Low Pressure Gas Flow Calibration Facilities at CMS Chun-Min Su Center for Measurement Standards, ITRI APMP TCFF Workshop Taipei, Taiwan Nov. 22, 2013

Outline Overview of Low Pressure Flow Calibration Facilities KC Results Description of Low Pressure Flow Calibration Facilities Recent Work-PVTt Calibration Service Future Plan Overview of Low Pressure Flow Calibration Facilities KC Results Description of Low Pressure Flow Calibration Facilities Recent Work-PVTt Calibration Service Future Plan

Expanded Unc. of Mass Flow (U95) PVTt (0.01 − 300) L/min U < 0.2 % (estimated) 0.20 MOLBLOC (0.002 − 24) L/min U = 0.18 % Sonic Nozzle (0.01 − 20) L/min U = 0.18 % (100 − 1000) L/min U =0.14 % Sonic Nozzle Bank (6.5-100) L/min U = 0.18 % 0.18 Gravimetric (0.002 − 20) L/min U = 0.16 % 0.16 Bell Prover 60 L (4-100) L/min U = 0.15 % Expanded Unc. of Mass Flow (U95) 0.14 0.12 Bell Prover 600 L (20 − 1000) L/min U = 0.11 % Piston Prover (0.002 − 24) L/min U = 0.10 % 0.10 ~ ~ 0.0 10-3 10-2 10-1 1 10 102 103 Flow Rate (L/min)

Expanded Unc. of Mass Flow (U95) PVTt (0.01 − 300) L/min U < 0.2 % (estimated) 0.20 Sonic Nozzle + MOLBLOC U = 0.18 % (0.002 − 24) L/min Sonic Nozzle Bank (6.5-100) L/min U = 0.18 % 0.18 Gravimetric (0.002 − 20) L/min U = 0.16 % 0.16 Bell Prover 60 L (4-100) L/min U = 0.15 % (100 − 1000) L/min U =0.14 % Expanded Unc. of Mass Flow (U95) 0.14 0.12 Bell Prover 600 L (20 − 1000) L/min U = 0.11 % Piston Prover (0.002 − 24) L/min U = 0.10 % 0.10 ~ ~ 0.0 10-3 10-2 10-1 1 10 102 103 Flow Rate (L/min)

Key Comparison Participated Service Identifier System Flow Rate (L/min) U95 (%) Working Fluid Key Comparison Participated F06 Piston Prover 0.002 to 24 0.10 Dry air, N2, Ar, O2, CO2 APMP.M.FF-K6 (2010) > 0.02 He F07 Bell Prover (60 L) 4 to 100 0.15 Dry air N/A F08 Bell Prover (600 L) 20 to 1000 0.11 APMP.M.FF-K6 (2010) Sonic Nozzle Bank 6.5 to 1000 0.14 (100 to 1000 L/min) CCM.FF-K6 (2012) 0.18 (6.5 to 100 L/min) F09 Gravimetric 0.002 to 20 0.16 Dry air, N2… MOLBLOC 0.18 Sonic Nozzle 0.01 to 20 F12 PVTt 0.01 to 300 < 0.2 Dry air, N2, Ar, O2, CO2, He… Piston Prover氦氣與水銀會起化學反應?!小流容易洩漏，有水銀密封性問題，所以校正流率須>0.02LPM

Outline Overview of Low Pressure Flow Calibration Facilities KC Results Description of Low Pressure Flow Calibration Facilities Recent Work-PVTt Calibration Service Future Plan

