• Analytical Science and Technology
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• v.19 no.5
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• pp.369-375
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• 2006

Calibration gas mixtures were prepared using dynamic volumetric method according to ISO 6145-5 and the uncertainty was evaluated. Ten identical capillaries with 0.25 mm in inner diameter and 50 cm in length were applied in this system. Dilution ratio of parent gas was determined by the number of capillaries that passes parent gas and that passes balance gas through. Capillaries were made of Teflon which had good chemical stability against adsorption of gaseous substances. Mechanical valves were introduced in this system in order to minimize the thermal effect of solenoid valves. Concentration of prepared gases were compared with master grade standard gases in cylinders made by RiGAS Co. and calibration of the instrument were completed using comparison method according to ISO 6143. Experimental results showed that the coefficient of variance of diluted oxygen standard gases showed less then 0.2% in most dilution range, that of diluted hydrogen sulfide standard gases showed less then 1.0%. Therefore, it is proven that the standard gases prepared by this system are appropriate to be used as a calibration standards in ambient monitoring, etc.

• Journal of the Korean Institute of Gas
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• v.25 no.4
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• pp.49-56
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• 2021

Liquefied Petroleum Gas is divided into liquefied gases containing propane (C₃H₈) and butane (C₄H₁₀). The quality of LPG varies greatly depending on the composition of the mixture, so it is important to measure the composition accurately. It is difficult to determine the composition of the mixture because liquid and gas coexist at room temperature. Therefore, the uncertainty in determining the concentration of hydrocarbons by component is high, and there are many problems that differ from the actual content standard. Therefore, it is necessary to develop a mixed liquid propane standard gas for the composition and accurate concentration of hydrocarbon substances. Mixed liquid propane standard gas is manufactured into bellows-type constant-pressure cylinders by ISO-6142 (2015). The homogeneity of the four standard gases manufactured was confirmed to be GC-FID. The manufacturer's uncertainty of expansion was 0.01 % to 0.30 % and homogeneity was 0.03 % to 0.25 %. In this mixed liquid propane standard gas, the relative expansion uncertainty of weight method, manufacturing consistency, cylinder adsorption and long-term stability was developed within 0.26 %-1.3 9% (95% of confidence level, k=2).

• Analytical Science and Technology
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• v.30 no.5
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• pp.287-294
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• 2017

As the demand for natural gas increases with industrial development, the supply of natural gas is expected to become unstable with a shortage of imported natural gas. It is hence necessary to meet this demand by introducing and developing various types of natural gas, such as pipeline natural gas (PNG) and substituted natural gas (SNG), in addition to liquefied natural gas (LNG). The components included in PNG as well as their concentrations must be measured accurately, and a standard gas should be developed to accurately measure hydrocarbons ($C_6-C_{10}$), which are trace components included in natural gas. The components in the primary standard gas mixtures (PSMs) developed in the present study were hexane, heptane, octane, nonane, and decane with concentrations of $10-30{\mu}mol/mol$ with methane as the balance gas. Standard hydrocarbon ($C_6-C_{10}$) gas mixtures were prepared in aluminum cylinders by a gravimetric method with traceability following ISO 6142 with raw material gases, for which the purity of each component was analyzed completely. The prepared standard gas mixtures were analyzed by to evaluate the preparation consistency between the standard gas mixtures, the adsorbability of the cylinders, the variation of the stability, and the uncertainty. The results showed that aluminum cylinders have little adsorptive loss on their internal surfaces with excellent long-term stability. The developed standard gas mixture, containing hexane, heptane, octane, nonane, and decane with concentrations of $10-30{\mu}mol/mol$, showed an uncertainty in a range of 0.79 % - 1.63 %.

• 한국가스학회:학술대회논문집
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• 2007.04a
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• pp.42-49
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• 2007

가스크로마토그래피 불꽃이온화검출기(FID)에서, 천연가스 표준물질만을 사용하여 분석할 때 발생할 수 있는 분석 불확도에 대하여 연구하였다. 일반적으로 $10^5$ 범위 농도까지 직선성이 확보된 것으로 알려진 FID 검출기에 대하여 실제 분석에서 동일한 직선성이 확보되는지를 확인하였다. 본 연구에서 7성분으로 조성된 천연가스용 표준가스를 샘프링 loop의 크기를 1.0mL, 0.50mL, 0.25mL로 변환시키면서 GC/FID를 사용하여 분석한 상대표준불확도 결과는 다음과 같다. 메탄은, 0.458 %, 에탄은 0.20247%, 프로판은 0.1497%, i-부탄은 0.1854 %, n-부탄은 0.2977%, i-펜탄은 0.263%, n-펜탄은 0.383%이었다. 각 경우에서 직선성 상대표준불확도값이 $0.15%{\sim}0.45 %$까지 이른다. 일반적으로 농도가 높은 메탄의 경우에 직선성 불확도값이 큰 값을 보여 주었고 농도범위가 1-5%인 $C2{\sim}C5$의 경우는 작은 직선성 표준불확도를 나타내었다.

• LP가스
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• s.97
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• pp.59-65
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• 2005

한국가스안전공사에서는 소형 LPG저장탱크에 대한 시공표준화 및 품질향상을 위한 표준모델을 마련하고 배포에 들어갔다. 이와 관련하여 그 내용을 게재한다.

• 한국가스학회:학술대회논문집
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• 2005.10a
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• pp.12-14
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• 2005

• Analytical Science and Technology
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• v.19 no.6
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• pp.490-497
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• 2006

The sources of uncertainty in the analysis of liquified natural gas (LNG) process are evaluated. The uncertainty sources evaluated are the repeatability of measurement, non-linearity of GC, the uncertainty of standard gas used for calibration, difference of gas sampling and deviation after GC calibration and major revealed sources are the non-linearity of GC, the uncertainty of standard gas and the deviation after GC calibration. The determined values and uncertainties of methane and ethane as the major components are $90.0%mol/mol{\pm}1.9%$ (relative and 95% level of confidence) and $6.26%mol/mol{\pm}0.08$ (relative and 95% level of confidence), respectively. The contribution of uncertainty varies depending on the source of uncertainty and gas component. In the case of methane, non-linearity of GC, the uncertainty of standard gas and deviation after GC calibration contribute 0.28%, 0.25% and 0.24% of relative expanded uncertainty, respectively.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2012.04a
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• pp.361-364
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• 2012

최근의 건축물은 다양한 소재의 마감재를 사용함으로서 화재 발생시 다양한 연소가스를 배출한다. 이때 건축물 내부의 화재에 노출된 재실자는 열 및 화상의 위험성과 함께 연기 및 독성가스의 피해를 받기 쉽다. 본 연구에서는 건축물 화재시 발생될 수 있는 HCl에 대한 표준가스를 제작하여 가스유해성시험을 수행하고, HCl 표준가스에 노출된 실험용 쥐의 표적장기적출실험을 수행하였다. 이를 통해서 유독가스에 노출된 실험용 쥐의 해부를 통한 표적장기-심장(Heart), 간(Liver), 폐(Lung), 비장(Spleen), 신장(Kidney), 흉선(Thymus)-의 손상여부와 KS F 2271에 의한 평균행동정지시간과의 관계를 분석하였다.

• The Monthly Technology and Standards
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• s.140
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• pp.56-56
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• 2013

• The Monthly Technology and Standards
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• s.66
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• pp.28-28
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• 2007