Viscosity is a controlling factor in the dissipation of heat. Ageing and oxidation of the oil tend to increase viscosity, but the effect is not discernible at the deterioration levels.
Density is not significant in determining the quality of an oil but may be useful for type identification or to suggest marked compositional changes. In cold climates, density may be pertinent in determining suitability for use, e.g. ice crystal formed from separated water may float on oil of high density and lead to flashover on […]
Pour point is the lowest temperature at which oil will continue to flow when its cooled under standardized prescribed condition. After preliminary heating, the sample is cooled at specified rate and examined at intervals of 3 degreeÂ C for flow characteristics.
This test measured the lowest temperature from oil, corrected to a barometric pressure of 101,3 kPa, at which application of test causes the vapour of a test portion to ignite under specified condition of test. The result of this test can indicate the presence of contaminant.
The oil to be tested, through which a stream of oxygen is bubbled, is maintained for a carefully measured period at a temperature of 100Â degree C in the presence of metallic cooper. The degree of oxidation is estimated by determining theÂ amount of sludge and the neutralization value.