Final Report of International Comparison APMP.QM …Final Report International Comparison APMP.QM -S2.2015 Oxygen in Nitrogen at 0.2 mol/mol Nobuyuki Aoki1, Takuya Shimosaka1*, Tsai-Yin

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Final Report

International Comparison APMP.QM-S2.2015

Oxygen in Nitrogen at 0.2 mol/mol

Nobuyuki Aoki1, Takuya Shimosaka1*, Tsai-Yin Lin2, Hsin-Wang Liu2, Chiung-Kun Huang2, Arnuttachai Wongjuk3, Soponrat Rattanasombat3, Ratirat Sinweeruthai3, Shinji Uehara4, Vladimir Aleksandrov5 1) National Metrology Institute of Japan, National Institute of Advanced Industry and Science

Technology, Umezono 1-1-1, Tsukuba, Ibaraki, Japan 2) Center for Measurement Standards, Industrial Technology Research Institute, Kuang Fu

Rd, Hsinchu, 30011, Taiwan 3) National Institute of Metrology Thailand, ¾-5 Moo 3, Klong 5, Klong Luang, Pathumthani

12120, Thailand 4) Chemicals Evaluation and Research Institute, Japan, 1600 Shimotakano, Sugito-machi,

Kitakatsushika-gun, Saitama, Japan 5) Karaganda branch of RSE, Kazakhstan Institute of Metrology, Angerskaya st., 22/2,

100009, Kazakhstan *) Coordinator of this comparison Contents:

1. FIELD………………………………………………………………………………….2 2. SUBJECT……………………………………………………………………………...2 3. PARTICIPANTS……………………………………………………………………….2 4. INTRODUCTION………………………………………………………………….….2 5. MEASUREMENT SCHEDULE……………………………………………………....2 6. MEASUREMENT STANDARDS…………………………….………………………2 7. MEASUREMENT PROTOCOL………….…………………………………………...3 8. MEASUREMENT EQUATION………….…………………………………………...3 9. MEASUREMENT METHOD...………….…………………………………………...4 10. DEGREE OF EQUIVALENCE………….…………………………………………....4 11. RESULTS AND DISCUSSION……………………………………………………….5 12. CONCLUSION………………………………………………………………………..6 13. HOW FAR THE LIGHT SHINES…………………………………………………….6 14. REFERENCES………………………………………………………………………...6 ANNEX A: measurement reports

CERI CMS/ITRI KazInMetr NIMT NMIJ

ANNEX B: technical protocol

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1. Field Amount of substance. 2. Subject Comparison of oxygen in nitrogen at 0.2 mol/mol. 3. Participants Table 1 lists the participants in this supplementary comparison. Table 1. List of participants

Acronym Institute CERI Chemicals Evaluation and Research Institute, Japan

CMS/ITRI Center for Measurement Standards, Industrial Technology Research Institute

KazInMetr Karaganda branch of RSE "Kazakhstan Institute of Metrology" Republic of Kazakhstan

NIMT National Institute of Metrology Thailand

NMIJ National Metrology Institute of Japan

4. Introduction A bilateral comparison APMP.QM-S2.2015 was done to show a competence in measurement and calibration of oxygen in nitrogen. This comparison is a repeat of APMP.QM-S2 and is also designed to demonstrate the capabilities of the participants. The objective of this comparison is to support and improve the CMCs of the participants. This comparison was suggested and approved in the meetings of APMP TCQM on November 2013 and CCQM GAWG on April 2014. This document describes the results of the supplementary comparison for oxygen in nitrogen gas mixture. The nominal amount-of-substance fraction of oxygen is 0.20 mol/mol. 5. Measurement schedule June 2014 : Agreement of protocol Oct. 2014 : Registration Nov. 2014 : Preparation of mixtures and first verification May 2015 : Shipping cylinders to participants Sept. 2015 : Reporting results to NMIJ Nov. 2015 : Return the cylinders to NMIJ. Feb. 2016 : Second verification at NMIJ May 2016 : Draft A report July 2016 : Draft B report Jan. 2017 : Final report 6. Measurement standards A set of mixtures of 0.2 mol/mol oxygen in nitrogen was gravimetrically prepared for this supplementary comparison. Molar fraction of oxygen in the sample was determined before and after distribution of the sample by paramagnetic oxygen analyzer which was calibrated by three primary standard gas mixtures of oxygen in nitrogen prepared by gravimetry. Before the second verification, the three oxygen standard gases were re-prepared. The result of the verification is shown in Fig. 1. Deviations between measurement value by the analyzer and

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gravimetric value are plotted for each sample. The error bars in Fig. 1 represent expanded uncertainty (k = 2) combined with uncertainties of the gravimetric preparation and verification by the paramagnetic oxygen analyzer. All of the samples are consistent with their gravimetric values during this comparison.

7. Measurement protocol Each participant was requested to perform at least three independent measurements, obtained under repeatability conditions with at least three independent calibrations, e.g. calibration → measurement → calibration → measurement → calibration → measurement (etc.). One single measurement result is usually obtained from multiple readings (sub measurements), without recalibrations. Its standard deviation provides information about the performance of the measurement system. Additional measurement reports and additional information could be submitted jointly with the report forms to the coordinating laboratory and were taken into consideration during the evaluation. 8. Measurement equation The reference values used in this comparison are determined by the gravimetric preparation, including purity analysis. As shown in Fig. 1, all of the sample cylinders were verified prior to shipping them to each participant, and the samples were re-verified to confirm their stability after they were returned to the coordinating laboratory. Results of both verification experiments showed that the verified values were within the preparation uncertainties of all sample cylinders. Therefore, corrections due to stability and verification are set to zero for this comparison.

