| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a reference pressure type flow rate controller that easily performs flow rate calibration of a flow rate controller targeting corrosive gas, is inexpensive and high in flow rate control precision, and has corrosion resistance. <P>SOLUTION: A reference pressure type flow rate controller, used for a pressure control type flow rate reference unit, comprises a control valve provided on the upstream side of an orifice, a pressure detector provided between the control valve and orifice, and an operation control device computing a flow rate from detected pressure of the pressure detector and outputting a difference between a flow rate command signal and the computed flow rate signal as a control signal to a driving part of the control valve, and then controls a fluid flow rate on the orifice downstream side by adjusting orifice upstream-side pressure by opening and closing the control valve in a state in which the ratio of the upstream-side pressure and downstream-side pressure of the orifice is held at the critical pressure ratio of a fluid to be controlled or below. The reference pressure type flow rate controller has a gold plating coating formed over the entire surface of a part that the fluid in the reference pressure type flow rate controller comes into contact with to obtain a corrosion-resistant pressure type flow rate controller 9. <P>COPYRIGHT: (C)2012,JPO&INPIT |
