Chapter 2:  The FSU SEM User Manual

Imaging with the SEM

There are several different scanning modes for the SEM, and each produces a slightly different image. They are:

• TV Scanning Mode - used to "navigate" around the sample to find areas of interest.
• Small Scanning Mode - best mode to use for focusing the SEM.
• Vis1, Vis2, and Vis3 - each offers a progressively slower scan of the specimen and progressively greater detail.
• Photo Scanning Mode - the slowest scan of all, but it results in the best quality image.

The following procedure outlines how to capture an image from the SEM via computer.

1. If the computer is not in the SEM room, disconnect it carefully from the light microscope in the sample preparation area. Please note where the connectors go so you can reconnect it later (if needed).
2. Connect the SEM computer cable to the smallest port on the back of the computer CPU case.
3. Follow the procedures for verifying a working vacuum and filament.
4. Follow the procedure for obtaining an image. Use the Small Mode to focus.
5. Magnify the image a higher power than the one at which you wish to capture an image and focus it. Now, when you go back to the lower magnification, the image will be sharper.
6. The software used for SEM image capture is called SEM ODON and is located in the ADS directory under the program manager. Boot it up.
7. Make sure that the Visual Mode in the SEM ODON program is set to "slow", or it will not be possible to do a photo image capture (located in the "Setup" menu).
8. If there is not already an opened image window named "untitled" , open one using the "New" command under the File menu.
9. Set the program to record data.
10. Select the Photo scanning mode on the SEM instrument panel.
11. Hit "Photo Start Reset" to began taking a "picture".
12. The image should be recorded on the computer. You can then save it. NOTE: The image capture program only save images in the *.tiff format. They are extremely large (about 789 KB). To fit your images onto a floppy disk, use the OEM program in the ADS directory to load your images and convert them to *.jpg files. The commands for this are under the "Load Image" menu. It is possible to convert them back later with little loss of pixel data (Click here for more information, "About Image Formats.")
13. After you are done collecting images, turn the filament off (counterclockwise), turn the magnification to its lowest setting, and turn off the beam by pressing the BEAM button. If the magnification is not returned to the lowest setting, it will be extremely difficult to find the sample, let alone obtain a quality image, when the SEM is used again.
14. Press VACUUM PUMP to vent chamber.
15. After the chamber has vented, you can change specimens.
16. After your done collecting all of your images, follow step 13, then remove your specimen, close and secure the specimen hatch, and press the VACUUM PUMP button to pump down the chamber.

After the raster appears on the CRT (looks like green "snow"), turn the OPERATE key to the off position and turn off the power to the SEM by using the red POWER button on the SEM control panel.

Now, I would like to discuss how I used the SEM for the following project: Metal Fatigue Observed in Paperclips.

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