BIPM/CIPM Key Comparison Transfer Standard CMS/Taiwan Rotary gas meter Actaris Delta S-Flow Range of flow rate: (0.39 to 60) m3/h Temperature: (23  1.5) ℃ Working pressure: Atmospheric pressure Uncertainty (k=2): 0.15 % (≧ 6 m3/h) 0.18 % (< 6 m3/h) Type: Delta 2050 S-Flow Manufacturer: ActarisGaszählerbau GmbH, Germany Size: G65 Serial number: GN-HD-001 Flow range: (2 to 100) m3/h Pmax: 40 bar Inside diameter: DN 50 The transfer standard was a rotary gas meter, a new model of S-Flow meter inside the body Actaris Delta 2050. The transfer standard, a pulse transmitter connector, and a filter were shipped in one transfer box. The reference standard used in this low pressure gas flow key comparison is a set of four critical flow Venturis (CFVs) with throat diameters ranging from 0.6096 mm (0.024 inch) to 5.1816 mm (0.204 inch), having a flow range from 6.5 L/min to 1000 L/min. The reference standard is calibrated by the primary flow standard (Bell Prover) maintained by CMS once every 2 years. A photograph of the calibration setup is shown in the figure. The traceability hierarchy of the reference standard is illustrated in Fig. 3. Compressed air is dried first to reach a dew point of -40 C by flowing through refrigeration dryer and an adsorption dryer successively. The dry air is then stored in three tanks with a total volume of 5 m3 and maximum gauge pressure of 8 bars. The CFVs are installed upstream of the meter under test (MUT). Pressure and temperature sensors are installed upstream of the CFVs for the measurement of flow. Instrumentation for measuring pressure, differential pressure, pulse, time or temperature may be selected to acquire outputs from the MUT. During calibration, the dry air discharged from the pressurized storage tanks passes through two stages of manual pressure regulation to adjust the pressure at the CFV and hence flow. To set up the reference standard, a CFV is selected to achieve the desired range of flows. May 9th to May 28th, 2012

Expanded Uncertainties of Participating Laboratories

Schematic of the APMP.M.FF-K6 transfer standard APMP Key Comparison Schematic of the APMP.M.FF-K6 transfer standard Piston prover : expanded uncertainty (U) 0.10 % Bell prover 1: expanded uncertainty (U) 0.11 % Bell prover 2: expanded uncertainty (U) 0.15 % CMS Taiwan NIST USA NMIJ Japan NEL UK PTB Germany U (%) 0.10 - 0.15 0.05 0.15 0.08 - 0.15

Results for Small Aup. Results for Small Adwn.

Outline Overview of Low Pressure Flow Calibration Facilities KC Results Description of Low Pressure Flow Calibration Facilities Recent Work-PVTt Calibration Service Future Plan

Piston Prover Interferometer for Piston Displacement Measurement 5-Tube Piston (0.002 − 24) L/min U = 0.10 % Interferometer for Piston Displacement Measurement Photo-sensor for Timer Trigger Ring Gauge /Plug Gauge for Tube Diameter Measurement

Traceability Chart of Piston Prover(qm) qm,s={[(πDm2L/4)s(T,P)+VCV△s(T,P)]/t} SI Unit: Density(kg/m3) Time(s) Length (m) Length (m) NML Ring Gauge Database of Gas Properties ITRI Frequency Measuring System NML He-Ne Stabilized Laser Ring Gauge, Dr,20 19.01 /25.9/44.45 /76.24/143.68 mm NIST REFPROP Ideal Gas Law LVDT Length Comparator F06之管式校正器由五具精密製造的標準玻璃管組成，配合安裝於移動機構上之雷射干涉儀，可精確量測由光電開關啟動與結束計時期間活塞之位移量 。 進行流量計校正時，先將被校件安裝於上游側，並以調壓閥及流量調節閥調整至所需工作壓力及流率，待流率穩定後，將流體由旁通管路導入標準玻璃管，推動玻璃管內活塞向上移動，當活塞通過底部光電開關，氣密用水銀反射訊號觸發計時器及雷射干涉儀之計數器，同步擷取標準系統與被校件位置氣體之溫度與壓力，被校件流率通常為人工讀取 (若其輸出訊號可接入校正系統則可以自動化擷取)，當活塞通過上部光電開關附近，氣密用之水銀反射光線觸發計時器及雷射干涉儀計數器，結束擷取標準系統與被校件位置氣體之溫度與壓力，並停止被校件流率讀取，並送出兩個光電開關間之位移行程、收集時間、標準系統及被校件位置之氣體在收集時間內之平均溫度及壓力。利用光電開關間位移行程、收集時間、標準系統及被校件位置之氣體在收集時間內之平均溫度及壓力，配合事前量測之直徑，即可計算出流經被校件之標準流率及流量計流出係數。 以LVDT比較儀為載具，量測標準玻璃管與追溯至NML長度實驗室之環規內徑之差值，並將此值與修正溫度效應後之環歸內徑相加即可求出玻璃管內徑。 Dm (mm) Primary Gas Flow Standard-Piston Prover, qm,s (0.0024 to 28.8) g/min Low Pressure Gas Flow System -F06 Mass Flow Rate of MUT, qm,m (0.0024 to 28.8) g/min Performance Indicator Cd or ER (%)

