Decide the vapor capacity which utilizes Boyle's doctrine manner and the device

摘要

PURPOSE: To reduce a back pressure generated at a gas flow path and automate operation by providing a sensor for sensing the gas pressure is a sealed volume portion provided with a gas flow inlet. ;CONSTITUTION: When a valve 15 is at an actuation position by means of a control signal, a tank 20 (sealed volume portion) communicates with a flow outlet via a center port 17, a movable valve member 19, and an outlet port 18. At an inactive position, an inlet port 14 and a tank 20 are communicated with each other via the member 19 and the center port 17, and gas flows from an inlet 11 and the tank 20. A pressure sensor 25 is arranged so as to sense the pressure in the tank 20. This device is based on the principle of Boyle's law in which the multiple of the pressure and volume of gas are constant at a constant temperature. Therefore, when gas flow is pressure-stored in a constant capacity, the pressure raises in proportional to the flow rate. That is, the flow to be measured is pressure-stored over the known time length in the tank 20 of the known capacity. That pressure rise is measured by means of the pressure sensor 25 and is converted to the flow rate value.;COPYRIGHT: (C)1994,JPO