QA/SAC - Americas

Inter-laboratory Comparison Study 62 has been postponed due to the COVID-19 pandemic. Shipments will occur no earlier than 15 May.

Further delays may be needed.

Please keep your contact information up to date by logging into the QA-SAC database or by emailing


Updated: Mar 22, 2020 UTC

Welcome to the Quality Assurance/Science Activity Centre – Americas (QA/SAC-Americas), one of five QA/SACs operating to ensure data quality and support science activities in the World Meteorological Organization Global Atmosphere Watch (GAW).

The QA/SAC-Americas seeks to document and help improve the quality of precipitation chemistry measurements from around the world. It conducts semi-annual inter-laboratory comparison studies. Graphical and tabular results of past studies are available by accessing Study Results.

Guidance on all aspects of collecting precipitation for chemical analysis is provided in the GAW Guidelines for Precipitation Chemistry and Deposition Measurements.

Visit the World Data Centre for Precipitation Chemistry Website for information about the Global Assessment of Precipitation Chemistry and Deposition.

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