Question

how does the rotameter (flow meter) measure volumetric flow rate of air in the system?explain using a digram and 2-3 sentence discussion of the forces acting on the rotameter ball.

Answer 1

Rotameters are the most widely used type of variable-area (VA) flowmeter. In these devices, the falling and rising action of a float in a tapered tube provides a measure of flow rate . Rotameters are known as gravity-type flowmeters because they are based on the opposition between the downward force of gravity and the upward force of the flowing fluid. When the flow is constant, the float stays in one position that can be related to the volumetric flow rate. That position is indicated on a graduated scale. Note that to keep the full force of gravity in effect, this dynamic balancing act requires a vertical measuring tube.

Other forms of gravity-type VA meters may incorporate a piston or vane that responds to flow in a manner similar to the float's behavior. All these devices can be used to measure the flow rates of most liquids, gases, and steam. There are also similar types that balance the fluid flow with a spring rather than gravitational force. These do not require vertical mounting, but corrosive or erosive fluids can damage the spring and lead to reduced accuracy.