Introduction. (hqp:// units/new- si/)

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1 OUT US WORLDWIDE METROLOGY INTERNATIONAL EQUIVALENCE the future revision of the SI MEASUREMENT UNITS Introduction SERVICES PUBLICATIONS (hqp:// units/new- si/) Future revision of the SI What? Why? When? Ongoing work Communication and debate; draft documents FAQs; More info. The AtNew SI based fixed values of: CGPM adopted a its 25th meetingon (November 2014) the on the future revision of the International System of Units. Resolution Planck constant, h This Resolution built on the CGPM's previous Resolution (2011), which note of the CIPM's intentionn to propose a revision of the SI and took Avogadro constant, set out a detailed road-map towardsathe future changes. elementary charge, e In the "New SI" four of the SI base units namely the Boltzmann constant, k and the mole will be kilogram, the ampere, the kelvin redefined in terms of constants; the new definitions will be based on fixed numerical values of the Planck constant (h), the elementary charge (e),ththe Boltzmann constant (kb), and the Avogadro constant (NA), respectively. Further, the definitions of all seven base units of the SI will also be uniformly expressed using the explicit-constant formulation, and specific mises en pratique will be drawn up to explain the realization of the definitions of each of the base units in a practical way. ResoluCon 1 of the 24 meecng of the CGPM: Invites: CODATA to concnue to provide adjusted values of the fundamental physical constants... since these CODATA values and uncertain4es will be those used for the revised SI SI road-map (updated 2014) Resolution 1 of the CGPM (2014): On the future revision of the International System of Units, the SI Resolution 1 of the CGPM (2011): On the possible future revision of the International System of Units, the SI

2 TGFC members F. Cabiati, Istituto Nazionale di Ricerca Metrologica, Italy J. Fischer, Physikalisch-Technische Bundesanstalt, Germany J. Flowers*, National Physical Laboratory, United Kingdom K. Fujii, National Metrology Institute of Japan, Japan S. G. Karshenboim, D. I. Mendeleyev Institute of Metrology, Russia, and Max-Planck-Institut für Quantenoptik, Germany E. de Mirandés, Bureau International des Poids et Mesures, France P. J. Mohr, National Institute of Standard and Technology, USA D. B. Newell, National Institute of Standard and Technology, USA F. Nez, Laboratoire Kastler-Brossel, France K. Pachucki, University of Warsaw, Poland T. J. Quinn, CBE FRS, France B. N. Taylor, National Institute of Standard and Technology, USA C. C. Thomas, Bureau International des Poids et Mesures, France B. M. Wood, National Research Council, Canada Z. Zhang, National Institute of Metrology, China *Deceased

3 TGFC LSA Methodology Collect all data Older data form previous LSAs Include new data since the last LSA Preliminary review of the data Check for up-to-date input and corrections, full uncertainty analysis, and internal consistency Select acceptable data by lowest uncertainties Assess relation with other input data Supersedes previous results? Covariance - sort by common uncertainty components

4 TGFC LSA Methodology (cont.d) Run mini LSA for each of the main constants and use standard statistic tools to investigate goodness of fit Chi squared (χ 2 ), Probability of reduced χ 2, Birge ratio R B, Maximum Normalized Residuals (MNR), Maximum Normalized Difference (MND), etc. Adjust expansion factors, include/exclude specific data 1% self sensitivity test Run final multi-variant LSA, argue, re-run LSA, etc. Minimize total disagreement

5 2014 Input data related to the Gravita5onal constant χ 2 : 318 DOF: 13 Prob. χ 2 : % R B : 4.95 Max. reduced residuals: , NIST-82 UWash-00 JILA-10 TR&D G BIPM-01 HUST-05 LENS-14 UCI-14 MSL-03 HUST-09 BIPM-14 LANL-97 UZur G/(10 11 m 3 kg 1 s 2 ) UWup-02 CODATA-06 CODATA-10

6 2014 Input data related to the Boltzmann constant χ 2 : 5.50 DOF: 7 Prob. χ 2 : 60.0% R B : 0.89 Max. reduced residuals: , k AGT NIST-88(Ar) AGT LNE-09(He) AGT NPL-10(Ar) AGT LNE-11(Ar) CODATA-10 AGT AGT NIM-13(Ar) NPL-13(Ar) DCGT PTB-15 AGT LNE-15(He) CODATA- 14 Rel. Unc.: CODATA [k/(10 23 J/K) 1.380] 10 4