In the gravimetric preparation, the amount-of-substance fraction of a target component

Figure 1 Deviation of measurement values from gravimetric values in first (black circle) and second (red square) verifications. The measurement values were determined by the paramagnetic oxygen analyzer.

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(oxygen) is determined by the following equation.

𝑥𝑥𝑖𝑖,prep = 𝑥𝑥𝑖𝑖,grav + ∆𝑥𝑥𝑖𝑖,purity (1)

where xi,prep is the amount-of-substance fraction of the target component in mixture (i), xi,grav is the amount-of-substance fraction of the target component in mixture (i) gravimetrically prepared, and Δxi,purity is the correction based on purity analysis. The uncertainty of the fractional amount is estimated as

𝑢𝑢𝑖𝑖,prep2 = 𝑢𝑢𝑖𝑖,grav2 + 𝑢𝑢𝑖𝑖,purity2 (2)

where ui,prep, ui,grav and ui,purity are the uncertainty of xi,prep, xi,grav and Δxi,purity, respectively. As shown in Fig. 1, the verification experiments demonstrated that the verification values agreed with the gravimetric values of this comparison mixtures within the preparation uncertainties. Therefore, the reference value, xi,ref, of mixture i is set to xi,prep. The uncertainty of the reference value is given as

𝑢𝑢𝑖𝑖,ref2 = 𝑢𝑢𝑖𝑖,prep2 + 𝑢𝑢𝑖𝑖,ver2 (3)

where ui,ref is standard uncertainty of xi,ref, and ui,ver is standard uncertainty due to the verification by the oxygen analyzer. 9. Measurement method Measurement methods of each participant are summarized in Table 2. More detailed descriptions about the methods are available in annex A of this report. Table 2. Calibration methods and measurement traceability Laboratory acronym Cylinder Measurement

dates Calibration Traceability Number of measurements

Measurement technique

CERI CPC00612 30/06/2015 – 02/07/15

Multiple points

Own standards 3 Magnetomechanical

Analyzer

CMS/ITRI CPC00610 05/08/2015 – 13/08/2015 One point Own

standards 5 GC-TCD

KazInMetr CPC00609 13/08/2015 – 21/08/2015

Multiple points

Own standards 3 GC-TCD

NIMT CPC00613 17/08/2015 –17/08/2015

Multiple points

Own standards 3 Paramagnetic

Oxygen Analyzer

NMIJ CPB32030 15/06/2015 – 16/06/2015

Multiple points

Own standards 6 Paramagnetic

Oxygen Analyzer 10. Degree of equivalence A degree of equivalence in the comparison is determined by the following equation [1]. 𝐷𝐷𝑖𝑖 = 𝑥𝑥lab − 𝑥𝑥𝑖𝑖,ref (4)

where xlab is a reported value by each participant. The standard uncertainty of the degree of equivalence, uDi is determined by the following equation. 𝑢𝑢𝐷𝐷𝑖𝑖2 = 𝑢𝑢lab2 + 𝑢𝑢𝑖𝑖,ref2 (5)

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11. Results and Discussion A complete set of results reported from each participant is described in annex A of this report. The reference values and uncertainties of the measurement standards are obtained by eqs (1) and (3), respectively (Table 3). The results of the participants are summarized in Table 4, and the degrees of equivalence for the results of the participants are shown in Figure 2. All of the results are consistent with the reference values as the deviations from the reference values are within the associated uncertainties. Table 3. Reference value and standard uncertainty

Laboratory acronym Cylinder xref

(mol/mol) uprep

(mol/mol) uver

(mol/mol) uref

(mol/mol) CERI CPC00612 0.2017145 4.3×10-6 4.2×10-6 6.0×10-6

CMS/ITRI CPC00610 0.2032915 4.2×10-6 4.5×10-6 6.2×10-6 KazInMetr CPC00609 0.2058388 4.4×10-6 5.5×10-6 7.0×10-6

NIMT CPC00613 0.2004254 4.3×10-6 4.1×10-6 5.9×10-6 NMIJ CPB32030 0.1980561 4.4×10-6 4.4×10-6 6.3×10-6

Table 4. Summary of measurement results. “u” represents standard uncertainty, and “U” represents expanded uncertainty (k=2, 95 % confidence interval).

Laboratory acronym

xref (mol/mol)

uref (mol/mol)

Reported Value (mol/mol) Ulab (mol/mol) klab

D (mol/mol)

U(D) (mol/mol) k

xlab Ulab

(relative)

CERI 0.2017145 6.0×10-6 0.20172 0.019% 38×10-6 2 5.5×10-6 40×10-6 2 CMS/ITRI 0.2032915 6.2×10-6 0.20327 0.012 cmol/mol 120×10-6 2 -21.5×10-6 121×10-6 2 KazInMetr 0.2058388 7.0×10-6 0.205718 0.3% 617×10-6 2 -120.8×10-6 617×10-6 2 NIMT 0.2004254 5.9×10-6 0.20039 0.12% 240×10-6 2 -35.4×10-6 241×10-6 2 NMIJ 0.1980561 6.3×10-6 0.1980543 0.004% 8×10-6 2 -1.8×10-6 15×10-6 2

