Patent ID: 8104323

Claim:
A method for testing a flow controller comprising a valve, a flow measuring section for measuring the flow rate of a fluid passing the valve, and a valve control mechanism for controlling the valve so as to make the actual flow-rate measurement determined in the flow measuring section be an assigned target flow rate, the flow controller testing method comprising: providing in series, in a flow channel through which flows fluid whose flow is to be controlled, a testing-subject flow controller and a testing-standard flow controller, in that order from the upstream side; put the testing-subject flow controller in a flow-uncontrolled state in which the valve is practically in the full-open state; and with the fluid flow controlled to a predetermined flow rate by the testing-standard flow controller, judging whether or not the actual flow-rate measurement according to the testing-subject flow controller falls within a predetermined range of actual flow-rate measurements according to the testing-standard flow controller.