Manual of Petroleum Measurement Standards Chapter 15 - Guidelines for the Use of the International System of Units (SI) in the Petroleum and Allied Industries (SECOND EDITION)
Scope and Field of Application This publication specifies the API preferred units for quantities involved in petroleum industry measurements and indicates factors for conversion of quantities expressed in customary units to the API-preferred metric units. The quantities that comprise the tables are grouped into convenient categories related to their use. They were chosen to meet the needs of the many and varied aspects of the petroleum industry but also should be useful in other@ similar process industries.