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Figure 2 Degree of equivalence for the APMP.QM-S2.2015 and the expanded uncertainty (k = 2) represented as error bars. 12. Conclusion This comparison studies the measurement capability of Oxygen in Nitrogen at a level of 0.2 mol/mol. All of the results from the participants are consistent with the KCRV within their associated uncertainties. 13. How far the light shines This supplementary comparison supports CMC claims for oxygen in nitrogen of amount-of-substance fractions from 0.05 mol/mol to 0.30 mol/mol. 14. Reference [1] CIPM MRA 2014 Measurement comparisons in the CIPM MRA, CIPM MRA-D-05 version 1.5 *Corresponding coordinator (or author) National Metrology Institute of Japan Dr. Takuya Shimosaka Umezono 1-1-1, Tsukuba, Ibaraki, 305-8563, Japan Phone +81-29-861-6851 E-mail : [email protected]

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ANNEX A Report Form APMP QM-S2.2015

Laboratory : Chemicals Evaluation and Research Institute, Japan

Cylinder number :CPC-00612

: Measurement #1

Component Date (dd/mm/yy)

Result (mol/mol)

Standard deviation (% relative)

number of replicates

O2 30/06/15 0.201715 0.001717 4

Measurement #2


Result (mol/mol)



O2 01/07/15 0.201712 0.006627 4

Measurement #3


Result (mol/mol)



O2 02/07/15 0.201746 0.005624 4

Results )

Component Result (mol/mol)

Expanded Uncertainty (% relative)

Coverage factor*

O2 0.20172 0.019 2

*) The coverage factor shall be based on approximately 95% confidence.

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Measurement Details for APMP.QM-S2.2015

Please complete the following data regarding the description of the methods, and the uncertainty evaluation. Laboratory : Chemicals Evaluation and Research Institute, Japan Cylinder number : CPC-00612 Calibration standards Please provide a brief description of the calibration standards used, including

method of preparation, weighing data, purity tables (composition), impurity analysis of the parent gases, and verification measures.

-Method of preparation: ISO 6142

-Weighing data (0.20 mol/mol O2 in N2) 1) Evacuated cylinder - Tare cylinder : 0.670 g 2) Cylinder filled with NMIJ CRM - Tare cylinder : 344.532 g 3) Cylinder filled with nitrogen - Tare cylinder : 1547.641 g NMIJ CRM was used for pure oxygen. Purity analysis of oxygen was performed by NMIJ and provided as a certified reference material to CERI. Impurities of nitrogen were analysed by CERI. Purity table of oxygen Component Purity (Certificated value)

mol/mol Expanded uncertainty

(k=2) Verification measure

O2 1.0000002 3.1×10-6 magnetic oxygen analyzer Purity table of nitrogen Component Analytical value

µmol/mol Distribution Mole fraction

µmol/mol Uncertainty µmol/mol

Verification measure

CO ≤ 0.01 Rectangular 0.005 0.002890 GC-FID with methanizer

CO2 ≤ 0.01 Rectangular 0.005 0.002890 GC-FID with methanizer

CH4 ≤ 0.01 Rectangular 0.005 0.002890 GC-FID

Ar ≤ 1 Rectangular 0.5 0.2890 GC-MS

O2 ≤ 0.1 Rectangular 0.05 0.02890 GC-MS

N2 - - 999999.435 0.2905 -

NMIJ CRM (Pure oxygen)

A : 0.25 mol/mol O2 in N2

B : 0.20 mol/mol O2 in N2

C : 0.10 mol/mol O2 in N2

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Instrumentation Please provide a brief description of the particulars of the instrument(s) used in this supplementary comparison Instrument: Magnetomechanical analyzer (Model Magnos 206) made in ABB Ltd Calibration method and value assignment Please provide a brief description how the equipment was calibrated and how the assigned value was calculated (including the necessary formulae). The instrument was calibrated using three gravimetrically prepared PRMs ranging in concentration from 0.25 mol/mol to 0.10 mol/mol. Analytical scheme was , Std. A – Std. B – APMP sample – Std. C. This scheme was repeated 4-times in a day. These mesasurements were carried out for 3-day. Uncertainty evaluation Please provide a brief description of the evaluation of measurement uncertainty, including the expressions used and uncertainty budget. Budget Sheet for 0.25 mol/mol O2 in N2

Uncertainty source of xi

Value (xi)

Estimate +/-

Assumed probability distribution

Divisor Standard

uncertainty u(xi)

Sensitivity coefficient

(ci)

Contribution u(yi)

NMIJ CRM 1.0000002 mol/mol

3.1 μmol/mol

normal 2 1.550 μmol/mol

0.1935 0.2999×10-6

Weighing data 1)

2.622 g

3.597 ×10-3 g

- 1 3.597 ×10-3 g

0.4170 ×10-3 g-1

1.500×10-6

Weighing data 2)

431.45 g

3.597 ×10-3 g

- 1 3.597 ×10-3 g

0.6116 ×10-3 g-1

2.200×10-6

Weighing data 3)

1543.696 g

30.71 ×10-3 g

- 1 30.71 ×10-3 g

0.1693 ×10-3 g-1

5.199×10-6

Molar mass of oxygen

31.9988 g/mol

0.00042 g/mol

normal 2 0.00021 g/mol

0.005714 mol/g

1.200×10-6

Molar mass of nitrogen

28.0134 g/mol

0.00028 g/mol


0.007143 mol/g

1.000×10-6

Combined uncertainty : 6.054 μmol/mol

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Budget Sheet for 0.20 mol/mol O2 in N2


Value (xi)

Estimate +/-


Divisor Standard

uncertainty u(xi)


(ci)

Contribution u(yi)


3.1 μmol/mol


0.1290 0.2000×10-6

Weighing data 1)

0.670 g

3.597 ×10-3 g

- 1 3.597 ×10-3 g

0.4726 ×10-3 g-1

1.700×10-6

Weighing data 2)

