Rotameter

What is a rotameter? A rotameter (variable area flow meter) is a flow meter that measures the volumetric flow of liquids and gases. There is no difference between a rotameter and a flow meter, and these terms are interchangeable.The variable-area flowmeter is called a rotameter because the float spins, or rotates, as the flow passes it. The spinning float is a clear indication that fluid is flowing. Variable-area technology was invented in Germany more than 100 years ago.