Bell Prover 600 L Bell 60 L Bell (20 − 1000) L/min U = 0.11 %

Sonic Nozzle Bank (100 − 1000) L/min U = 0.14 %

2. Measurement Facilities and KCs @ FERL 8/16 Gravimetric Vacuum Pump Gravimetric (0.002 − 20) L/min U = 0.16 % Weighing Scale Molbloc/Molbox1 Sonic Nozzle Diverter 2. Measurement Facilities and KCs @ FERL 8/16 17 17

MOLBLOC/Sonic Nozzle MOLBLOC (0.002 − 24) L/min U = 0.18 %

Outline Overview of Low Pressure Flow Calibration Facilities KC Results Description of Low Pressure Flow Calibration Facilities Recent Work-PVTt Calibration Service Future Plan

Pressure Volume Temperature and Time (PVTt) System The Working Gas Flow Standard( WGFS) uses critical nozzles that have been calibrated in the PVTt standards as working standards or reference flow meters to calibrate customer flow meters. Collection tanks: 2 L, 30 L, 500 L Flow range: (0.01 − 300) L/min U < 0.2 % (estimated)

Process Flow Diagram of PVTt

Schematic of 3-Way Ball Valve: Original (left) and Modified (right) Seal (a) (b) Port Disc (Ball) 下圖為三向閥示意圖，左(a)為原始三向閥， 右(b)為我們請廠商加工過的三向閥:使port的寬度相對較小，不會產生兩邊同時導通的情況。 Schematic of 3-Way Ball Valve: Original (left) and Modified (right)

Traceability Chain of PVTt (qv) SI Unit: Density (kg/m3) Mass (kg) Time (s) Database of Gas Properties Standard Weights Collection Tank Volume (500L, 30L, 2 L) Primary Standard : PVTt qv,s Second Standard : Sonic Nozzle Bank (Pressure Mode) qv,s,PM @ Reference Conditions (0.01 to 300) L/min Sonic Nozzle Bank (Vacuum Mode) qv,s,VM Volumetric Flow Rate of MUT qv,m

Outline Overview of Low Pressure Flow Calibration Facilities KC Results Description of Low Pressure Flow Calibration Facilities Recent Work-PVTt Calibration Service Future Plan

Industries Served Natural Gas Metering Environmental Analysis Gas Analysis Semiconductor Industry Electronic Industry

International System Service for NIMT

Outline Overview of Low Pressure Flow Calibration Facilities KC Results Description of Low Pressure Flow Calibration Facilities Recent Work-PVTt Calibration Service Future Plan

Expanded Unc. of Mass Flow (U95) PVTt (0.01 − 300) L/min U < 0.2 % (estimated) 0.20 Sonic Nozzle + MOLBLOC (0.002 − 24) L/min U = 0.18 % Sonic Nozzle Bank (6.5-100) L/min U = 0.18 % 0.18 Gravimetric (0.002 − 20) L/min U = 0.16 % 0.16 Bell Prover 60 L (4-100) L/min U = 0.15 % Sonic Nozzle + MOLBLOC (0.002 − 24) L/min U = 0.14 % (expected) Sonic Nozzle Bank (6.5-100) L/min U = 0.14 % (expected) (100 − 1000) L/min U =0.14 % Expanded Unc. of Mass Flow (U95) 0.14 0.12 Bell Prover 600 L (20 − 1000) L/min U = 0.11 % Piston Prover (0.002 − 24) L/min U = 0.10 % Piston Prover (0.002 − 50) L/min U = 0.10 % PVTt (0.01 − 300) L/min U < 0.1 % (expected) 0.10 ~ ~ 0.0 10-3 10-2 10-1 1 10 102 103 Flow Rate (L/min)

Thank you for your attention!! CMSu@itri.org.tw

60∘diversion consumes approximately 12 ms Actuate: 90∘diversion consumes 21 ms, 180∘diversion consumes 35 ms #1011: 0∘ #1031: 90∘ #1045: 180∘ Return: 90∘diversion consumes 22 ms, 180∘diversion consumes 36 ms 圖為用高速攝影機拍照，測試diverter去程及回程所需的時間， 60度的時候兩邊擋死， dead end time #1663: 180∘ #1684: 90∘ #1698: 180∘ 60∘diversion consumes approximately 12 ms