344.532 g

3.597 ×10-3 g

- 1 3.597 ×10-3 g

0.5838 ×10-3 g-1

2.100×10-6

Weighing data 3)

1547.641 g

30.71 ×10-3 g

- 1 30.71 ×10-3 g

0.1335 ×10-3 g-1

4.100×10-6


31.9988 g/mol

0.00042 g/mol


0.005240 mol/g

1.100×10-6


28.0134 g/mol

0.00028 g/mol


0.005714 mol/g

0.8000×10-6

Combined uncertainty : 5.099 μmol/mol Budget Sheet for 0.10 mol/mol O2 in N2


Value (xi)

Estimate +/-


Divisor Standard

uncertainty u(xi)


(ci)

Contribution u(yi)


3.1 μmol/mol


0.1290 0.2000×10-6

Weighing data 1)

2.880 g

3.597 ×10-3 g

- 1 3.597 ×10-3 g

0.5282 ×10-3 g-1

1.900×10-6

Weighing data 2)

168.264 g

3.597 ×10-3 g

- 1 3.597 ×10-3 g

0.6116 ×10-3 g-1

2.200×10-6

Weighing data 3)

1470.600 g

30.71 ×10-3 g

- 1 30.71 ×10-3 g

0.06838 ×10-3 g-1

2.100×10-6


31.9988 g/mol

0.00042 g/mol


0.002857 mol/g

0.6000×10-6


28.0134 g/mol

0.00028 g/mol


0.003571 mol/g

0.4999×10-6

Combined uncertainty : 3.675 μmol/mol

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Budget Sheet for APMP.QM-S2.2015


Value (xi)

Estimate +/-


Divisor Standard

uncertainty u(xi)


(ci)

Contribution u(yi)

Std. 0.25 252400 µmol/mol

6.054 µmol/mol

- 1 6.054 µmol/mol

0.4295 2.600 µmol/mol


5.099 µmol/mol

- 1 5.099 µmol/mol

0.3530 1.800 µmol/mol


3.675 µmol/mol

- 1 3.675 µmol/mol

0.1905 0.7001 µmol/mol

Measurement 201720 µmol/mol

18.57 µmol/mol

- 1 18.57 µmol/mol

1 18.57 µmol/mol

Oxygen in nitrogen

0.1 µmol/mol

0.05 µmol/mol

rectangular √3 0.02887 µmol/mol

1 0.02887 µmol/mol

Round off - 5 µmol/mol

rectangular √3 2.887 µmol/mol

1 2.887 µmol/mol

Result : 0.20172 mol/mol Combined uncertainty: 0.00001907 mol/mol Expanded uncertainty: 0.000038 mol/mol Expanded uncertainty (relative): 0.019 % References ISO 6142 Authorship Shinji UEHARA

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Report for Key Comparison on

APMP.QM-S2: Oxygen in Nitrogen at 0.2 mol/mol

Laboratory name: CMS/ITRI Cylinder number: CPC00610 Measurement #1 Component Date

(dd/mm/yy) Result

(cmol/mol) Standard deviation

(% relative) Number of replicates

O2 05/08/2015 20.334 0.091 5 Measurement #2 Component Date

(dd/mm/yy) Result




(dd/mm/yy) Result




(dd/mm/yy) Result




(dd/mm/yy) Result



O2 13/08/2015 20.322 0.017 5 Results

Component Result (cmol/mol)

Expanded Uncertainty (cmol/mol)

Coverage factor

O2 20.327 0.012 2 Calibration standards

The primary reference materials (PRMs) of oxygen in N2 were gravimetrically prepared according to ISO 6142: 2001 by CMS/ITRI. The high purity oxygen and BIP Nitrogen from Air Products were used to prepare the PRMs. The impurities in oxygen and nitrogen were

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determined with various gas analyzers and were described in Table 1 and Table 2 individually. The uncertainty associated with the oxygen determination was taken into account during the gravimetric calculations and uncertainty evaluation. The prepared PRMs were verified by analytical comparisons against existing gravimetrically prepared standards, and the characteristics of calibration standards are described in Table 3.

Table 1. Purity table for oxygen Component Mole fraction

(μmol/mol) Standard uncertainty

(μmol/mol) Method

N2 0.12 0.067 QMS CO2 0.11 0.064 FTIR CO 0.45 0.26 FTIR CH4 0.50 0.29 FTIR O2 999998.835 0.40 -

Table 2. Purity table for nitrogen Component Mole fraction

(μmol/mol) Standard uncertainty

(μmol/mol) Method

O2 0.005 0.0029 Trace oxygen analyzer CO 0.011 0.0064 GC-PDHID CO2 0.046 0.027 GC-PDHID CH4 0.023 0.014 GC-PDHID CF4 0.005 0.0029 FTIR SF6 0.0045 0.0026 FTIR SO2 0.18 0.11 FTIR NO 0.005 0.0029 NOx analyzer N2 999999.7205 0.11 -

Table 3. Oxygen concentration of primary reference materials (PRMs)

Instrumentation

A GC specifically set up for oxygen in N2 analysis was described in Table 4. Table 4. Analytical conditions

Body Agilent GC-7890A Software for data collection Agilent ChemStation Column HP-molesieve (30 m × 0.53 mm × 0.25 µm) Oven temp. 30°C isothermal Detector TCD (reference gas flow, He: 25 ml/min) Detector temp. 150°C Carrier gas He: 5 ml/min Analytical time for one injection 5 min

Cylinder number Assigned value (cmol/mol)

Expanded uncertainty (cmol/mol) (k=2)

