Mass liquid flow switches and mass gas flow switches are devices used for measuring the flow or quantity of a moving liquid or gas in terms of a unit of mass per unit time, such as pounds per minute.

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

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

Flow controllers monitor and maintain flow-rate variables, typically in process applications

Mass spectrometers separate ions by their mass-to-charge (m/z) ratios.

A mass flow meter is a device that consist of a mass flow sensor or transducer and signal processing electronics.

Flow computers, totalizers, and rate indicators integrate the functions of flow and temperature measurement, computation, data acquisition, input / output (I/O) standardization, and closed loop control.