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 i | Di | Ui |
| / µK | / µK | |
| BIPM | -22 | 90 |
| LNE-INM | -76 | 134 |
| CEM | -36 | 85 |
| CENAM | -27 | 58 |
| NMISA | 83 | 150 |
| NMIA | -51 | 72 |
| INRIM | -37 | 58 |
| IPQ | 18 | 322 |
| KRISS | 47 | 115 |
| MSL | 95 | 39 |
| NIM | 11 | 124 |
| NIST | -62 | 69 |
| NMIJ | 32 | 304 |
| NMi-VSL | -6 | 113 |
| NPL | 23 | 81 |
| NRC | 62 | 52 |
| PTB | -37 | 113 |
| SMU | 47 | 109 |
| A*STAR | 11 | 144 |
| UME | -75 | 183 |
| VNIIM | 0 | 94 |
Results are presented under A4 printable format in Summary Results (PDF file).
| Metrology area, Sub-field | Thermometry, Fixed Point Cells |
| Description | Comparison of water triple point cells |
| Time of measurements | 2008 - 2011 |
| 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 | COOMET (Euro-Asian Cooperation of National Metrological Institutions) |
| RMO Internal Identifier | COOMET 395/BY/07 |
| Comments | Results published on 22 May 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 |
BelGIM
Belarussian State Institute for Metrology Belarus |
| Contact person | Dikun Tamara Iosifovna +375 17 233 04 21 |
| Pilot laboratory | |
|---|---|
| BelGIM |
Belarussian State Institute for Metrology, Belarus, COOMET |
| GEOSTM |
Georgian National Agency for Standards and Metrology, Georgia, EURAMET |
| INIMET |
Instituto Nacional de Investigaciones en Metrologia, Cuba, COOMET |
| INSM |
National Institute of Standardization and Metrology of the Republic of Moldova, Moldova, Republic of, EURAMET |
| KazStandard |
Kazakhstan Institute of Standardization and Metrology, Kazakhstan, COOMET |
| NSC IM |
National Scientific Centre "Institute of Metrology", Ukraine, EURAMET |
| VNIIM |
D.I. Mendeleyev Institute for Metrology, Rosstandart, Russian Federation, COOMET |
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" :
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
| 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. |
| 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. |
| 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). |
| 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. |
| 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). |
|
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). |
|
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. |
|
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
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 |
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 |
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.
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".
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".
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.
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".
