METHOD FOR MEASURING ACID VALUE AND BASE VALUE OF LUBRICATING OIL

摘要

PURPOSE:To measure the acid value and the base value in lubricating oil quickly without skill, by continuously neutralizing and reacting acidic or basic component in the sample lubricating oil in a tubular reactor, and continuously detecting the pH change in reacting liquid. CONSTITUTION:A sample lubricating oil is sent to a stirring part 4 through a check valve 3 with a constant quantity pump 2. Meanwhile, a mixing solvent including an indicator is sent into the stirring part 4 from a mixing solvent capsule 7. An electromagnetic stirrer 5 uniformly dissolves the sample lubricating oil into the mixing solvent. The sample and the solvent are continuously sent into a next stirring part 4' through a check valve 3'. Furthermore, standard titrating liquid in a standard titrating liquid capsule 9 is injected through a branch pipe, which is provided between the check valve 3' and the stirring part 4', with a constant quantity pump 10. Said liquid is mixed, neutralized and reacted with the sample and the solvent liquid. Then the liquid is continuously sent into the stirring part 4'. The color changing step of the mixed liquid is detected in a neutralization detecting part 11 and recorded as a light transmitting rate through a photodetector 15. The Acidic or basic component in the sample lubricating oil is determined based on the flow rate ratio of the standard titrating liquid to the sample lubricating oil at the terminating point of pH change.