• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.27 no.8
• /
• pp.1071-1080
• /
• 2003

A national standard system was developed in order to calibrate and test the oil flowmeters for the petroleum field. A stop valve and a gyroscopic weighing scale were employed for the primary standard of the flow quantity. It is operated by the standing start and finish mode and the static weighing method. The model equation for uncertainty evaluation was based on the calibration principle of standard system. The sources of the uncertainties were quantified and combined according to the GUM(Guide to the Expression of Uncertainty in Measurement). It was found that the standard system had the relative expanded uncertainty of 0.04 % in the range of 18 - 350 ㎥/ｈ. According to the uncertainty budget, the uncertainties of the fluid density and the volume of pipeline, which were temperature dependent, contributed 92% of final uncertainty in the oil flow standard system.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.29 no.10 s.241
• /
• pp.1130-1138
• /
• 2005

A national standard system for the petroleum field has been developed to calibrate and test the oil flow meters in Korea. The operating system and the uncertainty of the system were evaluated by the peer reviewers of foreign national metrology institutes in 2002. Since the characteristics of the system might be changed by time, the uncertainty of the system is reevaluated with the consideration of the long term stability of the system. It is found that the system has a relative expanded uncertainty of 0.048 $\%$ in the range of $15\~120\;m^3/h$. According to the uncertainty budget, the uncertainties of the fluid density and the final mass measurement, which are temperature dependent, contribute about $94\%$ of the total uncertainty in the oil flow standard system

• Proceedings of the Korean Vacuum Society Conference
• /
• 2000.02a
• /
• pp.52-52
• /
• 2000

저진공 펌프 제작시 ISO, AVS 등의 국제규격에 ？춤은 필수이고, 도달진공도, 압력구간별·가스별 배기속도, 소음, 기름증기 역류, 압축비 등이 이에 해당된다. 큰 체적의 시험용기가 구비되어 있지 않은 경우에는 배기감압법 대신 일정유량 Q를 흘려 시험용기내에 일정압력 P를 유지시키면서 배기속도를 S=Q/P식으로 구하는 일정압력법을 사용한다. 이 실험은 800~2000 l/min급 유회전 펌프와 드라이 펌프로 압력별 배기속도를 측정, 분석하여 평가방법을 수립하였다. 또 국가 유량 표준기인 sonic nozzle을 reference로 하여, 기존의 유량측정 장비와의 오차를 비교하였다. 온도 상승도를 측정, 압력과의 상관관계를 비교하였고, 오차가 적은 CDG(1, 10, 100torr)를 사용하여, 압력측정의 정확도를 높였다. 비교적 outgassing이 적은 SUS 재질의 chamber를 썼고, 유량조절 장치로 미세누출밸브를 사용하였다.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.30 no.12 s.255
• /
• pp.1139-1146
• /
• 2006

Light Oil Flow Standard System(LOFSS) in Korea Research Institute of Standards and Science(KRISS) was designed for oil flowmeter calibration. In order to extend the flow range from 120 $m^3/h$ to 200 $m^3/h$, the build-up technique was applied with two positive displacement flowmeters as master flowmeter. The master flowmeters were calibrated against with LOFSS, which has 0.04 % uncertainty of flow quantity determination, then the test flowmeter is calibrated against two master flowmeters. For uncertainty analysis, the repeatability of master flowmeters, the variation of the fluid density and the pipe volume due to temperature change were scrutinized. The contribution of each uncertainty factors to the calibrator and the correlation of each factors were discussed. For investigating the feasibility of uncertainty analysis, a turbine flowmeter as a transfer package was tested with LOFSS and two reference flowmeter. The hypothesis test for both results was coincide with a 95 % significant level. This means that the uncertainty analysis procedure of the calibrator is reasonable and the extension of flow range with master meters was carry out successfully.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.32 no.9
• /
• pp.712-719
• /
• 2008

Light Oil Flow Standard System(LOFSS), as a national oil flow standard system, in Korea Research Institute of Standards and Science(KRISS) was developed for oil flowmeter calibration, and the expanded uncertainty of flow quantity determination was estimated within 0.04 %. In order to improve the reliability of the LOFSS measurement, a proficiency test was carried out in the flow range of 20 and $240\;m^3/h$ (Reynolds number $20,000{\sim}900,000$). A turbine flowmeter was used as a transfer package in round robin test. The water flow standard system of KRISS, the pipe prover of the national calibration and test organization and the master meter calibrator of the turbine flowmeter supplier, which used the different working fluid respectively, were compared with the turbine flowmeter measurement. The maximum difference of measurement was 0.15 % between the LOFSS and the pipe prover. The En numbers of the each system measurement were evaluated at the same Reynolds number. It was found that the En numbers were less than 1 in the comparison, which means the procedures of the uncertainty estimation of the each calibrators were reasonable and reliable.

• Korean Journal of Food Science and Technology
• /
• v.7 no.4
• /
• pp.187-193
• /
• 1975

A supplemental effect of Undaria Pinnatifida extract on the composite flour prepared from a blend of wheat, barley, sweet potato, potato, and defatted soybean flours was studied in terms of binding properties, cooking test, and sensory analysis. Dry noodle of the composite flour was made by the conventional method and air dried. Instant noodle was prepared in a hot vegetable oil bath after the noodle was made. The standard was made of wheat flour only. 1. The noodle prepared with composite flour (wheat flour : barley flour, 5 : 5) and Undaria Pinnatifida extract (1 or 2%) showed same results of cooking and sensory tests as well as properties of texture as the standard. 2. The mixture of wheat, barley and defatted soybean flour (10%) had a less efficient binding capacity with Undaria Pinnatifida extract. The binding effect was, however, significantly improved with the wheat and barley flour mixture with either sweet potato or potato flour. 3. The instant noodle prepared with the composite flour (either barley, or sweet potato, or potato was mixed with wheat flour up to 70% separately) and hydroxypropyl methyl cellulose (1% as final) showed the higher oil absorption and the sensory results were the same as the standard. Nevertheless, the binding properties and cooking quality were less efficient.