This publication is to be used as a reference to select, design, install, operate, and maintain homogeneous, single-phase liquid mass measurement systems that operate in the density range from 0.3 to 0.7 grams per cubic centimeter (18.73 to 43.70 poundsper cubic foot). Measurement of liquids with densities below 0.3 and above 0.7 grams per cubic centimeter and measurement of cryogenic fluids are excluded from the scope of this document. Sampling equipment and techniques are discussed, and standards for analytic methods used to determine the composition of the sampled product are also cited. This standard was developed jointly by the Gas Processors Association (GPA), Section H, Product Measurement and Handling, and the American Petroleum Institute, Committee on Natural Gas Fluids Measurement.