API MPMS Chapter 3.4 (R2021) PDF
This new standard provides guidance on the selection, installation, calibration, and verification of automatic tank gauges (ATGs) for measuring the level of liquid hydrocarbons having a Reid vapor pressure less than 15 pounds per square inch absolute (103 kPa), transported aboard marine vessels (tankers and barges). This standard also provides guidance on the requirement for data collection, transmission, and receiving. This standard supersedes all applicable sections of API Standard 2545.
This standard provides guidance on the selection, installation, calibration, and verification of automatic tank gauges (ATGs) for measuring the level of liquid hydrocarbons having a Reid vapor pressure less than 15 pounds per square inch absolute (103 kPa), transported aboard marine vessels (tankers and barges).
Marine ATGs are not normally used in custody transfers because of the limitations described in Appendix A. However, level measurement by marine ATGs may be used in custody transfer when no other alternative measurement is available. The use of marine vessel-based ATGs for custody transfer normally requires mutual contractual agreement between the buyer and the seller and may be subject to government regulations.
This standard also provides guidance on the requirements for data collection, transmission, and receiving. The Appendix B briefly describes the operation of the most commonly used marine ATG equipment.