The principle of the constant-pressure-drop flowmeter is based
on the comparison of the force exerted by the dynamic pressure
of a fluid on a piston with the force exerted by its weight. As
piston / travels up and down in accordance with the pressure.
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m pipeline 2, the clear opening of outlet 5 co ntinu ally varies,
a ri'sult of which the fluid flow rate also changes. Piston 1 is
11 tin IumI to iron core 3, which moves along inside coils 4, chang-
иir I In n self-inductance. This is used to measure the rate of
flow of the fluid.