Comparison Display

CCQM-K19, CCQM-K19.1 and APMP.QM-K19

MEASURAND : Acidity function at zero chloride molality of an unknown borate buffer, pH ~ 9.17

TEMPERATURE : 15 °C

Degrees of equivalence D_i and expanded uncertainty U_i (k = 2)

Red diamonds: participants in CCQM-K19
Green triangles: participants in CCQM-K19.1 only
Blue circles: participants in APMP.QM-K19 only

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CCQM-K19, CCQM-K19.1 and APMP.QM-K19

MEASURAND : Acidity function at zero chloride molality of an unknown borate buffer, pH ~ 9.17

TEMPERATURE : 25 °C

Degrees of equivalence D_i and expanded uncertainty U_i (k = 2)

Red diamonds: participants in CCQM-K19
Green triangles: participants in CCQM-K19.1 only
Blue circles: participants in APMP.QM-K19 only

Note: D_NPLI = -0.2030 and U_NPLI = 0.0686

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CCQM-K19, CCQM-K19.1 and APMP.QM-K19

MEASURAND : Acidity function at zero chloride molality of an unknown borate buffer, pH ~ 9.17

TEMPERATURE : 37 °C

Degrees of equivalence D_i and expanded uncertainty U_i (k = 2)

Red diamonds: participants in CCQM-K19
Green triangles: participants in CCQM-K19.1 only
Blue circles: participants in APMP.QM-K19 only

Note: D_NPLI = -0.2455 and U_NPLI = 0.1144

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CCQM-K19, CCQM-K19.1 and APMP.QM-K19

MEASURAND : Acidity function at zero chloride molality of an unknown borate buffer, pH ~ 9.17

TEMPERATURE : 15 °C

Degrees of equivalence D_i and expanded uncertainty U_i(k = 2)

Dark blue: participants in CCQM-K19
Green: participants in CCQM-K19.1 only
Blue: participants in APMP.QM-K19 only

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

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CCQM-K19, CCQM-K19.1 and APMP.QM-K19

MEASURAND : Acidity function at zero chloride molality of an unknown borate buffer, pH ~ 9.17

TEMPERATURE : 25 °C

Degrees of equivalence D_i and expanded uncertainty U_i(k = 2)

Dark blue: participants in CCQM-K19
Green: participants in CCQM-K19.1 only
Blue: participants in APMP.QM-K19 only

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

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CCQM-K19, CCQM-K19.1 and APMP.QM-K19

MEASURAND : Acidity function at zero chloride molality of an unknown borate buffer, pH ~ 9.17

TEMPERATURE : 37 °C

Degrees of equivalence D_i and expanded uncertainty U_i(k = 2)

Dark blue: participants in CCQM-K19
Green: participants in CCQM-K19.1 only
Blue: participants in APMP.QM-K19 only

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

Comparison

Comparison close

CCQM-K19

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Information & contact
Participants

Metrology area, Sub-field	Chemistry and Biology, Electrochemistry
Description	pH measurement of borate buffer solutions
Time of measurements	2005
Status	Approved for equivalence

Final Reports of the comparisons	Metrologia, 2006, 43, Tech. Suppl., 08015
Measurand	pH 9.2
Parameters	Temperature: 15 °C, 25 °C and 37 °C
Transfer device	Borate 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	Results published on 25 October 2006 CCQM-K19.1 and APMP.QM-K19 results are linked to those of CCQM-K19 pH of a borate buffer
Pilot institute	PTB Physikalisch-Technische Bundesanstalt Germany
Contact person	P. Spitzer +49 (0) 531 592 3130

Pilot laboratory
PTB	Physikalisch-Technische Bundesanstalt, Germany, EURAMET

CENAM

Centro Nacional de Metrologia, Mexico, SIM

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

KRISS

Korea Research Institute of Standards and Science, Korea, Republic of, APMP

NIST	National Institute of Standards and Technology, United States, SIM

NMIJ AIST

National Metrology Institute of Japan, Japan, APMP

SMU	Slovensky Metrologicky Ustav, Slovakia, EURAMET

VNIIFTRI

Institute of Physical Technical and Radiotechnical Measurements, Rosstandart, Russian Federation, COOMET

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CCQM-K19, CCQM-K19.1 and AMPM.QM-K19

MEASURAND : Acidity function at zero chloride molality of an unknown borate buffer, pH ~ 9.17
TEMPERATURE : 15 °C

Key comparison CCQM-K19

The key comparison reference value, x_R, is computed as the median of all results except the NCM result, which is identified as an outlier and thus is not taken into account (see Annex B of the CCQM-K19 Final Report).
Its standard uncertainty, u_R, is the standard uncertainty of the median.

x_R = 9.3222 and 2u_R = 0.0014

The degree of equivalence of each laboratory i with respect to the key comparison reference value is given by a pair of terms: D_i= (x_i - x_R) and U_i, its expanded uncertainty (k = 2), U_i = 2(u_i² + u_R²)^1/2.
The NCM degree of equivalence is not computed.

