ASTM D3827 Test Method for Estimation of Solubility of Gases in Petroleum and Other Organic Liquids
7. Precision and Bias
7.1 Precision - The precision of this test is not known to have been obtained in accordance with currently accepted guidelines (for example, in Committee D-2 Research Report RR:D02-1007, Manual on Determination of Precision Data for ASTM Methods on Petroleum Products and Lubricants).
7.1.1 Lubricants:
7.1.1.1 The gases for which reliable data were available are listed in Table 3. The nature of the correlation was such that solubilities calculated from the corresponding parameters in Table 1 will have an average precision of less than 3 %.
7.1.1.2 In this correlation, 257 data points from 9 sources were included. The breakdown by gases is shown in Table 3. Overall, the standard error of estimate was 21 %. At the 95 % confidence level, this predicts a maximum error of +/-42 % from the true value.
7.1.2 Distillate Fuels:
7.1.2.1 The gas parameters were adjusted to give less than 1 % precision on distillate fuels. When δ2 had been adjusted for lubricants, the fuel factor was set empirically. If both were free, the fuel factor was set at 1.37 and δ2 adjusted.
7.1.2.2 With this correlation, 176 data points gave a standard error of 18 %, or at the 95 % confidence level, a maximum error of 36 % from the true value.
7.1.3 Halogenated Solvents:
7.1.3.1 No attempt was made to remove precision from the solvent estimates, and the fuel parameters were used. The precision was -13 %; the details are shown in Table 3.
7.1.3.2 With the fuel correlation used on solvents, the standard error was 44 %, or at 95 % confidence level, +/-88 % from the true value maximum error. Details are shown in Table 3 on these 64 data points.
7.2 Bias:
7.2.1 No general statement is made for bias by Test Method D3827 since the data used to determine the condition cannot be compared with accepted reference material.
8. Keywords
8.1 gases; liquids; organic liquids; petroleum liquids; solubility
