Veeco Dimension 3100, Руководство пользователя

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Force Imaging
Force Calibration Control Panels and Menus
Rev. D Dimension 3100 Manual 217
13.3.5 Scan Mode Panel (Advanced Mode Only)
Trigger Mode
The Scan Mode panel allows you to use various triggers when obtaining Force Plot and Force
Volume plots. The idea of triggering simple: it limits the total amount of force exerted by the tip
upon the sample. Depending upon which trigger you use and how it is set, you may operate the
trigger independent of drift (
Relative ) or at some arbitrarily fixed point ( Absolute ).
Figure 13.3b Absolute and Relative Triggers
The plots in Figure 13.3b show the effect of drift on each of the two trigger types. The plot series
shown on the right side of Figure 13.3b utilizes a Relative trigger and maintains force at a constant
level defined by the Trig threshold parameter. The Relative trigger threshold is relative to the data
at the right of the plot where the cantilever is typically undeflected. As illustrated, the total force is
maintained, even as the system drifts.
The plot series on the left side of Figure 13.3b utilizes an Absolute trigger. Notice that as the
system drifts (plot moves slowly downward), total force increases. Drift may be due to mechanical
causes, or due to thermal effects on the cantilever. An
Absolute trigger permits the total force to be
set using Setpoint values.
Trigger Channel
This parameter defines the channel to watch to determine when to reverse the ramp.
Total Force