摘要 |
A flow rate verification unit that uses the pressure fluctuation value per unit time of a pressure measurement value measured by a pressure gauge and a temperature measurement value measured by a thermometer in a state where a second shut-off valve is closed to calculate the volume between a flow-rate control valve and the second shut-off valve and verifies the flow rates of mass flow controllers one at a time, wherein a first verification side connection part 2 attachably and detachably connected to an integrated gas unit is provided upstream from the pressure gauge and a serially connected verification gas input valve, verification side mass flow controller, and verification side flow rate control valve are provided in parallel with the second shut-off valve. |