API Publ 2566 pdf download.State of the Art Multiphase Flow Metering 2- NOMENCLATURE AND TERMS USED IN MULTIPHASE FLOW A number of terms and definitions are employed in describing multiphase flow and measurements. The Norwegian Society For Oil and Gas Measurement (NFOGM) have catalogued these terms in their Handbook Of Multiphase Metering” in reference XII-3. As a contribution to further...