CAL013042 20.0078 0.0056

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Calibration method and value assignment GC-TCD was used to determine oxygen concentration in the sample cylinder. The

standard with concentration close to that of the sample cylinder CPC00610 was chosen for single-point calibration to determine the concentration of oxygen in sample cylinder. The sample cylinder was analyzed with a reference cylinder in the following order. Reference – Sample – Reference – Sample – Reference – Sample – Reference – Sample – Reference – Sample – Reference The mathematical model shown below was used to calculate the concentration of oxygen in sample cylinder:

( ) ( )

1,,

5

1

5

1 2;5

;;5 +

==

+==×==

∑∑isis

ii

ii

isiii

i

RRRr

rrCrC

CC

C =the reported concentration, CPC00610

Ci = the ith measured concentration of sample, CPC00610

Cs = concentration of standard, CAL013042

ir = the average ratio of GC-TCD response of sample to standard

ri = the ith calculated ratio of response of sample to standard

Ri = the ith response of GC-TCD for sample, CPC00610

Rs,i = the ith response of GC-TCD for reference standard, CAL013042

Uncertainty evaluation

The final uncertainty was estimated by combining two uncertainty components (i.e., PRM and analysis).

- total standard uncertainty of oxygen mole fraction in PRMs (including uncertainty of weighing of parent gases and pre-mixture, uncertainty in the purity of the parent gas and balance gas);

- standard uncertainty of the measurement result of oxygen mole fraction in cylinder number CPC00610 (including uncertainties of repeatability and reproducibility)

The equations described below were used to evaluate the uncertainty for oxygen measurement.

( ) ( )

1,,

5

1

5

1 2;5

;;5 +

==

+==×==

∑∑isis

ii

ii

isiii

i

RRRr

rrCrC

CC

( ) ( ) ( ) ( ) ( )issii ruCCurCu 22222 ×+×=

5

5

1

2∑== i

i

p

ss

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( ) ( ) ( ) 2222

2 )5

( pssi

SCCurCu ×+×

=

ir = the average of calculated mean ratios, ir , for the five sets of measurements

sp = pooled standard deviation of the five sets of measurements

si = standard deviation of each set of measurements

The uncertainty budget for oxygen measurement in the cylinder number CPC00610 is shown in Table 5.

Table 5. Uncertainty budget for oxygen measurement Uncertainty source

Xi Estimate

xi

Evaluation type and distribution

Standard uncertainty

u(xi)


ci

Contribution to the uncertainty of the

reporting value ui(y)

Repeatability and reproducibility of ratio of signal, r

ir ;

1.016

Type A;

Normal 2.63×10-4 20.0078 5.27×10-3

Uncertainty of calibration standard

Cs ;

20.0078

Type A;

Normal 0.0028 1.016 2.84×10-3

Combined Uncertainty, (cmol/mol) 0.0060 Expanded Uncertainty, (k=2) , (cmol/mol) 0.012

Expanded Uncertainty, (k=2) , (% relative) 0.06

Authorship Tsai-Yin Lin, Hsin-Wang Liu, Chiung-Kun Huang Center for Measurement Standards, Industrial Technology Research Institute, Kuang Fu Rd., Hsinchu, 30011, Taiwan

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Report Form APMP QM-S2.2015

Laboratory : National Institute of Metrology (Thailand)

Cylinder number : CPC00613

Participants : Mr.ArnuttachaiWongjuk, Mr.SoponratRattanasombat,

Ms.RatiratSinweeruthai

Measurement #1


Result (mol/mol)



O2 17/08/2015 0.20041 0.003 3

Measurement #2


Result (mol/mol)



O2 17/08/2015 0.20037 0.004 3

Measurement #3


Result (mol/mol)



O2 17/08/2015 0.20038 0.002 3

Results



Coverage factor*)

O2 0.20039 0.12 2 *) The coverage factor shall be based on approximately 95% confidence.

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Laboratory : National Institute of Metrology (Thailand)

Cylinder number : CPC00613

Calibration standards

The standard gas mixtures used are traceable to the National Institute of Metrology (Thailand) and are prepared and verified according to ISO 6142 and ISO 6143. The standard uncertainty of standard gas mixtures, u(xk), is calculated from the following equations; Where u(xi)6142 is the standard uncertainty of preparation, u(xs)6143 is the standard uncertainty of verification and u(xstability) is the standard uncertainty of stability. The characteristics of the standard gas mixtures used for APMP.QM-S2.2015 are listed in Table 1. Table 1. Concentration of standard gas mixtures.

Cylinder number Assigned value Expanded uncertainty (Relative value, k = 2)

PRM300748 0.18005 mol/mol 0.1%

PRM300770 0.20012 mol/mol 0.1%

PRM200796 0.25004 mol/mol 0.1%

Instrumentation

The analysis was performed by using the paramagnetic oxygen analyzer. The gas flow rate was set at 200 mL/min.

Calibration method and value assignment

The content of oxygen was determined by using Paramagnetic Oxygen Analyzer. This gas mixture was measured against primary gas reference materials (PGRMs) of NIMT for traceable measurement results. The three-calibration point measurement was performed according to ISO 6143. The measurement procedure is shown as follow; “Calibration 1 – Sample APMP QM-S2.2015 – Calibration 2 - Sample APMP QM-S2.2015 – Calibration 3 – Sample APMP QM-S2.2015

( ) ( ) ( ) ( )stabilitysik xuxuxuxu 26143

26142

2 ++=

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Uncertainty of sample gas mixture

The analytical function is calculated by ISO 6143 implementation software namely “B_LEAST version 1.11” and the measurement uncertainty has been determined in accordance with EA-4/02 “Expression of the Uncertainty of Measurement in Calibration” and JCGM 100:2008 “Evaluation of Measurement Data−Guide to the Expression of Uncertainty in Measurement”.

