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New Turbo Adapter and Re-evacuating the EDX Dewar

A project log for Hitachi S-450 Scanning Electron Microscope

Getting an old (1980s) SEM running and adding digital capture

Jerry BiehlerJerry Biehler 02/27/2015 at 19:550 Comments

I finally got around to shortening the turbo pump adapter that allowed me to mount the new turbo where the old diff pump was. I wanted to take about 4" off the length of it so I could install the second vibration isolator. I chopped off the bolt flange with a bandsaw and then trimmed the tubing off the ISO-100 flange to about 2". Chucked up the bolt flange in the lathe and cut out the old tubing to the weld and then flipped it over and cut a groove in the stainless for a face seal. I tigged up the two pieces using a Atlas rotary positioner. Put it all together an no apparent leaks.

I also took this opportunity to re-evacuate the dewar on the EDX. I got one of the CryoLab vacuum operators from a friend and made up a hose to go to the chamber of the SEM to pump it down. I am going to let it run for about 24 hours to get it down as low as I can. As best as I can tell it was up to a few torr, at least.

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