CCQM-K91.2022
MEASURAND: Acidity function at zero chloride molality, pa0, of an unknown phthalate buffer
SAMPLE: Potassium hydrogen phthalate in deionized water
Measurements at 15 °C
NOMINAL VALUE: pH ~ 4.0
Degrees of equivalence represented by Di = (xI - xR) and its expanded uncertainty Ui at a 95 % level of confidence.
Enlarged graph
CCQM-K91.2022
MEASURAND: Acidity function at zero chloride molality, pa0, of an unknown phthalate buffer
SAMPLE: Potassium hydrogen phthalate in deionized water
Measurements at 25 °C
NOMINAL VALUE: pH ~ 4.0
Degrees of equivalence represented by Di = (xI - xR) and its expanded uncertainty Ui at a 95 % level of confidence.
Enlarged graph
CCQM-K91.2022
MEASURAND: Acidity function at zero chloride molality, pa0, of an unknown phthalate buffer
SAMPLE: Potassium hydrogen phthalate in deionized water
Measurements at 37 °C
NOMINAL VALUE: pH ~ 4.0
Degrees of equivalence represented by Di = (xI - xR) and its expanded uncertainty Ui at a 95 % level of confidence.
Enlarged graph
CCQM-K91.2022
MEASURAND: Acidity function at zero chloride molality, pa0, of an unknown phthalate buffer
SAMPLE: Potassium hydrogen phthalate in deionized water
Measurements at 15 °C
NOMINAL VALUE: pH ~ 4.0
Degrees of equivalence represented by Di = (xI - xR) and its expanded uncertainty Ui at a 95 % level of confidence.
LABi | Di | Uneg,i | Upos,i | |
---|---|---|---|---|
dimensionless |
dimensionless |
dimensionless |
||
BFKH | -0.0020 | 0.0055 | ||
BIM | -0.0039 | 0.0042 | ||
CENAM | -0.0043 | 0.0346 | ||
CMI | 0.0003 | 0.0019 | ||
INMETRO | 0.0034 | 0.0023 | ||
NIM | -0.0028 | 0.0034 | ||
NMIJ | -0.0006 | 0.0025 | ||
VNIIFTRI | -0.0004 | 0.0034 |
CCQM-K91.2022
MEASURAND: Acidity function at zero chloride molality, pa0, of an unknown phthalate buffer
SAMPLE: Potassium hydrogen phthalate in deionized water
Measurements at 25 °C
NOMINAL VALUE: pH ~ 4.0
Degrees of equivalence represented by Di = (xI - xR) and its expanded uncertainty Ui at a 95 % level of confidence.
LABi | Di | Uneg,i | Upos,i | |
---|---|---|---|---|
dimensionless |
dimensionless |
dimensionless |
||
BFKH | 0.0001 | 0.0047 | ||
BIM | -0.0005 | 0.0043 | ||
SNSU-BSN | -0.0041 | 0.0047 | ||
CENAM | 0.0076 | 0.0266 | ||
CMI | -0.0002 | 0.0017 | ||
IBMETRO | -0.0049 | 0.0103 | ||
INMETRO | 0.0033 | 0.0024 | ||
INTI | 0.0190 | 0.0360 | ||
LATU | 0.0010 | 0.0034 | ||
NIM | -0.0025 | 0.0034 | ||
NMIJ | -0.0008 | 0.0024 | ||
UME | -0.0032 | 0.0057 | ||
VNIIFTRI | -0.0004 | 0.0032 |
CCQM-K91.2022
MEASURAND: Acidity function at zero chloride molality, pa0, of an unknown phthalate buffer
SAMPLE: Potassium hydrogen phthalate in deionized water
Measurements at 37 °C
NOMINAL VALUE: pH ~ 4.0
Degrees of equivalence represented by Di = (xI - xR) and its expanded uncertainty Ui at a 95 % level of confidence.
LABi | Di | Uneg,i | Upos,i | |
---|---|---|---|---|
dimensionless |
dimensionless |
dimensionless |
||
BFKH | -0.0003 | 0.0053 | ||
BIM | 0.0023 | 0.0043 | ||
CENAM | 0.0418 | 0.0342 | ||
CMI | -0.0001 | 0.0014 | ||
INMETRO | 0.0017 | 0.0028 | ||
NIM | -0.0027 | 0.0034 | ||
NMIJ | -0.0004 | 0.0023 | ||
VNIIFTRI | -0.0001 | 0.0034 |
Metrology area, Sub-field | Chemistry and Biology, Electrochemistry |
Description | Acidity function of an unknown phthalate buffer at zero chloride molality |
Time of measurements | 2025 - 2026 |
Status | Planned |
Measurand | Acidity function at zero chloride molality, pa0 Nominal value of pH ~4.01 at temperature 25 °C |
Parameters | Temperature: 15 °C, 25 °C and 37 °C, and optional at 5 °C and 50 °C Measurement by Harned cell and differential potentiometric |
Transfer device | Aqueous phthalate buffer |
Comparison type | Key Comparison |
Consultative Committee | CCQM (Consultative Committee for Amount of Substance) |
Conducted by | EURAMET (European Association of National Metrology Institutes) |
Pilot institute |
CMI
Czech Metrology Institute Czechia |
Contact person | Matilda Rozikova +420 545 555 321 |
Pilot laboratory | |
---|---|
CMI |
Czech Metrology Institute, Czechia, EURAMET |
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CCQM-K91.2022
MEASURAND: Acidity function at zero chloride molality, pa0, of an unknown phthalate buffer
SAMPLE: Potassium hydrogen phthalate in deionized water
Measurements at 15 °C
NOMINAL VALUE: pH ~ 4.0
The key comparison reference value xR and its associated standard uncertainty uR are computed from the weighted mean uncorrected for observed dispersion according to equation 7 to 9 of the CCQM-K91.2022 Final report, from results obtained using primary method CENAM excluded.