The standard uncertainty, u(xs) of the sample gas mixture is calculated from the following equations;

( ) ( ) ( )BsAks XuXuXuxu 2

6143,222 .)( ++=

Where u(Xk) is the standard uncertainty of the standard gas mixtures, u(xA,s)6143 is the standard uncertainty, of the sample content from analytical equation was calculated by using B-Least software and u(XB) is the standard uncertainty due to the measurement bias.

Uncertainty evaluation Uncertainty budget of gas calibration following a 3-point calibration when xs = b0 + b1y.

Uncertainty source

Estimate xi

(cmol/mol)

Evaluation type

(A or B)

Distribution Standard uncertainty

u(xi)


ci

Contribution u(yi)

- The standard gas mixture (xk,)

20.012 B Normal 0.010 1.000 0.010

- Analytical content of sample, u(xA,s)6143

20.039 A Normal 0.006 1.000 0.006

- Measurement Bias, u(xB) 0.000 B Rectangular 0.000 1.000 0.000

Combined standard uncertainty 0.012 Expanded uncertainty (k = 2) 0.023

Expanded uncertainty (k = 2), % relative 0.12 References

[1] ISO 6142, Gas analysis – Preparation of calibration gas mixtures- Gravimetric method, 2001.

[2] ISO 6143, Gas analysis – Comparison methods for determining and checking the composition of calibration gas mixtures, 2001.

[3]JCGM 100 “Evaluation of Measurement Data-Guide to The Expression of Uncertainty in Measurement", 2008.

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Laboratory :National Metrology Institute of Japan

Cylinder number : CPB 32030

: Measurement #1


Result (mol/mol)



O2 15/06/15 0.1980542 0.0021 1

Measurement #2


Result (mol/mol)



O2 15/06/15 0.1980541 0.0021 1

Measurement #3


Result (mol/mol)



O2 15/06/15 0.1980537 0.0021 1

Measurement #4


Result (mol/mol)



O2 16/06/15 0.1980542 0.0021 1

Measurement #5


Result (mol/mol)



O2 16/06/15 0.1980544 0.0021 1

Measurement #6

25/28


Result (mol/mol)



O2 16/06/15 0.1980554 0.0021 1

Results



Coverage factor*

O2 0.1980543 0.004

2


26/28


Laboratory : National Metrology Institute of Japan Cylinder number : CPB 32030 Calibration standards Preparation method Three calibration standards were used for determining mole fraction of oxygen in nitrogen. The standards were prepared from pure nitrogen and pure oxygen in accordance with ISO 6142:2001. Gravimetric values and their uncertainties of the calibration standards are shown in Table 1.

Table 1. Gravimetric value and itsexpanded uncertainty of calibration standards

Cylinder number Gravimetric value (µmol/mol)

Expanded uncertainty [k=2] (µmol/mol)

CPC00611 197568.76 8.80

CPC00643 199629.43 8.98

CPB16308 198028.44 8.53

Purity analysis The purities of nitrogen and oxygen used as the parent gases were determined from the following equation,

∑=

−=n

jji xx

1,impurity purity, 1 , (1)

where xpurity, i is the mole fraction “purity” of the parent gas i (i = O2, N2);

ximpurity,j: the mole fraction of impurity j, determined by analysis;

n: the number of impurities likely to be contained by the parent gas i.

The results of purity analyses are shown in Table 2 and 3.

Table 2. Purity table of pure nitrogen

Components Applied

concentration (µmol/mol)

Standard uncertainty (µmol/mol)

Distribution Analytical method

O2 0.033 0.019 Rectangular GC-TCD

CO2 0.002 0.001 Rectangular FT-IR

CH4 0.005 0.003 Rectangular FT-IR

CO 0.038 0.101 Rectangular FT-IR

H2O 0.439 0.253 Rectangular Capacitance-type moisture meter

N2 999999.48

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Table 3. Purity table of pure oxygen

Components Applied concentration

(µmol/mol) Standard uncertainty

(µmol/mol) Distribution Analytical method

N2 0.064 0.037 Rectangular GC-TCD

Ar 0.033 0.019 Rectangular GC-TCD

CO2 0.049 0.003 Normal FT-IR

CH4 0.005 0.003 Rectangular FT-IR

CO 0.038 0.022 Rectangular FT-IR

H2O 0.439 0.253 Rectangular Capacitance-type moisture meter

O2 999999.37

Instrumentation A sample of APMP QM-S2.2015 was analyzed by a paramagnetic oxygen analyzer. The analytical conditions are shown in Table 4. Table 4. Analytical conditions of paramagnetic oxygen analyzer

Instrument Japan Air Gases POM-6E Pressure of comparison gas 300 kPa (A)

Flow rate of comparison gas 5 ml/min

Pressure of sample gas 180 kPa (A) Flow rate of sample gas 100 ml/min

Calibration method and value assignment The APMP QM-S2.2015 sample had been in the analytical room over a day before it was measured. The mole fraction in the APMP QM-S2.2015 sample was analyzed by the paramagnectic oxygen analyzer calibrated by the three primary standard gases. The standard gases and the sample were measured in the following measurement sequence:

STD1 – sample – STD2 – STD3

The oxygen mole fraction in the sample was determined in every sequence using the generalized least-square method in which uncertainties for the standard gases and measurement were considered to estimate the mole fraction and its uncertainty.

