CCQM-K18 and CCQM-K18.1
MEASURAND : Acidity function at zero chloride molality of a carbonate buffer
pH ~ 10
TEMPERATURE : 25 °C
Degrees of equivalence Di and expanded uncertainty Ui (k = 2)
Red diamonds : participants in CCQM-K18
Green triangles : participants in CCQM-K18.1
In CCQM-K18: DINPL = 0.0663 and UINPL = 0.0105
Open symbols represent values for laboratories in Associate States and Economies of the CGPM
CCQM-K18 and CCQM-K18.1
MEASURAND : Acidity function at zero chloride molality of a carbonate buffer
pH ~ 10
TEMPERATURE : 25 °C
Degrees of equivalence Di and expanded uncertainty Ui (k = 2)
* participation in CCQM-K18.1
Results are presented under A4 printable format in Summary Results (.PDF file).
| Metrology area, Sub-field | Chemistry and Biology, Electrochemistry |
| Description | pH measurement of carbonate buffer solutions |
| Time of measurements | 2007 |
| Status | Approved for equivalence |
| Final Reports of the comparisons | |
| Measurand | pH 10 |
| Parameters | Temperature: 25 °C |
| Transfer device | Carbonate buffer solutions |
| Comparison type | Key Comparison |
| Consultative Committee | CCQM (Consultative Committee for Amount of Substance) |
| Conducted by | CCQM (Consultative Committee for Amount of Substance) |
| Comments | This is a follow-up to key comparison CCQM-K18. Results published on 29 September 2008 CCQM-K18.1 results are linked to those of CCQM-K18 pH of a carbonate buffer |
| Pilot institute |
SMU
Slovensky Metrologicky Ustav Slovakia |
| Contact person | L. Vyskocil +421 2 602 94 225 |
| Pilot laboratory | |
|---|---|
| SMU |
Slovensky Metrologicky Ustav, Slovakia, EURAMET |
| CENAM |
Centro Nacional de Metrologia, Mexico, SIM |
| DFM |
Danish Fundamental Metrology A/S, Denmark, EURAMET |
| INMETRO |
Instituto Nacional de Metrologia, Qualidade e Tecnologia, Brazil, SIM |
| INPL |
National Physical Laboratory of Israel, Israel, N/A |
| LNE |
Laboratoire national de métrologie et d'essais, France, EURAMET |
| NIM |
National Institute of Metrology, China, APMP |
| PTB |
Physikalisch-Technische Bundesanstalt, Germany, EURAMET |
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" :
CCQM-K18 and CCQM-K18.1
MEASURAND : Acidity function at zero chloride molality of a carbonate buffer
pH ~ 10
TEMPERATURE : 25 °C
|
The key comparison reference value, xR, is computed as the median of results of all participants except INPL. Its standard uncertainty, uR, is the standard uncertainty of the median. xR = 10.1985 and uR = 0.0019 |
| The degree of equivalence of each laboratory i with respect to the key comparison reference value is given by a pair of terms: Di = (xi - xR) and Ui, its expanded uncertainty (k = 2), Ui = 2(ui2 + uR2)1/2. |
| The degree of equivalence between two laboratories i and j is given by a pair of terms: Dij = Di - Dj = xi - xj and Uij, its expanded uncertainty (k = 2), Uij = 2(ui2 + uj2)1/2. No pair-wise degrees of equivalence are explicitely computed. |
|
SMU provides the linkage between both key comparisons, as explained on page 9 of the CCQM-K18.1 Final Report. |
| The degree of equivalence of each laboratory i participant in CCQM-K18.1 with respect to the CCQM-K18 key comparison reference value is given by a pair of terms: Di = DSMU (K18) + xi (K18.1) - xSMU (K18.1) and Ui, its expanded uncertainty (k = 2), Ui = [USMU (K18)2 + [2ui (K18.1)]2 + [2uSMU (K18.1)]2]1/2. |
| No pair-wise degrees of equivalence are explicitely computed. |
CCQM-K18 and CCQM-K18.1
MEASURAND : Acidity function at zero chloride molality of a carbonate buffer
pH ~ 10
TEMPERATURE : 25 °C
xi : result of measurement carried out by laboratory i
ui : combined standard uncertainty (k = 1) of xi
|
Lab i |
xi | ui | Date of measurement |
| NIM | 10.1815 | 0.0018 | Aug - Sep 06 |
| LNE | 10.1852 | 0.0036 | Aug 06 |
| NCM | 10.1945 | 0.0037 | Sep 06 |
| NIST | 10.1969 | 0.0008 | Sep 06 |
| GUM | 10.1975 | 0.0017 | Sep 06 |
| UkrCSM | 10.1975 | 0.0030 | Sep 06 |
| SMU | 10.1995 | 0.0015 | Aug 06 |
| CMI | 10.2003 | 0.0012 | Sep - Oct 06 |
| NMIJ | 10.2014 | 0.0013 | Aug 06 |
| INMETRO | 10.2051 | 0.0032 | Oct 06 |
| CENAM | 10.2102 | 0.0011 | Sep 06 |
| PTB |
10.2107 |
0.0015 |
Aug - Sep 06 |
| INPL |
10.2648 |
0.0049 |
Sep 06 |
MEASURAND : Acidity function at zero chloride molality of a carbonate buffer
pH ~ 10
TEMPERATURE : 25 °C
xi (K18.1) : result of measurement carried out by laboratory i
ui (K18.1) : combined standard uncertainty (k = 1) of xi
|
Lab i |
xi (K18.1) | ui (K18.1) | Date of measurement |
| LNE | 10.0857 | 0.0034 | Jul 07 |
| NIM | 10.0861 | 0.0018 | Jul 07 |
| INMETRO | 10.1032 | 0.0016 | Jul 07 |
| SMU | 10.1033 | 0.0015 | Jul 07 |
| PTB | 10.1048 | 0.0015 | Jul 07 |
| DFM | 10.1076 | 0.0006 | Jul 07 |
| CENAM | 10.1092 | 0.0018 | Jul 07 |
| INPL | 10.1409 | 0.0033 | Jul 07 |
