EUROMET.TK3, EURAMET.TK3.3 and EURAMET.TK3.5
NOMINAL TEMPERATURE : Argon Triple Point, 83.8058 K
Degrees of equivalence, D_{i} and expanded uncertainty U_{i} (k = 2),
both expressed in mK
Blue circles: participants in EUROMET.TK3
Pink triangle: participant in EURAMET.TK3.3 only
Green square: participant in EURAMET.TK3.5 only
U_{LACOMET} = 12 mK
EUROMET.TK3, EURAMET.TK3.3, EURAMET.TK3.1 and EURAMET.TK3.5
NOMINAL TEMPERATURE : Mercury Triple Point, 234.3156 K
Degrees of equivalence, D_{i} and expanded uncertainty U_{i} (k = 2),
both expressed in mK
Blue circles: participants in EUROMET.TK3
Pink triangle: participant in EURAMET.TK3.3 only
Brown diamond: participant in EURAMET.TK3.1 only
Green square: participant in EURAMET.TK3.5 only
EUROMET.TK3, EURAMET.TK3.3, EURAMET.TK3.1 and EURAMET.TK3.5
NOMINAL TEMPERATURE : Gallium Melting Point, 302.9146 K
Degrees of equivalence, D_{i} and expanded uncertainty U_{i} (k = 2),
both expressed in mK
Blue circles: participants in EUROMET.TK3
Pink triangle: participant in EURAMET.TK3.3 only
Brown diamond: participant in EURAMET.TK3.1 only
Green square: participant in EURAMET.TK3.5 only
EUROMET.TK3, EURAMET.TK3.3, EURAMET.TK3.1 and EURAMET.TK3.5
NOMINAL TEMPERATURE : Indium Freezing Point, 429.7485 K
Degrees of equivalence, D_{i} and expanded uncertainty U_{i} (k = 2),
both expressed in mK
Blue circles: participants in EUROMET.TK3
Pink triangle: participant in EURAMET.TK3.3 only
Brown diamond: participant in EURAMET.TK3.1 only
Green square: participant in EURAMET.TK3.5 only
EUROMET.TK3, EURAMET.TK3.3, EURAMET.TK3.1 and EURAMET.TK3.5
NOMINAL TEMPERATURE : Tin Freezing Point, 505.078 K
Degrees of equivalence, D_{i} and expanded uncertainty U_{i} (k = 2),
both expressed in mK
Blue circles: participants in EUROMET.TK3
Pink triangle: participant in EURAMET.TK3.3 only
Brown diamond: participant in EURAMET.TK3.1 only
Green square: participant in EURAMET.TK3.5 only
EUROMET.TK3, EURAMET.TK3.3, EURAMET.TK3.1 and EURAMET.TK3.5
NOMINAL TEMPERATURE : Zinc Freezing Point, 692.677 K
Degrees of equivalence, D_{i} and expanded uncertainty U_{i} (k = 2),
both expressed in mK
Blue circles: participants in EUROMET.TK3
Pink triangle: participant in EURAMET.TK3.3 only
Brown diamond: participant in EURAMET.TK3.1 only
Green square: participant in EURAMET.TK3.5 only
CCTK4, EUROMET.TK4, EURAMET.TK3.3, APMP.TK4 and EURAMET.TK3.5
MEASURAND : Freezingpoint temperature of Aluminium (Al) fixedpoint cells
NOMINAL TEMPERATURE : 660.323 °C
Degrees of equivalence D_{i }and expanded uncertainty U_{i }(95% level of confidence) expressed in mK
Click on the graph for a closer view
EUROMET.TK3, EURAMET.TK3.3 and EURAMET.TK3.5
NOMINAL TEMPERATURE : Argon Triple Point, 83.8058 K
All values given in the following Table are expressed in mK
Lab i  D_{i}  U_{i} 
PTB  0.17  0.79 
GUM  0.74  0.99 
INM(RO)  0.28  0.89 
UME  1.00  0.89 
NPL  0.11  0.45 
JV  0.17  0.94 
SMD  0.87  0.86 
INRIM  0.28  0.59 
CEM  0.57  1.07 
METAS  0.32  0.92 
IPQ  0.23  0.98 
MIRS/FELMK  0.05  0.92 
NMiVSL  0.01  0.52 
MIKES  0.30  1.14 
SP  0.30  0.96 
LNEINM  0.12  0.77 
LACOMET: participant in EURAMET.TK3.3 only
D_{LACOMET} = 0.1 mK and U_{LACOMET} = 12 mK
ROTH+CO.AG: participant in EURAMET.TK3.5 only
D_{ROTH+CO.AG} = 0.72 mK and U_{ROTH+CO.AG} = 1.14 mK
Results are presented under A4 printable format in Summary Results (PDF file).
EUROMET.TK3, EURAMET.TK3.3, EURAMET.TK3.1 and EURAMET.TK3.5
NOMINAL TEMPERATURE : Mercury Triple Point, 234.3156 K
All values given in the following Table are expressed in mK
Lab i  D_{i}  U_{i} 
PTB  0.03  0.39 
GUM  0.13  0.74 
CMI  0.01  0.70 
INM(RO)  0.74  0.84 
UME  0.61  0.71 
NPL  0.30  0.52 
JV  0.17  0.91 
EIM  0.42  0.69 
SMD  0.34  0.67 
NML(IE)  0.42  0.80 
INRIM  0.11  0.37 
CEM  0.19  0.57 
METAS  0.04  0.51 
IPQ  0.19  0.66 
BEV  0.90  1.07 
MIRS/FELMK  0.17  0.68 
NMiVSL  0.11  0.45 
MIKES  0.05  0.82 
VMT/PFI  0.07  0.65 
SP  0.05  0.87 
DTI  2.66  3.08 
SMU  0.16  0.84 
OMH  0.29  0.63 
LNEINM  0.25  0.68 
LACOMET: participant in EURAMET.TK3.3 only
D_{LACOMET} = 0.29 mK and U_{LACOMET} = 0.85 mK
BIM: participant in EURAMET.TK3.1 only
D_{BIM} = 0.06 mK and U_{BIM} = 0.67 mK
ROTH+CO.AG: participant in EURAMET.TK3.5 only
D_{ROTH+CO.AG} = 0.51 mK and U_{ROTH+CO.AG} = 1.06 mK
Results are presented under A4 printable format in Summary Results (PDF file).
