Rockwell hardness tester oil tank refueling method:
When the hardness tester applies the main test force, the indicator pointer starts to rotate quickly and then slowly, indicating that there is too little oil in the buffer. At this time, you can lift the felt pad on the oil cylinder and slowly inject clean 20# engine oil.
At the same time, push and pull the unloading handle multiple times to make the piston move up and down multiple times to remove all the air in the buffer until oil overflows when the piston reaches the bottom.