The sequence was repeated 6 times. The mole fraction in the sample (𝑥𝑥O2,sample) to be reported was the weighted mean of the mole fractions of oxygen for six sequences (𝑥𝑥𝑘𝑘(𝑘𝑘 = 1~6)).

𝑥𝑥O2,sample = ∑ 𝑤𝑤𝑘𝑘𝑥𝑥𝑘𝑘6𝑘𝑘=1∑ 𝑤𝑤𝑘𝑘6𝑘𝑘=1

, (2)

The weighing factor wk is described in the next section.

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Uncertainty evaluation The mole fraction for each sequence (𝑥𝑥𝑘𝑘) has a correlation with one another because the mole fraction for each sequence is calculated from the mole fractions in the same standard gases. The standard uncertainty of 𝑥𝑥O2,sample was calculated using the following formula.

𝑢𝑢�𝑥𝑥O2,sample� = �𝜎𝜎𝑥𝑥O2,sample2 + 𝑢𝑢𝑠𝑠2, (3)

where 𝑢𝑢𝑠𝑠 is the common uncertainty among 𝑥𝑥𝑘𝑘 and 𝜎𝜎𝑥𝑥O2,sample is the standard uncertainty due to the other factors. The uncertainty 𝜎𝜎𝑥𝑥O2,sample is given as

𝜎𝜎𝑥𝑥O2,sample2 = 1

∑ 𝑤𝑤𝑘𝑘6𝑘𝑘=1

, (4)

where 𝑤𝑤𝑘𝑘 is the weighting factor. The weighting factor 𝑤𝑤𝑘𝑘 is given as 𝑤𝑤𝑘𝑘 = 1 (𝑢𝑢𝑘𝑘2 − 𝑢𝑢𝑠𝑠2)⁄ = 1 𝑢𝑢𝑟𝑟𝑘𝑘

2⁄ , (5) where 𝑢𝑢𝑘𝑘 is the standard uncertainty of 𝑥𝑥𝑘𝑘 and 𝑢𝑢𝑟𝑟𝑘𝑘 is the statistical dispersion not to depend on the common uncertainty. The determined mole fraction (𝑥𝑥O2,sample) and the standard uncertainty (𝑢𝑢�𝑥𝑥O2,sample�) in the APMP QM-S2.2015 sample are 198054.3 µmol/mol and 3.89 µmol/mol, respectively, as shown in Table 5. Table 5 Results of the determination of the oxygen mole fraction in the APMP QM-S2.2015 sample

Analytical date (yyyy/mm/dd)

Mole fraction (𝒙𝒙𝒌𝒌) (µmol/mol)

Standard uncertainty(𝒖𝒖𝒌𝒌) (µmol/mol)

𝑢𝑢𝑟𝑟𝑘𝑘 𝑢𝑢𝑠𝑠

2015/6/15 198054.2 4.09 1.39

3.85

2015/6/15 198054.1 4.11 1.45 2015/6/15 198053.7 4.07 1.33 2015/6/16 198054.2 4.06 1.30 2015/6/16 198054.4 4.15 1.55 2015/6/16 198055.4 4.12 1.47

𝒙𝒙𝐎𝐎𝟐𝟐,𝐬𝐬𝐬𝐬𝐬𝐬𝐬𝐬𝐬𝐬𝐬𝐬 198054.3 µmol/mol 𝒖𝒖�𝒙𝒙𝐎𝐎𝟐𝟐,𝐬𝐬𝐬𝐬𝐬𝐬𝐬𝐬𝐬𝐬𝐬𝐬�

𝝈𝝈𝒙𝒙𝐎𝐎𝟐𝟐,𝐬𝐬𝐬𝐬𝐬𝐬𝐬𝐬𝐬𝐬𝐬𝐬

𝒖𝒖𝒔𝒔

3.89 µmol/mol 0.57 µmol/mol 6.07 µmol/mol

I

ANNEX B

Comparison APMP.QM-S2.2015 Oxygen in nitrogen at atmospheric level

Protocol and Report Forms

Takuya Shimosaka

NMIJ/AIST, Tsukuba, Ibaraki, Japan

II

Table of contents

Table of contents II

Background 1

Transfer Standards 1

Transport 1

Reporting 2

Supported claims 2

Participants 2

Schedule 2

Cylinder information 3

Coordinator 3

Report Form APMP QM-S2.2015 4

Measurement Details for APMP.QM-S2.2015 5

Registration Form of APMP.QM-S2.2015 (oxygen in nitrogen at 0.2 mol/mol) 6

1

Background A bilateral comparison APMP.QM-S2 was done to show a competence in measurement and calibration of

oxygen in nitrogen. This comparison is a repeat of APMP.QM-S2 and is also designed to test the

capabilities of the participants. The objective of this comparison is to support and improve the CMCs of

the participants. This comparison was suggested and approved in the meetings of APMP TCQM on

November 2013 and CCQM GAWG on April 2014.

This document describes the protocol of this supplementary comparison for oxygen in nitrogen gas mixture.

The nominal amount-of-substance fraction of oxygen will be 0.20 mol/mol.

Transfer Standards Mixtures of oxygen in nitrogen prepared gravimetrically by NMIJ will be used as transfer standards. The

mixtures will be verified against a set of NMIJ’s primary standard gas mixtures. Nominal pressure and

inner volume of the cylinder are 10 MPa and 10 dm3, respectively. The amount-of-substance fraction of

oxygen as obtained from gravimetry, molar mass, and purity verification of the parent gases will be used as

a reference value for this comparison. Each transfer standard will have its individual reference value.

