Korea Research of Institute Standard and Science (KRISS)

Transcription

1 Gravimetric standard scales of SF6 and N2O at ambient level Jeong Sik Lim, Dong Min Moon, Jin Bok Lee, Miyeon Park, A-rang Lim, Haeyoung Lee, Duellae Min, Jeong Soon Lee* Korea Research of Institute Standard and Science (KRISS) ( : Korea Meteorological Administration) 5th Asia Asia--Pacific GAW Workshop on GHGs

2 Contents 1 Development of SF6/air calibration scale 2 Development of N2O/air calibration scale - Through close partnership with customers worldwide

3 Comparability vs. Compatibility GAW report No. 206

4 Recommended compatibility goal of measurements The numbers in this table are the scientifically desirable value, They may not be the currently achievable minimal measurement uncertainty (1 sigma) for individual analyses of most species

5 For instance, 1 point calibration Measurement uncertainty 2 point calibration R R C = + unknown unknown ref 1 ( )( Cref 2 Cref 1) Cref 1 Rref 2 Rref 1 Where, = R: instrument response C: mole fraction

6 Measurement sequence Hz ECD1 A, Front Signal (130627\EB D) Air <Analytical condition> Specification Condition Detector μecd Detector temp. 350 Reference flow Oven temp. 15 ml/min 35, 75 min 30 /min min Column AA-F1 80/100 12ft* 1/8 inch SUS Hz 450 CFCs N 2 O N 2 O N 2 O N 2 O SF 6 SF 6 SF 6 SF min ECD1 A, Front Signal (130627\EB D) Standard Sample loop Carrier flow Sample flow 10 ml P-5, 95psi 100 ml/min SF 6 SF 6 SF 6 SF min

7 Measurement capability For SF 6 Number of measurements * Peak area Ratio Value Deviation S /( R + R ) [%] i 2 i i+ 1 Instrumental drift [%] R S R S R S R S R S R Average Standard deviation (0.19%) * 3 injection per a measurement

8 Uncertainty budget of gravimetric preparation Molar mass Purity of pure gas

9 Impurity analysis of pure SF 6 gas 고순도 SF 6 순도분석 Counts AED3 A, Carbon 193 (130429\YA D) AED3 A, Carbon 193 (130429\F D) Blue : YA000941(Standard) Red: F679860(Pure SF6) Counts 800 AED3 B, Nitrogen 174 (130510\ES D) AED3 B, Nitrogen 174 (130510\F D) Blue : ES (Srandard) Red : F679890(Sample) C 2 F N CF 4 CO min min Blue: ES (Standard) Red : F679860(Pure SF 6 ) Blue: ES (Standard) Red : F679860(Pure SF6) H 2 O 2 + Ar H 2 CH 4 CO

10 Impurity table Component Measured Conc. (μmol/mol) Detector Distribution Applied Conc. (μmol/mol) Standard Uncertainty (μmol/mol) H 2 <0.02 GC-PDD rectangular O 2 +Ar 0.56 GC-PDD normal N GC-AED normal CH GC-PDD normal CO <0.03 GC-PDD rectangular CO GC-AED normal THC <1.00 GC-AED rectangular H 2 O 13 Dew point meter normal CF GC-AED normal C 2 F GC-AED normal C 3 F 8 <1.00 GC-AED rectangular SO 2 <0.005 GC-AED rectangular S compounds <0.005 GC-AED rectangular Impurities SF 6 Purity {%(mole fraction)} (k =2)

11 SF 6 impurity in pure gases (N 2, O 2, Ar) <Analytical condition> Specification Detector Condition GC-μECD with cryogenic system Detector temp. 250 Oven temp. 60 Column AA-F1 80/100 24ft* 1/8 inch SUS ECD1 A, (130725\ D) ECD1 A, (130726\N D) ECD1 A, (130726\O D) ECD1 A, (130729\AR D) Hz Reference ~0.06 pmol/mol SF 6 Run time Carrier flow Sample flow Cryogenic time 50 min P-5, 90psi 200 ml/min 10 min Trap heating 5 min min SF 6 in O 2 <0.002 pmol/mol SF 6 in N 2 <0.002 pmol/mol SF 6 in Ar <0.002 pmol/mol Preconcentrator/GC-ECD

