1. Check the door seal.
Check whether there is any damage, impurities or dust. If so, wipe the door seal tightly and then apply the high vacuum grease evenly.
2. Check whether the backing pump is faulty.
● Observe the oil window of the mechanical pump. The oil level is high and the oil will be spray, the low oil level will affect the lubrication, affect the pumping speed of the system, and cause damage to the equipment.
● Observe whether the color of the oil is clear. If it is black, it shows that there are impurities or abrasion in the pump cavity; if the color of the oil is white; it shows that there is cooling oil mixed in, it will affect the lubrication and sealing, and affect the pumping speed, which leads to pumping rapid decline.
● Check the solenoid valve of the mechanical pump. Hold down the inlet of the solenoid valve by hand. If there is air intake, the valve is damaged and it needs to be replaced.
● Measure the pre-pumping time of the mechanical pump. Under normal conditions, the vacuum degree of 3-4 minutes can be pumped to 10 Pa. If the pumping time is longer, it means that the mechanical pump causes the pumping speed to be slow.
3. Check the diffusion pump and electric furnace.
● Check whether the temperature of the electric cabinet is decreasing, the electric wire is intact, and the temperature of the furnace is suitable.
● Check whether the main shaft of the frame is leaking and the vacuum of the compound gauge to judgment whether it is leaking.
● Check the vacuum valve at the top of the vacuum chamber to see if there is any leakage.
If none of the above methods have detected leaks area, it is necessary to take acetone leak detection, spray the area where there may be a leak, check the leakage point and solve it in time.