Title :
Generation of precise micro gas flows by a constant pressure flowmeter
Author :
Arai, K. ; Yoshida, H. ; Akimichi, H. ; Hirata, M.
Author_Institution :
Nat. Metrol. Inst. of Japan, Nat. Inst. of Adv. Ind. Sci. & Technol., Tsukuba
Abstract :
Micro He gas flows ranging from 10-7 to 10-5 Pa m3/s are generated by a constant pressure flowmeter with an uncertainties of 1.1~0.91%, when the pressure in the flowmeter is changed from 1 to 100 Pa. Holding a pressure in the flowmeter during an operation of this type of the flowmeter is one of the important parameters to generate precise and stabilized gas flow rates. By controlling the volume reduction rate based on the proportional-integral-derivative (PID) algorithm, a relative fluctuation ratio of the pressure is kept within 0.03% above the pressure of 1 Pa
Keywords :
computational fluid dynamics; flow control; flow measurement; flowmeters; helium; three-term control; vacuum measurement; He; PID algorithm; constant pressure flowmeter; fluctuation ratio; micro helium gas flows; proportional-integral-derivative algorithm; stabilized gas flow rates; vacuum metrology; volume reduction rate; Bellows; Fluid flow; Helium; Hydraulic actuators; Metrology; Pressure control; Pressure measurement; Temperature; Valves; Volume measurement; constant pressure flowmeter; primary flow; vacuum metrology;
Conference_Titel :
SICE-ICASE, 2006. International Joint Conference
Conference_Location :
Busan
Print_ISBN :
89-950038-4-7
Electronic_ISBN :
89-950038-5-5
DOI :
10.1109/SICE.2006.315070
