Comparison
Comparison close

CCQM-K34, CCQM-K34.1 and CCQM-K34.2

MEASURAND : Amount content of weak acid in potassium hydrogen phthalate
NOMINAL VALUE : ~ 4.897 mol/kg

Degrees of equivalence: Di = (xi - xR) and expanded uncertainty Ui (k = 2), both expressed in mol/kg

Degrees of equivalence: (Di / xR) and expanded uncertainty (Ui / xR) (k = 2), both expressed in %

Red diamonds: participants in CCQM-K34
Green triangle: participant in CCQM-K34.1
Blue circles: participants in CCQM-K34.2

Comparison
Comparison close

CCQM-K34, CCQM-K34.1 and CCQM-K34.2

MEASURAND : Amount content of weak acid in potassium hydrogen phthalate
NOMINAL VALUE : ~ 4.897 mol/kg

   
Lab iDiUi
 / (mol/kg)/ (mol/kg)
NMIJ-0.00080.0015
KRISS-0.000120.00046
SMU-0.000010.00046
NIM0.000010.00064
NIST0.000280.00046
UNIIM0.00190.0016
BAM*0.00010.00058
INMETRO**-0.00040.00057
UNIIM**-0.00030.00082

* participant in CCQM-K34.1
** participants in CCQM-K34.2

Degrees of equivalence with respect to the key comparison reference value, expressed in relative terms: (Di / xR) and (Ui / xR) :

* participant in CCQM-K34.1
** participants in CCQM-K34.2

Sets of absolute and relative degrees of equivalence are available in Summary Results (PDF file, presented under A4 printable format).

Comparison
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CC comparison
Linked comparison
CCQM-K34.2
Metrology area, Sub-field Chemistry and Biology, Electrochemistry
Description Assay of potassium hydrogen phthalate
Time of measurements 2008
Status Approved for equivalence
Final Reports of the comparisons
Measurand Amount content, expressed in mol/kg
Transfer device Dedicated samples
Comparison type Key Comparison
Consultative Committee CCQM (Consultative Committee for Amount of Substance)
Conducted by CCQM (Consultative Committee for Amount of Substance)
Comments

CCQM-K34.1 and CCQM-K34.2 results are linked to those of CCQM-K34

CCQM-K34.2 results published on 05 January 2010

Amount content of weak acid in potassium hydrogen phthalate

Pilot institute SMU
Slovensky Metrologicky Ustav
Slovakia
Contact person Michal Mariassy
mariassy@smu.gov.sk
+421 2 602 94 522
First Name Last Name
wwww@ww.www +356719836 Institute 1 Institute 1 Khmelnitskiy
Pilot laboratory
SMU

Slovensky Metrologicky Ustav, Slovakia, EURAMET

INMETRO

Instituto Nacional de Metrologia, Qualidade e Tecnologia, Brazil, SIM

UNIIM

Ural Scientific and Research Institute for Metrology, Rosstandart, Russian Federation, COOMET

Comparison
Comparison close

CCQM-K34, CCQM-K34.1 and CCQM-K34.2

MEASURAND : Amount content of weak acid in potassium hydrogen phthalate
NOMINAL VALUE : ~ 4.897 mol/kg

  • Key comparison CCQM-K34

The key comparison reference value, xR, is calculated as the median of the participant results. Its standard uncertainty, uR, is based on the median of the absolute deviations, see on page 7 of the CCQM-K34 Final Report.

xR = 4.89270 mol/kg, uR = 0.00016 mol/kg

The degree of equivalence of laboratory i relative to the key comparison reference value is given by a pair of terms, both expressed in mol/kg:
Di = (xi - xR) and its expanded uncertainty Ui (k = 2) where Ui = 2(ui2 + uR2)1/2.

The degree of equivalence between two laboratories i and j is given by a pair of terms both expressed in mol/kg:
Dij = (Di - Dj) = (xi - xj) and its expanded uncertainty Uij (k = 2) where
Uij = 2(ui2 + uj2)1/2.
  • Linking CCQM-K34.1 and CCQM-K34.2 to CCQM-K34

SMU result is used as a link to the key comparison reference value from CCQM-K34. The results in the comparisons differ by less than 0.1 %, so the degrees of equivalence are directly comparable.

The degree of equivalence of participant i with respect to the key comparison reference value is given by a pair of terms, both expressed in mol/kg:
Di = (DSMU-K34 + xi-K34.a - xSMU-K34.a) and its expanded uncertainty Ui (k = 2) where Ui = 2(uSMU-K34.a2 + ui-K34.a2 + uR2)1/2, with a = 1 or 2.

The degree of equivalence between BAM and laboratory j participant in CCQM-K34 is given by a pair of terms both expressed in mol/kg:
DBAM, j = (DBAM - Dj) and its expanded uncertainty UBAM, j (k = 2) where
UBAM, j = 2(uBAM-K34.12 + uSMU-K34.1 + uj2)1/2.
Pair-wise degrees of equivalence involving CCQM-K34.2 participants are not calculated.
Comparison
Comparison close

CCQM-K34, CCQM-K34.1 and CCQM-K34.2

  • Key comparison CCQM-K34

MEASURAND : Amount content of weak acid in potassium hydrogen phthalate
NOMINAL VALUE : ~ 4.897 mol/kg

xi : result of measurement carried out by laboratory i
ui : combined standard uncertainty of xi

 Lab i xi
/ (mol/kg)
ui
/ (mol/kg)

(ui / xi)
/ %

Date of measurement
 NMIJ 4.89192 0.00074

0.0151

Jun / Jul 2004
 KRISS

4.89259

0.00016

0.0034

Aug 2004

 SMU

4.89269

0.00016

0.0033

Jul 2004

 NIM

4.89272

0.00027

0.0056

Jul / Aug 2004

 NIST 4.89298 0.00016

0.0034

Jul 2004
 UNIIM 4.89458 0.00076

0.0155

Aug 2004

Graph of laboratory individual measurements :
xi and expanded uncertainties (k = 2)

  • Key comparison CCQM-K34.1

MEASURAND : Amount content of weak acid in potassium hydrogen phthalate
NOMINAL VALUE : ~ 4.897 mol/kg

xi-K34.1 : result of measurement carried out by laboratory i participating in CCQM-K34.1
ui-K34.1 : combined standard uncertainty of xi-K34.1

 Lab i xi-K34.1
/ (mol/kg)
ui-K34.1
/ (mol/kg)

(ui-K34.1 / xi-K34.1)
/ %

Date of measurement
 BAM 4.89530 0.00016

0.0033

May / Jun 2005
 SMU

4.89520

0.00018

0.0037

May / Jun 2005

  • Key comparison CCQM-K34.2

MEASURAND : Amount content of weak acid in potassium hydrogen phthalate
NOMINAL VALUE : ~ 4.897 mol/kg

xi-K34.2 : result of measurement carried out by laboratory i participating in CCQM-K34.2
ui-K34.2 : combined standard uncertainty of xi-K34.2

 Lab i xi-K34.2
/ (mol/kg)
ui-K34.2
/ (mol/kg)

(ui-K34.2 / xi-K34.2)
/ %

Date of measurement
 INMETRO

4.89643

0.00018

0.0036

Oct 2008

 UNIIM 4.89656 0.00034

0.0070

Dec 2008
 SMU

4.89683

0.00015

0.0031

Oct 2008