What Is an SEM?
SEM stands for Scanning Electron Microscope. It is, of course, a microscope, which means it is used to look at objects on a very small scale. The primary difference between this microscope and the typical optical lab microscope is how we look at small objects.
Optical microscopes use light as the "probing" device – light hits the object in question, and light waves bounce back. They are magnified through a series of lenses, and finally we see the image through the eyepiece, larger than actual size.
The problem with light waves and object magnification is there is a limit to how small we can see, or how large we can magnify. Light waves can only resolve detail to a limit of about 0.2 mm, and magnify effectively up to 1000x.
To get past this limit we need a new way to "look" at things. An electron microscope can do this.
West Georgia Microscopy Center Department of Geosciences University of West Georgia 1601 Maple Street Carrollton, GA 30118 (678) 839-6479
