Purchasing a Scanning Electron Microscope (SEM)

Being new to my company, new to microscopy, and new to purchasing, I have been given a tremendous responsibility by my company.  I'll be deciding on which electron microscope to purchase by next Friday.  Over the past six months, I've travelled all over the country looking at microscope vendors, EDS vendors, and workshops trying to cram as much information as possible into my tiny brain. 

So far, after gathering my notes, I have learned that I did a horrific job on comparing images from vendor to vendor.  In a SEM (scanning electron microscope), there are a lot of things that can affect your image and how well it is in focus.  You can have different accelerating voltages, pressure environments, working distance, spot size, and magnification, etc etc.  If you are going to compare a vendor's instrument to another vendor's instrument, these conditions all need to be the same for each sample. 

Let me repeat:  take the SAME samples and test them in the exact same environments.  Like your own personal little recipe.  I wish I had figured this out BEFORE I sat down and started to realize what a dumbass I am.  Either way, I was lucky enough to capture a few images in the same environment of each sample.  Thank God. 

And don't be fooled by the best dinner.  Although, the seafood in Massachusetts was a lot better than in Portland.  But the asparagus....right, microscope.  Not food. 

Scanning Electron Microscope Picture

This is my idea of photography.  

I took this picture ('captured this image' is the technical phrase) with a scanning electron microscope.  This microscope is not the one you have in your high school lab.  For instance, this particle has been magnified 15,000 times its original size. 

It's chemically oxidized zinc.  We think the round particle in the center is atomized zinc.  They melt the zinc, blow it up into the air with nitrogen and while cooling, it turns into a very round shape. This semi-spherical particle may be one that was not milled and so retained its shape.

This picture was taken with a Hitachi S-3400-N instrument.  It's probably the one that we will be buying. Maybe.