| 摘要 |
PROBLEM TO BE SOLVED: To provide a pressure-type flow control device with a flow range switching type flow monitor which enlarges a flow range and improves flow or control accuracy by combining a build-down flow monitor part with a pressure-type flow control part.SOLUTION: The pressure-type flow control device with the build-down flow monitor is formed from a signal transmission circuit CT for transmitting a flow Q of a build-down flow monitor part BDM to a pressure-type flow control part FCS, and a flow setting value adjustment mechanism QSR for adjusting a setting flow Qs of the pressure-type flow control part in accordance with the flow Q. In the case of a large flow, an outlet-side opening/closing switch valve PVis kept in an open state and flow calculation is performed on a gas passage content volume between an outlet side of an inlet-side opening/closing switch valve PVand a control valve CV of the pressure-type flow control part as build-down capacitance. In the case of a small flow, the inlet-side opening/closing switch valve PVis kept in an open state and flow calculation is performed on a gas passage content volume between the outlet side of the outlet-side opening/closing switch valve PVand the control valve CV of the pressure-type flow control part FCS as build-down capacitance. |