EUROMET.TK3, EURAMET.TK3.3, EURAMET.TK3.1 and EURAMET.TK3.5
NOMINAL TEMPERATURE : Gallium Melting Point, 302.9146 K
All values given in the following Table are expressed in mK
Lab i  D_{i}  U_{i} 
PTB  0.15  0.30 
GUM  0.17  0.59 
CMI  0.18  0.56 
INM(RO)  0.16  0.44 
UME  0.02  0.57 
NPL  0.11  0.42 
JV  0.55  0.63 
EIM  0.25  0.61 
SMD  0.18  0.56 
NML(IE)  0.10  0.74 
INRIM  0.11  0.28 
CEM  0.20  0.55 
METAS  0.02  0.68 
IPQ  0.13  0.83 
BEV  0.42  1.04 
MIRS/FELMK  0.16  0.51 
NMiVSL  0.17  0.35 
MIKES  0.02  0.67 
VMT/PFI  0.18  0.54 
SP  0.21  0.56 
DTI  0.14  0.61 
SMU  0.13  0.51 
OMH  0.28  0.66 
LNEINM  0.09  0.28 
LACOMET: participant in EURAMET.TK3.3 only
D_{LACOMET} = 0.46 mK and U_{LACOMET} = 0.82 mK
BIM: participant in EURAMET.TK3.1 only
D_{BIM} = 0.16 mK and U_{BIM} = 0.63 mK
ROTH+CO.AG: participant in EURAMET.TK3.5 only
D_{ROTH+CO.AG} = 0.66 mK and U_{ROTH+CO.AG} = 1.06 mK
Results are presented under A4 printable format in Summary Results (PDF file).
EUROMET.TK3, EURAMET.TK3.3, EURAMET.TK3.1 and EURAMET.TK3.5
NOMINAL TEMPERATURE : Indium Freezing Point, 429.7485 K
All values given in the following Table are expressed in mK
Lab i  D_{i}  U_{i} 
PTB  0.16  0.92 
GUM  1.71  1.35 
CMI  1.24  1.18 
INM(RO)  3.90  4.95 
UME  0.22  1.71 
NPL  0.73  0.83 
JV  0.28  1.92 
EIM  1.25  1.68 
SMD  0.56  1.68 
INRIM  0.03  0.72 
CEM  0.17  1.25 
METAS  0.40  1.12 
IPQ  0.92  2.03 
BEV  0.41  1.15 
MIRS/FELMK  0.41  1.41 
NMiVSL  0.45  0.56 
MIKES  0.14  1.99 
SP  0.29  1.24 
DTI  0.29  2.14 
SMU  0.33  0.99 
LNEINM  0.15  0.99 
LACOMET: participant in EURAMET.TK3.3 only
D_{LACOMET} = 0.6 mK and U_{LACOMET} = 2.1 mK
BIM: participant in EURAMET.TK3.1 only
D_{BIM} = 0.14 mK and U_{BIM} = 1.1 mK
ROTH+CO.AG: participant in EURAMET.TK3.5 only
D_{ROTH+CO.AG} = 1.09 mK and U_{ROTH+CO.AG} = 2.07 mK
Results are presented under A4 printable format in Summary Results (PDF file).
EUROMET.TK3, EURAMET.TK3.3, EURAMET.TK3.1 and EURAMET.TK3.5
NOMINAL TEMPERATURE : Tin Freezing Point, 505.078 K
All values given in the following Table are expressed in mK
Lab i  D_{i}  U_{i} 
PTB  0.43  0.90 
GUM  0.37  1.26 
CMI  0.00  0.95 
INM(RO)  2.34  2.72 
UME  0.15  1.22 
NPL  0.29  0.87 
JV  0.65  1.45 
EIM  0.16  1.42 
SMD  2.24  1.22 
NML(IE)  0.06  1.59 
INRIM  0.06  0.95 
CEM  0.61  1.43 
METAS  0.69  1.07 
IPQ  1.07  1.43 
BEV  1.02  1.40 
MIRS/FELMK  0.44  1.15 
NMiVSL  0.22  0.92 
MIKES  0.50  1.34 
VMT/PFI  0.03  1.63 
SP  0.09  1.20 
DTI  0.39  1.98 
SMU  0.18  1.39 
OMH  0.20  1.90 
LNEINM  0.06  1.00 
LACOMET: participant in EURAMET.TK3.3 only
D_{LACOMET} = 0.7 mK and U_{LACOMET} = 2.2 mK
BIM: participant in EURAMET.TK3.1 only
D_{BIM} = 0.05 mK and U_{BIM} = 1.4 mK
ROTH+CO.AG: participant in EURAMET.TK3.5 only
D_{ROTH+CO.AG} = 0.82 mK and U_{ROTH+CO.AG} = 2.13 mK
Results are presented under A4 printable format in Summary Results (PDF file).
EUROMET.TK3, EURAMET.TK3.3, EURAMET.TK3.1 and EURAMET.TK3.5
NOMINAL TEMPERATURE : Zinc Freezing Point, 692.677 K
All values given in the following Table are expressed in mK
Lab i  D_{i}  U_{i} 
PTB  0.49  1.44 
GUM  1.21  1.51 
CMI  0.07  1.38 
INM(RO)  1.70  3.57 
UME  0.50  1.61 
NPL  0.73  1.57 
JV  0.92  2.21 
EIM  0.75  2.20 
SMD  1.35  2.31 
NML(IE)  0.34  3.09 
INRIM  0.43  1.96 
CEM  0.30  2.36 
METAS  0.27  2.13 
IPQ  1.92  2.21 
BEV  0.92  2.13 
MIRS/FELMK  0.30  2.54 
NMiVSL  0.82  1.58 
MIKES  0.19  1.98 
VMT/PFI  0.37  2.11 
SP  0.44  1.87 
DTI  0.16  2.34 
SMU  0.60  1.32 
OMH  0.91  2.39 
LNEINM  0.86  1.69 
LACOMET: participant in EURAMET.TK3.3 only
D_{LACOMET} = 2.1 mK and U_{LACOMET} = 3.2 mK
BIM: participant in EURAMET.TK3.3 only
D_{BIM} = 1.62 mK and U_{BIM} = 2.2 mK
ROTH+CO.AG: participant in EURAMET.TK3.5 only
D_{ROTH+CO.AG} = 1.72 mK and U_{ROTH+CO.AG} = 2.82 mK
Results are presented under A4 printable format in Summary Results (PDF file).
