Participants The 15 participants and the time schedule are shown in Table 1. The comparison measurements started in February 2010 and finished in May 2011. The CCM.FF-K6.2011 using the same transfer standard started in August 2010 and finished in December 2012. Each laboratory had several weeks for providing the measurements and for sending the transfer standard to the next laboratory. Due to some problems with customs documents the transfer standard shipment was delayed several times. The transfer standard was calibrated 7 times by the pilot laboratory before, during and after the comparison to assess its calibration stability. Tab.1 - Participants and the time schedule Country NMI Contact Date of calibration Slovakia (PILOT LAB) SMU Slovak Institute of Metrology Stefan Makovnik 15.2. to 28.2.2010 Germany PTB Physikalisch-Technische Bundesanstalt Bodo Mickan 1.3.to 20.3.2010 Spain CEM (Centro Español de Metrología) Enagas S.A. Nieves Medina 20.3. to 30.4.2010 France LNE-LADG Laboratoire Associé de Débitmétrie Gazeuse Christophe Windenberg 5.5. to 12.5.2010 Netherlands VSL National Metrology Institute of the Netherlands Mijndert P. van der Beek 18.5. to 28.5.2010 Czech Republic CMI Czech Metrology Institute Regional Inspectorate Pardubice Tomas Valenta 31.5. to 9.6.2010 Slovakia (PILOT LAB) SMU Slovak Institute of Metrology Stefan Makovnik 9.6. to 14.6.2010 Austria BEV Bundesamt für Eich- und Vermessungswesen Manfred Macek 14.6. to 20.6.2010 Poland GUM Główny Urząd Miar (Central Office of Measures) Monika Kusyk 24.6. to 30.6.2010 Hungary MKEH Hungarian Trade Licensing Office. Section of Flow Measurement Csaba Czibulka 2.7. to 6.7.2010 Sweden SP Technical Research Institute of Sweden Per Jacobsson 10.7. to 23.7.2010
(6) Where is the standard uncertainty determined by laboratory i and presented in results of laboratory I, uTS is estimated standard uncertainty caused by the stability (reproducibility) and temperature sensitivity of the transfer standard. The transfer standard was tested 7 times in the pilot laboratory (based on the time schedule) and the transfer standard calibration stability was determined based on these results. A maximum error of 0.103 % was found during the experiments eexp (see Figure 3). Combining the uncertainties due to transfer standard calibration stability and temperature sensitivity by root-sum-of-squares leads to a transfer standard uncertainty of 0.031 %. = 0.031 % (7) This transfer standard uncertainty component was combined by root-sum-of-squares with the standard uncertainty provided by each participating laboratory (Equation 6) and the results are stated in annex B. The ratio of the transfer standard uncertainty to any participant´s flow standard uncertainty is ≤ 1.0. Evaluation Linking to the CCM.FF-K6.2011 Key comparison CCM.FF-K6.2011 was performed simultaneously with EURAMET.M-FF-K6 with the same transfer standard. The linking procedure and its uncertainty analysis are based on the principles which are given in the papers of Elster et al, [4], Kharitonov et al, [5] and Decker et al, [6]. The EURAMET.M.FF-K6 is linked to the CCM.FF-K6.2011 [10] by correcting results of three linking laboratories (Slovakia SMU, Germany PTB and France LNE LADG) with the following procedure. These results are plotted in Figure 8 with the KCRV. The results from EURAMET.M-FF-K6 are corrected by the procedure described by Delahaye and Witt [8]. The calculation was determined for each flow separately. A correction, which should be applied to the result from KCRV, was obtained by equation (8) (8) where Dl is the difference between the results from CCM.FF-K6.2011 and EURAMET.M-FF-K6 at a same linking laboratory (SMU, PTB, LNE-LADG) as presented by equation (9) and wl is the weighting coefficient obtained from the uncertainty at each linking laboratory as presented by equation (10). )