Participating laboratories are requested to specify in detail which analytical method(s) have been used and

how the evaluation of measurement uncertainty has been performed. The participating laboratories will be

responsible for the calibration of its own equipment. For a proper evaluation of the data, it is necessary that

the participants report the calibration method as well as the way in which the calibration mixtures have

been prepared. This information is needed for the evaluation of the preparation facilities (as part of this

comparison). After each calibration, the measurements on the gas mixture can be performed and recorded.

The participating laboratories have to express the uncertainty on all results submitted, as expanded

uncertainty. The evaluation of measurement uncertainty should be in accordance to the “Guide to the

expression of uncertainty in measurement”. The participant should provide a detailed description of the

uncertainty budget, including

– method of evaluation (type A or type B)

– (assumed) probability distribution

– standard uncertainties and sensitivity coefficients

After the measurements, the participants have to return the cylinders with a sufficient amount of gas

(pressure at least 3 MPa) to the coordinating laboratory for re-analysis.

Transport Transport of the cylinder from the coordinating laboratory to the participants will be arranged and

paid by the coordinating laboratory. Transport of the cylinders back to the coordinating laboratory

(NMIJ) will be arranged and paid for by the participants. The participants are also responsible for

2

returning the cylinders promptly after completing the measurements. If other documentation is required

(such as a Certificate of origin), please contact the coordinating laboratory well in advance.

Reporting The measurement report requires per cylinder at least three independent measurements, obtained under

repeatability conditions with at least three independent calibrations, e.g. calibration → measurement →

calibration → measurement → calibration → measurement (etc.). This is a strict requirement to come to

proper statistical analysis of the reported data.

One single measurement result is usually obtained from multiple readings (sub measurements), without

recalibrations. Its standard deviation provides information about the performance of the measurement

system.

Additional measurement reports and additional information can be submitted jointly with the report forms

to the coordinating laboratory and will be taken into consideration during the evaluation.

Supported claims This comparison may be used to support CMC claims for oxygen in nitrogen for amount-of-substance

fractions from 0.05 mol/mol to 0.30 mol/mol.

Participants By now the following NMIs/DIs expressed interest in participation in this key comparison.

Participants: CMS/ITRI, NIMT, NMIJ

Schedule Date Event

May 2014 Draft protocol of this comparison

June 2014 Agreement of Protocol of this comparison

October 2014 Registration of participants

November 2014 Preparation of mixtures + first verification measurement

May 2015 Shipment of sample cylinder to participating laboratories

August 31st 2015 Deadline of submission of measurement report to the coordinating laboratory

September 2015 Return the sample cylinder back to the coordinating laboratory

November 2015 Second verification (Stability test) by the coordinating laboratory

December 2015 Draft A report

January 2016 Draft B report

3

Cylinder information Transfer standards will be supplied in an aluminium cylinder whose inner volume is approximately 10 dm3.

Type of the cylinder valve is W22-14-threads right male.

Coordinator Coordinator Takuya Shimosaka

National Metrology Institute of Japan (NMIJ), National Institute of Advanced Industrial Science and

Technology (AIST). Organic Analytical Chemistry Division Standard Gas Section

AIST Central-3, Umezono1-1-1, Tsukuba, Ibaraki, 305-8563, Japan

Phone +81 29 861 6851

E-mail [email protected]

Technical expert Nobuyuki Aoki


Technology (AIST). Organic Analytical Chemistry Division Standard Gas Section

AIST Central-3, Umezono1-1-1, Tsukuba, Ibaraki, 305-8563, Japan

Phone +81 29 861 6851


4


Laboratory :

Cylinder number :

Measurement #1 Component Date

(dd/mm/yy)

Result

(mol/mol)

Standard deviation

(% relative)

number of

replicates

O2


(dd/mm/yy)

Result

(mol/mol)

Standard deviation

(% relative)

number of

replicates

O2


(dd/mm/yy)

Result

(mol/mol)

Standard deviation

(% relative)

number of

replicates

O2

Results Component Result

(mol/mol)

Expanded Uncertainty

(% relative)

Coverage factor*)

O2


5

Measurement Details for APMP.QM-S2.2015 Please complete the following data regarding the description of the methods, and the uncertainty evaluation. Laboratory : Cylinder number : Calibration standards Please provide a brief description of the calibration standards used, including

method of preparation, weighing data, purity tables (composition), impurity analysis of the parent gases, and verification measures.

Instrumentation Please provide a brief description of the particulars of the instrument(s) used in this supplementary comparison Calibration method and value assignment Please provide a brief description how the equipment was calibrated and how the assigned value was calculated (including the necessary formulae). Uncertainty evaluation Please provide a brief description of the evaluation of measurement uncertainty, including the expressions used and uncertainty budget.


Estimate (xi)

Standard uncertainty

u(xi)

Sensitivity coefficient (ci)

Contribution to the uncertainty of the reporting value

References

6

Registration Form of APMP.QM-S2.2015 (oxygen in nitrogen at 0.2 mol/mol) Please complete this document and send it, preferably electronically, by 31 October 2014, to: Nobuyuki Aoki


Technology (AIST), Organic Analytical Chemistry Division Standard Gas Section

AIST Central-3, Umezono1-1-1, Ibaraki, 305-8563, Japan

Phone +81 29 861 6851


1. Participating Institute Information:

Institute : Physical address (for the shipment of the cylinder) Contact person Telephone Fax e-mail Financial address (for the payment of the shipping invoice)

2. Participation (Yes / No) (please delete as appropriate)

Documents

Final Report of International Comparison APMP.QM …Final Report International Comparison APMP.QM -S2.2015 Oxygen in Nitrogen at 0.2 mol/mol Nobuyuki Aoki1, Takuya Shimosaka1*, Tsai-Yin