| 摘要 |
PROBLEM TO BE SOLVED: To provide a vacuum pressure control system that easily controls pressure in a wide range from atmospheric pressure or a low vacuum close to atmospheric pressure to a high vacuum, and reliably prevents scattering of particles by slow evacuation while controlling a pressure with high accuracy. SOLUTION: The vacuum pressure control system for controlling, through a vacuum pressure sensor 3 measuring a vacuum pressure in a vacuum vessel 4, an opening of an opening/closing valve 2 changing the vacuum pressure in the vacuum vessel 4 through a vacuum pump 5 includes: a control unit means 10 having an arithmetic function of calculating an arrival function f(x), a timer 60 for opening/closing the opening/closing valve 2 with an arbitrary time width, and a function of calculating an opening/closing opening value from output of the vacuum pressure sensor 3 and the arrival function f(x); a drive means 12 driving the opening value; and an input means 13 for inputting a command for an arrival pressure P and the time T required for pressure reduction, from the outside. Thereby, a pressure is reduced from atmospheric pressure or an arbitrary pressure to an arbitrary target pressure. COPYRIGHT: (C)2011,JPO&INPIT
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