CCT-K7, EUROMET.T-K7, EURAMET.T-K7.2, K7.3 & K7.1,
COOMET.T-K7 and APMP.T-K7.1

MEASURAND : Temperature of triple point of water
NOMINAL VALUE : 273.16 K

Full set of degrees of equivalence Di and expanded uncertainty Ui (k = 2), relative to the CCT-K7 key comparison reference value, expressed in µK

Click here to download the Graph of Equivalence

 

In CCT-K7 NMISA, MSL and NRC realized systematically higher temperatures, because they were the only laboratories which based their realizations on the recommendation of the Supplementary Information for the ITS-90 to use water with the isotopic composition of standard mean ocean water.
Since the publication of CCT-K7 results, the CIPM approved Recommendation 2 (CI-2005) "Clarification of the definition of the kelvin, unit of thermodynamic temperature": see on pages 23 and 24 of the EUROMET.T-K7 Final Report for detailed information on the application of this recommendation by the participants.

CCT-K7, EUROMET.T-K7, EURAMET.T-K7.2, K7.3 & K7.1,
COOMET.T-K7 and APMP.T-K7.1

MEASURAND : Temperature of triple point of water
NOMINAL VALUE : 273.16 K

Full set of degrees of equivalence Di and expanded uncertainty Ui (k = 2), relative to the CCT-K7 key comparison reference value, expressed in µK

 

In dark blue: CCT-K7 participants
In green: EUROMET.T-K7 participants
In orange: EURAMET.T-K7.2 participant
In braun: EURAMET.T-K7.3 participant
In grey: EURAMET.T-K7.1 participants
In blue: COOMET.T-K7 participants

In pink: APMP.T-K7.1 participant

Pair-wise degrees of equivalence are computed inside CCT-K7 and EUROMET.T-K7 only.

Full matrix of equivalence for CCT-K7

   
Lab iDiUi
 / µK/ µK
BIPM-2290
LNE-INM-76134
CEM-3685
CENAM-2758
NMISA83150
NMIA-5172
INRIM-3758
IPQ18322
KRISS47115
MSL9539
NIM11124
NIST-6269
NMIJ32304
NMi-VSL-6113
NPL2381
NRC6252
PTB-37113
SMU47109
A*STAR11144
UME-75183
VNIIM094

Results are presented under A4 printable format in Summary Results (PDF file).

EURAMET.T-K7.3
Metrology area, Sub-field Thermometry, Fixed Point Cells
Description Comparison of water triple point cells
Time of measurements 2011 - 2012
Status Approved for equivalence
Final Reports of the comparisons
Measurand Temperature: 273.16 K
Transfer device Water triple point cells
Comparison type Key Comparison
Consultative Committee CCT (Consultative Committee for Thermometry)
Conducted by EURAMET (European Association of National Metrology Institutes)
RMO Internal Identifier EURAMET Project No 1211
Comments

This is a follow-up to comparison EUROMET.T-K7.

Results published on 20 September 2012

EUROMET.T-K7, EURAMET.T-K7.2, EURAMET.T-K7.3, EURAMET.T-K7.1, COOMET.T-K7 and APMP.T-K7.1 results are linked to those of CCT-K7

Comparison of water triple point cells

Pilot institute VSL
VSL
Netherlands
Contact person A. Peruzzi
no-email1@vsl.nl
+31 (0) 15 269 1519
First Name Last Name
wwww@ww.www +356719836 Institute 1 Institute 1 Khmelnitskiy
Pilot laboratory
VSL

