Machine-readable data and metadata of international key comparisons in radionuclide metrology

The digitalization of key comparisons in radionuclide metrology is being studied at the BIPM. Results of comparisons are made available on the BIPM KCDB platform where a PDF/A document can be downloaded. Access to the metadata contained in the PDF is not straightforward. Therefore, the XML and JSON versions of the report are now embedded in the PDF/A document, allowing direct access to the metadata. This achievement is a first step towards the implementation of FAIR (findable, accessible, interoperable, reusable) principles and does not affect the current policy of publishing comparison results. The combination of PDF/A and XML technologies seems to be an effective way to carry out digitalization. The strengths of both technologies can be brought together to meet the FAIR principles and ISO/IEC 17025 compliance. This approach benefits from robust data exchange features such as XML Schema and XML namespaces, as well as secure digital signatures and long-term archiving of PDF/A-3 documents.