PROBLEM TO BE SOLVED: To provide a pressure type flow control device capable of controlling the amount of flow that passes through an orifice with a high degree of precision, by simultaneously measuring fluid pressure and fluid temperature at the same point in a fluid under noncritical expansion conditions.
SOLUTION: The pressure type flow control device includes: an orifice 4 for controlling the amount of flow; a control valve 22 disposed at the pipework on the upstream side of the orifice 4; an upstream-side pressure sensor 10 disposed between the orifice 4 and the control valve 22 for detecting an upstream side pressure P
1; and a downstream-side pressure sensor 12 disposed at the pipework on the downstream side of the orifice 4 for detecting a downstream-side pressure P
2 . The amount of flow that passes through the orifice is controlled by the opening and closing of the control valve, while the amount of flow that passes through the orifice is calculated from the upstream-side pressure P
1 and the downstream-side pressure P
2 by the flow expression Qc=KP
2
m (P
1 -P
2 )
n . The upstream-side pressure sensor 10 or the downstream-side pressure sensor 12 is constituted of a resistance element of which electrical resistance changes, when pressure is applied; and this resistance element as a pressure sensor is used simultaneously as a temperature sensor.
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