This standard describes the procedures for calibrating upright cylindrical tanks used primarily for the storage of petroleum liquids. Section 2A first addresses procedures for making necessary measurements to determine total and incremental tank volumes and then presents the recommended procedures for computing volumes. Both SI (metric) and customary units are presented where appropriate in the chapter. SI and customary conversions may not necessarily be exact. The SI units often reflect what is available in commercial equipment. The standard also provides guidelines for recalibration and for computerization of capacity tables.