MEASURAND : Mass fraction of Silicon (Si) as Silicon Oxide (SiO2) in clay

Degrees of equivalence relative to the key comparison reference value shown in relative terms

xR = 658.04 mg/g, uR = 1.91 mg/g

MEASURAND : Mass fraction of Aluminum (Al) as Aluminum Oxide (Al2O3) in clay

Degrees of equivalence relative to the key comparison reference value shown in relative terms

xR = 147.82 mg/g, uR = 0.87 mg/g

MEASURAND : Mass fraction of Iron (Fe) as Iron Oxide (Fe2O3) in clay

Degrees of equivalence relative to the key comparison reference value shown in relative terms

xR = 56.14 mg/g, uR = 0.21 mg/g

MEASURAND : Mass fraction of Calcium (Ca) as Calcium Oxide (CaO) in clay

Degrees of equivalence relative to the key comparison reference value shown in relative terms

xR = 24.325 mg/g, uR = 0.12 mg/g

MEASURAND : Mass fraction of Magnesium (Mg) as Magnesium Oxide (MgO) in clay

Degrees of equivalence relative to the key comparison reference value shown in relative terms

xR = 7.72 mg/g, uR = 0.09 mg/g

MEASURAND : Mass fraction of Silicon (Si) as Silicon Oxide (SiO2) in clay

Degrees of equivalence relative to the key comparison reference value expressed in mg/g and in relative terms

xR = 658.04 mg/g, uR = 1.91 mg/g

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

MEASURAND : Mass fraction of Aluminum (Al) as Aluminum Oxide (Al2O3) in clay

Degrees of equivalence relative to the key comparison reference value expressed in mg/g and in relative terms

xR = 147.82 mg/g, uR = 0.87 mg/g

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

MEASURAND : Mass fraction of Iron (Fe) as Iron Oxide (Fe2O3) in clay

Degrees of equivalence relative to the key comparison reference value expressed in mg/g and in relative terms

xR = 56.14 mg/g, uR = 0.21 mg/g

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

MEASURAND : Mass fraction of Calcium (Ca) as Calcium Oxide (CaO) in clay

Degrees of equivalence relative to the key comparison reference value expressed in mg/g and in relative terms

xR = 24.325 mg/g, uR = 0.12 mg/g

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

MEASURAND : Mass fraction of Magnesium (Mg) as Magnesium Oxide (MgO) in clay

Degrees of equivalence relative to the key comparison reference value expressed in mg/g and in relative terms

xR = 7.72 mg/g, uR = 0.09 mg/g

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

Comparison
Comparison close
CC comparison
Linked comparison
CCQM-K57
Metrology area, Sub-field Chemistry and Biology, Inorganics
Description Chemical composition of clay
Time of measurements 2007
Status Approved for equivalence
Final Reports of the comparisons
Measurand Mass fraction of SiO2: ~ 650 mg/g to 700 mg/g
Mass fraction of MgO: ~ 5 mg/g to 15 mg/g
Mass fraction of CaO: ~ 10 mg/g to 50 mg/g
Mass fraction of Fe2O3: ~ 20 mg/g to 100 mg/g
Mass fraction of Al2O3: ~ 100 mg/g to 200 mg/g

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

Results published on 21 July 2009, then amended on 11 August 2009

Chemical composition of clay

Pilot institute CENAM
Centro Nacional de Metrologia
Mexico
Contact person J. Antonio SALAS

+52 442 211 05 60
First Name Last Name
wwww@ww.www +356719836 Institute 1 Institute 1 Khmelnitskiy
Pilot laboratory
CENAM

Centro Nacional de Metrologia, Mexico, SIM

BAM

Bundesanstalt für Materialforschung und -prüfung, Germany, EURAMET

NIST

National Institute of Standards and Technology, United States, SIM

NMIJ AIST

National Metrology Institute of Japan, Japan, APMP

VNIIM

D.I. Mendeleyev Institute for Metrology, Rosstandart, Russian Federation, COOMET

MEASURAND : Mass fraction of Silicon (Si) as Silicon Oxide (SiO2) in clay

The key comparison reference value, xR, is computed as the median of all results. Its standard uncertainty, uR, is based on the estimation of the dispersion around the median (see Section 9 of the Final Report). Its expanded uncertainty, UR, is estimated with a coverage factor of 2.57.

xR = 658.04 mg/g, uR = 1.91 mg/g, UR = 4.90 mg/g

The degree of equivalence of laboratory i relative to the key comparison reference value is given by a pair of terms, both expressed in mg/g: Di = (xi - xR) and its expanded uncertainty Ui (k = 2), computed as  explained in Section 10 of the Final Report. Relative values are also computed as Direl = Di/xR and Uirel = Ui/xR.

No pair-wise degrees of equivalence are computed for this key comparison.

MEASURAND : Mass fraction of Aluminum (Al) as Aluminum Oxide (Al2O3) in clay

The key comparison reference value, xR, is computed as the median of all results. Its standard uncertainty, uR, is based on the estimation of the dispersion around the median (see Section 9 of the Final Report). Its expanded uncertainty, UR, is estimated with a coverage factor of 2.57.

xR = 147.82 mg/g, uR = 0.87 mg/g, UR = 2.23 mg/g

The degree of equivalence of laboratory i relative to the key comparison reference value is given by a pair of terms, both expressed in mg/g: Di = (xi - xR) and its expanded uncertainty Ui (k = 2), computed as explained in Section 10 of the Final Report. Relative values are also computed as Direl = Di/xR and Uirel = Ui/xR.

No pair-wise degrees of equivalence are computed for this key comparison.

