CCEM.EM-K8, EUROMET.EM-K8, CCEM-K8.1 and EUROMET.EM-K8.1

MEASURAND : DC voltage ratio 1000 V / 10 V
NOMINAL VALUE : 100

Degrees of equivalence Di and expanded uncertainty Ui at a 95% level of confidence in 10-6

Click on the graph to get a closer view and the acronyms of the laboratories

Red diamonds: participants in CCEM-K8
Green triangles: participants in EUROMET.EM-K8
Black square: participant in CCEM-K8.1
Blue circles: participants in EUROMET.EM-K8.1

The dates of measurement are available from Laboratory Individual Meaurements.

The graph of equivalence can be printed out from page 8 of the .PDF file Summary Results.

CCEM.EM-K8, EUROMET.EM-K8, CCEM-K8.1 and EUROMET.EM-K8.1

MEASURAND : DC voltage ratio 100 V / 10 V
NOMINAL VALUE : 10

Degrees of equivalence Di and expanded uncertainty Ui at a 95% level of confidence in 10-6

Click on the graph to get a closer view and the acronyms of the laboratories

Red diamonds: participants in CCEM-K8
Green triangles: participants in EUROMET.EM-K8
Black square: participant in CCEM-K8.1
Blue circles: participants in EUROMET.EM-K8.1

The dates of measurement are available from Laboratory Individual Meaurements.

The graph of equivalence can be printed out from page 16 of the .PDF file Summary Results.

CCEM-K8, EUROMET.EM-K8, CCEM-K8.1 and EUROMET.EM-K8.1

MEASURAND : DC voltage ratio 1000 V / 10 V
NOMINAL VALUE : 100

Degrees of equivalence Di and expanded uncertainty Ui at a 95% level of confidence:

  • Participants in CCEM-K8



* indicate the laboratories which did not participate in the computation of the
CCEM-K8 key comparison reference value

  • Participants in EUROMET.EM-K8



** indicate the laboratories which did not participate in the computation of the EUROMET.EM-K8 reference value

  • Participant in CCEM-K8.1

  • Participant in EUROMET.EM-K8.1

    The dates of measurement are available from Laboratory Individual Meaurements.

    CCEM-K8, EUROMET.EM-K8, CCEM-K8.1 and EUROMET.EM-K8.1

    MEASURAND : DC voltage ratio 100 V / 10 V
    NOMINAL VALUE : 10

    Degrees of equivalence Di and expanded uncertainty Ui at a 95% level of confidence:

    • Participants in CCEM-K8



    * indicates the laboratories which did not participate in the computation of the
    CCEM-K8 key comparison reference value

    • Participants in EUROMET.EM-K8



    ** indicates the laboratories which did not participate in the computation of the EUROMET.EM-K8 reference value

    • Participant in CCEM-K8.1

    • Participant in EUROMET.EM-K8.1

    The dates of measurement are available from Laboratory Individual Meaurements.

    Comparison
    Comparison close
    CC comparison
    Linked comparison
    EUROMET.EM-K8
    Metrology area, Sub-field Electricity and Magnetism, DC Voltage and Current
    Description Comparison of DC voltage ratios
    Time of measurements 1998 - 2002
    Status Approved for equivalence
    Final Reports of the comparisons
    Measurand Ratio: 100 V/10 V and 1000 V/10 V
    Transfer device Datron 4902S standard divider, s/n 12422
    Comparison type Key Comparison
    Consultative Committee CCEM (Consultative Committee for Electricity and Magnetism)
    Conducted by EURAMET (European Association of National Metrology Institutes)
    RMO Internal Identifier EUROMET Project No 449
    Comments

    A subsequent comparison was decided between CMI, SMU, UME, NMi-VSL and IEN. It is registered into the BIPM key comparison database under the identifier EUROMET.EM-K8.1.

    EUROMET.EM-K8 results, CCEM-K8.1 results, and EUROMET.EM-K8.1 results are linked to those of CCEM-K8.

    CCEM-K8 results were published on 16 January 2003.
    EUROMET.EM-K8 results were published on 16 January 2004, CCEM-K8.1 results on 03 June 2004, and EUROMET.EM-K8.1 results on 26 January 2005.

    Two DC voltage ratios, 1000 V / 10 V (nominal value: 100) and 100 V / 10 V (nominal value: 10) are measured using Datron standard dividers as travelling standards.