VSL, Netherlands, EURAMET

GUM

Glowny Urzad Miar, Central Office of Measures, Poland, EURAMET

CCT-K7, EUROMET.T-K7, EURAMET.T-K7.2, K7.3 & K7.1,
COOMET.T-K7 and APMP.T-K7.1

MEASURAND : Temperature of triple point of water
NOMINAL VALUE : 273.16 K

  • Key comparison CCT-K7
The key comparison reference value, xR, is calculated as the arithmetic mean of the results, xi, from all participants, including some laboratories who made corrections for the influence of chemical impurities and isotopic composition, and some who did not.
xR = 22 µK (expressed as the difference from the BIPM value).
The uncertainty of xR, uR, is calculated as the standard deviation of the mean of the data set. uR = 11 µK.
Because the distribution of the pooled data is multimodal, care should be taken when using this quantity for calculating confidence intervals.
The degree of equivalence of laboratory i with respect to the key comparison reference value is given by a pair of terms:
Di = (xi - xR) and its expanded uncertainty Ui (k = 2), both expressed in µK.
The uncertainty includes the participant's uncertainty, the comparison uncertainty and the uncertainty of the key comparison reference value.
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 Uij (k = 2), both expressed in µK. The uncertainty includes both participants' uncertainties and twice the comparison uncertainty.
  • Key comparison EUROMET.T-K7
The EUROMET reference value referred to the NMi-VSL reference cell (VSL-094),
xR EUR, and its standard uncertainty, uR EUR, are computed from the weighted mean of the individual results, with the exclusion of the CMI and GUM results, as explained in Section 7.1 on page 29 of the
EUROMET.T-K7 Final Report:
xR EUR = 15.6 µK, and uR EUR = 10.5 µK
The degree of equivalence of laboratory i, participant in EUROMET.T-K7, with respect to the EUROMET reference value is given by a pair of terms: DiEUR = xiEUR - xR EUR, and its expanded uncertainty UiEUR (k = 2), both expressed in µK.
  • Linking EUROMET.T-K7 to CCT-K7
The linkage process of EUROMET.T-K7 results to those of CCT-K7 is explained in Section 7.3 on page 36 of the EUROMET.T-K7 Final Report. It is based on the common participation of CEM, IPQ, LNE-INM, NMi-VSL, and SMU in both comparisons.
The degree of equivalence of laboratory i, participant in EUROMET.T-K7, with respect to the CCT-K7 key comparison reference value is given by a pair of terms:
Di = DiEUR + dLINK with dLINK = 64.7 µK, and its expanded uncertainty (k = 2)
Ui = 2[(UiEUR/2)2 + (uLINK)2]1/2, with uLINK = 19.7 µK, both expressed in µK.
Pair-wise degrees of equivalence are computed inside EUROMET (see Section 7.2 on page 30 of the EUROMET.T-K7 Final Report).
  • Linking COOMET.T-K7 to CCT-K7
The linkage process of COOMET.T-K7 results to those of CCT-K7 is explained in Section 6 of the COOMET.T-K7 Final Report. It is based on the common participation of VNIIM in both comparisons
The degree of equivalence of laboratory i, participant in COOMET.T-K7, with respect to the CCT-K7 reference value is given by a pair of terms: Di, and its expanded uncertainty (k = 2) Ui, both expressed in µK.
No pair-wise degrees of equivalence are computed inside COOMET.T-K7.
  • Linking EURAMET.T-K7.2 to CCT-K7
The degree of equivalence of INTiBS relative to the CCT-K7 key comparison reference value is computed through the common participation of VSL in EURAMET.T-K7.2 and EUROMET.T-K7 (see Section 6 of the EURAMET.T-K7.2 Final Report).
  • Linking EURAMET.T-K7.3 to CCT-K7

The degree of equivalence of GUM relative to the CCT-K7 key comparison reference value is computed through the common participation of VSL in EURAMET.T-K7.3 and EUROMET.T-K7 (see Sections 6 and 7 of the EURAMET.T-K7.3 Final Report).

  • Linking EURAMET.T-K7.1 to CCT-K7

New degrees of equivalence relative to the CCT-K7 key comparison reference value are obtained in EURAMET.T-K7.1 for SMU and CMI, through the common participation of SMU in EURAMET.T-K7.1 and EUROMET.T-K7, taking into account the change of national reference cell at SMU since the completion of EUROMET.T-K7.

  • Linking APMP.T-K7.1 to CCT-K7

The degree of equivalence of VMI-STAMEQ relative to the CCT-K7 key comparison reference value is computed through the common participation of NMIJ in APMP.T-K7 and CCT-K7 (see Section 8 of the APMP.T-K7.1 Final Report).

