ASTM D3524 Diesel Fuel Diluent in Used Diesel Engine Oils
ASTM D3524 Standard Test Method for Diesel Fuel Diluent in Used Diesel Engine Oils by Gas Chromatography
1. Scope
1.1 This test method covers the determination of diesel fuel as a contaminant in used lubricating oil. The method is limited to SAE 30 oil.
NOTE 1 - This test method may be applicable to higher viscosity grade oils. However, such oils were not included in the program used to develop the precision statement.
1.2 There is some overlap of the boiling ranges of diesel fuel and SAE 30 engine oils. Moreover, the boiling range of SAE 30 oils from various sources can vary appreciably. As a result, the calibration can be altered by as much as 2 %, in terms of fuel dilution. When testing unknown or mixed brands of used engine oil, it should be realized that the precision of the method may be poorer than the precision obtained when calibrating with a new oil representative of the used oil being tested.
1.3 The values stated in SI units are to be regarded as the standard. The values stated in inch-pound units are for information only.
1.4 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.
2. Terminology
2.1 Definitions of Terms Specific to This Standard:
2.1.1 fuel dilution - the amount, expressed as a percentage, of engine fuel found in engine lubricating oil. This may be the result of engine wear or improper performance.
2.2 Abbreviations:
2.2.1 A common abbreviation of hydrocarbon compounds is to designate the number of carbon atoms in the compound. A prefix is used to indicate the carbon chain form, while a subscripted suffix denotes the number of carbon atoms.
For example:
normal decane n-C10
iso-tetradecane i-C14
3. Summary of Test Method
3.1 A mixture of n-decane and used lubricating oil is introduced into a gas chromatographic column which separates hydrocarbons in boiling point order. The column temperature is raised at a reproducible rate and the resulting chromatogram is interpreted for diesel fuel dilution.
4. Significance and Use
4.1 Some fuel dilution of the engine oil may take place during normal operation. However, excessive fuel dilution is of concern in terms of possible performance problems.
