AC Tune Window and AC Mode Tune Dialog Box L4

AC Tune Window and AC Mode Tune Dialog Box L4 - AC Tune...

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AC Tune Window and AC Mode Tune Dialog Box The AC Tune window and AC Mode Tune dialog box let you match the AC Mode oscillation signal to the frequency of the particular cantilever in use. The AC signal is generated by the MAC Mode or MAC III Controller . In the case of the Agilent 5400 SPM the Head Electronics Box can also supply the drive signal. To tune the AC mode signal: 1. Choose Controls > AC Mode Tune to open the AC Tune window and AC Mode Tune dialog box. 2. In the upper Auto Tune area of the AC Mode Tune dialog box, enter the Start and End frequencies (in kHz) for the tuning sweep. For a new or unknown cantilever, use the stated minimum and maximum frequencies given on the cantilever's storage box. If you happen to know the resonance frequency more exactly, you can use a smaller range to speed the tuning process. 3. Set the Peak Amplitude , which is the maximum desired amplitude of cantilever oscillation during the sweep. 2 volts is a typical starting value. With the MAC III controller you can simply enter 2V. With a standard MAC Mode controller , however the peak amplitude must be multiplied by 4.3 to give the equivalent value (e.g., enter 2*4.3 = 8V for a peak amplitude of 2V). The amplitude will appear as 2V in the AC controller display and 8.6V in PicoView. 4. Since the peak tends to shift down when near the surface, the oscillation frequency should be set slightly below the actual resonance frequency of the cantilever. To achieve this, enter an Off Peak value to offset the oscillation frequency from the cantilever's resonance frequency. A typical starting value is -0.200 kHz. 5. Click the Auto Tune button. The system will sweep several times from the Start to End frequencies, locating the peak oscillation amplitude.The sweeps will appear in the AC Tune window. PicoView will locate the peak and zoom in on it. It will also adjust the drive to make the peak match the Peak Amplitude setting. 6. The AC signal oscillation will be set to the frequency where this amplitude occurs, taking into account the specified Off Peak offset.
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AC Tune Window In the AC Tune window you'll tune the AC Mode oscillation signal to match the frequency of the particular cantilever in use. The AC signal is generated by the MAC Mode or MAC III Controller , or, in the case of the Agilent 5400 SPM, by the Head Electronics Box. A description of the AC Mode tuning procedure is given under AC Tune Window and AC Mode Tune Dialog Box . Based on the check boxes at the bottom of the AC Mode Tune dialog box you can display the Amplitude , Phase , X component and/or Y component from the lock-in amplifier. When you move your cursor over the vertical axis at the left of any plot, the cursor will change to an
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This note was uploaded on 09/08/2010 for the course MATE 145 at San Jose State University .

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AC Tune Window and AC Mode Tune Dialog Box L4 - AC Tune...

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