CCQM-K90, formaldehyde in nitrogen, 2 μmol mol⁻¹ Final report

Viallon, le,Flores, Edgar,Idrees, Faraz,Moussay, Philippe,Wielgosz, Robert Ian,Kim, D,Kim, Y D,Lee, S,Persijn, S,Konopelko, L A,Kustikov, Y A,Malginov, A V,Chubchenko, I K,Klimov, A Y,Efremova, O V,Zh BUREAU INTERNATIONAL DES POIDS ET MESURES 2017 METROLOGIA -BERLIN- Vol.54 No.1

CCQM-K120 (Carbon dioxide at background and urban level)

Flores, Edgar,Viallon, Joë,le,Choteau, Tiphaine,Moussay, Philippe,Idrees, Faraz,Wielgosz, Robert I,Lee, Jeongsoon,Zalewska, Ewelina,Nieuwenkamp, Gerard,Veen, Adriaan van der,Konopelko, L A,Kustiko BUREAU INTERNATIONAL DES POIDS ET MESURES 2019 METROLOGIA -BERLIN- Vol.56 No.-

<P></P> <P>CCQM-K120.a comparison involves preparing standards of carbon dioxide in air which are fit for purpose for the atmospheric monitoring community, with stringent requirements on matrix composition and measurement uncertainty of the CO<SUB>2</SUB> mole fraction. This represents an analytical challenge and is therefore considered as a Track C comparison. The comparison will underpin CMC claims for CO<SUB>2</SUB> in air for standards and calibrations services for the atmospheric monitoring community, matrix matched to real air, over the mole fraction range of 250 μmol/mol to 520 μmol/mol.</P> <P>CCQM-K120.b comparison tests core skills and competencies required in gravimetric preparation, analytical certification and purity analysis. It is considered as a Track A comparison. It will underpin CO<SUB>2</SUB> in air and nitrogen claims in a mole fraction range starting at the smallest participant's reported expanded uncertainty and ending at 500 mmol/mol. Participants successful in this comparison may use their result in the flexible scheme and underpin claims for all core mixtures</P> <P>This study has involved a comparison at the BIPM of a suite of 44 gas standards prepared by each of the participating laboratories. Fourteen laboratories took part in both comparisons (CCQM-K120.a, CCQM-K120.b) and just one solely in the CCQM-K120.b comparison.</P> <P>The standards were sent to the BIPM where the comparison measurements were performed. Two measurement methods were used to compare the standards, to ensure no measurement method dependant bias: GC-FID and FTIR spectroscopic analysis corrected for isotopic variation in the CO<SUB>2</SUB> gases, measured at the BIPM using absorption laser spectroscopy. Following the advice of the CCQM Gas Analysis Working Group, results from the FTIR method were used to calculate the key comparison reference values.</P> <P>KEY WORDS FOR SEARCH</P> <P>FTIR, CO2, GC-FID, Carbon dioxide at background level, Carbon dioxide at urban level, Delta Ray, CO2 gas standards</P> <P></P> <H2>Main text</H2> <P> To reach the main text of this paper, click on <A HREF='https://www.bipm.org/utils/common/pdf/final_reports/QM/K120/CCQM-K120.pdf'>Final Report</A>. Note that this text is that which appears in Appendix B of the BIPM key comparison database <A HREF='http://kcdb.bipm.org/'>kcdb.bipm.org/</A>.</P> <P>The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).</P>

International comparison CCQM-K82: methane in air at ambient level (1800 to 2200) nmol/mol

Flores, Edgar,Viallon, Joë,le,Choteau, Tiphaine,Moussay, Philippe,I Wielgosz, Robert,Kang, Namgoo,Moon Kim, Byung,Zalewska, Ewelina,(A M H) van der Veen, Adriaan,Konopelko, Leonid,Wu, Hai,Han, Qia IOP 2015 Metrologia Vol.52 No.-

<P>The CCQM-K82 comparison was designed to evaluate the degrees of equivalence of NMI capabilities for methane in air primary reference mixtures in the range (1800 to 2200) nmol/mol. The balance gas for the standards was either scrubbed dry real air or synthetic air.</P> <P> CH<SUB>4</SUB> in air standards have been produced by a number of laboratories for many years, with more recent developments focused on standards at atmospheric measurement concentrations and aimed at obtaining agreement between independently produced standards. A comparison of the differences in primary gas standards for methane in air was previously performed in 2003 (CCQM-P41 Greenhouse gases. 1 and 2) with a standard deviation of results around the reference value of 30 nmol/mol and 10 nmol/mol for a more limited set of standards. This can be contrasted with the level of agreement required from field laboratories routinely measuring atmospheric methane levels, set by Data Quality Objectives (DQO) established by the World Meteorological Organization (WMO) to reflect the scientifically desirable level of compatibility for CH<SUB>4</SUB> measurements at the global scale, currently set at 2 nmol/mol (1 sigma).</P> <P> The measurements of this key comparison took place from May 2012 to June 2012.</P> <P> Eight laboratories took part in this comparison coordinated by the BIPM and NIST. Key comparison reference values were calculated based on Cavity Ring Down Spectroscopy Measurements performed at the BIPM, combined with participant's gravimetric values to identify a consistent set of standards. Regression analysis allowed predicted values for each standard to be calculated which acted as the KCRVs. In this comparison reported standard uncertainties by participants ranged from 0.50 nmol/mol to 2.4 nmol/mol and the uncertainties of individual KCRVs ranged from 0.68 nmol/mol to 0.71 nmol/mol.</P> <P> The standard deviation of the ensemble of standards about the KCRV value was 1.70 nmol/mol. This represents a greater than tenfold improvement in the level of compatibility of methane in air standards compared to that demonstrated in 2003. Further improvements in the compatibility of standards will require improved methods and uncertainties for the measurement of trace level methane in balance gases. </P> <P><B>Main text.</B> To reach the main text of this paper, click on <A HREF='http://www.bipm.org/utils/common/pdf/final_reports/QM/K82/CCQM-K82.pdf'>Final Report</A>. Note that this text is that which appears in Appendix B of the BIPM key comparison database <A HREF='http://kcdb.bipm.org/'>kcdb.bipm.org/</A>.</P> <P>The final report has been peer-reviewed and approved for publication by CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).</P>