The degree of equivalence between two laboratories i and j is given by a pair of terms: D_ij = D_i - D_j = x_i - x_j and U_ij, its expanded uncertainty (k = 2),
U_ij = 2(u_i² + u_j²)^1/2.
No pair-wise degrees of equivalence are explicitely computed here.

Linking key comparison CCQM-K19.1 to key comparison CCQM-K19

The linkage of key comparison CCQM-K19.1 to key comparison CCQM-K19 is explained on page 15 of the CCQM-K19.1 Final Report. It relies on the common participation of NMIJ, PTB and SMU. Each of these laboratories demontrated consistent results and uncertainties in both comparisons.
The degrees of equivalence of participants in CCQM-K19.1 only, relative to the CCQM-K19 key comparison reference value, is given by two terms: D_i and U_i, its expanded uncertainty (k = 2), computed according to equations 11 and 12 of the CCQM-K19.1 Final Report.

Linking key comparison APMP.QM-K19 to key comparison CCQM-K19

The results of the participants in APMP.QM-K19 are linked to those of CCQM-K19 through the results of the two linking laboratories, NMIJ and SMU, as explained in Section 8 of the APMP.QM-K19 Final Report.

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CCQM-K19, CCQM-K19.1 and APMP.QM-K9

MEASURAND : Acidity function at zero chloride molality of an unknown borate buffer, pH ~ 9.17
TEMPERATURE : 25 °C

Key comparison CCQM-K19

The key comparison reference value, x_R, is computed as the median of all results.
Its standard uncertainty, u_R, is the standard uncertainty of the median.

x_R = 9.2300 and 2u_R = 0.0013

Linking key comparison CCQM-K19.1 to key comparison CCQM-K19

Linking key comparison APMP.QM-K19 to key comparison CCQM-K19

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CCQM-K19, CCQM-K19.1 and APMP.QM-K19

MEASURAND : Acidity function at zero chloride molality of an unknown borate buffer, pH ~ 9.17
TEMPERATURE : 37 °C

Key comparison CCQM-K19

The key comparison reference value, x_R, is computed as the median of all results.
Its standard uncertainty, u_R, is the standard uncertainty of the median.

x_R = 9.1421 and 2u_R = 0.0024

Linking key comparison CCQM-K19.1 to key comparison CCQM-K19

Linking key comparison APMP.QM-K19 to key comparison CCQM-K19

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CCQM-K19, CCQM-K19.1 and APMP.QM-K19

Key comparison CCQM-K19

MEASURAND : Acidity function at zero chloride molality of an unknown borate buffer, pH ~ 9.17
TEMPERATURE : 15 °C

x_i : result of measurement carried out by laboratory i
U_{Lab i}: expanded uncertainty (k = 2) of x_i, U_Lab_i = 2u_i

Lab i	*x_i*	U_{Lab i}	Date of measurement

CENAM	9.3212	0.0148	Sep 05
Radiometer A/S	9.3268	0.0019	Sep 05
GUM	9.3266	0.0026	Oct 05
KRISS	9.3247	0.0034	Sep 05
NCM	9.2955	0.0045	Sep 05
NMIJ	9.3224	0.0028	Sep 05
NIST	9.3220	0.011	Sep 05
OMH	9.3220	0.0054	Sep 05
PTB	9.3214	0.0025	Aug - Sep 05
SMU	9.3210	0.0025	Sep 05
VNIIFTRI	9.3296	0.0040	Sep 05

Key comparison CCQM-K19.1

MEASURAND : Acidity function at zero chloride molality of an unknown borate buffer, pH ~ 9.17
TEMPERATURE : 15 °C

x_i1 : result of measurement carried out by laboratory i
u_i1: combined standard uncertainty (k = 1) of x_i1

Lab i	x_i1	u_i1	Date of measurement

INMETRO	9.3250	0.0039	2010
NIM	9.3385	0.0016	2010
PTB	9.3314	0.0011	2010
DFM	9.3352	0.00085	2010
LNE	9.3236	0.0025	2010
NMIJ	9.3305	0.00119	2010
SMU	9.3325	0.00110	2010
NIST	9.3337	0.00069	2010

Key comparison APMP.QM-K19

MEASURAND : pH of an unknown borate buffer, pH ~ 9.2
TEMPERATURE : 15 °C

x_i : result of measurement carried out by laboratory i
u_i: combined standard uncertainty of x_i

Lab i	x_i	u_i	Date of measurement

NMIJ	9.2726	0.0012	2013
NIMT	9.2905	0.0045	2013
GL	9.280	0.0073	2013
NML-SIRIM	9.2919	0.0035	2013
VMI-STAMEQ	9.270	0.0065	2013
SMU	9.2739	0.0014	2013
LNE	9.2735	0.0014	2013
NPLI	-	-	-
INDECOPI	9.274	0.002	2013
INMETRO	9.2682	0.0010	2013
CMI	9.2759	0.0011	2013
BelGIM	9.297	0.0032	2013
KazInMetr	-	-	-

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CCQM-K19, CCQM-K19.1 and APMP.QM-K19

