What is the difference between a mass flow meter and a volumetric flow meter? It is possible to calculate the total number of molecules flowing in a gas or air using mass flow. By measuring volumetric flow, we can determine how much space air or gas molecules occupy. Volumetric flows vary as gases are compressed; the rates can fluctuate due to changes in temperature and pressure.To learn more please visit:https://www.silverinstruments.com/flow-meter-volumetric-and-mass-flow-rate.html