ISO 12213 specifies methods for the calculation of compression factors of natural gases, natural gases containing a synthetic admixture and similar mixtures at conditions under which the mixture can exist only as a gas.
EN ISO 12213-2:2009 history
2009EN ISO 12213-2:2009 Natural gas - Calculation of compression factor - Part 2: Calculation using molar-composition analysis (ISO 12213-2:2006)
2005EN ISO 12213-2:2005 Natural gas ?Calculation of compression factor ?Part 2: Calculation using molar-composition analysis