| 摘要 |
PURPOSE:To control accurately an initial flow rate by controlling the degree of opening of a valve during the period from the start to the time when a certain flow rate is flowed. CONSTITUTION:When a button 11 is depressed to generate a start signal ST, a mode changeover switch 15 is connected to the (a) side, and an initial flow speed set value Ma is outputted as an operation output MV to control the degree of opening of the valve, and a valve 4 is opened in a certain degree. When a pump 2 is started in this state, a flow rate is flowed after a delay, and a measured value PV rises. As a result, a flow rate monitor circuit 17 generates a flow rate detection signal FS. After a certain time from the generation of the signal FS, an FF19 is reset, and the switch 15 is switched to the (b) side, and an output Mb of a PI controller 13 is given as the operation output MV to the valve 4, and thereafter, the proportional plus integral PI control is performed till the batch end. |
