• 제목/요약/키워드: Particle Counter

검색결과 212건 처리시간 0.022초

Hy-CPC의 개발 및 성능평가 (Development and Evaluation of Hy-CPC)

  • 이홍규;황인규;안강호
    • 한국입자에어로졸학회지
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    • 제10권3호
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    • pp.93-97
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    • 2014
  • Condensation particle counter (CPC) has been one of the most important basic instrument for measuring number concentration of submicron aerosols. The principle of the CPC is to expose aerosols to a supersaturated vapor and cool down which causes adiabatic expansion. The particles grow by heterogenous nucleation to a sufficient size for easy detection by optical method. However, for growth by condensation, CPC essentially needs both saturater and condensor causing a heavy system. Therefore, it is hard to install commercial CPC to tethered balloon package system. In this study, we developed customized CPC for tethered balloon package system called Hy-CPC which is lighter and smaller in structure than commercial CPCs, and evaluated activation efficiency and detection efficiency by Hy-CPC using electrostatic method (electrometer and Faraday cup).

초순수 물(Ultra Pure Water)내 비휘발성 잔류 물질(Nonvolatile Residue, NVR)의 모니터링을 위한 NVR 측정시스템의 개발 (The Development of Nonvolatile Residue (NVR) Particle Monitoring System in Ultra Pure Water)

  • 정혁;안진홍;안강호
    • 반도체디스플레이기술학회지
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    • 제9권1호
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    • pp.55-59
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    • 2010
  • In this study, we developed nonvolatile residue (NVR) real-time monitoring system to measure the nonvolatile residue particle in ultra pure water (UPW). This device has a capability of measuring 4 different channels, i.e., 10 nm, 30 nm, 50 nm, and 100 nm. Until now, the light scattering method to detect RAE(residue after evaporation) was the only choice. However, this method can detect RAE larger than ca. 50 nm. In ultra pure water, RAE particles are usually very small and hard to detect with conventional laser scattering devices. To detect very small RAEs, a new system is developed and tested. The system consists of an atomizer that generates RAE particles and a four channel condensation particle counter (CPC). During the several months' operation in manufacturing line, the system was successfully tested and showed reliable results.

수중유형 마이크로에멀젼의 물리화학적 평가 (Physicochemical Evaluation of Oil in Water Microemulsions)

  • 정명화;정엽;정대식;권종원;양중익;민신홍
    • Journal of Pharmaceutical Investigation
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    • 제18권1호
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    • pp.9-13
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    • 1988
  • Physicochemical properties of oil in water microemulsions containing soybean oil and egg phosphatide were observed for 3 weeks under the storage condition of $4^{\circ}C$ refrigerator. Changes in major fatty acid content, particle size distribution, rheogram, acid value and pH value were measured by gas chromatograph, laser particle sizer, Coulter counter and rheometer. From above experiments following conclusions were obtained; 1) Mean particle diameter was shifted from 240 to 266mm. 2) No significant changes were observed in the content of major fatty acids of soybean oil, rheogram, acid value and pH value.

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타코나이트 광산 공정에서의 실시간 질량측정기기와 실시간 수농도의 환산에 의한 질량농도와의 연관성 (Relationships between a Calculated Mass Concentration and a Measured Concentration of PM2.5 and Respirable Particle Matter Sampling Direct-Reading Instruments in Taconite Mines)

