MEASURAND   Amount fraction of Nitrogen dioxide in Nitrogen

NOMINAL VALUE 10 µmol mol^-1

Measurement 1

Degrees of equivalence represented by D_i and its expanded uncertainty U_i at a 95 % level of confidence, both expressed in µmol mol^-1 .

MEASURAND   Amount fraction of Nitrogen dioxide in Nitrogen

NOMINAL VALUE 10 µmol mol^-1

Measurement 2

Degrees of equivalence represented by D_i and its expanded uncertainty U_i at a 95 % level of confidence, both expressed in µmol mol^-1 .

MEASURAND   Amount fraction of Nitrogen dioxide in Nitrogen

NOMINAL VALUE 10 µmol mol^-1

Measurement 3

Degrees of equivalence represented by D_i and its expanded uncertainty U_i at a 95 % level of confidence, both expressed in µmol mol^-1 .

MEASURAND   Amount fraction of Nitrogen dioxide in Nitrogen

NOMINAL VALUE 10 µmol mol^-1

Measurement 1

Degrees of equivalence represented by D_i and its expanded uncertainty U_i at a 95 % level of confidence, both expressed in µmol mol^-1 .

The degrees of equivalence for the two cylinders of NPL were not computed due unstable mixtures.

MEASURAND   Amount fraction of Nitrogen dioxide in Nitrogen

NOMINAL VALUE 10 µmol mol^-1

Measurement 2

Degrees of equivalence represented by D_i and its expanded uncertainty U_i at a 95 % level of confidence, both expressed in µmol mol^-1 .

MEASURAND   Amount fraction of Nitrogen dioxide in Nitrogen

NOMINAL VALUE 10 µmol mol^-1

Measurement 3

Degrees of equivalence represented by D_i and its expanded uncertainty U_i at a 95 % level of confidence, both expressed in µmol mol^-1 .

MEASURAND   Amount fraction of Nitrogen dioxide in Nitrogen

NOMINAL VALUE 10 µmol mol^-1

Measurement 1

The key comparison reference value is the Nitrogen dioxide mole fraction assigned by the BIPM, x_Ri, to a cylinder of laboratory i , as explained in Section 6.1 on page 35 of the Final Report.  Its associated standard uncertainty, u_Ri, is calculated as explained in Annex 3 on page 51 of the Final Report.

One degree of equivalence for one standard of one laboratory i participant at one date of the measurement performed by the coordinating laboratory is defined by two terms , both expressed in µmol/mol:

D_i = (x_i - x_Ri)  where x_i denotes the estimation of the NO₂ amount fraction in the participant's standard at the date of the key comparison reference value and x_Ri denotes the reference value given by the BIPM on that date.

Its associated expanded uncertainty is U_i = (u_i ² - u_Ri ²)^1/2 at a 95 % level of confidence where U_i = 2 u_i.

MEASURAND   Amount fraction of Nitrogen dioxide in Nitrogen

NOMINAL VALUE 10 µmol mol^-1

Measurement 2

The key comparison reference value is the Nitrogen dioxide mole fraction assigned by the BIPM, x_Ri, to a cylinder of laboratory i , as explained in Section 6.1 on page 35 of the Final Report.  Its associated standard uncertainty, u_Ri , is calculated as explained in Annex 3 on page 51 of the Final Report.

One degree of equivalence for one standard of one laboratory i participant at one date of the measurement performed by the coordinating laboratory is defined by two terms, bothe expressed in µmol/mol:

D_i = (x_i - x_{R i})  where x_i denotes the estimation of the NO₂ amount fraction in the participant's standard at the date of the key comparison reference value and x_Ri  denotes the reference value given by the BIPM on that date.

Its associated expanded uncertainty is U_i = (u_i ² - u_Ri ²)^1/2 at a 95 % level of confidence where U_i = 2 u_i.

MEASURAND   Amount fraction of Nitrogen dioxide in Nitrogen

NOMINAL VALUE 10 µmol mol^-1

Measurement 3

The key comparison reference value is the Nitrogen dioxide mole fraction assigned by the BIPM, x_Ri, to a cylinder of laboratory i , as explained in Section 6.1 on page 35 of the Final Report.  Its associated standard uncertainty, u_Ri, is calculated as explained in Annex 3 on page 51 of the Final Report.

One degree of equivalence for one standard of one laboratory i participant at one date of the measurement performed by the coordinating laboratory is defined by two terms , both expressed in µmol/mol:

D_i = (x_i - x_Ri)  where x_i denotes the estimation of the NO₂ amount fraction in the participant's standard at the date of the key comparison reference value and x_Ri denotes the reference value given by the BIPM on that date.

Its associated expanded uncertainty is U_i = (u_i ² - u_Ri ²)^1/2 at a 95 % level of confidence where U_i = 2 u_i.

MEASURAND   Amount fraction of Nitrogen dioxide in Nitrogen

NOMINAL VALUE 10 µmol mol^-1

Measurement 1

x_i   estimated value of the NO₂ amount fraction in the participant’s standard at the date of the evaluation of the key comparison value as explained in section 6.2 of the Final Report.

u_i   uncertainty of x_i

The values for the laboratory individual measurements can be found in the Table 9 of the Annex I of the Final Report.

Note: A model to calculate the participants’ NO₂ amount fraction in their standards was applied at the date of the evaluation of the he key comparison values (BIPM measurements). A difference was made between cylinders with a NO₂ amount fraction decay and without, as observed when applying a linear model to participants’ results. Table 6 (see Final Report) list the parameters (slope and intercept) of a linear regression performed on the NO₂ amount fractions submitted by participants. Calculated decay rates faster than -10^-4 μmol mol^-1/day were taken to indicate a cylinder in which NO₂ was decreasing.

MEASURAND   Amount fraction of Nitrogen dioxide in Nitrogen

NOMINAL VALUE 10 µmol mol^-1

Measurement 2

x_i   estimated value of the NO₂ amount fraction in the participant’s standard at the date of the evaluation of the key comparison value as explained in section 6.2 of the Final Report.

u_i   uncertainty of x_i

The values for the laboratory individual measurements can be found in the Table 9 of the Annex I of the Final Report.

Note: A model to calculate the participants’ NO₂ amount fraction in their standards was applied at the date of the evaluation of the he key comparison values (BIPM measurements). A difference was made between cylinders with a NO₂ amount fraction decay and without, as observed when applying a linear model to participants’ results. Table 6 (see Final Report) list the parameters (slope and intercept) of a linear regression performed on the NO₂ amount fractions submitted by participants. Calculated decay rates faster than -10^-4 μmol mol^-1/day were taken to indicate a cylinder in which NO₂ was decreasing.

MEASURAND   Amount fraction of Nitrogen dioxide in Nitrogen

NOMINAL VALUE 10 µmol mol^-1

Measurement 3

x_i   estimated value of the NO₂ amount fraction in the participant’s standard at the date of the evaluation of the key comparison value as explained in section 6.2 of the Final Report.

u_i   uncertainty of x_i

The values for the laboratory individual measurements can be found in the Table 9 of the Annex I of the Final Report.

Note: A model to calculate the participants’ NO₂ amount fraction in their standards was applied at the date of the evaluation of the he key comparison values (BIPM measurements). A difference was made between cylinders with a NO₂ amount fraction decay and without, as observed when applying a linear model to participants’ results. Table 6 (see Final Report) list the parameters (slope and intercept) of a linear regression performed on the NO₂ amount fractions submitted by participants. Calculated decay rates faster than -10^-4 μmol mol^-1/day were taken to indicate a cylinder in which NO₂ was decreasing.