1. Reagent
(1) Petroleum ether: 60-90℃, analytically pure.
(2) Ethanol: 95%, chemically pure.
2. Preparatory work
(1) Turn on the power switch of instrument, and use the above method to set the suitable constant temperature (40℃), time for constant temperature (15 minutes), test number (4 times).
(2)Then select “sample testing” and press “Confirm” key, the instrument will enter into the state of temperature rise, and stirrer begins to stir at the same time.
3. Preparation of samples
(1) When the samples contain water or mechanical impurities, they shall be dewatered before testing and the mechanical impurities shall be filtered and removed with filter paper.
As for the lubricating oil with high viscosity, it can be filtered with porcelain funnel, flow pump or other vacuum pumps, and can be heated to temperature of 50-100℃foufor dewatering and filtering. r .
(2) Selection principle of viscometer (capillary): select and use proper viscometer according to the testing temperature. Make sure that the flow time of sample is no less than 200s, and the flow time of viscometer with 0.4mm of inner diameter is no less than 350s.
(3) Before measuring the viscosity of sample, wash the viscometer with solvent naphtha or petroleum ether. If there is dirt on the viscometer, use chromic acid wash, water, distilled water or 95% of ethanol to wash the dirt successively, then put it in the oven to dry or blow it dry by means of the hot air filtered by cotton.
(4) When measuring kinematic viscosity, put the sample in the clean and dry capillary viscometer with inner diameter meeting the requirement. Before putting in the sample, cover the rubber tube into Branch Pipe 7, and plug up the pipe orifice of Pipe Body 6 with finger. Meanwhile, place the viscometer upside down, then insert Pipe Body 1 into the vessel filled with sample; at this moment, use rubber pipette bulb to inhale the liquid up to the marked line b. Meanwhile, pay attention not to make the liquid in Pipe Body 1, Expansion Parts 2 and 3 bubble and crack. When the liquid level reaches to the marked line b, take up the viscometer from vessel, and recover its normal condition rapidly. Meanwhile, wipe off the redundant sample on the outer wall of the pipe end of Pipe Body 1, and take the rubber tube down from Branch Pipe 7 and cover it around Pipe Body 1.
4. Test procedures
(1) As shown by the temperature of instrument for observation, when the temperature is shown as 40±0.1℃ (with voice prompting), with the state of “constant temperature”, fix the viscometer (capillary) filled with sample to capillary frame. Notes: immerse at least half of the Extension Part 2 of viscometer (capillary).
(2) Adjust the viscometer to be in plumbness, and use the plumb line to inspect the verticality of capillary from two directions which are perpendicular to each other.
(3)Then press “Confirm” key, and the instrument will begin to time with the set constant temperature time.
(4) When the time for constant temperature is up, use the rubber tube covered by Pipe Body 1 of capillary viscometer to inhale the sample to Extension Part 3, and make the liquid level of sample a little higher than the marked line a. Moreover, pay attention not to make the liquid in capillary and Expansion Part 3 bubble or crack. Then press the “Confirm” key.
