| 摘要 |
PURPOSE: To provide the differential pressure type mass flow rate control unit which can sufficiently cope with temperature variation of gas by eliminating the influence of pressure on a Reynold's number. CONSTITUTION: Mass flow rate control which can follows up variation in gas pressure and variation in gas temperature over a wide range can be done since both a difference pressure signal of pressure values detected at at least two upstream and downstream places across a laminar flow element 16 and the signal from a temperature sensor 15 for correcting the influence of the temperature of the gas are converted into a mass flow rate and a control valve 7 is controlled by using the mass flow rate as an output signal. This system is >=100 times as fast in response as a conventional thermal mass flow rate controller, and can perform high-precision, fast-response control. |
