DIFFERENTIAL PRESSURE TYPE FLOWMETER AND DIFFERENTIAL PRESSURE TYPE FLOWMETER CONTROLLER

摘要

A differential pressure type flow meter in which production cost is lowered by simplifying the structure and high-accuracy measurement of flow rate can be carried out in real time under inline state with an error E not higher than (1%SP) over a wide flow rate range of 100%-1%. The differential pressure type flow meter comprises an orifice, a detector of pressure P1 on the upstream side of the orifice, a detector of pressure P2 on the downstream side of the orifice, a detector of fluid temperature T on the upstream side of the orifice, and a control operation circuit for operating the flow rate Q of fluid passing through the orifice using detected pressures P1 and P2 and detected temperature T from respective detectors, wherein the flow rate Q of fluid is operated according to the following expression; Q=C1·P1/√T·((P2/P1)m-(P2/P1)n)1/2 (where, C1 is a proportional constant, m and n are constants).