Final report on CCQM-K19.1 : pH of borate buffer

• Autor(a) principal: Spitzer, Petra
• Data de Publicação: 2011
• Outros Autores: Adel, Beatrice, Meyer, Joachim, Matzke, J., Borges, Paulo Paschoal, Dias, Júlio Cesar, Gonzaga, Fabiano Barbieri, Hongyu, Xiu, Bing, Wu Xiao, Jakobsen, Pia Tonnes, Champion, Rachel, Ohata, Masaki, Maksimov, Igor, Hioki, Akiharu, Vyskočil, Leoš, Máriássy, Michal, Pratt, Kenneth W., Inmetro, Instituto Nacional de Metrologia, Qualidade e Tecnologia
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional do INMETRO
• Texto Completo: http://hdl.handle.net/10926/1236

The subsequent key comparison CCQM-K19.1 has been carried out in 2010 as a follow-up comparison to CCQM-K19. Three laboratories (NMIJ, PTB and SMU) took part in both com-parisons. Their results are consistent. The assigned uncertainties are reliable and in the same order. These results provide the link to CCQM-K19. As well as the original comparison the subsequent key comparison was organised to demon-strate the capability of the interested National Metrology Institutes to measure the pH value of an unknown borate buffer by a primary method at 15 °C, 25 °C and 37 °C. Eight laborato-ries took part in CCQM-K19.1. The participants either were not able to participate in the original comparison or participate only in the Pilot Study CCQM-P82 running in parallel to CCQM-K19. In one case the laboratory expressed doubts on the integrity of the sample pro-vided in CCQM-K19. The result in CCQM-K19.1 is the acidity function at zero chloride molality, AF0 of the un-known borate buffer solution. Most participants in the key comparison CCQM-K19.1 demonstrated improved capabilities. This especially applies for the laboratories original taken part in the pilot study CCQM-P82. In some cases previous results could be confirmed. The hidden reasons for that have still to be clarified.