12 Preparation of Reference Gas Mixture Pure SF %(mole fraction) in N 2 EA EA EA EA Direct dilution 950 μmol/mol in N 2 Direct dilution 24 μmol/mol in N 2 EA EA EA EA EA EA EA EA Direct dilution 590 nmol/mol in N 2 Direct dilution 16 nmol/mol in N 2 D D D D D D D D Direct dilution 440 pmol/mol in N 2 D D D D Pure O 2, Ar Direct dilution D D D ~ 15 pmol/mol in Air D D Schematic diagram of preparation for SF 6 gases D D068026

13 Automatic weighing <Gravimetric method excel sheet>

14 Gravimetric preparation value and associated uncertainties Cylinder no Concentration (ppt) Expanded uncertainty (ppt) Rel U (k=2) uncertainty(%) Balance gas D Air D Air D Air D Air D Air D Air D Air

15 Consistency check of gravimetric dilution 6 th step <Analytical condition> Specification Detector Condition μecd Detector temp. 350 Reference flow 20 ml/min Oven temp. 65 Column Sample loop Carrier flow Sample flow PP-Q 80/100 13ft* 1/8 inch SUS 5 ml P-5, 50psi 150 ml/min <Chromatogram of 6step SF 6 mother gas>

16 Stability test Short-term stability <Analytical condition> Specification Detector Condition μecd Detector temp. 390 Reference flow 20 ml/min Oven temp. 75 <Equal division Method> Column Sample loop Carrier flow Sample flow AA-F1 80/100 24ft* 1/8 inch SUS 10 ml P-5, 85psi 150 ml/min Stable longer than 6 month!

17 Combined uncertainties of the certified values Cylinder Mole fraction (pmol/mol) % Uncertainty of Gravimetry (k=1) % Uncertainty of stability (k=1) % Uncertainty of verification (k=1) % Uncertainty (k=2) Uncertainty (k=2) (pmol/mol) D D D D D D D

18 <Analytical condition> Specification Detector KRISS SF 6 scale Condition μecd Detector temp Reference flow 15 ml/min Oven temp. 35 Column AA-F1 80/100 12ft* 1/8 inch SUS Sample loop 10 ml Signal (Hz) SF 6 Carrier flow P-5, 95psi Sample flow 100 ml/min <Concentration range : 5 pmol/mol ~ 15 pmol/mol> y= x x R 2 = Cylinder Time(min) SF 6 mole fraction (pmol/mol) Gravimetry Calibration Residual (ppt) Responce Norminal analytical uncertainty(k=2) : 0.4 % SF6 mole fraction (pmol/mol) D [0.029%] D [-0.013%] D [0.052%] D [-0.097%] D [0.109%] D [0.012%] D [-0.062%]

19 Comparison between NOAA and KRISS scales Specification Condition Detector μecd Detector temp FB03441 FB03443 FB03444 N 2 O Oven temp. 70, 13 min 30 /min min response 300 Column Sample loop AA-F1 80/100 12ft* 1/8 inch SUS 10 ml 100 Carrier flow P-5, 25 ml/min Sample flow 50 ml/min 200 SF 6 time [min] Concentration range 3.5 ~ 12 pmol/mol Cyl. No. Grav. conc. [pmol/mol] Corr. Sens. residual [%] FB NOAA KRISS y= x R 2 = FB FB FB FB KRISS KRISS Responce Norminal analytical Unc. = 0.6% KRISS SF 6 /N 2 standards were biased by 0.13 ppt from NOAA scale SF6 mole fraction (ppt)

20 N 2 O in air scale

21 Analytical condition and chromatogram Specification Condition Specification Condition Detector μecd Detector μecd Detector temp. 380 Detector temp. 350 Reference flow 20 ml/min Reference flow 20 ml/min Oven temp. 45 Oven temp. 75 Column PP-Q 80/100 13ft* 1/8 inch SUS Column AA-F1 80/100 12ft* 1/8 inch SUS Sample loop 1 ml Sample loop 2 ml Carrier flow P-5(CH 4 5%/ Ar), 45psi Carrier flow P-5(CH 4 5%/ Ar), 95psi Sample flow 140 ml/min Sample flow 100 ml/min 200 SF 6 -less standard 200 SF 6 -less standard 180 N 2 O N 2 O Hz 140 Hz Time(min) Time(min)

