Discussion Category: Centrifuge
Routine Maintenance
Besides changing diffusion pump oil and roughing pump oil, what other regular maintenance should be performed? This is for a model LE-80K.
Asked by
Typically you would be checking the condition of the vacuum hose between the fore and diffusion pumps for cracking which is not at all uncommon because of the tightness of the bend in the hose and the high temperature generated by the diffusion pump. Also check out the condition of the filter on the vacuum pump. If there are any signs of oil inside of the filter assembly or if it has a very strong smell of oil then it should probably be replaced. You want to clean under the chamber door and if it is heavily caked with old vacuum grease then it should be removed from the centrifuge for proper cleaning or if you are careful you may be able to get to the right hand underside of the door by sliding it part of the way over and wiping underneath. Also clean the o'ring at the top of the centrifuge. If you remove the door then also remove the o'ring to thoroughly clean it before regreasing with high vacuum grease. This is probably the biggest pain in the butt about the whole process but if you get an accumulation of debris around the top plate and the o'ring it can cause vacuum issues. Check for smooth operation of the door latch assembly because over time, vacuum grease can work its way down into the hole where the latch plunger goes up and down causing door latch errors. Carefully remove the safety plate around the drive spindle and check for any accumulation of oil underneath it. If so, then mop it up with paper towels. Also check for any oil accumulation within the radiometer assembly. If there is ANY oil in it then it must be cleaned out. being very careful to not bump the tach and ID rotor sensors, remove the radiometer and carefully use a kimwipe to try to absorb the oil but you need to be VERY careful around the flake inside of the housing. You can use 95% ethanol to flush out any oil residue. Afterwards, after cleaning off the mounting plate of the radiometer of any old thermal paste, reapply a THIN layer of thermal paste before reinstalling the radiometer. If the old radiometer cover is really messed up then you should replace it or at the very least carefully remove any excess oil from it but do NOT use anything to cover the radiometer other than the original film or get a replacement one. Saran wrap or any other plastic wrap will NOT work properly on the radiometer.
If I think of anything else other than just cleaning up the panels, I will let you know but this should keep you busy for awhile. A typical pm call should take around 2 to 3 hours but that depends on the condition of the centrifuge and your own abilities.
Don
Don,
Thank you for your detailed post. Much appreciated!
Peter
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