How to get accurate grease drip point measurement results?

Proper operation is very important to obtain accurate grease dropping point results.

1) First of all, the dropping point determination method should be selected:

●When the dropping point of lubricating grease is higher than 260℃, only GB/T3498 "Measurement of dropping point of lubricating grease in wide temperature range" can be selected;

●When the dropping point of lubricating grease is between 220~260℃, it is better to choose GB/T4929 "Measurement of dropping point of lubricating grease" to obtain higher repeatability.

2) The mercury head of the thermometer should be in the correct position in the grease cup:

●Before each test, use a gauge to adjust the length of the thermometer so that the mercury head of the thermometer is at the standard position;

●In order to ensure that the thermometer does not shake in the test tube, it is also necessary to properly adjust the position of the thermometer bushing.

3) Grease should fill the grease cup as much as possible, while reducing the mixing of air bubbles:

●Put a small amount of lubricating grease on the flat plate first, and use a scraper to roll out the lubricating grease on the flat plate repeatedly to remove air bubbles;

●Turn the grease cup upside down, with the big mouth facing down, with a small angle between the cup mouth and the flat plate, so that the fat cup slides on the flat plate, and rotates an angle every time it slides, until there is grease at the base of the small mouth;

●Insert a metal rod with a diameter of 2mm from the small opening, put the fat cup against the index finger, slide down the index finger to the thumb, the metal rod will come out from the big mouth of the fat cup with the rotation of the fat cup, carefully pull the metal rod out of the fat cup take out.

4) Carefully assemble the test tube, grease cup, thermometer and other components, and pay attention to the position of the mercury end of the thermometer not to move. The assembly is then placed in the bath. Before that, the bath temperature should be adjusted according to different test methods.

5) Correctly read the grease dripping temperature:

●In order to accurately judge the dropping point, there should be lighting equipment behind the test tube. Once a substance is found to be squeezed out from the small opening of the fat cup, it is not far from dripping.

●The time from a small amount of substance being extruded from the mouth of the cup to completely dripping varies greatly among different samples, so we can only pay attention to observation. Once the first drop is found, immediately read the temperature of the substance at the moment.

●When using GB/T3498 to measure the dropping point of lubricating grease, because the bath temperature has already reached a temperature higher than the actual dropping point, if the time to read the dropping temperature of the first drop of lubricating grease is too long, the test result will be incorrect precise.