CCM.M-K8.2024
MEASURAND Realization of the kilogram
NOMINAL VALUE 1 kg
Degrees of equivalence represented by Di = (xi - xR) and its expanded uncertainty Ui at a 95 % level of confidence, both expressed in mg.
The CCM has decided that, until the dispersion between enough results of individual realizations of the kilogram becomes compatible with the individual realization uncertainties, NMIs should base their dissemination on an agreed “consensus value”. The details of this international coordination of the kilogram dissemination are described in the “CCM detailed note on the dissemination process after the redefinition of the kilogram”, available from the BIPM web site.
CCM.M-K8.2024
MEASURAND Realization of the kilogram
NOMINAL VALUE 1 kg
Degrees of equivalence represented by Di = (xi - xR) and its expanded uncertainty Ui at a 95 % level of confidence, both expressed in mg.
| LABi | Di | Uneg,i | Upos,i | |
|---|---|---|---|---|
mg |
mg |
mg |
||
| BIPM | -0.0070 | 0.0711 | ||
| CMS | 0.0147 | 0.0753 | ||
| LNE | 0.0099 | 0.0724 | ||
| METAS | -0.0404 | 0.1075 | ||
| NIM | -0.0215 | 0.0572 | ||
| NIST | -0.0043 | 0.0236 | ||
| NMIJ | -0.0107 | 0.0401 | ||
| NRC | 0.0202 | 0.0198 | ||
| PTB | -0.0078 | 0.0241 | ||
| UME | -0.0252 | 0.0723 |
The CCM has decided that, until the dispersion between enough results of individual realizations of the kilogram becomes compatible with the individual realization uncertainties, NMIs should base their dissemination on an agreed “consensus value”. The details of this international coordination of the kilogram dissemination are described in the “CCM detailed note on the dissemination process after the redefinition of the kilogram”, available from the BIPM web site.
| Metrology area, Sub-field | Mass and related quantities, Mass Standards |
| Description | Realization of the kilogram |
| Time of measurements | 2024 - 2025 |
| Status | Approved for equivalence |
| Final Reports of the comparisons | |
| Measurand | Mass 1 kg |
| Parameters | Measurement under vacuum or in air |
| Transfer device | 1 kg mass standards |
| Comparison type | Key Comparison |
| Consultative Committee | CCM (Consultative Committee for Mass and Related Quantities) |
| Conducted by | CCM (Consultative Committee for Mass and Related Quantities) |
| Comments | Results published 26 January 2026 |
| Pilot institute |
BIPM
Bureau International des Poids et Mesures BIPM - International Organization |
| Contact person | M. Stock +33 (0) 1 45 07 70 24 |
| Pilot laboratory | |
|---|---|
| BIPM |
Bureau International des Poids et Mesures, BIPM - International Organization, N/A |
| CMS (became CMS/ITRI) |
ITRI Center for Measurement Standards (became Industrial Technology Research Institute/Center for Measurement Standards), Chinese Taipei, APMP |
| LNE |
Laboratoire national de métrologie et d'essais, France, EURAMET |
| METAS |
Federal Institute of Metrology, Switzerland, EURAMET |
| NIM |
National Institute of Metrology, China, APMP |
| NIST |
National Institute of Standards and Technology, United States, SIM |
| NMIJ AIST |
National Metrology Institute of Japan, Japan, APMP |
| NRC |
National Research Council, Canada, SIM |
| PTB |
Physikalisch-Technische Bundesanstalt, Germany, EURAMET |
| UME |
TÜBITAK Ulusal Metroloji Enstitüsü, Türkiye, EURAMET |
This page proposes print-out on A4 paper (portrait) of the comparison details (best printed out using a black and white printer).
Please, select items to be printed out, then click on "OK" :
CCM.M-K8.2024
MEASURAND Realization of the kilogram
NOMINAL VALUE 1 kg
The key comparison reference value xR is calculated as the weighted mean of the participants' results, excluding the results of CMS, which is not a member state of the BIPM. It deviates by -0.0107 mg with respect to the previous definition of the kilogram, the mass of the International Prototype of the Kilogram, as maintained by the BIPM working standards.
The associated standard uncertainty uR (xR) = 0.0064 mg
The degree of equivalence of laboratory i relative to the key comparison reference value xR is given by a pair of terms, both expressed in mg:
Di = (xi - xR) and its expanded uncertainty Ui at a 95 % level of confidence where Ui = 2 (ui2 - uR2)1/2 for participants which contributed to the calculation of the KCRV and Ui = 2 (ui2 + uR2)1/2 for CMS which did not contribute to the KCRV.
CCM.M-K8.2024
MEASURAND Realization of the kilogram
NOMINAL VALUE 1 kg
Information on measurement data are given in the CCM.M-K8.2024 Final Report.
