Comparison
Comparison close
Results

BIPM.EM-K10.a and EUROMET.EM.BIPM-K10.a

MEASURAND : DC voltage, Josephson standards
NOMINAL VALUE : close to 1 V

Degrees of equivalence, Di and expanded uncertainty (95% level of confidence) Ui, expressed in nV


Click on the graph for a closer view

Red diamonds: participants in BIPM.EM-K10.a
Blue circles: participants in EUROMET.EM.BIPM-K10.a

Comparison
Comparison close
Results

BIPM.EM-K10.a and EUROMET.EM.BIPM-K10.a

MEASURAND : DC voltage, Josephson standards
NOMINAL VALUE : close to 1 V

  • Key comparison BIPM.EM-K10.a

   
Lab iDiUi
 / nV/ nV
DFM*0.20.6
PTB-0.10.6
NIST0.10.6
NRC0.20.6
NPL-0.11.0
BNM-LCIE*-0.10.3
NMIJ0.00.4
NMi-VSL0.20.4
KRISS0.20.4
MSL-0.20.4
NMIA0.00.3
NIM0.00.2
SP0.10.6
IEN0.10.4
CEM0.00.4
A*STAR1.81.8
INTI-1.14.0
METAS*0.30.9

* For these laboratories, only the most recent comparison is retained.

  • Key comparison EUROMET.EM.BIPM-K10.a

The following table gives the degrees of equivalence, Di and expanded uncertainty
(95% level of confidence) Ui, for laboratories participant in EUROMET.EM.BIPM-K10.a.


The degrees of equivalence between two laboratories i and j participant in EUROMET.EM.BIPM-K10.a, Dij and expanded uncertainty (95% level of confidence) Uij, are available from EUROMET.EM.BIPM-K10.a results.

The degrees of equivalence between one laboratory participant in EUROMET.EM.BIPM-K10.a and one laboratory participant in BIPM.EM-K10.a may be computed as:
Dij = (Di - Dj) and its expanded uncertainty (95% level of confidence)
Uij = (Ui2 + Uj2)1/2.

The full matrix of equivalence is available in Summary Results (summary of the results as a .PDF file).

Comparison
Comparison close
BIPM comparison
Linked comparison
BIPM.EM-K10.a
Metrology area, Sub-field Electricity and Magnetism, DC Voltage and Current
Description DC voltage, Josephson standards
Time of measurements 1991 -
Status Continuous, approved for equivalence
Final Reports of the comparisons
References

BIPM.EM-K10 Technical Protocol Option B

BIPM.EM-K10 Technical Protocol Option A

Measurand DC voltage: 1.018 V
Transfer device Josephson standard
Comparison type Key Comparison
Consultative Committee CCEM (Consultative Committee for Electricity and Magnetism)
Conducted by BIPM (Bureau International des Poids et Mesures)
Comments

Last publication of BIPM.EM-K10.a results: 16 August 2012

EUROMET.EM.BIPM-K10.a results are linked to those of BIPM.EM-K10.a

DC voltage, Josephson standards, 1.018 V

Pilot institute BIPM
Bureau International des Poids et Mesures
BIPM - International Organization
Contact person S. Solve
ssolve@bipm.org
+33 (0) 1 45 07 70 26
First Name Last Name
wwww@ww.www +356719836 Institute 1 Institute 1 Khmelnitskiy
Pilot laboratory
BIPM

Bureau International des Poids et Mesures, BIPM - International Organization, N/A

BNM-LCIE

Bureau National de Métrologie - Laboratoire Central des Industries Electriques (became LNE in 2005), France, EURAMET

CEM

Centro Español de Metrologia, Spain, EURAMET

CSIRO-NML

Commonwealth Scientific and Industrial Research Organization - National Measurement Laboratory; became National Measurement Institute, Australia, NMIA in 2004, Australia, APMP

DFM

Danish Fundamental Metrology Ltd, Denmark, EURAMET

DMDM

Directorate of Measures and Precious Metals, Serbia, EURAMET

IEN

Istituto Elettrotecnico Nazionale Galileo Ferraris; from 1st January 2006: Istituto Nazionale di Ricerca Metrologica, INRIM, Italy, EURAMET

INTI

Instituto Nacional de Tecnologia Industrial, Argentina, SIM

KRISS

Korea Research Institute of Standards and Science, Korea, Republic of, APMP

METAS

Federal Institute of Metrology, Switzerland, EURAMET

MSL

Measurement Standards Laboratory, New Zealand, APMP

NIM

National Institute of Metrology, China, APMP

NIMT

National Institute of Metrology (Thailand), Thailand, APMP

NIST

National Institute of Standards and Technology, United States, SIM

NMC, A*STAR

National Metrology Centre, Agency for Science, Technology and Research, Singapore, APMP

NMIJ AIST

National Metrology Institute of Japan, Japan, APMP

NMi-VSL

Nederlands Meetinstituut - Van Swinden Laboratorium (became VSL in 2009), Netherlands, EURAMET

NPL

National Physical Laboratory, United Kingdom, EURAMET

NRC

National Research Council, Canada, SIM

PTB

Physikalisch-Technische Bundesanstalt, Germany, EURAMET

SP

Technical Research Institute of Sweden from 2017 Research Institutes of Sweden AB, Sweden, EURAMET

Comparison
Comparison close
Results

BIPM.EM-K10.a and EUROMET.EM.BIPM-K10.a

MEASURAND : DC voltage, Josephson standards
NOMINAL VALUE: close to 1 V

  • Key comparison BIPM.EM-K10.a

The key comparison reference value is the BIPM value. Its standard uncertainty is evaluated to be 0.1 nV and is included in the ui's values.

