Instruction manual

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objective lens by clicking the DeGauss button in the Column tab.
Precise Aperture Alignment is difficult at low magnifications of 10,000 times or lower.
After coarse alignment at low magnifications, do fine alignment at high magnifications
of a few ten thousand times. It is important to adjust the focus optimally in order to
carry out precise aperture alignment.
NOTE: You can bring Aperture Alignment mode directly by clicking the Align
button on
the Control Panel.
(3) Stigma Alignment X, Y
Stigma Alignment is necessary to minimize image drift seen when correcting the astigmatism.
(a) Set the magnification to about 5,000× and position a point of interest in the center of the
display.
(b) Focus the image and correct astigmatism.
(c) Click
Stigma Align X
button in the
Alignment
dialog window and make adjustments so
that the wobbling motion of the image is minimized.
(d) Click the
Stigma Align Y
button in the
Alignment
dialog window and repeat the same
adjustment as above (c).
(e) Turn off the Stigma Align mode (click
Off
button in the
Alignment
dialog window).
NOTICE: Stigma Alignment may cause mis-aligning of Aperture Alignment.
Repeat Aperture Alignment again after completing Stigma Alignment (X/Y).
Stigma Alignment does not change by Aperture Alignment.
(4) Adjustment of Low Mag Position
The S-4800 has two magnification modes: High Mag mode and Low Mag mode.
Low Mag Position adjustment is necessary to minimize a shift in the field of view for the two
magnification modes. Perform the following procedure to keep the area of interest centered
when going between Low Mag and High Mag modes.
(a) In High Mag mode, go to the minimum magnification allowable and place a point of interest
in the center of the display. It is recommended to display the cross hair cursor by
checking the
Area Marker
box on the
Operation panel.
(b) Go to Low Mag mode by clicking
H/L
button in the magnification display area.
(c) Focus the image and correct astigmatism.
(d) Click the
Low Mag Position
button in the
Alignment
dialog window and make
adjustments so that the point of interest on the specimen is in the center of the display
(drag the mouse holding down the left button in the Alignment operation area, or adjust
STIGMA/ALIGNMENT
knobs on the operation panel).