API MPMS 14.7:2018 describes the criteria for the equipment selection, design, installation, calculation processes, operation, and maintenance of single-phase dynamic liquid mass measurement systems that operate in the density range of 351 .7 kg/m 3 to 687.8 kg/m 3 at 1 5 °C and equilibrium vapor pressure. The mass measurement systems within the scope of this document include inferred mass measurement, where volume at flowing conditions is combined with density at similar conditions to result in measured mass, as well as direct mass measurement.