Dissemination of the kilogram from the second Consensus Value

The second Consensus Value, the internationally agreed mean of the kilogram realizations, will come into force on 1 March 2023. The final report of the most recent key comparison used for the 2023 calculation is available in Metrologia. 

Completion of the second key comparison of kilogram realizations

Human- and machine-readable key comparison reports using the PDF/A-3 format

The BIPM is pleased to announce the publication of the first key comparison report embedding machine-readable versions of the document.

Preparing for the transition from a GaAs to a graphene-based quantum Hall resistance reference at the BIPM

The BIPM is studying new graphene-based QHR samples which offer an alternative to GaAs based standards and which will allow the transition to a compact graphene-based reference in a few years.

Beginning a new phase of the dissemination of the kilogram

Following completion of the first key comparison of realizations of the kilogram, CCM.M-K8.2019, the internationally coordinated dissemination of the kilogram is entering into a new phase. From 1 February 2021, the traceability of the mass unit to the Planck constant will be taken from the 'consensus value' of the kilogram.

BIPM Kibble balance makes significant progress towards realizing the new kilogram definition in 2019

Significant progress towards the completion of the BIPM Kibble balance for realizing the new kilogram definition has been made in 2019. The BIPM will participate in the first key comparison of realizations of the new definition of the kilogram, CCM.M-K8.2019.

Review paper in Metrologia: "The revision of the SI - the result of three decades of progress in metrology"

Following three decades of intensive work by the world-wide metrology community, the 26th meeting of the CGPM agreed a major revision of the SI on 16 November 2018. This open-access review paper in Metrologia describes the changes.