IS 1448 : Part 55 : Sec 1 : 2025 Petroleum and its Products - Methods of Test - Part 55 Saponification Value - Section 1 Colour Indicator and Potentiometric Titration
1 SCOPE
1.1 This standard specifies methods for determining the amount of constituent A in petroleum products such as straight mineral oils, compounded mineral oils, and waxes that will undergo saponification under the test conditions. Two methods have been prescribed in this standard, Method A - Colour indicator titration, and Method B - Potentiometric titration. The methods are applicable to materials having saponification numbers in the range of 2 mg KOH/g to 200 mg KOH/g.
1.2 Compounds of sulphur, phosphorus, halogens and some other compounds interfere by reacting with the alkali and acids under the test conditions.
NOTES
1 The results on used crankcase and turbine oils, and on oils containing the interfering compounds above as additive constituents, should be interpreted with care, bearing in mind the possible higher values obtainable due to these additional reactants.
2 The interfering compounds above are contained in extraneous materials including certain organic acids and most non alkali soaps. The odour of hydrogen sulphide near the end of the back-titration step is an indication of the presence of certain reactive sulphur compounds, but other reactive sulphur compounds, as well as those of chlorine, phosphorus and other interfering materials, give no simple indication during the test. A gravimetric determination of fatty acid content is an alternative procedure for the estimation of such compounds.