Rotameters are typically tapered glass tubes positioned vertically in the fluid flow.

Turbine flow meters measure the rate of flow in a pipe or process line via a rotor that spins as the media passes through its blades.

Ultrasonic flow meters use sound frequencies to determine flow rates.

Flow meters (flowmeters) and flow sensors are devices used for measuring the flow rate or quantity of a moving fluid or gas.

Gas flow meters are used for measuring the flow or quantity of a moving gas in an enclosed pipe or passage.

Liquid flow meters are used for measuring the flow or quantity of a moving fluid.

Gas flow switches and liquid flow switches, velocity, are used to measure the flow or quantity of a moving fluid in terms of velocity, such as feet per minute.