Final report of the pilot study CCQM-P110-B1: A comparison of nitrogen dioxide (NO₂) in nitrogen standards at 10 µmol/mol by Fourier transform infrared spectroscopy (FT-IR)

Flores, Edgar,Idrees, Faraz,Moussay, Philippe,Viallon, Joë,le,Wielgosz, Robert,Ferná,ndez, Teresa,Rojo, André,s,Ramí,rez, Sergio,Aoki, Nobuyuki,Kato, Kenji,Jeongsoon, Lee,Moon, D Springer-Verlag 2012 METROLOGIA -BERLIN- Vol.49 No.-

<P>This pilot study compares the performance of participants in analyzing gas mixtures of nitrogen dioxide in nitrogen by comparison with in-house gravimetric standards using Fourier transformed infrared spectroscopy (FT-IR). In this study the same gas mixtures were used as in the key comparison CCQM-K74, which was designed to evaluate the level of comparability of National Metrology Institutes' measurement capabilities for nitrogen dioxide (NO<SUB>2</SUB>) at a nominal mole fraction of 10 µmol/mol. In the comparison CCQM-K74 most of the participants used chemiluminescence, with a small number using UV absorption or FT-IR spectroscopy, and thus it is of interest to improve understanding of the comparative performance of these techniques because they do not exhibit any cross-sensitivity to nitric acid (HNO<SUB>3</SUB>), which was known to be present in the mixtures used for the comparison.</P><P>The results of this pilot study indicate good consistency and a level of agreement similar to that reported in the comparison CCQM-K74, demonstrating that FT-IR can be operated as a comparison method when calibrated with appropriate gas standards and can achieve similar measurement uncertainties to chemiluminescence and UV absorption techniques.</P><P>An additional pilot study, CCQM-P110-B2, was conducted on the same gas mixtures in parallel with this pilot study. The second study addressed FT-IR spectroscopy when used to measure the gas mixtures with respect to reference spectra. The results of this second study will be reported elsewhere.</P><P>Main text.To reach the main text of this paper, click on Final Report.</P><P>The final report has been peer-reviewed and approved for publication by the CCQM-GAWG.</P>

Final report on international comparison CCQM-K74: Nitrogen dioxide, 10 µmol/mol

Flores, Edgar,Idrees, Faraz,Moussay, Philippe,Viallon, Joë,le,Wielgosz, Robert,Ferná,ndez, Teresa,Ramí,rez, Sergio,Rojo, André,s,Shinji, Uehara,Waldé,n, Jari,Sega, Michela Springer-Verlag 2012 METROLOGIA -BERLIN- Vol.49 No.-

<P>There is a high international priority attached to activities which reduce NO<SUB>x</SUB> in the atmosphere. The current level of permitted emissions is typically between 50 µmol/mol and 100 µmol/mol, but lower values are expected in the future. Currently, ambient air quality monitoring regulations also require the measurement of NO<SUB>x</SUB> mole fractions as low as 0.2 µmol/mol. The production of accurate standards at these levels of mole fractions requires either dilution of a stable higher concentration gas standard or production by a dynamic technique, for example one based on permeation tubes.</P><P>The CCQM-K74 key comparison was designed to evaluate the level of comparability of National Metrology Institutes' measurement capabilities and standards for nitrogen dioxide (NO<SUB>2</SUB>) at a nominal mole fraction of 10 µmol/mol.</P><P>The measurements of this key comparison took place from June 2009 to May 2010.</P><P>Seventeen laboratories took part in this comparison coordinated by the BIPM and VSL. The key comparison reference value was based on BIPM measurement results, and the standard measurement uncertainty of the reference value was 0.042 µmol/mol.</P><P>This key comparison demonstrated that the results of the majority of the participants agreed within limits of ±3% relative to the reference value. The results of only one laboratory lay significantly outside these limits. Likewise this comparison made clear that a full interpretation of the results of the comparison needed to take into account the presence of nitric acid (in the range 100 nmol/mol to 350 nmol/mol) in the cylinders circulated as part of the comparison, as well as the possible presence of nitric acid in the primary standards used by participating laboratories.</P><P>Main text.To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.</P><P>The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).</P>

전 지구 대기 오존 측정에 대한 새로운 오존흡수단면적 적용 이행을 위한 활동

이상일,Paul J. Brewer,Andrew S. Brown,Joele Viallon,Robert I. Wielgosz,Edgar Flores,Joseph J. Hodges,Jennifer Carney,James Norris,Louise Sorensen,Joann Rice,Christoph Zellweger,Hiroshi Tanimoto,Bernhard 한국대기환경학회 2022 한국대기환경학회 학술대회논문집 Vol.2022 No.10