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

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

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.

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 0.2+0.1/u(m/s) Based on APMP.ff-K3 TS reproducibility, see "Air Speed" worksheet. K4 Volume graduated vessel 0.0065+0.035/V(dm3) See the worksheet "Volume" for plots of these volume uncertainty functions. K4 Volume volumetric flask 0.0046+0.045/V(cm3) K4 Volume pipette 0.0065+0.073/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

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)

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

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)

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