CCTK4, EUROMET.TK4, EURAMET.TK3.3, APMP.TK4 and EURAMET.TK3.5
MEASURAND : Freezingpoint temperature of Aluminium (Al) fixedpoint cells
NOMINAL TEMPERATURE : 660.323 °C
Degrees of equivalence, D_{i} and expanded uncertainty U_{i}, relative to the CCTK4 key comparison reference value
* LNEINM was named "BNMINM" at the time of key comparison CCTK4
** INRIM was named "IMGC" at the time of key comparison CCTK4
Results are presented under A4 printable format in Summary Results (PDF file).
Metrology area, Subfield  Thermometry, Standard Platinum Resistance Thermometers 
Description  Realizations of the ITS90 from 83.8 K to 933.5 K 
Time of measurements  2013 
Status  Approved for equivalence 
Final Reports of the comparisons  
Measurand  Temperature: 83.8 K to 933.5 K 
Transfer device  Standard Platinum Resistance Thermometer 
Comparison type  Key Comparison 
Consultative Committee  CCT (Consultative Committee for Thermometry) 
Conducted by  EURAMET (European Association of National Metrology Institutes) 
Comments  Results published on 24 July 2014 EURAMET.TK3.3, EURAMET.TK3.1 and EURAMET.TK3.5 results are linked to those of EUROMET.TK3 for the Ar, Hg, Ga, In, Sn and Zn fixed points EUROMET.TK4, EURAMET.TK3.3, APMP.TK4 and EURAMET.TK3.5 results are linked to those of CCTK4 for the Al fixed point Realizations of the ITS90 from 83.8 K to 933.5 K

Pilot institute 
VSL
VSL Netherlands 
Contact person  A. Peruzzi +31 (0) 15 269 1519 
Pilot laboratory  

VSL 
VSL, Netherlands, EURAMET 
ROTH+CO.AG 
ROTH+CO.AG, Switzerland, EURAMET 
This page proposes printout 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" :
EUROMET.TK3, EURAMET.TK3.3 and EURAMET.TK3.5
NOMINAL TEMPERATURE : Argon Triple Point, 83.8058 K
For each fixedpoint temperature, the difference (T_{R}  T_{P}) between the EUROMET reference value, T_{R}, and T_{P}, is computed as the weighted mean of all participants' results (T_{i}  T_{P}), with weights inversely proportional to u_{iP}, as explained in Section 8.1 of the Final Report. 
For each fixedpoint temperature, the degree of equivalence of laboratory i with respect to the EUROMET reference value is given by a pair of terms, both expressed in mK: D_{i} = (T_{i}  T_{R}), obtained from the differences relative to the Pilot Laboratory 
For each fixedpoint temperature, the degree of equivalence between two laboratories i and j is given by a pair of terms, both expressed in mK: D_{ij} = D_{i}  D_{j}, and U_{ij}, its expanded uncertainty at a 95 % level of confidence. The computation of U_{ij} between participants in the same loop, and participants in different loops is explained in Sections 11.1 and 11.2 of the Final Report. 
The Pilot Laboratory and the five CoPilots have participated in both comparisons.
The comparison of their averaged results in both exercises shows that they perform equally within 0.1 mK for all temperatures, except for the Zinc fixedpoint temperature (0.23 mK) and the Tin fixedpoint temperature (0.14 mK), as explained in Section 10.1 of the Final Report.
The uncertainty linked with the reproducibility between both exercises in also computed (see Table 28 on page 60 of the Final Report) and taken into account for the estimation of the pairwise degrees of equivalence between participants in EUROMET.TK3 and CCTK3 (see Section 11.3 of the Final Report).
For each fixedpoint temperature, the BIPM key comparison database displays the degrees of equivalence relative to the EUROMET reference value, and the pairwise degrees of equivalence computed inside the EUROMET key comparison.
The LACOMET results obtained in EURAMET.TK3.3 are linked to the results of EUROMET.TK3 and CCTK3 using the participation of CEM in EUROMET.TK3, whose results are linked to those of CCTK3, as described above.
The ROTH+CO.AG results obtained in EURAMET.TK3.5 are linked to the results of EUROMET.TK3 and CCTK3 using the participation of VSL in EUROMET.TK3.
This makes it possible to extend the EUROMET.TK3 graphs of equivalence with LACOMET and ROTH+CO.AG results.
LACOMET degrees of equivalence relative to the CCTK3 ARV are given on page 17 of the EURAMET.TK3.3 Final Report.
The computation of ROTH+CO.AG degrees of equivalence relative to the CCTK3 ARV is explained in Section 8.1 of the EURAMET.TK3.5 Final Report.
EUROMET.TK3, EURAMET.TK3.3, EURAMET.TK3.1 and EURAMET.TK3.5
NOMINAL TEMPERATURE : Mercury Triple Point, 234.3156 K
For each fixedpoint temperature, the difference (T_{R}  T_{P}) between the EUROMET reference value, T_{R}, and T_{P}, is computed as the weighted mean of all participants' results (T_{i}  T_{P}), with weights inversely proportional to u_{iP}, as explained in Section 8.1 of the Final Report. 
For each fixedpoint temperature, the degree of equivalence of laboratory i with respect to the EUROMET reference value is given by a pair of terms, both expressed in mK: D_{i} = (T_{i}  T_{R}), obtained from the differences relative to the Pilot Laboratory 
For each fixedpoint temperature, the degree of equivalence between two laboratories i and j is given by a pair of terms, both expressed in mK: D_{ij} = D_{i}  D_{j}, and U_{ij}, its expanded uncertainty at a 95 % level of confidence. The computation of U_{ij} between participants in the same loop, and participants in different loops is explained in Sections 11.1 and 11.2 of the Final Report. 
The Pilot Laboratory and the five CoPilots have participated in both comparisons.
The comparison of their averaged results in both exercises shows that they perform equally within 0.1 mK for all temperatures, except for the Zinc fixedpoint temperature (0.23 mK) and the Tin fixedpoint temperature (0.14 mK), as explained in Section 10.1 of the Final Report.
The uncertainty linked with the reproducibility between both exercises in also computed (see Table 28 on page 60 of the Final Report) and taken into account for the estimation of the pairwise degrees of equivalence between participants in EUROMET.TK3 and CCTK3 (see Section 11.3 of the Final Report).
