| 摘要 |
PROBLEM TO BE SOLVED: To provide a mass flow controller capable of controlling a stable flow rate without being affected by pressure fluctuation in a primary side. SOLUTION: This mass flow controller 10 comprises a base 20, a valve part 30, a bypass part 40 and a thermal flow rate sensor part (flow rate sensor part) 50, and a pressure sensor 110 is provided on the upstream side of the valve part 30, so that the valve part 30 is controled on the basis of not only a flow rate detected by the flow rate sensor part 50 but also primary side pressure detected by the pressure sensor 110. The base 20 is provided with fluid passages 22 and 24, an upstream side joint 26 connected to the primary side and a downstream side joint 28 connected to a secondary side. Disturbance in flow rate control caused by the pressure fluctuation in the primary side is suppressed by applying a correction operation to the flow rate control of the valve part 30 in accordance with a value detected by the pressure sensor 110. COPYRIGHT: (C)2005,JPO&NCIPI
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