Method and apparatus for gas flow control

An apparatus for controlling the flow rate of a gas includes a controllable valve in which the position of the valve and the pressure of the gas upstream of the valve are measured and used in combination with a first lookup table to determine the flow rate of the gas through the valve; and a flow restrictor upstream of the controllable valve, where the temperature of the flow restrictor and the gas pressures upstream and downstream of the flow restrictor are measured and used in combination with a second lookup table to determine the flow rate of the gas through the flow restrictor. 一种用于控制气体的流量的设备，其包含可控制阀，其中，测量所述阀的位置和所述阀的上游的气体压力，并将其与第一查找表结合使用，以确定通过所述阀的气体的流速；以及所述可控制阀的上游的流量限制器，其中，测量流量限制器的温度以及流量限制器的上游和下游的气体压力，并将其与第二查找表结合使用，以确定通过流量限制器的气体的流速。