FLOW MEASURING METHOD AND DEVICE

摘要

PROBLEM TO BE SOLVED: To enable optimal use to the measurements of ultrapure water and chemicals and to enable accurate measurements even in the case that supply pressure of a fluid fluctuates. SOLUTION: In a flow measuring method, the pressure of a fluid is controlled by a pressure control valve 10 provided with both a body main body 11 with a chamber 20 and a pressure regulating means M for regulating the pressure of a fluid in a chamber 20. A throttle part 80 is provided on the more downstream side than the pressure regulating means M of the chamber 20. The pressure of the fluid is detected on the downstream side from the throttle part 80 to compute the differential pressure between the pressure of the fluid and the pressure for pressure regulation of the pressure regulating means M and to measure the quantity of flow of the fluid.