For each fixedpoint temperature, the BIPM key comparison database displays the degrees of equivalence relative to the EUROMET reference value, and the pairwise degrees of equivalence computed inside the EUROMET key comparison.
The LACOMET results obtained in EURAMET.TK3.3 are linked to the results of EUROMET.TK3 and CCTK3 using the participation of CEM in EUROMET.TK3, whose results are linked to those of CCTK3, as described above.
The BIM results obtained in EURAMET.TK3.1 are linked to the results of EUROMET.TK3 and CCTK3 using the participation of VSL in EUROMET.TK3.
The ROTH+CO.AG results obtained in EURAMET.TK3.5 are linked to the results of EUROMET.TK3 and CCTK3 using the participation of VSL in EUROMET.TK3.
This makes it possible to extend the EUROMET.TK3 graphs of equivalence with LACOMET, BIM and ROTH+CO.AG results.
LACOMET and BIM degrees of equivalence relative to the CCTK3 ARV are given on page 17 of the EURAMET.TK3.3 Final Report and on pages 10 and 11 of the EURAMET.TK3.1 Final Report, respectively.
The computation of ROTH+CO.AG degrees of equivalence relative to the CCTK3 ARV is explained in Section 8.1 of the EURAMET.TK3.5 Final Report.
EUROMET.TK3, EURAMET.TK3.3, EURAMET.TK3.1 and EURAMET.TK3.5
NOMINAL TEMPERATURE : Gallium Melting Point, 302.9146 K
For each fixedpoint temperature, the difference (T_{R}  T_{P}) between the EUROMET reference value, T_{R}, and T_{P}, is computed as the weighted mean of all participants' results (T_{i}  T_{P}), with weights inversely proportional to u_{iP}, as explained in Section 8.1 of the Final Report. 
For each fixedpoint temperature, the degree of equivalence of laboratory i with respect to the EUROMET reference value is given by a pair of terms, both expressed in mK: D_{i} = (T_{i}  T_{R}), obtained from the differences relative to the Pilot Laboratory 
For each fixedpoint temperature, the degree of equivalence between two laboratories i and j is given by a pair of terms, both expressed in mK: D_{ij} = D_{i}  D_{j}, and U_{ij}, its expanded uncertainty at a 95 % level of confidence. The computation of U_{ij} between participants in the same loop, and participants in different loops is explained in Sections 11.1 and 11.2 of the Final Report. 
The Pilot Laboratory and the five CoPilots have participated in both comparisons.
The comparison of their averaged results in both exercises shows that they perform equally within 0.1 mK for all temperatures, except for the Zinc fixedpoint temperature (0.23 mK) and the Tin fixedpoint temperature (0.14 mK), as explained in Section 10.1 of the Final Report.
The uncertainty linked with the reproducibility between both exercises in also computed (see Table 28 on page 60 of the Final Report) and taken into account for the estimation of the pairwise degrees of equivalence between participants in EUROMET.TK3 and CCTK3 (see Section 11.3 of the Final Report).
For each fixedpoint temperature, the BIPM key comparison database displays the degrees of equivalence relative to the EUROMET reference value, and the pairwise degrees of equivalence computed inside the EUROMET key comparison.
The LACOMET results obtained in EURAMET.TK3.3 are linked to the results of EUROMET.TK3 and CCTK3 using the participation of CEM in EUROMET.TK3, whose results are linked to those of CCTK3, as described above.
The BIM results obtained in EURAMET.TK3.1 are linked to the results of EUROMET.TK3 and CCTK3 using the participation of VSL in EUROMET.TK3.
The ROTH+CO.AG results obtained in EURAMET.TK3.5 are linked to the results of EUROMET.TK3 and CCTK3 using the participation of VSL in EUROMET.TK3.
This makes it possible to extend the EUROMET.TK3 graphs of equivalence with LACOMET, BIM and ROTH+CO.AG results.
LACOMET and BIM degrees of equivalence relative to the CCTK3 ARV are given on page 17 of the EURAMET.TK3.3 Final Report and on pages 10 and 11 of the EURAMET.TK3.1 Final Report, respectively.
The computation of ROTH+CO.AG degrees of equivalence relative to the CCTK3 ARV is explained in Section 8.1 of the EURAMET.TK3.5 Final Report.
EUROMET.TK3, EURAMET.TK3.3, EURAMET.TK3.1 and EURAMET.TK3.5
NOMINAL TEMPERATURE : Indium Freezing Point, 429.7485 K
For each fixedpoint temperature, the difference (T_{R}  T_{P}) between the EUROMET reference value, T_{R}, and T_{P}, is computed as the weighted mean of all participants' results (T_{i}  T_{P}), with weights inversely proportional to u_{iP}, as explained in Section 8.1 of the Final Report. 
For each fixedpoint temperature, the degree of equivalence of laboratory i with respect to the EUROMET reference value is given by a pair of terms, both expressed in mK: D_{i} = (T_{i}  T_{R}), obtained from the differences relative to the Pilot Laboratory 
For each fixedpoint temperature, the degree of equivalence between two laboratories i and j is given by a pair of terms, both expressed in mK: D_{ij} = D_{i}  D_{j}, and U_{ij}, its expanded uncertainty at a 95 % level of confidence. The computation of U_{ij} between participants in the same loop, and participants in different loops is explained in Sections 11.1 and 11.2 of the Final Report. 
The Pilot Laboratory and the five CoPilots have participated in both comparisons.
The comparison of their averaged results in both exercises shows that they perform equally within 0.1 mK for all temperatures, except for the Zinc fixedpoint temperature (0.23 mK) and the Tin fixedpoint temperature (0.14 mK), as explained in Section 10.1 of the Final Report.
The uncertainty linked with the reproducibility between both exercises in also computed (see Table 28 on page 60 of the Final Report) and taken into account for the estimation of the pairwise degrees of equivalence between participants in EUROMET.TK3 and CCTK3 (see Section 11.3 of the Final Report).
For each fixedpoint temperature, the BIPM key comparison database displays the degrees of equivalence relative to the EUROMET reference value, and the pairwise degrees of equivalence computed inside the EUROMET key comparison.
The LACOMET results obtained in EURAMET.TK3.3 are linked to the results of EUROMET.TK3 and CCTK3 using the participation of CEM in EUROMET.TK3, whose results are linked to those of CCTK3, as described above.