7 2014 Input data related to the Planck constant h χ 2 : 8.49 DOF: 4 Prob. χ 2 : 7.52% R B : 1.45 Max. reduced residuals: 1.98, 1.86 CODATA- 14 Rel. Unc.: KJ 2R K NIST-98 N A ( 28 Si) IAC-11 KJ 2R K NRC-14 KJ 2R K NIST-15 N A ( 28 Si) IAC-15 CODATA [h/(10 34 Js) ] 10 5

8 LETTER doi: /nature13026 High-precision measurement of the atomic mass of the electron S. Sturm 1,F.Köhler 1,2, J. Zatorski 1, A. Wagner 1, Z. Harman 1,3, G. Werth 4, W. Quint 2, C. H. Keitel 1 & K. Blaum 1 Factor 13 more accurate than other data Silicon and carbon frequency ratio measurements correlated 10-9 A r (e) CODATA 2010 Need to review ionization energies of carbon and silicon MPIK [A r (e) ] 10 12

9 2014 Input data related to the Fine- structure constant χ 2 : 5.82 DOF: 2 Prob. χ 2 : 5.8% R B : 1.71 Max. reduced residuals: 1.51, α 1 a e Harvard-08/ QED-10 h/m(rb) LKB-11 CODATA-10 a e Harvard-08/ QED-14 h/m(rb) LKB-11/14 h/m(cs) Berkeley-13 CODATA- 14 Rel. Unc.: CODATA (α ) 10 5

10 Rydberg constant, muonic hydrogen, and the proton radius

11 CODATA TGFC mee5ng 1 2 November, 2014 codata-tgfc jpg 1,800 1,093 pixels 2/3/15, 6:55 PM

12 the intergovernmental organization through which Member States act together hqp:// tgfc/ on matters related to measurement science and measurement standards. Search facility:!!site map!!news!!contact us ABOUT US WORLDWIDE METROLOGY INTERNATIONAL EQUIVALENCE MEASUREMENT UNITS SERVICES PUBLICATIONS MEETINGS CODATA Task Group on Fundamental Constants Introduction Membership Recommended values of the fundamental constants Contact info. Minutes Members' area The purpose of the CODATA Task Group on Fundamental Constants (TGFC) is "to periodically provide the scientific and technological communities with a self-consistent set of internationally recommended values of the basic constants and conversion factors of physics and chemistry based on all of the relevant data available at a given point in time." The CODATA-TGFC is not constituted under the auspices of the BIPM, but because of the close linkage between the SI units and fundamental constants, it enjoys a close relationship with the CCU and the BIPM; this portal, created as a working website for the Task Group, is an example. The public section of this website provides information about the activities of the Task Group on Fundamental Constants including meeting dates, meeting minutes, and membership. CODATA internationally recommended values of the Fundamental Physical Constants (2010 LSA) The next meeting of the TGFC will take place on 31 August and 1st September 2015 at the BIPM.! More!! Members of the CODATA Task Group on Fundamental Constants Group photograph (November 2014, BIPM) Meeting reports Paper on the 2010 LSA CODATA-TGFC Working Documents : (TGFC members only) More information on CODATA:

13 On the road to redefini5on Joint CCM and CCU roadmap for the new SI 14 CCM CCU Convocation CGPM Metrologia special edition Mise en pratique (mep kg) 15 CCM mep kg (with references for the mep) approved BIPM extraordinary calibration with IPK Traceability to IPK Initial pilot study (kg) (preparation, measurements & report) CCM R3 CCU updated mep kg 16 approved CCM CCM R4 Consultation / announcement BIPM pool established XRCD and available WB publish consistent results and characterized EMRP know and NewKILO projects CCM R1&2 Pool linked to experiments NMI directors meetings Closing date for new data CIPM Convocation CCU CODATA (final LSA) CGPM Conditions from CCM Recommendation G1 (2013) 3

14 Cri5cal Closing Dates for Data 1 July 2017 Closing date for data for special CODATA constants adjustment to determine exact values of h, e, k, and N A for 2018 revised SI (International System of Units). BY this date data must be published or available in a preprint accepted for publication.

15 Cri5cal Closing Dates for Data 1 July 2018 Closing date for data for CODATA constants adjustment to determine new set of CODATA recommended values consistent with the revised SI (replaces 31 December 2018 normal closing date). By this date data should be published or available in a preprint for publication.