Fluid enters the inlet of the metering tube exerting a force on the float. As the force overcomes
the weight of the float, the float rises in the tube. When the forces of gravity, float weight, and
the fluid force reach an equilibrium, the float stabilizes in the tube. The position of the float at
equilibrium corresponds directly to the flow rate. The flow rate is indicated on a scale etched
directly onto the metering tube. This scale may be either a direct reading scale or a reference
scale. A reference scale requires the use of a calibration data chart.
Variable area flow meters must be mounted vertically with the flow moving upward through the
metering section to assure accuracy. Within this restriction, they offer the flexibility of being
bench-mounted or mounted directly in a pipeline, control panel, bypass system, or backup
system for electronic controllers. |