Key comparison CCQM-K19

MEASURAND : Acidity function at zero chloride molality of an unknown borate buffer, pH ~ 9.17
TEMPERATURE : 25 °C

x_i : result of measurement carried out by laboratory i
U_{Lab i}: expanded uncertainty (k = 2) of x_i, U_Lab_i = 2u_i

Lab i	*x_i*	U_{Lab i}	Date of measurement

CENAM	9.2291	0.0063	Sep 05
Radiometer A/S	9.2361	0.0017	Sep 05
GUM	9.2269	0.0046	Oct 05
KRISS	9.2343	0.0030	Sep 05
NCM	9.2295	0.0044	Sep 05
NMIJ	9.2303	0.0030	Sep 05
NIST	9.2300	0.011	Sep 05
OMH	9.2230	0.0054	Sep 05
PTB	9.2300	0.0025	Aug - Sep 05
SMU	9.2289	0.0023	Sep 05
VNIIFTRI	9.2372	0.0040	Sep 05

Key comparison CCQM-K19.1

MEASURAND : Acidity function at zero chloride molality of an unknown borate buffer, pH ~ 9.17
TEMPERATURE : 25 °C

x_i1 : result of measurement carried out by laboratory i
u_i1: combined standard uncertainty (k = 1) of x_i1

Lab i	x_i1	u_i1	Date of measurement

INMETRO	9.2367	0.0022	2010
NIM	9.2465	0.0017	2010
PTB	9.2399	0.0011	2010
DFM	9.2432	0.00094	2010
LNE	9.2321	0.0020	2010
NMIJ	9.2379	0.00117	2010
SMU	9.2390	0.00109	2010
NIST	9.2409	0.00056	2010

Key comparison APMP.QM-K19

MEASURAND : pH of an unknown borate buffer, pH ~ 9.2
TEMPERATURE : 25 °C

x_i : result of measurement carried out by laboratory i
u_i: combined standard uncertainty of x_i

Lab i	x_i	u_i	Date of measurement

NMIJ	9.1802	0.0011	2013
NIMT	9.2110	0.0034	2013
GL	9.188	0.0061	2013
NML-SIRIM	9.2030	0.0035	2013
VMI-STAMEQ	9.208	0.0053	2013
SMU	9.1799	0.0010	2013
LNE	9.1804	0.0014	2013
NPLI	8.9775	0.0343	2013
INDECOPI	9.182	0.002	2013
INMETRO	9.1759	0.0011	2013
CMI	9.1787	0.0018	2013
BelGIM	9.1977	0.0022	2013
KazInMetr	9.1814	0.0015	2013

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CCQM-K19, CCQM-K19.1 and APMP.QM-K19

Key comparison CCQM-K19

MEASURAND : Acidity function at zero chloride molality of an unknown borate buffer, pH ~ 9.17
TEMPERATURE : 37 °C

x_i : result of measurement carried out by laboratory i
U_{Lab i}: expanded uncertainty (k = 2) of x_i, U_Lab_i = 2u_i

Lab i	*x_i*	U_{Lab i}	Date of measurement

CENAM	9.1401	0.0034	Sep 05
Radiometer A/S	9.1485	0.0017	Sep 05
GUM	9.1429	0.0054	Oct 05
KRISS	9.1471	0.0031	Sep 05
NCM	9.1400	0.0045	Sep 05
NMIJ	9.1426	0.0026	Sep 05
NIST	9.1420	0.011	Sep 05
OMH	9.1370	0.0040	Sep 05
PTB	9.1421	0.0025	Aug - Sep 05
SMU	9.1415	0.0023	Sep 05
VNIIFTRI	9.1495	0.0040	Sep 05

Key comparison CCQM-K19.1

MEASURAND : Acidity function at zero chloride molality of an unknown borate buffer, pH ~ 9.17
TEMPERATURE : 37 °C

x_i1 : result of measurement carried out by laboratory i
u_i1: combined standard uncertainty (k = 1) of x_i1

Lab i	x_i1	u_i1	Date of measurement

INMETRO	9.1541	0.0041	2010
NIM	9.1592	0.0016	2010
PTB	9.1522	0.0011	2010
DFM	9.1550	0.00098	2010
LNE	9.1441	0.0024	2010
NMIJ	9.1503	0.00117	2010
SMU	9.1505	0.00109	2010
NIST	9.1516	0.00078	2010

Key comparison APMP.QM-K19

MEASURAND : pH of an unknown borate buffer, pH ~ 9.2
TEMPERATURE : 37 °C

x_i : result of measurement carried out by laboratory i
u_i: combined standard uncertainty of x_i

Lab i	x_i	u_i	Date of measurement

NMIJ	9.0912	0.0011	2013
NIMT	9.1156	0.0041	2013
GL	9.100	0.0062	2013
NML-SIRIM	9.1125	0.0035	2013
VMI-STAMEQ	9.131	0.0052	2013
SMU	9.0898	0.0018	2013
LNE	9.0907	0.0014	2013
NPLI	8.845	0.0572	2013
INDECOPI	9.093	0.002	2013
INMETRO	9.0853	0.0017	2013
CMI	9.0875	0.0011	2013
BelGIM	9.1073	0.0031	2013
KazInMetr	-	-	-

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