5.1 When applied to aviation gasoline, water reaction volume change using the technique reveals the presence of water–soluble components such as alcohols. When applied to aviation turbine fuels, water reaction interface rating using the technique is not reliable in revealing the presence of surfactants which disarm filter-separators quickly and allow free water and particulates to pass; but can reveal the presence of other types of contaminants. Other tests, such as Test Method D3948, are capable of detecting surfactants in aviation fuels.

1.1 This test method covers the determination of the presence of water-miscible components in aviation gasoline and turbine fuels, and the effect of these components on volume change and on the fuel-water interface.

1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. This standard involves the use of hazardous chemicals identified in Section 7. Before using this standard, refer to suppliers' safety labels, Material Safety Data Sheets and other technical literature.