    Pilot institute IEN
    Istituto Elettrotecnico Nazionale Galileo Ferraris; from 1st January 2006: Istituto Nazionale di Ricerca Metrologica, INRIM
    Italy
    Contact person G. Marullo Reedtz
    marullo@ien.it
    +39 011 3919 421
    First Name Last Name
    wwww@ww.www +356719836 Institute 1 Institute 1 Khmelnitskiy
    Pilot laboratory
    IEN

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

    BEV

    Bundesamt für Eich- und Vermessungswesen, Austria, EURAMET

    CEM

    Centro Español de Metrologia, Spain, EURAMET

    CMI

    Czech Metrology Institute, Czechia, EURAMET

    DFM

    Danish Fundamental Metrology Ltd, Denmark, EURAMET

    EIM

    Hellenic Institute of Metrology, Greece, EURAMET

    INETI

    Instituto Nacional de Engenharia e Tecnologia Industrial (merged into IPQ), Portugal, EURAMET

    JV

    Justervesenet, Norway, EURAMET

    LCIE

    Laboratoire Central des Industries Electriques, France, EURAMET

    METAS

    Federal Institute of Metrology, Switzerland, EURAMET

    MIKES

    VTT Technical Research Centre of Finland Ltd, Centre for Metrology/Mittatekniikan keskus, Finland, EURAMET

    MIRS/SIQ

    Metrology Institute of the Republic of Slovenia - Slovenian Institute of Quality and Metrology (became MIRS/SIQ/Metrology), Slovenia, EURAMET

    NMi-VSL

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

    NPL

    National Physical Laboratory, United Kingdom, EURAMET

    OMH

    Országos Mérésügyi Hivatal; Subsequently MKEH, now BKFH, Hungary, EURAMET

    PTB

    Physikalisch-Technische Bundesanstalt, Germany, EURAMET

    SMD

    Service de la Métrologie Belge, Belgium, EURAMET

    SMU

    Slovensky Metrologicky Ustav, Slovakia, EURAMET

    SP

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

    UME

    TÜBITAK Ulusal Metroloji Enstitüsü, Turkey, EURAMET

    CCEM-K8, EUROMET.EM-K8, CCEM-K8.1 and EUROMET.EM-K8.1

    MEASURAND : DC voltage ratio 1000 V / 10 V
    NOMINAL VALUE : 100

    • Key comparison CCEM-K8

    The key comparison reference value, R, is the arithmetic mean of the differences i, obtained from twelve participants. (Statistical tests indicate that there is a high probability that the result of each of the other three participants does not belong to the same statistical distribution as the other twelve).
    The mean relative deviation of the ratio from nominal is given by the sum R + d0,IEN. The standard uncertainty, u(R), associated with R is the standard deviation of the mean.

    R = -0.048x10-6 with standard uncertainty of 0.062x10-6
    and 11 degrees of freedom

    The degree of equivalence of each laboratory with respect to the reference value is given by a pair of terms: Di = (i - R), and the corresponding expanded uncertainty Ui, assessed for a level of confidence of 95%. For the 12 laboratories contributing to the definition of the reference value, the correlation with the reference value is taken into account in the computation of Ui.
    • Key comparison EUROMET.EM-K8

    The reference value of EUROMET.EM-K8, R-EUR, is the arithmetic mean of the differences i-EUR, obtained from seventeen participants. (Statistical tests indicate that there is a high probability that the result of each of the two other participants does not belong to the same statistical distribution as the other seventeen).
    The mean relative deviation of the ratio from nominal is given by the sum R-EUR + d0,IEN-EUR. The standard uncertainty associated with R-EUR is the standard deviation of the mean.

    R-EUR = -0.097x10-6 with standard uncertainty of 0.103x10-6
    and 16 degrees of freedom

    The degree of equivalence of each laboratory with respect to the reference value is given by a pair of terms: Di-EUR = (i-EUR - R-EUR), and the corresponding expanded uncertainty Ui-EUR, assessed for a level of confidence of 95%. For the 17 laboratories contributing to the definition of the reference value, the correlation with the reference value is taken into account in the computation of Ui-EUR.
    • Linking EUROMET.EM-K8 to CCEM.EM-K8

    In a measurement of voltage ratio, no national standard is involved. Therefore any participant in EUROMET.EM-K8 and CCEM-K8 comparisons can be considered equally able, in principle, to perform an unbiased measurement of the travelling standard. Since the number of participants in each comparison is significant and different methods of measurement were used, it is unlikely that the corresponding comparison reference values are affected by systematic errors. Therefore they are equivalent and the degrees of equivalence obtained from the EUROMET.EM-K8 comparison are assumed to be the same as if the participants had taken part in the CCEM-K8 comparison:
    Di = Di-EUR and Ui = Ui-EUR for the participants in EUROMET.EM-K8 comparison.

    The Linkage Report gives a verification of this assumption based on the results of the common participants in both comparisons.

