Abstract: Mass flow controllers and methods for controlling mass flow rates are disclosed. A mass flow controller includes a pressure value measurement means that measures one or two or more pressure values derived from pressure P1 of fluid on an upstream side of a pressure difference generate means and pressure P2 of the fluid on a downstream side of the pressure difference generate means, an acceleration means accelerates time variation of the obtained pressure values, a flow meter calculates a flow rate of the fluid based on a pressure value obtained according to the accelerated time variation (accelerated pressure value), and a flow control valve controls the flow rate of the fluid based on the calculated flow rate.

Abstract: A control means configured to perform flow rate control in which the control means outputs a control signal to a flow control valve to control a valve opening such that a measured flow rate of gas measured by a flow meter matches a set flow rate adjusts intensity of the control signal such that an absolute value of a change amount of the valve opening becomes larger as measured temperature of the gas measured by a thermometer becomes further higher than reference temperature, while the absolute value of the change amount of the valve opening becomes smaller as the measured temperature becomes further lower than the reference temperature. Thereby, change of response time on changing the valve opening of the flow control valve due to the difference between the measured temperature of the gas and the reference temperature can be reduced.

Abstract: A control means configured to perform flow rate control in which the control means outputs a control signal to a flow control valve to control a valve opening such that a measured flow rate of gas measured by a flow meter matches a set flow rate adjusts intensity of the control signal such that an absolute value of a change amount of the valve opening becomes larger as measured temperature of the gas measured by a thermometer becomes further higher than reference temperature, while the absolute value of the change amount of the valve opening becomes smaller as the measured temperature becomes further lower than the reference temperature. Thereby, change of response time on changing the valve opening of the flow control valve due to the difference between the measured temperature of the gas and the reference temperature can be reduced.

Abstract: Mass flow controllers and methods for controlling mass flow rates are disclosed. A mass flow controller includes a pressure value measurement means that measures one or two or more pressure values derived from pressure P1 of fluid on an upstream side of a pressure difference generate means and pressure P2 of the fluid on a downstream side of the pressure difference generate means, an acceleration means accelerates time variation of the obtained pressure values, a flow meter calculates a flow rate of the fluid based on a pressure value obtained according to the accelerated time variation (accelerated pressure value), and a flow control valve controls the flow rate of the fluid based on the calculated flow rate.