MEASURAND : Mass fraction of Iron (Fe) as Iron Oxide (Fe2O3) in clay

The key comparison reference value, xR, is computed as the median of all results. Its standard uncertainty, uR, is based on the estimation of the dispersion around the median (see Section 9 of the Final Report). Its expanded uncertainty, UR, is estimated with a coverage factor of 2.57.

xR = 56.14 mg/g, uR = 0.21 mg/g, UR = 0.55 mg/g

The degree of equivalence of laboratory i relative to the key comparison reference value is given by a pair of terms, both expressed in mg/g: Di = (xi - xR) and its expanded uncertainty Ui (k = 2), computed as explained in Section 10 of the Final Report. Relative values are also computed as Direl = Di/xR and Uirel = Ui/xR.

No pair-wise degrees of equivalence are computed for this key comparison.

MEASURAND : Mass fraction of Calcium (Ca) as Calcium Oxide (CaO) in clay

The key comparison reference value, xR, is computed as the median of all results. Its standard uncertainty, uR, is based on the estimation of the dispersion around the median (see Section 9 of the Final Report). Its expanded uncertainty, UR, is estimated with a coverage factor of 2.57.

xR = 24.325 mg/g, uR = 0.12 mg/g, UR = 0.30 mg/g

The degree of equivalence of laboratory i relative to the key comparison reference value is given by a pair of terms, both expressed in mg/g: Di = (xi - xR) and its expanded uncertainty Ui (k = 2), computed as explained in Section 10 of the Final Report. Relative values are also computed as Direl = Di/xR and Uirel = Ui/xR.

No pair-wise degrees of equivalence are computed for this key comparison.

MEASURAND : Mass fraction of Magnesium (Mg) as Magnesium Oxide (MgO) in clay

The key comparison reference value, xR, is computed as the median of all results. Its standard uncertainty, uR, is based on the estimation of the dispersion around the median (see Section 9 of the Final Report). Its expanded uncertainty, UR, is estimated with a coverage factor of 2.57.

xR = 7.72 mg/g, uR = 0.09 mg/g, UR = 0.24 mg/g

The degree of equivalence of laboratory i relative to the key comparison reference value is given by a pair of terms, both expressed in mg/g: Di = (xi - xR) and its expanded uncertainty Ui (k = 2), computed as explained in Section 10 of the Final Report. Relative values are also computed as Direl = Di/xR and Uirel = Ui/xR.

No pair-wise degrees of equivalence are computed for this key comparison.

MEASURAND : Mass fraction of Silicon (Si) as Silicon Oxide (SiO2) in clay

xi : result of measurement carried out by laboratory i
ULab i : expanded uncertainty of xi at a 95 % level of confidence
ui : standard uncertainty of xi
ULab i = ki ui where ki is the coverage factor

 Lab i xi
/ (mg/g)
ULab i
/ (mg/g)

ki

Date of measurement
 BAM 659.0 9.86

2

2007
 CENAM

662.3

3.1

2.1

2007

 NIST

665.6

13.2

2

2007

 NMIJ

653.52

0.83

2

2007

 SP 656.0 5.2

2

2007
 VNIIM 657.08 3.81

2

2007

MEASURAND : Mass fraction of Aluminum (Al) as Aluminum Oxide (Al2O3) in clay

xi : result of measurement carried out by laboratory i
ULab i : expanded uncertainty of xi at a 95 % level of confidence
ui : standard uncertainty of xi
ULab i = ki ui where ki is the coverage factor

 Lab i xi
/ (mg/g)
ULab i
/ (mg/g)

ki

Date of measurement
 BAM 147.3 1.3

2

2007
 CENAM

150.22

1.29

2.1

2007

 NIST

146.35

1.45

2

2007

 NMIJ

148.34

2.74

2

2007

 SP 145.9 2.1

2

2007
 VNIIM 149.22 2.66

2

2007

MEASURAND : Mass fraction of Iron (Fe) as Iron Oxide (Fe2O3) in clay

xi : result of measurement carried out by laboratory i
ULab i : expanded uncertainty of xi at a 95 % level of confidence
ui : standard uncertainty of xi
ULab i = ki ui where ki is the coverage factor

 Lab i xi
/ (mg/g)
ULab i
/ (mg/g)

ki

Date of measurement
 BAM 56.3 2.8

2

2007
 CENAM

55.89

0.32

2.1

2007

 NIST

55.98

0.36

2

2007

 NMIJ

54.54

0.59

2

2007

 SP 56.6 1.2

2

2007
 VNIIM 59.54 1.94

2

2007

MEASURAND : Mass fraction of Calcium (Ca) as Calcium Oxide (CaO) in clay

xi : result of measurement carried out by laboratory i
ULab i : expanded uncertainty of xi at a 95 % level of confidence
ui : standard uncertainty of xi
ULab i = ki ui where ki is the coverage factor

 Lab i xi
/ (mg/g)
ULab i
/ (mg/g)

ki

Date of measurement
 BAM 24.42 0.64

2

2007
 CENAM

24.58

0.23

2.3

2007

 NIST

24.19

0.69

2

2007

 NMIJ

24.23

1.37

2

2007

 SP 24.7 0.8

2

2007
 VNIIM 23.138 0.926

2

2007

MEASURAND : Mass fraction of Magnesium (Mg) as Magnesium Oxide (MgO) in clay

xi : result of measurement carried out by laboratory i
ULab i : expanded uncertainty of xi at a 95 % level of confidence
ui : standard uncertainty of xi
ULab i = ki ui where ki is the coverage factor

 Lab i xi
/ (mg/g)
ULab i
/ (mg/g)

ki

Date of measurement
 BAM 7.91 0.12

2

2007
 CENAM

7.75

0.24

2.8

2007

 NIST

7.70

0.21

2

2007

 NMIJ

7.460

0.145

2

2007

 SP 7.6 0.7

2

2007
 VNIIM 9.157 0.513

2

2007