The BIM results obtained in EURAMET.TK3.1 are linked to the results of EUROMET.TK3 and CCTK3 using the participation of VSL in EUROMET.TK3.
The ROTH+CO.AG results obtained in EURAMET.TK3.5 are linked to the results of EUROMET.TK3 and CCTK3 using the participation of VSL in EUROMET.TK3.
This makes it possible to extend the EUROMET.TK3 graphs of equivalence with LACOMET, BIM and ROTH+CO.AG results.
LACOMET and BIM degrees of equivalence relative to the CCTK3 ARV are given on page 17 of the EURAMET.TK3.3 Final Report and on pages 10 and 11 of the EURAMET.TK3.1 Final Report, respectively.
The computation of ROTH+CO.AG degrees of equivalence relative to the CCTK3 ARV is explained in Section 8.1 of the EURAMET.TK3.5 Final Report.
EUROMET.TK3, EURAMET.TK3.3, EURAMET.TK3.1 and EURAMET.TK3.5
NOMINAL TEMPERATURE : Tin Freezing Point, 505.078 K
For each fixedpoint temperature, the difference (T_{R}  T_{P}) between the EUROMET reference value, T_{R}, and T_{P}, is computed as the weighted mean of all participants' results (T_{i}  T_{P}), with weights inversely proportional to u_{iP}, as explained in Section 8.1 of the Final Report. 
For each fixedpoint temperature, the degree of equivalence of laboratory i with respect to the EUROMET reference value is given by a pair of terms, both expressed in mK: D_{i} = (T_{i}  T_{R}), obtained from the differences relative to the Pilot Laboratory 
For each fixedpoint temperature, the degree of equivalence between two laboratories i and j is given by a pair of terms, both expressed in mK: D_{ij} = D_{i}  D_{j}, and U_{ij}, its expanded uncertainty at a 95 % level of confidence. The computation of U_{ij} between participants in the same loop, and participants in different loops is explained in Sections 11.1 and 11.2 of the Final Report. 
The Pilot Laboratory and the five CoPilots have participated in both comparisons.
The comparison of their averaged results in both exercises shows that they perform equally within 0.1 mK for all temperatures, except for the Zinc fixedpoint temperature (0.23 mK) and the Tin fixedpoint temperature (0.14 mK), as explained in Section 10.1 of the Final Report.
The uncertainty linked with the reproducibility between both exercises in also computed (see Table 28 on page 60 of the Final Report) and taken into account for the estimation of the pairwise degrees of equivalence between participants in EUROMET.TK3 and CCTK3 (see Section 11.3 of the Final Report).
For each fixedpoint temperature, the BIPM key comparison database displays the degrees of equivalence relative to the EUROMET reference value, and the pairwise degrees of equivalence computed inside the EUROMET key comparison.
The LACOMET results obtained in EURAMET.TK3.3 are linked to the results of EUROMET.TK3 and CCTK3 using the participation of CEM in EUROMET.TK3, whose results are linked to those of CCTK3, as described above.
The BIM results obtained in EURAMET.TK3.1 are linked to the results of EUROMET.TK3 and CCTK3 using the participation of VSL in EUROMET.TK3.
The ROTH+CO.AG results obtained in EURAMET.TK3.5 are linked to the results of EUROMET.TK3 and CCTK3 using the participation of VSL in EUROMET.TK3.
This makes it possible to extend the EUROMET.TK3 graphs of equivalence with LACOMET, BIM and ROTH+CO.AG results.
LACOMET and BIM degrees of equivalence relative to the CCTK3 ARV are given on page 17 of the EURAMET.TK3.3 Final Report and on pages 10 and 11 of the EURAMET.TK3.1 Final Report, respectively.
The computation of ROTH+CO.AG degrees of equivalence relative to the CCTK3 ARV is explained in Section 8.1 of the EURAMET.TK3.5 Final Report.
EUROMET.TK3, EURAMET.TK3.3, EURAMET.TK3.1 and EURAMET.TK3.5
NOMINAL TEMPERATURE : Zinc Freezing Point, 692.677 K
For each fixedpoint temperature, the difference (T_{R}  T_{P}) between the EUROMET reference value, T_{R}, and T_{P}, is computed as the weighted mean of all participants' results (T_{i}  T_{P}), with weights inversely proportional to u_{iP}, as explained in Section 8.1 of the Final Report. 
For each fixedpoint temperature, the degree of equivalence of laboratory i with respect to the EUROMET reference value is given by a pair of terms, both expressed in mK: D_{i} = (T_{i}  T_{R}), obtained from the differences relative to the Pilot Laboratory 
For each fixedpoint temperature, the degree of equivalence between two laboratories i and j is given by a pair of terms, both expressed in mK: D_{ij} = D_{i}  D_{j}, and U_{ij}, its expanded uncertainty at a 95 % level of confidence. The computation of U_{ij} between participants in the same loop, and participants in different loops is explained in Sections 11.1 and 11.2 of the Final Report. 
The Pilot Laboratory and the five CoPilots have participated in both comparisons.
The comparison of their averaged results in both exercises shows that they perform equally within 0.1 mK for all temperatures, except for the Zinc fixedpoint temperature (0.23 mK) and the Tin fixedpoint temperature (0.14 mK), as explained in Section 10.1 of the Final Report.
The uncertainty linked with the reproducibility between both exercises in also computed (see Table 28 on page 60 of the Final Report) and taken into account for the estimation of the pairwise degrees of equivalence between participants in EUROMET.TK3 and CCTK3 (see Section 11.3 of the Final Report).
For each fixedpoint temperature, the BIPM key comparison database displays the degrees of equivalence relative to the EUROMET reference value, and the pairwise degrees of equivalence computed inside the EUROMET key comparison.
The LACOMET results obtained in EURAMET.TK3.3 are linked to the results of EUROMET.TK3 and CCTK3 using the participation of CEM in EUROMET.TK3, whose results are linked to those of CCTK3, as described above.
The BIM results obtained in EURAMET.TK3.1 are linked to the results of EUROMET.TK3 and CCTK3 using the participation of VSL in EUROMET.TK3.
The ROTH+CO.AG results obtained in EURAMET.TK3.5 are linked to the results of EUROMET.TK3 and CCTK3 using the participation of VSL in EUROMET.TK3.
This makes it possible to extend the EUROMET.TK3 graphs of equivalence with LACOMET, BIM and ROTH+CO.AG results.
