Patent ID: 8789556

Claim:
A flow rate control device including a flow rate measuring mechanism configured to measure a flow rate of fluid flowing through a flow channel, a flow rate control valve provided on the flow channel, and a valve control part configured to control an opening degree of the flow rate control valve so as to reduce an error between a target flow rate value and a measurement flow rate value measured by the flow rate measuring mechanism, the flow rate control device comprising: a fluid resistor provided on the flow channel; a pressure sensor provided in any one of an upstream side or a downstream side of the fluid resistor; a pressure calculating part configured to calculate a pressure in a side where the pressure sensor is not provided with respect to the fluid resistor based on a measurement flow rate value measured by the flow rate measuring mechanism and a measurement pressure value measured by the pressure sensor; a flow rate calculating part configured to calculate a flow rate of the fluid flowing through the flow channel based on the measurement pressure value and a calculation pressure value calculated by the pressure calculating part; and an abnormality diagnosing part configured to diagnose an abnormality of the measurement flow rate value based on the measurement flow rate value and a calculation flow rate value calculated by the flow rate calculating part.