Vol.3 No.1 2010

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Research paper : Development of primary standard for hydrocarbon flow and traceability system of measurement in Japan (T. Shimada et al.)−57−Synthesiology - English edition Vol.3 No.1 (2010) where any exterior load on the weighing tank be eliminated during the mass measurement. (3) Categorization by a flow switching method in the flying start and stop method• High-speed valve method: A method in which the flow of the test liquid from the test line is switched to the storage tank and the standard, by rotating the valve at high speed. While it is less expensive than the diverter method, large pressure change occurs when switching is done at high speed, and there is a limit to the switching speed. The effect of switching on the flowmeter to be calibrated cannot be neglected. Also, there are problems in the symmetry of the flow, and achieving high accuracy is limited.• Diverter method: A diverter is a device for switching the test liquid that jets out of the nozzle opened to the air to the storage tank and standard. Since the flow fluctuation during switching is small, it has absolutely no effect on the flowmeter to be calibrated. It has been used in water flow standard facilities, and there is a possibility for achieving high accuracy. On the other hand, since the liquid flows freely as a jet from the nozzle, there are dangers of explosion due to static electricity generated by mist. Also, the oil vapor and droplets released into the air may become sources of uncertainty. When the test liquid is poured in torrents into the weighing tank, large amount of air bubbles are formed, and when the test liquid containing the bubbles are circulated in the test line, the remaining gas may be a source of uncertainty.Table 1 shows the calibration capacities and the methods of the NMIs of other countries for the hydrocarbon flow 2.2 ~ 300~ 0.85~ 50Kerosene, light oil, heavy oil0.03~0.080.00012~720NELU.K.0.7, 1.8, 50.4Gasoline, kerosene, light oil0.040.001~250NMi-VSLTheNetherlandsLPG~300-20~ 120LPG, light oil, etc.0.10.36~1260SPSweden0.3~ 300Light oil0.10.4~ 400GUMPoland0.5~ 100.1~ 0.40~ 82Petroleum products0.06~ 0.080.002~ 340CENAMMexico600 ~ 22000.1~ 0.315~ 30Spindle oil (machine oil)0.111~14.8KRISSKorea1.4~1.9,4.4~7.80.1~ 0.715~ 350.0315(3)~300NMIJ*Japan0.15Kerosene, light oil0.10.0036~3.6IMGCItaly0.77mPas0.35Petroleum0.10.6~250PTBGermanyPetroleum products0.030.4~400FORCEDenmarkPipe prover(piston)0.1~ 3.50~ 850.15~0.300.29~396CMICzechRepublic< 0.8Wait-and-see0.1~ 0.23 ~300INIMETCubaWeighing tank2.5~ 150 < 0.510~ 45Light oil, spindle oil (machine oil)0.0518~360CMSTaiwanVolume tankstanding methodVolumetric method,0.05~ 0.614~ 17Gasoline, light oil0.07~0.10.0018~90BEVAustriaReferenceCalibrationmethodViscosity( mm2/s )Pressure( MPa )Temperature( ℃ )Test liquidUncertainty** (%)Flow rate( m3/h )NMICountry*)NMIJ:National Metrology Institute of Japan, AIST**)Uncertainty: Here, for simplification, the values for expanded uncertainty (95 % confidence level) are presented. (NationalMetrologyInstitute)Gasoline, kerosene, light oil, heavy oilKerosene, light oil, petroleum, LPGKerosene, light oilWait-and-seeWait-and-seeWait-and-seestanding methodGravimetric method,Volumetric methodflying methodVolumetric method,flying methodVolumetric method,standing methodVolumetric method,flying methodVolumetric method,flying methodGravimetric method,standing methodGravimetric method,flying methodVolumetric method,flying methodVolumetric method,flying methodVolumetric method,standing methodVolumetric method,standing methodGravimetric method,Pipe prover(piston)Volume tankPipe prover(piston)Weighing tankWeighing tankPipe prover(piston)Pipe prover(piston)Pipe prover(prover)Volume tankWeighing tankTable 1 Uncertainties and calibration methods of the national standard for hydrocarbon flow of various countries.

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