TGFC - Past Achievements

Achievements 2016

  • The TGFC has recently published the detailed review article on the 2014 CODATA adjustment of the fundamental constants in Reviews of Modern Physics (Rev. Mod. Phys. 88, 035009 (2016) and in the Journal of Physical and Chemical Reference Data (J. Phys. Chem. Ref. Data 45, 043102 (2016)).  If the revised SI is adopted in 2018, the 2014 CODATA adjustment of the fundamental constants is unique in that it is the last adjustment in the present SI.
  • Using the 2014 values as a template, the TGFC also assisted and advised the Consultative Committee for Units (CCU) during the 22nd meeting of the CCU (15 – 16 June, 2016, BIPM) on the draft resolution 1 adopted by the 105th meeting of the International Committee for Weights and Meaures (CIPM) (October, 2016).  In particular, the CIPM agreed with the proposal made by the CCU that the number of digits be kept in the numerical values of the defining constants (i.e. within the relative standard uncertainties from the special 2017 CODATA adjustment of the fundamental constants).


The latest recommended set of constants, called the 2010 LSA, was released early in 2011 on the NIST website ( and published in 2012 (Mohr et al., Rev. Mod. Phys. 84, 1527 (2012) and Mohr et al., J. Phys. Chem. Ref. Data 41043109 (2012)).


  • For 2015

1 – 6 February 2015 - Workshop on the determination of the fundamental constants, Eltville, Germany, Organized by the TGFC. 

  • For 2014

Task Group updates LSA for CCU/CIPM for CIPM meeting held in November. Update discussed within Task Group by email.

30 August 2014 – Task Group meeting in conjunction with the 2014 Conference on Precision Electromagnetic Measurements, Rio de Janeiro, Brazil.  Review new data for upcoming normal 2014 LSA, in particular new watt balance results and isotopic abundance measurements associated with the International Avogadro Project.

3-4 November 2014 – Second 2014 Task Group meeting at the BIPM.  Final meeting before closing date for new relevant data for 2014 LSA.  Focus on decisions on discrepant data.  Special session on data associated with the proton charge radius with invited guest speakers in the research fields of QED, electron-proton scattering, and muonic hydrogen.

Collection of new relevant data, entered into the Fundamental Constants Data Center, in preparation for 2014 LSA

  • For 2013

Consultative Committee for Electricity and Magnetism (CCEM) meeting, March 2013. Status report from the Task Group on fundamental constants given by Dr. Barry Wood.

Task Group meeting 10 June, 2013, BIPM. Acceptance of status report to be given to the CCU. Status report focused on relevant data impacting the values and uncertainties of h, e, k and NA since these are the four constants to be defined as exact in the new SI. Results of unofficial LSAs on the values and uncertainties of h, e, k and NA presented.

CCU meeting June, 2013, BIPM. Dr. David Newell represented CODATA and submitted status report. Presentation focused on the history and role of the CODATA TGFC, new data relevant to h, e, k and NA, and discrepant data associated with the proton charge radius.


Selected Working documents

Minutes :

The reports on the meeting of the CODATA Task Group on Fundamental Constants,
from 2000 to 2014 are available in open access here.


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