22 Impurity analysis Impurity Measured concentraton (µmol/mol) Distribution Applied concentration (µmol/mol) Standard uncertainty (µmol/mol) 1 H 2 <0.1 Rectangular O Normal N Normal CO Normal CH 4 <0.05 Rectangular CO <0.05 Rectangular H 2 O 0.3 Normal THC <0.01 Rectangular N 2 O

23 Dilution tree Pure N 2 O Pure N %mol/mol N 2 O in N 2 EA EA EA EA µmol/mol EA EA EA EA EA EA EA EA N 2 O in N 2 12 µmol/mol ME0453 ES ME0456 ES ME5568 ES ME5597 ES N 2 O in N 2 Pure O 2, Ar ~300 nmol/mol N 2 O in O 2 +N 2 +Ar D D D D D D Schematic diagram of preparation for N 2 O gases

24 Preparation of Reference Gas Mixture Gravimetric mole fraction and uncertainty Cylinder N 2 O (nmol/mol) [%U, k=2] O 2 (%mol/mol) [%U, k=2] N 2 (%mol/mol) [%U, k=2] Ar (%mol/mol) [%U, k=2] D [0.06] [0.002] [0.0005] [0.020] D [0.06] [0.002] [0.0005] [0.020] D [0.06] [0.002] [0.0005] [0.019] D [0.06] [0.002] [0.0005] [0.020] D [0.06] [0.002] [0.0005] [0.022] D [0.06] [0.002] [0.0005] [0.019]

25 Consistency check Sens sitivity (CRDS signal val lue/concentration) D D D D D D %

26 Verification Test of N 2 O CRM-μECD Verification test <Concentration range : 305 nmol/mol ~ 345 nmol/mol> y= x x R 2 = Peak Area Norminal analytical uncertainty(k=2) : 0.2 % Gravimetric Concentration (nmol/mol) Cylinder N 2 O concentration(nmol/mol) Gravimetry Calibration Residual[%] D [-0.009] D [0.029] D [-0.031] D [-0.005] D [0.017] D [-0.004]

27 Combined uncertainties of the certified values Cylinder Mole fraction (nmol/mol) % Uncertainty of Gravimetry (k=1) % Uncertainty of verification (k=1) % Uncertainty of analysis (k=1) Uncertainty (k=2) (%) Uncertainty (k=2) (nmol/mol) D D D D D D

28 Comparison between NOAA and KRISS scales Specification Condition Detector μecd Detector temp. 375 Make up gas 40 ml/min N 2 O KRISS (D01820) NOAA (FF03444) NOAA(FF03450) Oven temp. 32 Column PP-Q 80/100 12ft* 1/8 inch SS Sample loop 0.75 ml response Carrier flow Sample flow P-5, 30 psi 100 ml/min time(min) KRISS CRMs NOAA y= x R 2 = Cylinder Concentration (nmol/mol) Corr. Concentration (nmol/mol) Difference [%] D D Responce D D D Norminal analytical uncertainty(k=2) : 0.7 % N2O mole fraction (nmol/mol) FB FB NOAA

29 Thank you

30 Measurement of working standards Specification Condition Detector μecd Detector temp FB03441 DS-13 DS-19 N 2 O Oven temp. 70, 13 min 30 /min min response 300 Column AA-F1 80/100 12ft* 1/8 inch SUS 200 Sample loop Carrier flow Sample flow 10 ml P-5, 25 ml/min 50 ml/min SF time [min] Cyl. No. Grav. conc. [nmol/mol] Corr. Sens. residual [%] y= x x R 2 = FB FB Responce N2O mole fraction (ppb) NOAA multi 1 point 2 point Norminal analytical Unc. = 0.72% FB FB Cyl. No. peak area multi 1 point 2 point DS DS