  • 정은교;장재길;송세욱;김정호
    • 한국산업보건학회지
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    • 제24권1호
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    • pp.65-73
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    • 2014
  • Objectives: The purposes of this study are to investigate workers' exposures to respirable particles generated in taconite mines and to compare two metric methods for mass concentrations using direct-reading instruments. Methods: Air monitorings were conducted at six mines where subjects have been exposed primarily to particulate matters in crushing, concentrating, and pelletizing processes. Air samples were collected during 4 hours of the entire work shift for similarly exposure groups(SEGs) of nine jobs(N=37). Following instruments were employed to evaluate the workplace: a nanoparticle aerosol monitor(particle size range; 10-1000 nm, unit: ${\mu}m^2/cc$, Model 9000, TSI Inc.); DustTrak air monitors($PM_{10}$, $PM_{2.5}$, unit: $mg/m^3$, Model 8520, TSI Inc.); a condensation particle counter(size range; 20-1000 nm, unit: #/cc, P-Trak 8525, TSI Inc.); and an optical particle counter(particle number by size range $0.3-25{\mu}m$, unit: #/cc, Aerotrak 9306, TSI Inc.). Results: The highest airborne concentration among SEGs was for furnace operator followed by pelletizing maintenance workers in number of particle and surface area, but not in mass concentrations. The geometric means of $PM_{2.5}$ by the DustTrak and the Ptrak/Aerotrak were $0.04{\mu}m$(GSD 2.52) and $0.07{\mu}m$(GSD 2.60), respectively. Also, the geometric means of RPM by the DustTrak and the Ptrak/Aerotrak were $0.16{\mu}m$(GSD 2.24) and $0.32{\mu}m$(GSD 3.24), respectively. The Pearson correlation coefficient for DustTrak $PM_{2.5}$ and Ptrak/Aerotrak $PM_{2.5}$ was 0.56, and that of DustTrak RPM and Ptrak/Aerotrak RPM was 0.65, indicating a moderate positive association between the two sampling methods. Surface area and number concentration were highly correlated($R^2$ = 0.80), while $PM_{2.5}$ and RPM were also statistically correlated each other($R^2$ = 0.79). Conclusions: The results suggest that it is possible to measure airborne particulates by mass concentrations or particle number concentrations using real-time instruments instead of using the DustTrak Aerosol monitor that monitor mass concentrations only.

Evaluation of Rapid filtration System with Particle Size Distribution and Turbidity in Different Effective Sizes

  • Park, J.A.;Eo, S.M.;Shin, J.S.;Kim, M.H.;Yu, M.J.;Chung, S.H.
    • 한국환경보건학회:학술대회논문집
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    • 한국환경보건학회 2005년도 국제학술대회
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    • pp.381-385
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    • 2005
  • Characterization of particle behavior is becoming more important in performance evaluation of water treatment system as well as in operation of the system because conventional parameter, turbidity has lack of explaining ability on small sized microorganisms such like Cryptosporidium etc. Accordingly, particle counter has been introduced in evaluation and operation of the treatment system. However researches on the relationship between turbidity, particle count and/or different sand/anthracite sizes have not been concurrent. Therefore in this study, the relationship was investigated to improve performance evaluation of sand filter so as to help choosing sand/anthracite effective size as a design parameter of water treatment facility. According to the results, too small or too large effective size media filter reached to turbidity limit(0.1 NTU)earlier. However, because shallow sand layer may cause early breakthrough, the depth of sand layer should be provided enough in order to compromise water quality and productivity.

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비구형 입자의 형상에 따른 단극 확산 하전 특성 (Effects of Particle Shapes on Unipolar Diffusion Charging of Non-Spherical Particles)

  • 오현철;박형호;김상수
    • 대한기계학회논문집B
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    • 제28권5호
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    • pp.501-509
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    • 2004
  • Unipolar diffusion charging of non-spherical particles was investigated for various particle shapes. We researched with TiO$_2$agglomerates produced by the thermal decomposition of titanium tetraisopropoxide (TTIP) vapor. TTIP was converted into TiO$_2$, in the furnace reactor and was subsequently introduced into the sintering furnace. Increasing the temperature in the sintering furnace, aggregates were restructured into higher fractal dimensions. The aggregates were classified according to their mobility using a differential mobility analyzer. The projection area and the mass fractal dimension of particles were measured with an image processing technique performed by using transmission electron microscope (TEM) photograph. The selected aggregates were charged by the indirect photoelectric-charger and the average number of charges per particle was measured by an aerosol electrometer and a condensation particle counter. For the particles of same mobility diameter, our results showed that the particle charge quantity decreases as the sintering temperature increases. This result is understandable because particles with lower fractal dimension have larger capacitance and geometric surface area.

제주도 고산지역 입자특성 : 1994년 3월 11일 - 17일 측정결과 (Characteristics of particles at Kosan, Cheju Island: Intensive study results duting March 11 .sim. 17 1994)

