@beamshift@macona The JEOL microscope did have vacuum gauges, but the vacuum meter is just a microammeter calibrated in microamps. I’m not really sure what the actual vacuum pressure is.
@macona Yes, this TEM has a diffusion pump using Santovac 5 fluid, and I have a silicone heating tape that I might be able to use to bakeout the column, I’ll try that.
@macona Perhaps several years. When I received it, the gun section had been removed, and the top of the column was totally open, with a lot of dust inside, I have to clean it with no choice, There were even nut shells left by squirrels inside the electrical cabinet, horrible condition.
@beamshift Suspecting the problem might be with the cables or the gun, I unplugged the high-voltage connector from the HV tank. When starting up, it seems fine and never tripped the protection. At 100 kV, the beam current is about 100 µA, probably caused by the flow of oil inside the tank.
@beamshift However, sometimes it could stay on stably for a while under 60kV, with an even higher beam current (about 80 µA). When I raised the high voltage directly to 80 kV, it could not stabilize, and every time the beam current went off-scale and tripped the protection.
Completely refurbished but still not very satisfying.
Knowing I could down the rabbit hole but still I’ll design a secondary electron detector & scanning module for this scope, possibly hard decision.
@CALVINGINEERING These old balzers pumps are nasty cause they’re prone to failure when you got one of these nowadays. Considering its lifespan, cleaning and oil reservoir replacement is advised.
Update: Fixed the micrometer that used for sample stage displacement.
Vacuum system seems still in tight, when it arrives the camera chamber is still under vacuum.
Electronic components still require dust removal