• 제17권3호
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• pp.217-226
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• 2015

경기도 태화산 서울대학술림에 위치한 대기관측타워에서 BVOCs 중 이소프렌, 모노테르펜을 2013년 5월, 6월, 8월에 PTR-MS를 이용하여 측정하고 이들의 분포 특성을 분석하였다. $O_3$과 온도, 습도 그리고 광합성유효복사와 잎면적지수를 측정하였다. 측정기간 동안 BVOCs 농도는 온도가 가장 높은 8월보다는 6월에 더 높았다. 태화산에서 측정된 침엽수와 활엽수의 광합성량(NPP, net primary production) 모두 6월에 가장 높았다. 이는 식생의 활동이 6월에 더 활발함을 의미하는데 이는 동북아시아 몬순의 영향으로 생각된다. 이소프렌은 늦은 오후에 최고 농도를, 모노테르펜은 저녁부터 농도가 높아져 밤 늦게 최고 농도를 보였다. 이들 모두 높이에 따라 평균 농도에 차이가 있었는데, 이소프렌과 모노테르펜 모두 캐노피 아래에서 높은 농도를 보였다. 반면, 온도는 캐노피 아래가 위보다 낮았고 $O_3$ 또한 캐노피 위에서 높아 산림 내와 산림 밖의 대기 간에 차이가 있었다. 특히, 이소프렌은 오후시간에 $O_3$과 같은 시간에 최고농도 보여 $O_3$ 생성에, 반대로 $O_3$은 농도가 급격히 감소하는 저녁시간에 캐노피 아래에서 농도가 크게 증가하는 모노테르펜은 $O_3$의 소멸에 영향을 미치는 것으로 나타났다. MEGAN을 이용하여 태화산에서 산정된 이소프렌과 모노테르펜의 배출계수는 각각 $641.9g\;km^{-2}h^{-1}$, $116.8g\;km^{-2}h^{-1}$로 CAPSS에서 산정된 잣나무 배출계수와 비교하면 이소프렌은 높고 반대로 모노테르펜은 낮았다. 이를 바탕으로 연간 배출량은 이소프렌은 1.1(톤/년), 모노테르펜은 0.9(톤/년)으로 산정되었다.