| 摘要 |
PROBLEM TO BE SOLVED: To provide a massflow controller that eliminates the need to newly provide a fluid detector by keeping changes, if any, in the zero point of a flow detector due to characteristic changes over time from affecting how a finished product is made. SOLUTION: The massflow controller includes a computing device 21 that causes a controller 3 to start operating while a zero-point calculation start time Ps that is earlier by a first predetermined period of time Tback than a point of time P0 when a value detected by the flow detector 1 of the MFC 20 is determined to have reached a flow signal level L0 appropriate to determine that gas has been introduced from a gas supply device 4 to a processor 11 is used as a reference, and the average of the values detected by the flow detector 1 within a second predetermined period of timeΔT since the zero-point calculation start time Ps is set as a zero point, the second predetermined period of timeΔT being shorter than the first predetermined period of time Tback. COPYRIGHT: (C)2006,JPO&NCIPI
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