1. News from the Working Group on Fluid Flow
John Wright
NIST Fluid Metrology Group
May 12, 2011

2. WGFF Meetings Last met in October at FLOMEKO in Taiwan
International Symposium on Fluid Flow Measurement, June 18 and 19, 2012 Colorado Springs, USA
FLOMEKO, September 18 and 19, 2013 Paris, France

3. Updating Flow CMCs
RMO TC Flow members are working on updated flow CMCs
CIPM MRA-D-04 paragraph N5: CMCs incorporate “agreed-upon values for the best existing devices.“ (DUT uncertainties)
WGFF will use KC transfer standards as “best existing device”, reviewing proposed DUT uncertainties on BIPM Discussion Forum.

4. Proposed DUT Uncertainties on BIPM Discussion Forum http://www. bipm
Calibration Service
DUT Uncertainty (k=2)
Units
Comments
K1 Water flow
0.02 %
Based on CCM.ff-K1 report figures 5 to 8 and figures 19 to 22.
K2 Hydrocarbon liquid flow
Based on CCM.ff-K2 report figures 2 and 4 to 7 showing repeated cals of TS at NEL.
K3 Air speed
/u(m/s)
Based on APMP.ff-K3 TS reproducibility, see "Air Speed" worksheet.
K4 Volume graduated vessel
/V(dm3)
See the worksheet "Volume" for plots of these volume uncertainty functions.
K4 Volume volumetric flask
/V(cm3)
K4 Volume pipette
/V(cm3)
K5 High-pressure gas flow
0.05
Based on CCM.ff-K5b report table 2.
K6 Low-pressure gas flow
From Wright Flomeko 2007 paper on the uncertainty of the CCM K6 TS.
Cryogenic liquid flow

5. 2nd Round of KCs for CCM Approval
K2 Hydrocarbon Liquid Flow:
a) VSL (2 coriolis meters, HL & water)
b) NMIJ
K3 Air Speed: LNE-CETIAT and PTB (LDA & ultrasonic)
K4 Volume
a) CENAM
c) Micropipettes : IPQ (first KC)
K5 High-Pressure Gas Flow: PTB (merge 5a & 5b)
K6b Low-Pressure Gas Flow: SMU (already approved)

6. First Round Flow KC Schedules
Average completion time was 7 years!

7. First Round Flow KC Schedules
Start-up / idle + Procurement / Pre-tests = 51 %
Average KC data collection = 16 months (K5a=1 to K2=26)
Average Draft A + Draft B = 17 months (K5b=7 to K3=23)

8. Other WGFF Topics…
Guidelines on linkage, via common TS or common participants
Improving KC reports, shorter, standard format
Low uncertainties of accredited commercial labs, assist accrediting bodies with uncertainty checklists
COOMET, AFRIMET participation in other RMOs
Definition of air speed primary standard should not include 1) pitot tube, 2) rotating arm, 3)LDA without rotating disk