International Comparison CCQM-K51 - Carbon Monoxide (CO) in Nitrogen (5 µmol mol-1)

The first key comparison on carbon monoxide (CO) in nitrogen dates back to 1992 (CCQM-K1a). It was one of the first types of gas mixtures that were used in an international key comparison. Since then, numerous national metrology institutes (NMIs) have been setting up facilities for gas analysis, and have developed claims for their Calibration and Measurement Capabilities (CMCs) for these mixtures. Furthermore, in the April 2005 meeting of the CCQM (Consultative Committee for Amount of Substance) Gas Analysis Working Group, a policy was proposed to repeat key comparisons for stable mixtures every 10 years. This comparison was performed in line with the policy proposal and provided an opportunity for NMIs that could not participate in the previous comparison. NMISA from South Africa acted as the pilot laboratory. Of the 25 participating laboratories, 19 (76%) showed satisfactory degrees of equivalence to the gravimetric reference value. The results show that the CO concentration is not influenced by the measurement method used, and from this it may be concluded that the pure CO, used to prepare the gas mixtures, was not 13C-isotope depleted. This was confirmed by the isotope ratio analysis carried out by KRISS on a 1% mixture of CO in nitrogen, obtained from the NMISA. There is no indication of positive or negative bias in the gravimetric reference value, as the results from the different laboratories are evenly distributed on both sides of the key comparison reference value.

BOTHA Angelique;  JANSE VAN RENSBURG Mellisa;  TSHILONGO James;  LESHABANE Nompumelelo;  NTSASA Napo;  KATO Kenji;  MATSUMOTO Nobuhiro;  STUMMER Volker;  KONOPELKO L A;  KUSTIKOV Y A;  PANKRATOV V V;  VASSERMAN I I;  ZAVYALOV C V;  GROMOVA E V;  UPRICHARD Ian;  VARGHA Gergely;  MARUYAMA M;  HEINE Hans-Joachim;  RANGEL MURILLO Francisco;  SERRANO CABALLERO Victor M.;  PÉREZ CASTORENA Alejandro;  MACE Tatiana;  GUENTHER Frank;  MILLER Walter;  ROJO Andres;  FERNANDEZ Teresa;  CIECIORA Dariusz;  CUNHA Valnei S;  RIBEIRO Claudia C;  AUGUSTO Cristiane R;  QIAO Han;  ZHOU Zeyi;  SMEULDERS Damian;  GERBOLES Michel;  KAPUS Matej;  WESSEL Rob;  DIAS Florbela;  BAPTISTA Gonçalao;  GUPTA Prabhat K;  JOHRI P.;  LAONGSRI Bunthoon;  SINWEERUTHAI Ratirat;  NIEDERHAUSER Bernhard;  ACKERMANN Andreas;  FROEHLICH Marina;  WOLF Andreas;  LEE Jeongsoon;  MUSIL Stanislav;  VALKOVA Miroslava;  WALDEN Jari;  LAURILA Sisko; 

2011-01-14

IOP PUBLISHING LTD

JRC62817

0026-1394,   

http://www.bipm.org/utils/common/pdf/final_reports/QM/K51/CCQM-K51.pdf,    https://publications.jrc.ec.europa.eu/repository/handle/JRC62817,   

10.1088/0026-1394/47/1A/08008,