ASTM D2421-19,Standard Practice for Interconversion of Analysis of C5 and Lighter Hydrocarbons to Gas-Volume, Liquid-Volume, or Mass Basis.
ASTM D2421-19 describes the procedure for the interconversion of the analysis of C₅ and lighter hydrocarbon mixtures to gas-volume (mole), liquid-volume, or mass basis.
Significance and Use
3.1 For custody transfer and other purposes, it is frequently necessary to convert a component analysis of light hydrocarbon mixture from one basis (either gas volume, liquid volume, or mass) to another.
4. Procedure
4. 1 To convert from the original to the desired basis,multiply or divide the percent of each compound in the original basis according to the schedule shown in Table 1. Perform the calculation, using the corresponding factor indicated in Table 2. Carry at least one more significant figure in all of the calculations than the number of significant figures in the original analysis.
4. 1.1 The factors or percentages may be multiplied by any constant number for convenience (such as moving the decimal) without changing the end result.