LACOMET and BIM degrees of equivalence relative to the CCTK3 ARV are given on page 17 of the EURAMET.TK3.3 Final Report and on pages 10 and 11 of the EURAMET.TK3.1 Final Report, respectively.
The computation of ROTH+CO.AG degrees of equivalence relative to the CCTK3 ARV is explained in Section 8.1 of the EURAMET.TK3.5 Final Report.
CCTK4, EUROMET.TK4, EURAMET.TK3.3, APMP.TK4 and EURAMET.TK3.5
MEASURAND : Freezingpoint temperature of Aluminium (Al) fixedpoint cells
NOMINAL TEMPERATURE : 660.323 °C
Key comparison reference value for the nominal temperature of Al fixed point: the key comparison reference temperature, T_{R}, is the weighted average temperature calculated using the sum (u_{i}^{2} + u_{c}^{2}) of the squared uncertainties to set the weights. It has zero uncertainty by definition. 
The degree of equivalence of each laboratory with respect to the key comparison reference value is given by a pair of terms: D_{i} = (T_{i}  T_{R}) and U_{i}, its expanded uncertainty at a 95% level of confidence, both expressed in mK. U_{i} = [(2u_{c})^{2} + U_{lab i}^{2}]^{1/2}, where U_{lab i} is the expanded uncertainty of laboratory i at a 95% level of confidence. 
The degree of equivalence between two laboratories is given by a pair of terms: D_{ij}_{ }= D_{i}  D_{j} = T_{i}  T_{j} and U_{ij}, its expanded uncertainty at a 95% level of confidence (see equations 1 to 3 of the CCTK4 Final Report, pages 22 to 23), both expressed in mK. 
The reference value T_{EUR} of key comparison EUROMET.TK4 is computed as the simple mean of the EUROMET.TK4 participants' results, the EIM result being eliminated as an obvious outlier. The expanded uncertainty (k = 2) is calculated from the uncertainties of the laboratories. T_{EUR} = T_{PTB}  (1.18 +/ 1.06) mK, (k = 2) The linkage of EUROMET.TK4 results to those of CCTK4 is explained in Section 5.4 of the EUROMET.TK4 Final Report, and is based on the results of common participants to both comparisons: INRIM, LNEINM, NPL, PTB, VNIIM, and NMiVSL. T_{EUR} = T_{R} + (1.65 +/ 2.28) mK, (k = 2) 
This equation allows to deduce the degrees of equivalence of the EUROMET.TK4 participants relative to the CCTK4 key comparison reference value, each composed of the offset D_{i} and U_{i}, its expanded uncertainty (k = 2), expressed in mK. 
The pairwise degrees of equivalence inside key comparison EUROMET.TK4 are composed of two terms D_{ij}_{ }and U_{ij}, its expanded uncertainty (k = 2), expressed in mK, computed as explained in Section 7 of the EUROMET.TK4 Final Report. 
The LACOMET result obtained in EURAMET.TK3.3 is linked to the results of CCTK4 using the participation of CEM in EUROMET.TK4, whose results are linked to those of CCTK4, as described above.
The participants' results obtained in APMP.TK4 are linked to the results of CCTK4 using the common participation of KRISS and NMIJ in both key comparisons. The linkage process is explained in section 4.2 of the APMP.TK4 Final Report, and leads to the computation of the degrees of equivalence of participants in APMP.TK4 relative to the CCTK4 reference value.
The ROTH+CO.AG result obtained in EURAMET.TK3.5 is linked to the results of CCTK4 using the participation of VSL in EUROMET.TK4, whose results are linked to those of CCTK4, as described above.
EUROMET.TK3, EURAMET.TK3.3 and EURAMET.TK3.5
NOMINAL TEMPERATURE : Argon Triple Point, 83.8058 K
MEASURAND : Resistance ratio, W, at fixedpoint temperature
PILOT LABORATORY : LNEINM
The key comparison EUROMET.TK3 was carried out in five loops as described on Figure 1.1 on page 5 of the Final Report:
The individual laboratory measurements are given in Section 5 of the Final Report.
The temperature differences (T_{i}  T_{P}) and associated standard uncertainties u_{iP} are then deduced independently of the measurement loop. The indexes "i" and "P" refer respectively to laboratory i and to the Pilot Laboratory, and T to the temperature of a given fixed point.
Key comparison EURAMET.TK3.3 is a bilateral comparison between CEM and LACOMET carried out in 2009
For the Argon Triple Point, the temperature difference and corresponding expanded uncertainty (k = 2) are:
T_{LACOMET}  T_{CEM} = 0.4 mK and U(T_{LACOMET}  T_{CEM}) = 11 mK
Key comparison EURAMET.TK3.5 is a bilateral comparison between VSL and ROTH+CO.AG carried out in 2013
For the Argon Triple Point, the temperature difference and corresponding expanded uncertainty (k = 2) are:
T_{ROTH+CO.AG}  T_{VSL} = 0.72 mK and U(T_{ROTH+CO.AG}  T_{VSL}) = 1.02 mK
EUROMET.TK3, EURAMET.TK3.3, EURAMET.TK3.1 and EURAMET.TK3.5
NOMINAL TEMPERATURE : Mercury Triple Point, 234.3156 K
MEASURAND : Resistance ratio, W, at fixedpoint temperature
PILOT LABORATORY : LNEINM
The key comparison EUROMET.TK3 was carried out in five loops as described on Figure 1.1 on page 5 of the Final Report:
The individual laboratory measurements are given in Section 5 of the Final Report.
The temperature differences (T_{i}  T_{P}) and associated standard uncertainties u_{iP} are then deduced independently of the measurement loop. The indexes "i" and "P" refer respectively to laboratory i and to the Pilot Laboratory, and T to the temperature of a given fixed point.
