Carbon Coater for the SEM

I called up Ted Pella Co, regarding their carbon coater again. I spoke with Jack again also. Regarding maintenance, he stated that after 10K hours of operation the rotary pump should be greased with silicon grease, and that the oil should be changed. The rotary pump is a sort of pre-pump, and then a turbo-pump gets you to high vacuum.

As far as the Film Thickness Monitor, it monitors thickness by examining the changes in the frequency of a vibrating crystal in the chamber, as carbon accumulates on the surface of the crystal, the frequency changes. You don't clean the crystals, you just throw them away when you can visually observe flaking of carbon on the surface of the crystal. The device works by entering a density of carbon value along with a correction factor for the position of the crystal inside the chamber, which can all be stored in memory. Hitting the 'zero' button clears the device to get it ready for coating another sample. Things like the microprobe can then have the FTM information entered into them and then they make the necessary corrections to their readings. Jack said that many people use the FTM for a while, to get a handle on what their Carbon Coating procedure is putting down, but then don't use it every time thereafter. A rotary-tilting stage is, he said, still going to be very useful for larger specimens. I emailed Dr. Weisberg about all of this.