  • 김용표;심상규;문길주;백남준;김성주;허철구;강창희
    • 한국대기환경학회지
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    • 제11권3호
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    • pp.263-272
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    • 1995
  • Characteristics of anbient at Korean, Cheju Island have been studied during the intensive field study period on March 11 .sim. 17, 1994 in collaboration with other research organizations from Korea and abroad. The particle size distribution was measured using an Electrical Aerosol Analyzer(EAA) and an Optical particle Counter(OPC). Fine particles(PM1 and PM3) have been collected by filter pack samplers and their ionic compositions have been analyzed. sampling errors inherent to the filter pack sampling method are discussed and the method to analyze those errors are presented. The rine mass concentrations of this study show very similar mass concentrations when Seoul is clear. This is somewhat surprising result, because the most of researchers believe that Kosan is one of the cleanest area in Korea. Bimodal volume size distributions with peak values around 0.1 .sim. 0.2.mu.m and 3.mu.m in particle dimeter were observed for most of the measurement period, particle mass loadings and ionic composition data show a large fraction of particles are from non-sea salt origins. Estimation of water content and acidity of particles based on measurement by a gas/particle equilibrium model, SCAPE, reveals that the pH values of particles are comparable to or lower than those estimated based on measurements in Los Angeles, U.S.A. during the SCAQS study. These findings with the meteorological conditions during the study period suggest that the particles collected during the period have originated from outside Cheju Island.

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광학 입자 측정기 비교 측정에 의한 입경별 일평균 블랙카본 분석 - Part I (Diurnal Size Distributions of Black Carbon by Comparison of Optical Particulate Measurements - Part I)

  • 박다정;이광열;박기홍;배민석
    • 한국대기환경학회지
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    • 제32권1호
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    • pp.1-8
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    • 2016
  • Optical particle sizer (OPS), optical particle counter (OPC), and aethalomter were deployed to measure the particle number concentrations from 0.3 to $10.0{\mu}m$ and black carbon (BC) concentrations. Comparisons of particle number concentrations measured by OPS and OPC were conducted to evaluate the performance of the each optical instrument at the Gwangju sampling site ($35.23^{\circ}N$, $126.84^{\circ}E$) for 14 days from Dec. 27 in 2014. Although a good correlation ($r^2=0.99$) between the OPS and OPC was observed for both the particle number and volume concentrations, different relationships by BC concentrations can be associated with the intensities by different light scattering angles. In addition, based on diurnal patterns of size distributions in 24 hr running correlation coefficient determination, BC concentrations were highly related to the particles less than $0.3{\mu}m$ observed in the morning traffic hour.

PN-PEMS 장비의 개발 및 평가 (Development and Performance Evaluation of PN-PEMS)

  • 황인규;김민호;우승철;이기형;안강호
    • 한국입자에어로졸학회지
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    • 제10권4호
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    • pp.163-167
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    • 2014
  • Particle number portable emission measurement system (PN-PEMS) is an instrument for measuring number concentration of automobile exhaust. The principle of some pre-existing commercial PN-PEMS is to charge particles and display the number of particles by measuring current. However, this method has some problems for measuring exhaust. In this study, to solve these issues, we have developed a single particle counting PN-PEMS based condensation particle counter (CPC). The PN-PEMS based CPC does not affect driving conditions and it is convenient for mobile because the instrument is small and light in structure. We evaluated counting efficiency of PN-PEMS based CPC by using electrostatic method (electrometer and Faraday cup).

2010년 3월 20일 부산지역에 발생한 극심한 황사의 에어로솔 농도 분포 특성 (Characterization of Aerosol Concentration during Severe Asian Dust Period at Busan, Korea in 20 March 2010)

  • 정운선;박성화;이동인;강덕두;김동철
    • 한국환경과학회지
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    • 제23권2호
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    • pp.275-289
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    • 2014
  • Asian dust (or yellow sand) occurring mainly in spring in East Asia is affected by the distribution of weather systems. This study was performed to investigate the characteristics of suspended particulate for Asian dust at Busan, Korea in 20 March 2010, which was one of the extreme case for the last 10 years. There was used the data of weather chart, satellite, automatic weather system (AWS), $PM_{10}$, laser particle counter (LPC), and backward trajectories model. In synoptically, the high pressure was located in the northwestern part and low pressure was located in the northeastern part of Korea. The strong westerly winds from surface to upper layer makes it possible to move air masses rapidly. Air masses passing through Gobi Desert in Mongolia and Inner Mongolia plateau covered the entire Korean peninsula. As the results of aerosol analysis, $PM_{10}$ concentration at Gudeok mountain in Busan was recorded $2,344{\mu}g/m^3$ in 2300 LST 20 March 2010 and their concentration was markedly increased at coarse mode particle. In surface condition, westerly wind about 3 ~ 5 m/s was dominant and small particles of $0.3{\sim}0.5{\mu}m$ were distributed on the whole. In heavy metal components analysis, the elements from the land was predominated.