| 摘要 |
<p>A mass flow controller which can suppress a variation in flow rate even if pressure varies without sacrificing the speed for following up a variation in flow rate set value and can be employed even in a system generating crosstalk. The mass flow controller comprises a control section (5) for calculating and outputting the opening control signal of a flow rate control valve according to a predetermined expression for calculation including at least a flow rate measurement and a flow rate set value as parameters, and a pressure sensor section (4) for detecting the pressure of fluid on the upstream side or downstream side of a flow rate sensor section (2) and outputting a pressure detection signal indicative of that pressure value. The control section (5) differentiates the expressions for calculation during a variation period, i.e. a predetermined period from a moment in time when the flow rate set value is varied by a predetermined amount or more and during the other period, i.e. a stable period, wherein that pressure value is included additionally as the parameter of the expression for calculation at least during the stable period.</p> |
