| 摘要 |
PROBLEM TO BE SOLVED: To provide a mass flow rate control machine for a control purge and an operation method simultaneously providing two functions of a general control and the purge in a single mass flow rate control machine. SOLUTION: In performing a purge function, when a user sets to a control purge mode wherein the maximum flow rate is controlled for fixedly controlling the maximum flow rate, this mass flow rate control machine compares a set value of the flow rate to be input in a control circuit part with a preset threshold, switches to a purge gain resistance and controls a valve to fixedly hold the maximum flow rate; or switches to a general control gain resistance having a gain value performing a general control function and precisely controls the valve at a low flow rate. When the user sets to the valve open purge mode to make the maximum flow rate after setting to the purge function mode, this machine compares the set value of the flow rate to be input by the user from the control circuit part with the preset threshold and controls to open the valve to the maximum so as to flow the maximum flow rate or controls to precisely control the flow valve. COPYRIGHT: (C)2004,JPO&NCIPI
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