Revised Standard from Last Update.

1. SCOPE

This standard prescribes three methods for the determination of ash, sulphated ash and water soluble ash from petroleum products and greases.

1.1 Methods A1 and A2, are prescribed for the determination of ash from greases.

1.2 Method B describes procedure for determining the sulphated ash from unused lubricating oils containing additives and from additive concentrates used in compounding. These additives usually contain one or more of the metals namely, barium, calcium, magnesium, zinc, potassium, sodium and tin. The elements, such as sulphur, phosphorus, and chlorine may also be present in combined form.

1.2.1 Application of this method to sulphated ash levels below 0.02 percent (m/m) is restricted to oils containing ashless additives. The lower limit of the method is 0.005 percent (m/m) of sulphated ash.

1.2.2 There are evidences that magnesium does not react in the same way as other alkali metals in this test. If magnesium additives are present then the data should be interpreted with caution.

1.2.3 There are evidences that samples containing molybdenum may give low results because molybdenum compounds may not be fully recovered at the temperature of ashing.

1.2.4 The sulphated ash may be used to indicate the concentration of known metal-containing additives in new lubricating oils. When phosphorus is absent, barium, calcium, magnesium, sodium and potassium are converted to their sulphates, and tin (IV) and zinc to their oxides. Since zinc sulphate slowly decomposes to its oxide at the ignition temperature specified in the procedure, samples containing zinc may give variable results unless the zinc sulphate is completely converted to the oxide. Sulphur and chlorine do not interfere, but when phosphorus is present with metals, it remains partially or wholly in the sulphated ash as metal phosphates.

1.3 Method C describes the procedure for determining water soluble ash from all types of petroleum oils, either unused or used. When the sample under test contains lead compounds or alkali metals, the result does not express the true value as some of the metals will be lost by vaporization.

WARNING - The use of this document can involve hazardous materials, operations and equipment. This Standard does not purport to address all of the safety problems associated with its use. It is the responsibility of users of this document to take appropriate measures to ensure the safety and health of personnel prior to the application of the standard, and to determine the applicability of any other restrictions for this purpose.