xR = 4.0873 uR = 0.0006
The degree of equivalence of laboratory i relative to the key comparison reference value xR is given by a pair of terms:
Di = (xi - xR) and its expanded uncertainty Ui at a 95 % level of confidence where Ui = 2 (ui 2 - uR2)1/2 for resuts used in calculation of xR and
Ui = 2(ui 2 + uR2)1/2 for results not used in the calculation of xR.
CCQM-K91.2022
MEASURAND: Acidity function at zero chloride molality, pa0, of an unknown phthalate buffer
SAMPLE: Potassium hydrogen phthalate in deionized water
Measurements at 25 °C
NOMINAL VALUE: pH ~ 4.0
The key comparison reference value xR and its associated standard uncertainty uR are computed from the weighted mean uncorrected for observed dispersion according to equation 7 to 9 of the CCQM-K91.2022 Final report, from results obtained using primary method CENAM excluded.
xR = 4.0956 uR = 0.0005
The degree of equivalence of laboratory i relative to the key comparison reference value xR is given by a pair of terms:
Di = (xi - xR) and its expanded uncertainty Ui at a 95 % level of confidence where Ui = 2 (ui 2 - uR2)1/2 for resuts used in calculation of xR and
Ui = 2(ui 2 + uR2)1/2 for results not used in the calculation of xR.
CCQM-K91.2022
MEASURAND: Acidity function at zero chloride molality, pa0, of an unknown phthalate buffer
SAMPLE: Potassium hydrogen phthalate in deionized water
Measurements at 37 °C
NOMINAL VALUE: pH ~ 4.0
The key comparison reference value xR and its associated standard uncertainty uR are computed from the weighted mean uncorrected for observed dispersion according to equation 7 to 9 of the CCQM-K91.2022 Final report, from results obtained using primary method CENAM excluded.
xR = 4.1159 uR = 0.0006
The degree of equivalence of laboratory i relative to the key comparison reference value xR is given by a pair of terms:
Di = (xi - xR) and its expanded uncertainty Ui at a 95 % level of confidence where Ui = 2 (ui 2 - uR2)1/2 for resuts used in calculation of xR and
Ui = 2(ui 2 + uR2)1/2 for results not used in the calculation of xR.
CCQM-K91.2022
MEASURAND: Acidity function at zero chloride molality, pa0, of an unknown phthalate buffer
SAMPLE: Potassium hydrogen phthalate in deionized water
Measurements at 15 °C
NOMINAL VALUE: pH ~ 4.0
xi measured mass fraction reported by laboratory i, Labi
ui combined standard uncertainty of xi
Labi | xi | ui | |
dimensionless | dimensionless | ||
BFKH | 4.0853 | 0.0028 | |
BIM | 4.0834 | 0.0022 | |
CENAM | 4.0830 | 0.0173 | |
CMI | 4.0876 | 0.0011 | |
INMETRO | 4.0907 | 0.0013 | |
NIM | 4.0845 | 0.0018 | |
NMIJ | 4.0867 | 0.0014 | |
VNIIFTRI | 4.0869 | 0.0018 |
CCQM-K91.2022
MEASURAND: Acidity function at zero chloride molality, pa0, of an unknown phthalate buffer
SAMPLE: Potassium hydrogen phthalate in deionized water
Measurements at 25 °C
NOMINAL VALUE: pH ~ 4.0
xi measured mass fraction reported by laboratory i, Labi
ui combined standard uncertainty of xi
Labi | xi | ui | |
dimensionless | dimensionless | ||
BFKH | 4.0957 | 0.0024 | |
BIM | 4.0951 | 0.0022 | |
SNSU-BSN | 4.0915 | 0.0023 | |
CENAM | 4.1032 | 0.0133 | |
CMI | 4.0954 | 0.0010 | |
IBMETRO | 4.0907 | 0.0051 | |
INMETRO | 4.0989 | 0.0013 | |
INTI | 4.1146 | 0.0180 | |
LATU | 4.0966 | 0.0016 | |
NIM | 4.0931 | 0.0018 | |
NMIJ | 4.0948 | 0.0013 | |
UME | 4.0924 | 0.0029 | |
VNIIFTRI | 4.0952 | 0.0017 |
CCQM-K91.2022
MEASURAND: Acidity function at zero chloride molality, pa0, of an unknown phthalate buffer
SAMPLE: Potassium hydrogen phthalate in deionized water
Measurements at 37 °C
NOMINAL VALUE: pH ~ 4.0
xi measured mass fraction reported by laboratory i, Labi
ui combined standard uncertainty of xi
Labi | xi | ui | |
dimensionless | dimensionless | ||
BFKH | 4.1156 | 0.0027 | |
BIM | 4.1182 | 0.0022 | |
CENAM | 4.1577 | 0.0171 | |
CMI | 4.1158 | 0.0009 | |
INMETRO | 4.1176 | 0.0015 | |
NIM | 4.1132 | 0.0018 | |
NMIJ | 4.1155 | 0.0013 | |
VNIIFTRI | 4.1158 | 0.0018 |