A rotameter (variable area meter) is a flow meter that measures volumetric flow of liquids and gases. ... The technique for measuring flow is accomplished by a freely moving float finding equilibrium in a tapered tube. The flow rate is then read from either a scale next to the tube or a scale on the tube.

How does a rotameter flow meter work?

A Rotameter is a form of variable area flow meter which has a simplistic operation whereby a liquid or gas passes through a tapered tube. In order for this gas to pass through the tube it must first raise a float held within the tube. ... In both cases, the greater the flow then the higher up the tube the float moves.

What is rotameter used for?

A rotameter is a device that measures the volumetric flow rate of fluid in a closed tube. It belongs to a class of meters called variable-area flowmeters, which measure flow rate by allowing the cross-sectional area the fluid travels through to vary, causing a measurable effect.