ABB Rotameter (Variable Area Flow Meter) Application Notes

The Variable Area Flowmeter is an instrument for measuring the flow of liquids and gases in pipelines. It includes a vertical tube through which the fluid flows whose diameter increases from the bottom to the top and a float which can move vertically in the tube.

As the flow increases this float moves to a higher position until its resistance to the fluid flow is balanced by the float’s buoyed weight in the fluid, a value which is constant and independent of the flowrate. The position of the float is a measure of the flowrate. The flowrate values can be read on a scale.

Here is a listing of applications where rotameters (variable area flow meters) are commonly used and links to where their PDF documents can be downloaded.