Scanning Electron Microscope
EM-30PLUS Operating Manual
28
Bias Value
: It controls the voltage that pulls the electron beam generated from Filament towards
specimens.
After setting Filament Value, adjust the value of Emission Current by adjusting BIAS.
(Recommended Emission Current: 50±5uA)
Spot Size(SP, size of electron beam)
It adjusts the size of electron beam used for observing images.
You can change the current amount of electron beam by adjusting Spot size. (Range of
Spot size: 5~16)
High magnification: Setting Spot size small(Brightness decreases as electron decreases
but resolution increases)
Low magnification: Setting Spot size big(Brightness increases as electron increases but
resolution decreases)
* For the details on Spot Size, see [5.3.2 Setting Spot Size].
* If e-gun is not aligned properly, brightness may vary irregularly when Spot size is
changed. See [ 8.2 Method for e-gun alignment].
Average filtering
If there is a big occurrence of noise on images, you can use Filter function. This function
shows the average value of images after overlapping as many images as the steps chosen.
Choose the filter value you want.
(Filter value: 1~25 Steps)
When using Averaging Filter, noise is reduced but reaction speed slows down.
The filter value that has the best reaction speed is about 2~3.
Charge Reduction: N. A.(Being developed.)