Calibration, Maintenance, Troubleshooting and Warranty
Contact AFM Troubleshooting
318
MultiMode SPM Instruction Manual
Rev. B
Selecting a large
Scan size
and a high scan rate for a few scans can “sweep” an area clear.
Decreasing the
Scan size
to image within the “swept” area can improve the quality of atomic
images.
Finally, adjust the force exerted on the sample. Engagement requires a positive de
fl
ection of the
cantilever, but the microscope will operate at much lower forces and lowering the force sometimes
improves the image quality. Decrease the
Setpoint
in small increments to lower the force. Once
engaged and the
Scan
size
is signi
fi
cantly increased, sometimes more force is necessary to keep the
tip scanning on the sample surface. Increase the
Setpoint
in small increments to increase the force.
15.11.11 Force Calibration command does not seem to work
Most often, the
Force Cal.
command will not provide a meaningful display, when
fi
rst invoked.
Z
scan start
and
Scan size
as well as
Setpoint
affect the position and shape of the curve, and will
probably require adjustment to achieve a useful display. The negatively sloped sensitivity line
should, however, always be straight for a proper force curve.
15.11.12 Image features appear washed out
The
Data Scale
in the active
Channel
panel might be too large. Decrease the scale for more
contrast between features.
15.11.13 Image is only black and white
The
Data Scale
in the active
Channel
panel is to small. Increase the scale for less contrast between
features.
15.11.14 Image goes white
If, when using an “A” scanner, the image goes white after a couple of scans and the Z center voltage
is still within range, check the
Realtime Plane
fi
t
parameter on the active
Channel
panel. When
using an “A” scanner, it should be set to
Line
or
Offset
instead of
None
. In general, this will be a
problem anytime there is a signi
fi
cant amount of drift in the Z center voltage, but drift is especially
prevalent with “A” scanners.
