Fluid Operation
General Fluid Operation
Rev. B
MultiMode SPM Instruction Manual
133
2. To avoid sample damage, reduce the
Deflection Setpoint
as low as possible:
a. Stop when the tip pulls off the surface and the
Z Center Position
on the display
monitor jumps to
Limit
(
-220V
).
3. Increase the setpoint until the tip begins to touch the surface again and an image appears.
•
As an alternative, use the
Force Calibration
command
to select the setpoint and
estimate the contact force (see
•
Because the tip typically adheres to the sample surface much less in
fl
uid, it is possible
to image at much smaller contact forces in liquid than in air.
•
The optimal integral and proportional gains and scan rate may be different from air
operation, because the dynamics of the cantilever change in
fl
uid.
4. Set the two gains as high as possible (starting with the integral gain) without causing
oscillation distortion to appear in your image.
5. Choose a scan rate that is sufficiently slow to image without degrading your data.
8.2.10 Clean and Dry Parts When Done
1. When sample imaging is complete, drain the fluid cell and carefully remove it from the head.
Avoid spilling fluid.
2. Rinse and dry the fluid cell, and O-ring if applicable, to prevent the buildup of salts or other
contaminants on these parts.
CAUTION:
When cleaning the fluid cell, use care to avoid scratching the glass
surfaces in the center of the fluid cell.