Variable area flowmeters measure the volumetric flow of fluids and gases as they move through a system. Also known as rotameters, these instruments feature a vertical tapered tube and a float that moves as flow rates change. As flow increases, it pushes the float up the tube; the float moves down the tube as the flow decreases.Variable area flow meters are simple and versatile devices that operate at a relatively constant pressure drop and measure the flow of liquids, gases, and steam. The position of their float, piston or vane is changed as the increasing flow rate opens a larger flow area to pass the flowing fluid. The position of the float, piston or vane provides a direct visual indication of flow rate.
There are many advantages to using variable area flowmeters, including compatibility with liquids, gases, and steam. Use these flow instruments as a primary measurement source or a backup in the event of power failure. Other features and benefits of rotameters include:
- Versatile and compatible with a wide range of liquids and gases
- High accuracy measurements
- Good chemical resistance for use with corrosive substances
- Easy to install and read
- Mechanical operation requires no power supply
