抄録
Many of the fishing vessels have the lubricating oil stored in the storage tank. The troubles will be caused if some water get mix with diesel-engine oil in the tank. So it is important for the diesel-engine oil to have the water resistance. We decided the test method for the water resistant characteristics of diesel-engine oil. The test method is as follows.
Heat the bath liquid to 54°C. Add the sample of the oil under test to the test tube up to the 80mL. Place the test tube in the bath at 10 min. Add 0.4mL distilled water to the same test tube. Clamp the test tube under the stirring paddle. Lower the paddle into the test tube and stir for 30 min to a speed of 1500rpm. Pour the contents into the color comparison tube with tapered plug. Heat the bath liquid to 40°C. Place the color comparison tube in the bath for 4 weeks (672 hours) . Remove the color comparison tube and sample the test oil 5mL at 30mm under the surface of contents. Test the base number of the oil by JIS K 2501 (Petroleum products and lubricants - Determination of neutralization number) using potentiometric hydrochloric acid titration. Calculate the ratio of the base number after test to before test. 70% or above is passing.