    Because voltage ratios, and not national standards, were the object of these comparisons, the CCEM has decided not to publish the table of the bilateral degrees of equivalence, which are not really significant in the present case. They can, however, be calculated by the difference of the Di values, with corresponding 95% uncertainty given, within an approximation of about 5% or better, by twice the root-sum-square of the global standard uncertainties of the two laboratories involved.
    • Linking CCEM-K8.1 to CCEM-K8

    The degree of equivalence Di of laboratory i with respect to the key comparison reference value R, is given by the estimated difference (i - R) that the laboratory would have obtained if it had directly participated in comparison CCEM-K8, and by the corresponding 95% expanded uncertainty Ui.
    The link to CCEM-K8 is given by IEN, who was the pilot laboratory in both comparisons, with:
    Di = (i - IEN)CCEM-K8.1 + (IEN - R)CCEM-K8 = (i-K8.1 - IEN-K8.1) + DIEN
    ui = (u2G,i-K8.1 + u2transfer + u2(R))1/2,
    where utransfer represents the standard uncertainty of the link to CCEM-K8, evaluated to 0.08x10-6. The degrees of freedom are taken into account in the calculation of Ui.

    • Linking EUROMET.EM-K8.1 to CCEM-K8

    The link between EUROMET.EM-K8.1 and CCEM-K8 is computed in the same way, with utransfer = 0.08x10-6. The degrees of freedom have negligible influence in the calculation of Ui.

    The bilateral degrees of equivalence of laboratory i having participated in CCEM-K8.1 or EUROMET.EM-K8.1, with respect to any other laboratory participating in CCEM-K8 or EUROMET.EM-K8, can be calculated by the difference of the Di values of the two laboratories, with corresponding 95% uncertainty given, within an approximation of 5% or better, by twice the root-sum-square of three terms: the global standard uncertainty of laboratory i, the transfer standard uncertainty utransfer and the global standard uncertainty of the other laboratory.

    CCEM-K8, EUROMET.EM-K8, CCEM-K8.1 and EUROMET.EM-K8.1

    MEASURAND : DC voltage ratio 100 V / 10 V
    NOMINAL VALUE : 10

    • Key comparison CCEM-K8

    The key comparison reference value, R, is the arithmetic mean of the differences i, obtained from thirteen participants. (Statistical tests indicate that there is a high probability that the result of each of the other two participants does not belong to the same statistical distribution as the other thirteen).
    The mean relative deviation of the ratio from nominal is given by the sum R + d0,IEN. The standard uncertainty, u(R), associated with R is the standard deviation of the mean.

    R = -0.050x10-6 with standard uncertainty of 0.083x10-6
    and 12 degrees of freedom

    The degree of equivalence of each laboratory with respect to the reference value is given by a pair of terms: Di = (i - R), and the corresponding expanded uncertainty Ui, assessed for a level of confidence of 95%. For the 13 laboratories contributing to the definition of the reference value, the correlation with the reference value is taken into account in the computation of Ui.
    • Key comparison EUROMET.EM-K8

    The reference value of EUROMET.EM-K8, R-EUR, is the weighted mean of the differences i-EUR, obtained from sixteen participants. (Statistical tests indicate that there is a high probability that the result of each of the three other participants does not belong to the same statistical distribution as the other sixteen).
    The mean relative deviation of the ratio from nominal is given by the sum
    R-EUR + d0,IEN-EUR.
    The standard uncertainty associated with R-EUR is the weighted standard uncertainty.

    R-EUR = -0.039x10-6 with standard uncertainty of 0.039x10-6
    and 105 degrees of freedom

    The degree of equivalence of each laboratory with respect to the reference value is given by a pair of terms: Di-EUR = (i-EUR - R-EUR), and the corresponding expanded uncertainty Ui-EUR, assessed for a level of confidence of 95%. For the 16 laboratories contributing to the definition of the reference value, the correlation with the reference value is taken into account in the computation of Ui-EUR.
    • Linking EUROMET.EM-K8 to CCEM.EM-K8

    In a measurement of voltage ratio, no national standard is involved. Therefore any participant in EUROMET.EM-K8 and CCEM-K8 comparisons can be considered equally able, in principle, to perform an unbiased measurement of the travelling standard. Since the number of participants in each comparison is significant and different methods of measurement were used, it is unlikely that the corresponding comparison reference values are affected by systematic errors. Therefore they are equivalent and the degrees of equivalence obtained from the EUROMET.EM-K8 comparison are assumed to be the same as if the participants had taken part in the CCEM-K8 comparison:
    Di = Di-EUR and Ui = Ui-EUR for the participants in EUROMET.EM-K8 comparison.

    The Linkage Report gives a verification of this assumption based on the results of the common participants in both comparisons.