Key comparison EURAMET.TK3.3 is a bilateral comparison between CEM and LACOMET carried out in 2009
For the Mercury Triple Point, the temperature difference and corresponding expanded uncertainty (k = 2) are:
T_{LACOMET}  T_{CEM} = 0.10 mK and U(T_{LACOMET}  T_{CEM}) = 0.64 mK
Key comparison EURAMET.TK3.1 is a bilateral comparison between BIM and VSL carried out in 20082009
For the Mercury Triple Point, the temperature difference and corresponding expanded uncertainty (k = 2) are:
T_{BIM}  T_{VSL} = 0.17 mK and U(T_{BIM}  T_{VSL}) = 0.49 mK
Key comparison EURAMET.TK3.5 is a bilateral comparison between VSL and ROTH+CO.AG carried out in 2013
For the Mercury Triple Point, the temperature difference and corresponding expanded uncertainty (k = 2) are:
T_{ROTH+CO.AG}  T_{VSL} = 0.38 mK and U(T_{ROTH+CO.AG}  T_{VSL}) = 0.96 mK
EUROMET.TK3, EURAMET.TK3.3, EURAMET.TK3.1 and EURAMET.TK3.5
NOMINAL TEMPERATURE : Gallium Melting Point, 302.9146 K
MEASURAND : Resistance ratio, W, at fixedpoint temperature
PILOT LABORATORY : LNEINM
The key comparison EUROMET.TK3 was carried out in five loops as described on Figure 1.1 on page 5 of the Final Report:
The individual laboratory measurements are given in Section 5 of the Final Report.
The temperature differences (T_{i}  T_{P}) and associated standard uncertainties u_{iP} are then deduced independently of the measurement loop. The indexes "i" and "P" refer respectively to laboratory i and to the Pilot Laboratory, and T to the temperature of a given fixed point.
Key comparison EURAMET.TK3.3 is a bilateral comparison between CEM and LACOMET carried out in 2009
For the Gallium Melting Point, the temperature difference and corresponding expanded uncertainty (k = 2) are:
T_{LACOMET}  T_{CEM} = 0.26 mK and U(T_{LACOMET}  T_{CEM}) = 0.61 mK
Key comparison EURAMET.TK3.1 is a bilateral comparison between BIM and VSL carried out in 20082009
For the Gallium Melting Point, the temperature difference and corresponding expanded uncertainty (k = 2) are:
T_{BIM}  T_{VSL} = 0.01 mK and U(T_{BIM}  T_{VSL}) = 0.52 mK
Key comparison EURAMET.TK3.5 is a bilateral comparison between VSL and ROTH+CO.AG carried out in 2013
For the Gallium Melting Point, the temperature difference and corresponding expanded uncertainty (k = 2) are:
T_{ROTH+CO.AG}  T_{VSL} = 0.78 mK and U(T_{ROTH+CO.AG}  T_{VSL}) = 0.93 mK
EUROMET.TK3, EURAMET.TK3.3, EURAMET.TK3.1 and EURAMET.TK3.5
NOMINAL TEMPERATURE : Indium Freezing Point, 429.7485 K
MEASURAND : Resistance ratio, W, at fixedpoint temperature
PILOT LABORATORY : LNEINM
The key comparison EUROMET.TK3 was carried out in five loops as described on Figure 1.1 on page 5 of the Final Report:
The individual laboratory measurements are given in Section 5 of the Final Report.
The temperature differences (T_{i}  T_{P}) and associated standard uncertainties u_{iP} are then deduced independently of the measurement loop. The indexes "i" and "P" refer respectively to laboratory i and to the Pilot Laboratory, and T to the temperature of a given fixed point.
Key comparison EURAMET.TK3.3 is a bilateral comparison between CEM and LACOMET carried out in 2009
For the Indium Freezing Point, the temperature difference and corresponding expanded uncertainty (k = 2) are:
T_{LACOMET}  T_{CEM} = 0.4 mK and U(T_{LACOMET}  T_{CEM}) = 1.7 mK
Key comparison EURAMET.TK3.1 is a bilateral comparison between BIM and VSL carried out in 20082009
For the Indium Freezing Point, the temperature difference and corresponding expanded uncertainty (k = 2) are:
T_{BIM}  T_{VSL} = 0.31 mK and U(T_{BIM}  T_{VSL}) = 0.90 mK
Key comparison EURAMET.TK3.5 is a bilateral comparison between VSL and ROTH+CO.AG carried out in 2013
For the Indium Freezing Point, the temperature difference and corresponding expanded uncertainty (k = 2) are:
T_{ROTH+CO.AG}  T_{VSL} = 1.47 mK and U(T_{ROTH+CO.AG}  T_{VSL}) = 1.99 mK
EUROMET.TK3, EURAMET.TK3.3, EURAMET.TK3.1 and EURAMET.TK3.5
NOMINAL TEMPERATURE : Tin Freezing Point, 505.078 K
MEASURAND : Resistance ratio, W, at fixedpoint temperature
PILOT LABORATORY : LNEINM
The key comparison EUROMET.TK3 was carried out in five loops as described on Figure 1.1 on page 5 of the Final Report:
The individual laboratory measurements are given in Section 5 of the Final Report.
The temperature differences (T_{i}  T_{P}) and associated standard uncertainties u_{iP} are then deduced independently of the measurement loop. The indexes "i" and "P" refer respectively to laboratory i and to the Pilot Laboratory, and T to the temperature of a given fixed point.
Key comparison EURAMET.TK3.3 is a bilateral comparison between CEM and LACOMET carried out in 2009
For the Tin Freezing Point, the temperature difference and corresponding expanded uncertainty (k = 2) are:
T_{LACOMET}  T_{CEM} = 1.3 mK and U(T_{LACOMET}  T_{CEM}) = 1.7 mK
Key comparison EURAMET.TK3.1 is a bilateral comparison between BIM and VSL carried out in 20082009
For the Tin Freezing Point, the temperature difference and corresponding expanded uncertainty (k = 2) are:
T_{BIM}  T_{VSL} = 0.17 mK and U(T_{BIM}  T_{VSL}) = 1.0 mK
Key comparison EURAMET.TK3.5 is a bilateral comparison between VSL and ROTH+CO.AG carried out in 2013
For the Tin Freezing Point, the temperature difference and corresponding expanded uncertainty (k = 2) are:
T_{ROTH+CO.AG}  T_{VSL} = 0.65 mK and U(T_{ROTH+CO.AG}  T_{VSL}) = 1.92 mK
EUROMET.TK3, EURAMET.TK3.3, EURAMET.TK3.1 and EURAMET.TK3.5
NOMINAL TEMPERATURE : Zinc Freezing Point, 692.677 K
MEASURAND : Resistance ratio, W, at fixedpoint temperature
PILOT LABORATORY : LNEINM
The key comparison EUROMET.TK3 was carried out in five loops as described on Figure 1.1 on page 5 of the Final Report:
The individual laboratory measurements are given in Section 5 of the Final Report.
