Various means have been developed for use in analyzing characteristics of lubricating oils, including engine oils. In particular, methods and apparatus for testing the condition of oil and the sludge content of oil include chromatography and chemical analysis.
Other methods and apparatus for assessing the quality of used oil include placing a measured amount of oil upon an absorbent material, heating the sample, and awaiting dispersion of the sample. The amount of undispersed sludge may then be measured and rated quantitatively. These methods and apparatus, however, require significant controlled conditions, including measurement of the oil sample volume, and the use of a template to measure and rate the quantity of undispersed sludge in the sample. Additionally, these methods include heating of the sample, and awaiting dispersal of the sample. A need exists for a simple and rapid method of analyzing an oil sample on a qualitative basis.