The degree of equivalence of each laboratory with respect to the reference value is given by a pair of terms:
Di = xi and its expanded uncertainty (k = 2), Ui = 2 ui, both expressed in nV.

The degree of equivalence between two laboratories i and j is given by a pair of terms:
Dij = Di - Dj = (xi - xj) and its expanded uncertainty (k = 2), Uij, both expressed in nV.
Uij = 2[ui2 + uj2 - 2cov(i, j)]1/2.
cov(i, j) << (0.1 nV)2 is the estimated covariance that takes into account the correlation introduced by the BIPM measurements. This term is negligible.
  • Linking EUROMET.EM.BIPM-K10.a to BIPM.EM-K10.a

The EUROMET measurements are transferred to key comparison BIPM.EM-K10.a through the BIPM measurement.

The degree of equivalence of each laboratory participating in EUROMET.EM.BIPM-K10.a with respect to the key comparison reference value is given by a pair of terms:
Di =(dBIPM-EUR - di-EUR)Vo and its expanded uncertainty (at 95% level of confidence), Ui, both expressed in nV. Vo is the nominal value close to 1 V, and detailed information on the calculation of Ui can be found in page 6 of the EUROMET.EM.BIPM-K10.a Final Report.

The degree of equivalence between two laboratories participant in EUROMET.EM.BIPM-K10.a or between one laboratory participant in EUROMET.EM.BIPM-K10.a and one laboratory participant in BIPM.EM-K10.a is given by a pair of terms, both expressed in nV.
Dij = (Di - Dj) and its expanded uncertainty (at 95% level of confidence)
Uij = (Ui2 + Uj2)1/2.

These statements make it possible to extend the BIPM.EM-K10.a matrix of equivalence to participants in EUROMET.EM.BIPM-K10.a.

Comparison
Comparison close
Results

BIPM.EM-K10.a and EUROMET.EM.BIPM-K10.a

MEASURAND : DC voltage, Josephson standards

  • Key comparison BIPM.EM-K10.a

NOMINAL VALUE : 1.018 V

xi : result of measurement carried out by laboratory i expressed as the difference from the BIPM value; xi = (Vi - VBIPM), where "V" stands for "voltage"
ui : combined standard uncertainty of xi

 Lab i xi
/ nV
ui
/ nV
Date of measurement
 DFM -0.7 0.8 Jan 1991
 DFM 0.2 0.3 May 1991
 PTB -0.1 0.3 May 1991
 BNM-LCIE 0.1 0.3 Jul 1991
 NIST 0.1 0.3 Oct 1991
 NRC 0.2 0.3 Oct 1991
 NPL -0.07 0.52 Jan 1992
 BNM-LCIE -0.12 0.17 Feb 1992
 NMIJ -0.04 0.2 Mar 1992
 METAS -0.7 0.3 Nov 1992
 NMi-VSL 0.2 0.2 Mar 1993
 KRISS 0.20 0.21 Jan 1995
 MSL -0.24 0.21 Mar 1995
 NMIA -0.02 0.17 Apr 1995
 NIM -0.01 0.11 Nov 1995
 SP 0.1 0.3 Apr 1996
 IEN 0.1 0.2 Nov 1996
 CEM 0.0 0.2 Oct 1997
 A*STAR

1.8

0.9

Sep 2010

 INTI

-1.1

2.0

Nov 2011

 METAS

0.3

0.4

Jan 2012

  • Key comparison EUROMET.EM.BIPM-K10.a

NOMINAL VALUE : close to 1 V

di-EUR : result of measurement carried out by laboratory i expressed as the relative difference to the nominal value of the portable Josephson voltage standard (PJVS)
di-EUR = (VPJVS - Vi-EUR)/Vi-EUR, where "V" stands for "voltage"
ui-EUR : combined standard uncertainty of di-EUR

 Lab i di-EUR
/ 10-9
ui-EUR
/ 10-9
Date of measurement
 VNIIM 0.05 0.12 Sep 2003
 UME -0.06 0.36 Oct 2003
 PTB 0.01 0.23 Oct 2003
 SP 0.04 1.14 Oct 2003
 NPL 1.3 0.59 Nov 2003
 DFM -0.14 0.56 Nov 2003
 IEN 0.10 0.31 Nov 2003
 EIM 1.0 2.2 Feb 2004
 BIPM

0.07

0.13

Mar 2004

 MIKES -0.04 0.13 Mar 2004
 GUM -1.2 3.1 May 2004
 CMI 0.8 2.5 May 2004
 NMi-VSL -1.6 6.0 May 2004