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BIPM news: Revision of the SI
    The International System of Units - making measurements fundamentally better [2019]  
The 20th May 2019 marks a particularly special celebration of World Metrology Day because it is the day chosen for the implementation of the changes agreed to the definitions of the SI base units. These landmark changes were decided at the 26th meeting of the General Conference on Weights and Measures (CGPM), which took place in Versailles in November 2018.
    26th meeting of the CGPM: presentations and outcomes available on the BIPM website [2018]  
The presentations and outcomes of the 26th meeting of the CGPM are now available on the BIPM website. A recording of the live open session, which took place on Friday 16 November 2018, can be viewed on the BIPM's YouTube Channel.
    International System of Units revised in historic vote [2018]  
In a landmark decision, representatives from 54 of the BIPM's Member States voted on 16 November 2018 to revise the International System of Units (SI), changing the world's definition of the kilogram, the ampere, the kelvin and the mole.
    Maintaining and disseminating the kilogram following its redefinition [2018]  
The expected adoption of a new definition of the kilogram by the 26th CGPM in November 2018 will bring to an end the period during which the kilogram was defined as the mass of a material artefact, the IPK. The new definition opens the possibility for NMIs to develop their own realization experiments.
    Information for users about the proposed revision of the SI [2017]  
Joint Statement prepared in 2017 by the CIPM Consultative Committees on the proposed revision of the SI
    Important steps towards revising the SI in 2018 [2017]  
At its meeting on 20 October 2017, the CIPM agreed to recommend to the General Conference on Weights and Measures (CGPM) that it proceed in 2018 with the expected redefinition of the base units of the SI. The values of the constants that will be used to redefine the SI have been published in Metrologia.
    CCU Recommendation U 1 (2017) [2017]  
On the possible redefinition of the kilogram, ampere, kelvin and mole in 2018
    Input data for the special CODATA-2017 adjustment [2017]  
See the papers published in Metrologia providing input data for the special CODATA-2017 adjustment.
    CCM Pilot Study of future realizations of the kilogram [2017]  
The BIPM has carried out a CCM pilot comparison of mass calibrations based on methods that will be used to realize the kilogram after its redefinition.
    CCT Recommendation T 1 (2017) [2017]  
For a new definition of the kelvin in 2018
    CCM Recommendation G 1 (2017) [2017]  
For a new definition of the kilogram in 2018
    SI graphics and Brand Book [2017]  
Promotional files prepared by the Task Group for Promotion of the SI.
    Message to authors intending to submit values for the special 2017 adjustment [2017]  

Authors are aware of the CIPM Decision/104-9 that experimental results to be considered by the CODATA-TGFC should be accepted for publication by 1 July 2017.

To facilitate the smooth-running of the editorial review process – in particular to ensure that the timeline is agreed and appropriate referees are available – authors intending to submit a value for the special 2017 adjustment of the fundamental constants are invited to make contact with the editorial office of Metrologia (met(a)iop.org) as soon as possible, giving the approximate title and complete author list.

    Metrologia Focus on Realization, Maintenance and Dissemination of the Kilogram [2016]  
The first papers in this Focus Issue, which is one of the steps on the CCM/CCU roadmap towards the redefinition of the SI in 2018, are now available. Guest Editors: Horst Bettin (PTB) and Stephan Schlamminger (NIST).
    Responses to the survey concerning promotion of the new SI [2016]  
The CIPM Task Group for the Promotion of the New SI will use the findings of the survey to develop future materials that can be used by the NMIs and the broader metrology community to promote the benefits of the redefinitions as widely as possible.
    Survey concerning promotion of the new SI [2016]  
In order to help with the coordination of communications about the new SI, a CIPM Task Group for the Promotion of the New SI has been set up and is being advised by a small group of communications professionals from NMIs. The CIPM Task Group will prepare promotional material that will be made available for every NMI to use as part of its activities.

On behalf of the PR Expert Group, the BIPM has sent a survey to all NMI Directors. The Survey will help to identify information about promotional materials or activities that the NMIs themselves are planning.
    Crucial test for the kilogram redefinition [2016]  
The BIPM will act as the pilot laboratory for a comparison of the future realizations of the kilogram, a crucial test for the kilogram redefinition.
    Measuring the Planck constant with an aluminium cube [2015]  
Richard Davis of the BIPM has developed a simple experiment to determine the value of the Planck constant to better than 1 % by measuring the mass of a 20 g aluminium cube. The details have been published in the Journal of Chemical Education and the article is currently listed among the 20 most downloaded articles of the past 12 months.
    NIST donates demonstration watt balance to the BIPM [2015]  
The BIPM has received from NIST a demonstration watt balance made from LEGO bricks, to show visitors the basic features of the much more elaborate laboratory device.
    Results of measurements with the International Prototype of the Kilogram published [2015]  
Between January 2014 and January 2015, the BIPM Mass Department carried out a calibration campaign with respect to the International Prototype of the Kilogram (IPK), in anticipation of the planned redefinition of the kilogram. The results have been published in the latest edition of Metrologia. This calibration campaign, named "Extraordinary Calibrations", is an important element of the CCM roadmap towards the redefinition of the kilogram.
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