Flowmeters are devices that measure the amount of liquid, gas or vapor that passes through them. Some flowmeters measure flow as the amount of fluid passing through the flowmeter during a time period (such as 100 liters per minute). Other flowmeters measure the totalized amount of fluid that has passed through the flowmeter (such as 100 liters).
Mass flowmeters utilize techniques that measure the mass flow (W) of the flowing stream. Examples of flowmeter technologies that measure mass flow include Coriolis mass and thermal flowmeters.