The Rota Meter is a type of flowmeter which is also known as a variable area flowmeter. It is used to measure the velocity of air and liquid (water, oil, etc.) in industrial sectors. Besides that, it is also used in medical instruments such as oxygen concentrators, oxygen cylinders, and anesthesia machines. The measuring tube of the Rota Meter is mounted vertically, with the small end at the bottom. The fluid to be measured enters the bottom of the tube, passes upwards around the float and exits at the top.