    Because voltage ratios, and not national standards, were the object of these comparisons, the CCEM has decided not to publish the table of the bilateral degrees of equivalence, which are not really significant in the present case. They can, however, be calculated by the difference of the Di values, with corresponding 95% uncertainty given, within an approximation of about 10% or better, by twice the root-sum-square of the global standard uncertainties of the two laboratories involved.
    • Linking CCEM-K8.1 to CCEM-K8

    The degree of equivalence Di of laboratory i with respect to the key comparison reference value R, is given by the estimated difference (i - R) that the laboratory would have obtained if it had directly participated in comparison CCEM-K8, and by the corresponding 95% expanded uncertainty Ui.
    The link to CCEM-K8 is given by IEN, who was the pilot laboratory in both comparisons. It is given by:
    Di = (i - IEN)CCEM-K8.1 + (IEN - R)CCEM-K8 = (i-K8.1 - IEN-K8.1) + DIEN
    ui = (u2G,i-K8.1 + u2transfer + u2(R))1/2,
    where utransfer represents the standard uncertainty of the link to CCEM-K8, evaluated to utransfer = 0.12x10-6. The degrees of freedom are taken into account in the calculation of Ui.

    • Linking EUROMET.EM-K8.1 to CCEM-K8

    The link between EUROMET.EM-K8.1 and CCEM-K8 is computed in the same way, with utransfer = 0.12x10-6. The degrees of freedom have negligible influence in the calculation of Ui.

    The bilateral degrees of equivalence of laboratory i having participated in CCEM-K8.1 or EUROMET.EM-K8.1, with respect to any other laboratory participating in CCEM-K8 or EUROMET.EM-K8, can be calculated by the difference of the Di values of the two laboratories, with corresponding 95% uncertainty given, within an approximation of 5% or better, by twice the root-sum-square of three terms: the global standard uncertainty of laboratory i, the transfer standard uncertainty utransfer and the global standard uncertainty of the other laboratory.

    CCEM-K8, EUROMET.EM-K8, CCEM-K8.1 and EUROMET.EM-K8.1

    MEASURAND : DC voltage ratio 1000 V / 10 V
    NOMINAL VALUE : 100
    Pilot laboratory: IEN

    d0,i: fractional difference from nominal value of ratio x0,i, measured by laboratory i and corrected to standard ambient conditions; it is given by: x0,i = 100 x (1 + d0,i)
    The fractional differences d0,IEN assigned by IEN to the ratio are obtained by interpolation of the IEN measurement results to the measurement dates of the other laboratories.
    i = (d0,i - d0,IEN)
    uG,i: global standard uncertainty of laboratory i
    neff,i: number of effective degrees of freedom of laboratory i

    Note: the additional indexes "-K8.1", "-EUR" and "-EUR-K8.1" are used for the CCEM-K8.1, EUROMET.EM-K8 and EUROMET.EM-K8.1 key comparisons.

    • Key comparison CCEM-K8
      TRAVELLING STANDARD : voltage divider Datron 4902S, s/n 20335

    • Key comparison EUROMET.EM-K8
      TRAVELLING STANDARD : voltage divider Datron 4902S, s/n 12422

    • Key comparison CCEM-K8.1
      TRAVELLING STANDARD : voltage divider Datron 4902S, s/n 20335

    • Key comparison EUROMET.EM-K8.1
      TRAVELLING STANDARD : voltage divider Datron 4902S, s/n 20335

    CCEM-K8, EUROMET.EM-K8, CCEM-K8.1 and EUROMET.EM-K8.1

    MEASURAND : DC voltage ratio 100 V / 10 V
    NOMINAL VALUE : 10
    Pilot laboratory: IEN

    d0,i: fractional difference from nominal value of ratio x0,i, measured by laboratory i and corrected to standard ambient conditions; it is given by: x0,i = 10 x (1 + d0,i)
    The fractional differences d0,IEN assigned by IEN to the ratio are obtained by interpolation of the IEN measurement results to the measurement dates of the other laboratories.
    i = (d0,i - d0,IEN)
    uG,i: global standard uncertainty of laboratory i
    neff,i: number of effective degrees of freedom of laboratory i

    Note : the additional indexes "-K8.1", "-EUR" and "-EUR-K8.1" are used for the CCEM-K8.1, EUROMET.EM-K8 and EUROMET.EM-K8.1 key comparisons.

    • Key comparison CCEM-K8
      TRAVELLING STANDARD : voltage divider Datron 4902S, s/n 20335

    • Key comparison EUROMET.EM-K8
      TRAVELLING STANDARD : voltage divider Datron 4902S, s/n 12422

    • Key comparison CCEM-K8.1
      TRAVELLING STANDARD : voltage divider Datron 4902S, s/n 20335

    • Key comparison EUROMET.EM-K8.1
      TRAVELLING STANDARD : voltage divider Datron 4902S, s/n 20335