 

CCT-K7, EUROMET.T-K7, EURAMET.T-K7.2, K7.3 & K7.1,
COOMET.T-K7 and APMP.T-K7.1

  • Key comparison CCT-K7

MEASURAND : Temperature of triple point of water
NOMINAL VALUE : 273.16 K

xi : temperature difference between the national reference of laboratory i and the BIPM reference, xi = T(Lab i) - T(BIPM), where T is the temperature
ui : combined standard uncertainty of xi

 Lab i xi
/ µK
ui
/ µK
     
 BIPM 0 44
 LNE-INM -54 66
 CEM -14 41
 CENAM -5 27
 NMISA

105

74

 NMIA

-29

34

 INRIM

-15

27

 IPQ

40

160

 KRISS

69

56

 MSL

117

16

 NIM

33

61

 NIST

-40

33

 NMIJ

54

151

 NMi-VSL

16

55

 NPL

45

39

 NRC

85

23

 PTB

-14

56

 SMU

69

53

 A*STAR

34

71

 UME

-53

91

 VNIIM

22

46

 

  • Key comparison EUROMET.T-K7

MEASURAND : Temperature of triple point of water
NOMINAL VALUE : 273.16 K

xiEUR : temperature difference between the national reference of laboratory i and the NMi-VSL reference cell (VSL-094), xi = T(Lab i) - T(VSL-094), where T is the temperature
uiEUR : combined standard uncertainty of xiEUR

 Lab i xiEUR
/ µK
uiEUR
/ µK
     
 INM(RO) -3 64
 MKEH -77 69
 EIM 45 113
 MIKES -17 65
 PTB

39

37

 DTI

-51

68

 JV

-146

194

 VNIIM

63

52

 DZM/LPM

10

50

 UME

-86

77

 DMDM

-151

119

 BEV

-20

174

 IPQ

30

80

 NML(IE)

40

106

 CMI

-310

61

 GUM

-309

75

 VMT/PFI

-62

119

 CEM

51

44

 INRIM

2

29

 LNE-INM

16

56

 MIRS/FE-LMK

33

25

 SMD

44

34

 SMU

-4

58

 NMi-VSL

14

28

  • Key comparison COOMET.T-K7

MEASURAND : Temperature of triple point of water
NOMINAL VALUE : 273.16 K

The comparison was performed in three stages: 1) each participating laboratory carried out comparisons of the transfer cell with its national standard cell in local conditions; 2) the transfer cells were forwarded together with measurement results to BelGIM, where they were compared with the standard BelGIM cell using its laboratory equipment; and 3) the transfer cells were sent back to laboratories, where they were compared again to the national standard cells in order to determine the stability of the transfer cells.
The measurement results of the participating laboratories are given in section 2, 3, and 4 of the COOMET.T-K7 Final Report
.

  • Key comparison EURAMET.T-K7.2

MEASURAND : Temperature of triple point of water
NOMINAL VALUE : 273.16 K

The measurement results of this bilateral key comparison between VSL (The Netherlands) and INTiBS (Poland), carried out in 2010, are summarized in Sections 3 and 4, on pages 5 and 6 of the EURAMET.T-K7.2 Final Report.
They lead to the following numbers:
TINTiBS Nat. Ref. - TVSL Nat. Ref. = 2.9 µK and associated combined standard uncertainty (k = 1) u = 46 µK, where "Nat. Ref." stands for "National Reference".

  • Key comparison EURAMET.T-K7.3

MEASURAND : Temperature of triple point of water
NOMINAL VALUE : 273.16 K

The measurement results of this bilateral key comparison between VSL (The Netherlands) and GUM (Poland), carried out in 2011, are summarized in Sections 3 and 4, on pages 5 and 6 of the EURAMET.T-K7.3 Final Report.
They lead to the following numbers:
TGUM Nat. Ref. - TVSL Nat. Ref. = 11.5 µK and associated combined standard uncertainty (k = 1) u = 60 µK, where "Nat. Ref." stands for "National Reference".

  • Key comparison EURAMET.T-K7.1

MEASURAND : Temperature of triple point of water
NOMINAL VALUE : 273.16 K

The measurement results of this bilateral key comparison between CMI (Czech Republic) and SMU (Slovakia), carried out in 2009, are summarized in Sections 2 and 3 of the EURAMET.T-K7.1 Final Report.
It should be noted that SMU replaced its national reference cell with a cell with known isotopic composition after completion of key comparison EUROMET.T-K7.

  • Key comparison APMP.T-K7.1

MEASURAND : Temperature of triple point of water
NOMINAL VALUE : 273.16 K

The measurement results of this bilateral key comparison between VMI-STAMEQ (Viet Nam) and NMIJ (Japan), carried out in 2014 - 2015, are summarized in Sections 3 to 6 of the APMP.T-K7.1 Final Report.
They lead to the following numbers:
TVMI-STAMEQ Nat. Ref. - TNMIJ Nat. Ref. = -19.9 µK and associated combined standard uncertainty (k = 1) u = 46.3 µK, where "Nat. Ref." stands for "National Reference".