
Fluid Imaging
Operating Principles
Rev. D Dimension 3100 Manual 167
7. Center the peak on the frequency sweep plot shown on the display monitor using the Zoom
In and Offset commands after identifying the maximum amplitude peak with the lowest
frequency in the frequency response plot. This peak is usually in the 8-12kHz range.
Note: The Offset command sets the center frequency equal to the cursor position to
shift the plot. The Zoom In command decreases the sweep width and shifts the
center frequency value to stretch the plot.
8. Increase the Drive Amplitude until the peak appears.
9. Continue to Zoom In and center the peak until the peak coincides with the vertical center
line within 10Hz. The value displayed for center frequency is now used as the resonant
frequency of the cantilever.
Note: The system works well in TappingMode if the center frequency is at, or below,
the peak in the resonance plot. The center frequency can decrease to the point
where the oscillation amplitude reaches 90 percent of the maximum value.
Operate at a frequency lower than the resonant frequency to avoid shifting the
resonant frequency upon approach of the tip to the surface (see Figure 10.5e).
Figure 10.5d Cantilever Tune Control Panels for Main Controls
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