
Scanning Electron Microscope
EM-30PLUS Operating Manual
78
5.3 Setting Observation Magnification/Spot size
Select the acceleration voltage which is fit for the purpose and choose the magnification
you want. After setting Spot size adequate for selected magnification, save the images.
Recommended Value of Spot Size by Observation Magnification
Proper values of Spot size by magnification are as follows.
Magnification
Spot size
50~100K
5
30~50K
6~8
10~30K
8~10
3~10K
10~12
below 3K
12~16
As the value of Spot size gets higher, images get brighter and signal increases.
Therefore, the value of contrast should be small.
Spot size gets smaller, images get darker and signal value gets lower. Therefore
the value of contrast should be relatively high
.