Instruction manual

TappingMode AFM
Engaging The Microscope
Rev. B MultiMode SPM Instruction Manual 113
actual setpoint value adjusted by the user prior to engage is meaningless because the operating
setpoint is determined automatically during engage by the control program.
2. Select View > Image Mode, or click the Back to Image Mode button or the Image Mode
icon. and the parameters set in the Cantilever Tune control panel will now appear in the
Feedback Controls panel. The value of the RMS amplitude displayed on the laser signal
display will now hold steady at the amplitude that coincided with the selected Drive
frequency. After the microscope is engaged, the RMS amplitude value displayed on the
display monitor will match the Setpoint parameter specified in the Feedback Controls
panel.
7.3 Engaging The Microscope
After cantilever oscillation has been adjusted and the operating point is defined, the microscope is
nearly ready to engage. The following items remain to be done:
1. Recheck all control panel parameters. For the calibration standard, set the parameters as
shown in Figure 7.3a and Figure 7.3b. The feedback gains and the scan rate are the most
important parameters. Start with the Integral gain set to 0.50 and the Proportional gain set
to about 0.7 and set the LookAhead gain to zero. The scan rate should be set below 2Hz.
Figure 7.3a Suggested Scan Controls Settings During TappingMode Setup
006