FEI Quanta FEG 250, Руководство пользователя

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Software Control: xT microscope Control Software
4-13
Note:
When two above mentioned functions are active, it is represented in
the toolbar scan speed spiner with the letters LI / SI.
Live
is the default imaging mode, leaving the image unfiltered for collecting
raw direct images - one frame follows another.
Average
continuously averages a specified number (2 or more)
of frames, resulting in a better signal-to-noise ratio. This process continues
until stopped by changing the scanning condition or by pausing the quad.
This is used mostly for fast scanning to reduce image noise. During
averaging, the image is updated continuously and actions such as
focusing, moving the stage, etc. can still be performed.
Note:
The Average is set independently also for the optical window (option),
but using averaging with more than 4 frames is not recommended,
especially when moving the stage.
Integrate
allows accumulative noise reduction by true integration over a
specified number (1 or more) of frames. This process continues until
the selected number of frames is reached and then pauses the quad
automatically. During and after image accumulation, you cannot
change the focus or perform other image-influencing actions.
This can be used as an alternative to slow scanning to obtain high
quality images of slightly charging specimens.
Note:
Clicking the down-arrow next to the icon displays menu items Live /
Average / Integrate , Number of Frames enabling to select number
of averaged or integrated images (depending on the actually active
Filter Mode indicated by the icon image for the active quad). Clicking
the icon itself changes the Live / Average / Integrate mode in cycle.
The Number of Frames is set and remembered independently for the
Average and Integrate filters. Both the Filter mode and Number of
Frames is set and remembered per quad, so live and filtered images
can be observed at the same time. Settings are particular for the
Reduced Area and for the Full Frame also. The Photo function uses
the Filter Mode and Number of Frames pre-set (see the
Preferences… / Scanning tab).
As the scanning could take a significantly long time period, one can
restart it from the beginning with the use of
Ctrl + R keys (Restart
Scan).
Scan Rotation (Shift + F12)
activates the on-screen tool to rotate the scan field. It has no effect on
the stage movements and is solely a scan coil function used to orient
the image relative to a specimen feature and/or detector direction. A
non-zero scan rotation is indicated by an icon in the
Status module,
and its value can be also displayed in optical quads (see Chapter 7).
The Beam Menu (Alt + B)
opens the Beam menu functions:
Electron Beam / CCD Camera
makes the quad or single screen active to the Electron Beam / CCD
Camera with respect to the source, column, scanning, and detector