The temperature differences (T_{i}  T_{P}) and associated standard uncertainties u_{iP} are then deduced independently of the measurement loop. The indexes "i" and "P" refer respectively to laboratory i and to the Pilot Laboratory, and T to the temperature of a given fixed point.
Key comparison EURAMET.TK3.3 is a bilateral comparison between CEM and LACOMET carried out in 2009
For the Zinc Freezing Point, the temperature difference and corresponding expanded uncertainty (k = 2) are:
T_{LACOMET}  T_{CEM} = 2.4 mK and U(T_{LACOMET}  T_{CEM}) = 2.1 mK
Key comparison EURAMET.TK3.1 is a bilateral comparison between BIM and VSL carried out in 20082009
For the Zinc Freezing Point, the temperature difference and corresponding expanded uncertainty (k = 2) are:
T_{BIM}  T_{VSL} = 0.80 mK and U(T_{BIM}  T_{VSL}) = 1.6 mK
Key comparison EURAMET.TK3.5 is a bilateral comparison between VSL and ROTH+CO.AG carried out in 2013
For the Zinc Freezing Point, the temperature difference and corresponding expanded uncertainty (k = 2) are:
T_{ROTH+CO.AG}  T_{VSL} = 2.44 mK and U(T_{ROTH+CO.AG}  T_{VSL}) = 2.33 mK
CCTK4, EUROMET.TK4, EURAMET.TK3.3, APMP.TK4 and EURAMET.TK3.5
MEASURAND : Freezingpoint temperature of Aluminium (Al) fixedpoint cells
NOMINAL TEMPERATURE : 660.323 °C
T_{i}  T_{mc} : difference of Al fixedpoint temperature realized at laboratory i, T_{i}, relative to the master circulated cell (PTB/NIST Al 943) temperature T_{mc}
Cell : designation of Al cell at laboratory i
u_{i }: combined standard uncertainty of laboratory i
u_{c} = 0.5 mK : standard uncertainty representing the stability of the circulated cells
Lab i  Cell  (T_{i}  T_{mc}) / mK 
u_{i } / mK 
(u_{i}^{2} + u_{c}^{2})^{1/2} / mK 
BNMINM  Al 123  3.87  0.51  0.72 
IMGC  Al Co3  4.62  0.50  0.71 
KRISS  Al  1.36  0.90  1.03 
NIM  Al 1  3.49  0.90  1.03 
NIST  Al 942  4.63  0.19  0.54 
NMiVSL  93T267  0.74  1.93  1.99 
CSIRONML  Al 98/2  5.55  0.44  0.67 
NPL  Al 89  1.37  0.98  1.10 
NRC  Al6  4.18  0.50  0.71 
NMIJ  Al 971  1.83  0.61  0.79 
PTB  Al 972  2.87  0.55  0.75 
VNIIM  Al  2.12  0.71  0.87 
MEASURAND : Freezingpoint temperature of Aluminium (Al) fixedpoint cells
NOMINAL TEMPERATURE : 660.323 °C
T_{i}  T_{PTB} : difference of Al fixedpoint temperature realized at laboratory i, T_{i}, relative to the PTB result. PTB is the Pilot Laboratory and is the only laboratory with measurements in the four loops organized in key comparison EUROMET.TK4  see Section 5.2 of the EUROMET.TK4 Final Report
U_{Lab} _{i }: expanded uncertainty (k = 2) of T_{i}  T_{PTB}
Lab i 
(T_{i}  T_{PTB}) 
U_{Lab }_{i } / mK 
DTI  1.45  5.65 
JV  1.42  4.69 
MKEH  5.60  4.04 
SMU  0.52  3.65 
INM(RO)  6.63  3.77 
UME  2.08  4.34 
DZM/FSB  5.26  12.62 
CMI  1.30  4.49 
GUM 
1.58 
3.88 
LNEINM*  1.92  3.54 
MIRS  3.20  3.64 
METAS  3.42  3.04 
BEV  0.45  4.31 
NPL 
0.89 
2.81 
SP 
0.67 
3.46 
VMT/PFI 
0.67 
4.24 
VNIIM 
0.86 
2.86 
MIKES 
2.34 
4.55 
EIM 
14.82 
5.99 
INRIM** 
3.21 
4.62 
IPQ 
1.84 
4.42 
CEM 
1.53 
7.49 
NMiVSL 
0.47 
4.63 
PTB 
0.00 
3.36 
* LNEINM was named "BNMINM" at the time of key comparison CCTK4
** INRIM was named "IMGC" at the time of key comparison CCTK4
MEASURAND : Freezingpoint temperature of Aluminium (Al) fixedpoint cells
NOMINAL TEMPERATURE : 660.323 °C
This is a bilateral comparison carried out between CEM and LACOMET in 2009
T_{LACOMET}  T_{CEM} = 0.8 mK and U(T_{LACOMET}  T_{CEM}) = 5.4 mK (see on page 14 of the EURAMET.TK3.3 Final Report), with U being the expanded uncertainty considering a coverage factor k equal to 2
MEASURAND : Freezingpoint temperature of Aluminium (Al) fixedpoint cells
NOMINAL TEMPERATURE : 660.323 °C
T_{i}  T_{KRISS} : difference of Al fixedpoint temperature realized at laboratory i, T_{i}, relative to the KRISS result. KRISS is the Pilot Laboratory and is the only laboratory with measurements in the two loops organized in key comparison APMP.TK4  see page 4 of the APMP.TK4 Final Report
U_{Lab} _{i }: expanded uncertainty (k = 2) of T_{i}  T_{KRISS}
Lab i 
(T_{i}  T_{KRISS}) 
U_{Lab }_{i } / mK 
KRISS  0.00  5.10 
NMIJ  2.20  4.70 
SCL  4.18  4.56 
NMC, A*STAR  6.04  6.02 
CMS  0.07  5.46 
NIMT  0.43  8.28 
NMLSIRIM  11.34  7.70 
NPLI  5.83  5.12 
MEASURAND : Freezingpoint temperature of Aluminium (Al) fixedpoint cells
NOMINAL TEMPERATURE : 660.323 °C
This is a bilateral comparison carried out between VSL and ROTH+CO.AG in 2013
T_{ROTH+CO.AG}  T_{VSL} = 4.69 mK and U(T_{ROTH+CO.AG}  T_{VSL}) = 4.81 mK (see on page 11 of the EURAMET.TK3.5 Final Report), with U being the expanded uncertainty considering a coverage factor k equal to 2