TUBITAK-UME - TÜBİTAK National Metrology Institute national standard for gas flow rate measurement is the Bell Prover. Gas flow rate in the range of (0.2 to 100) m3/h is measured by this system with an uncertainty of 0.05 %. It is calibrated at UME Dimensional and Time & Frequency Laboratories with primary standards. HELLENIC INSTITUTE OF METROLOGY Mechanical Measurements Department Fluid Flow & Volume Laboratory Industrial Area of Thessaloniki Block 45. Sindos. GR-57 022. GREECE The reference facility used in this project is a volumetric device working on a positive displacement principle. Therefore, the reference flow rate was expressed in [sm3/h] which means that the actual flow rate was corrected to user defined STP conditions. In this case the standard conditions were 101325 Pa and 20 °C. The flow rate measured by the TS was also corrected to standard conditions and therefore also expressed in [sm3/h]. IMBiH – Bosnia and Herzegovina SARAJEVOGAS, LABORATORIJ ZA ISPITIVANJE I KALIBRACIJU MJERNIH INSTRUMENATA ZA GAS Rajlovacka bb, 71000 Sarajevo Ambient air is sucked by a fan through the standard meter and afterwards through the meter under test. The test was performed at atmospheric conditions with air temperature of about 21°C. System is automated by software and the flow rate is adjusted by regulation of the rotation speed of the fan and electromotive valve. After reaching the stable flow rate, the test was performed during minimum 360 seconds. The error of the meter under test was calculated after correction of indicated volume for pressure and temperature conditions. Standard meters used for this inter-laboratory comparison are rotary gas meters G16 in the range: (0.35 – 25) m3/h and G40 in the range: (0.5 – 65) m3/h and turbine gas meter G250 in the range (20 – 400) m3/h.
France/LNE-LADG Flow of the transfer standard Q/(m3/h) Relative error of the transfer standard x/(%) Expanded uncertainty of measurement declared by laboratory Uxi /(%) Expanded uncertainty of measurement extended by stability UTS and linking U(D) / (%) di/% Eni 13.07 0.15 0.25 0.267 0.046 0.17 16.09 0.18 0.25 0.267 0.035 0.13 24.35 0.19 0.25 0.267 0.021 0.08 32.60 0.21 0.25 0.267 0.034 0.12 40.78 0.23 0.25 0.267 0.042 0.16 51.18 0.24 0.25 0.267 0.029 0.11 60.82 0.24 0.25 0.267 0.016 0.06 70.87 0.25 0.25 0.267 0.004 0.01 80.89 0.25 0.25 0.267 -0.010 0.04 90.92 0.26 0.25 0.274 0.003 0.01 100.81 0.26 0.25 0.274 0.003 0.01 Netherlands/VSL Flow of the transfer standard Q/(m3/h) Relative error of the transfer standard x/(%) Expanded uncertainty of measurement declared by laboratory Uxi /(%) Expanded uncertainty of measurement extended by stability UTS and linking U(D) / (%) di/% Eni 2.00 -0.09 0.094 0.134 0.006 0.04 4.50 0.07 0.094 0.134 0.105 0.66 6.60 0.11 0.094 0.134 0.084 0.53
13.00 0.03 0.15 0.177 -0.076 0.39 16.00 0.04 0.16 0.186 -0.102 0.50 24.00 0.07 0.16 0.186 -0.104 0.51 32.00 0.10 0.16 0.186 -0.081 0.40 40.00 0.12 0.15 0.177 -0.072 0.37 50.00 0.15 0.16 0.186 -0.062 0.30 60.00 0.14 0.16 0.186 -0.085 0.42 70.00 0.18 0.16 0.186 -0.071 0.35 80.00 0.19 0.16 0.186 -0.066 0.32 90.00 0.18 0.19 0.220 -0.075 0.31 100.00 0.14 0.15 0.187 -0.113 0.53 Hungary/MKEH Flow of the transfer standard Q/(m3/h) Relative error of the transfer standard x/(%) Expanded uncertainty of measurement declared by laboratory Uxi /(%) Expanded uncertainty of measurement extended by stability UTS and linking U(D) / (%) di/% Eni 2.0 0.02 0.12 0.153 0.116 0.66 4.5 0.15 0.12 0.153 0.185 1.05 6.6 0.17 0.12 0.153 0.144 0.82 9.1 0.26 0.12 0.153 0.192 1.09 13.1 0.30 0.12 0.152 0.194 1.12 16.0 0.29 0.12 0.152 0.148 0.85 24.0 0.22 0.12 0.152 0.046 0.26 32.0 0.21 0.12 0.153 0.029 0.17 40.0 0.17 0.12 0.153 -0.022 0.13 50.0 0.22 0.12 0.153 0.008 0.05