1. Introduction of NMIJ Gas Flow Standards Section
Toshihiro Morioka
Gas Flow Standards Section
Flow Standards Division
NMIJ/AIST

2. Outline of GFSS Flow Rate Air Speed Low Gas Flow (various gases)
Medium Gas Flow (air only)
Air Speed
Low Air Speed
Medium Air Speed

3. List of Facilities Flow Rate Low Gas Flow Medium Gas Flow Air Speed
・CVT System
・Weighing System
・Calibration Facility based
on CFVNs
Medium Gas Flow
・CVT System
・Closed-Loop Calibration
Faccility
Air Speed
Low Air Speed
・Tow Carriage
in Underground Tunnel
Medium Air Speed
・Rotating Disk to Calibrate
LDV
・Calibration Wind Tunnel

4. Flow Rate Ranges Low Gas Flow Medium Gas Flow (various gases)
(air only)
5 m3/h
200 m3/h
CVT
10 μg/min
5 mg/min
180 g/min
Weighing System
CFNVs vs. Tank
CVT
CFVNs vs. CVT
1000 m3/h
Flowmeters vs. CVT
Closed-Loop Calibration Facility
Calibration Facility
Flowmeters vs. CFVNs
Multi-Nozzle
Chamber
Flowmeters vs. CFVNs
5 MPa MPa
10 μg/min g/min
8 mm3/h
245 cm3/h
5 m3/h
9 m3/h
1000 m3/h
5000 m3/h
Flow Rate converted into Atmospheric Condition

5. Rotating Disk, LDV, Wind Tunnel
Air Speed Ranges
Low Air Speed
Medium Air Speed
5 cm/s
1.5 m/s
Tow Carriage
in Underground Tunnel
1.3 m/s
40 m/s
Rotating Disk, LDV, Wind Tunnel

6. Automatic Pressure Controller
Low Gas Flow : Weighing System
10 μg/min - 5 mg/min g/min
Flow Rate converted into 1 bar : 245 cm3/h - 5 m3/h
Uncertainty : 0.05 % % (k=2)
Test Gases :
Air, N2, H2, CH4, ...
Vacuum Pump
Filter
Exhaust
High-Flow Line
Low-Flow Line
Balance Systems
Supply Gas
Automatic Pressure Controller
Three-Way Valve
Cylinder
Nozzle Holder
Calibration Lines
DUT : CFVNs
Electric Balance
Resolution : 0.01 mg
Mechanical Balance
Resolution : 0.1 mg

7. Automatic Pressure Controller
Low Gas Flow : CVT System
10 μg/min - 5 mg/min g/min
Flow Rate converted into 1 bar : 8 mm3/h cm3/h
Uncertainty : 0.42 % (k=2)
Vacuum Chamber
Vacuum Pump
Vacuum Pump
Exhaust
Exhaust
DUT
Constant Volume Tank
Three-Way Valve
Supply Gas
Test Gases :
Air, N2, H2, CH4, ...
Automatic Pressure Controller
CVT in Vacuum Chamber
Volumes : 0.1 L and 0.3 L
Calibration Lines

8. Low Gas Flow : Calibration Facility
10 μg/min - 5 mg/min g/min
Flow Rate converted into 1 bar : 245 cm3/h - 5 m3/h
Uncertainty : 0.07 % % (k=2)
Test Gases :
Air, N2, H2, CH4, ...
Reference Standard
DUT
Nozzle Holder
Supply Gas
Exhaust
Automatic Pressure Controller
Expand Flow Rate Range
Ref. : CFVNs
Multi-Nozzle Chamber
Parallel Connection of 5 CFVNs
Calibration Lines

9. Medium Gas Flow : CVT System
5 m3/h m3/h MPa
Flow Rate converted into 1 bar : 5 m3/h m3/h
Uncertainty : 0.17 % (k=2)
Test Gases : Air
Constant Volume Tank 11 m3
Double-Walled, Water Circulation
　　　　　　　　for Quick-Stabilization of Temperature

10. Medium Gas Flow : Closed-Loop CF
5 m3/h m3/h MPa
Flow Rate converted into 1 bar : 5 m3/h m3/h
Uncertainty : 0.28 % (k=2)
Test Gases : Air
Closed-Loop Calibration Facility
Ref. : Parallel Connection of 12 CFVNs

11. Low Air Speed : Tow Carriage
5 cm/s m/s
Total Length : 45 m
Uncertainty : 7 mm/s - 9 mm/s (k=2)
Double-Walled
Velocity Measurement by Laser Interferometer
Tow Carriage
Unmanned Space, Stable Temperature, No Wind
Tow Carriage in Underground Tunnel

12. Ref. : Ultrasonic Anemometer
Medium Air Speed : Rotating Disk, etc.
1.3 m/s - 40 m/s
Rotating Disk
Rotating Disk
LDV
Uncertainty : 0.1 % % (k=2)
Ref. : Ultrasonic Anemometer
Uncertainty : 0.3 % % (k=2)
Rotating Disk, LDV, and Wind Tunnel