International complimentary bilateral study SIM.QM-S3

Main text SIM member INMETRO, Brazil, approached NIST to conduct a bilateral comparison. NIST sent to INMETRO a gravimetric primary standard mixture (PSM) containing nominal 100 μmol/mol methane (CH4) in air. NIST prepared the primary standard mixture (PSM) gravimetrically and analysed against other NIST PSMs by gas chromatography/flame-ionization detection (GC/FID) before shipping to INMETRO and again after the test mixture arrived back at NIST. INMETRO analysed the unknown test mixture and submitted their results and findings to NIST. 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 https://www.bipm.org/kcdb/ . 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).