Hybrid Flow Meters utilize two different flow meter technologies in combination; vortex and differential pressure. The design has blended the two separate flow metering principles into one hybrid system where the two meters complement each other’s performance. This combination allows for the prediction of fluid density, volumetric flow rate and mass flow rate without any fluid density information being required from an external source. With addition of two differential pressure transmitters, advanced diagnostic software continually monitors and verifies the meter performance.