User`s guide

Additional Imaging Modes 7
Agilent 5500 SPM User’s Guide 135
4
Choose Controls > Spectroscopy to open the Spectroscopy
window (Figure 90).
Figure 90 Use the Spectroscopy window to optimize the Setpoint value
5 Select Amplitude vs Distance at the top of the Main tab.
6 On the Advanced tab set the Aux 1 Input to SP.
7 On the Lock-in 2 tab verify that the From Servo box is not checked.
8 To prevent damage to the tip during the Amplitude vs Distance
cycle, the total motion of the piezo needs to be reduced so that it does
not contact the sample surface. Note the position of the piezo in the
Servo window indicator. Enter a slightly more positive value for the
End parameter in the Spectroscopy window.
9 Click on the blue triangle to begin the piezo movement and observe
the SP response in the Spectroscopy window.
10 In the Advanced AC Mode Controls window’s Other tab, increase
the Setpoint value in small increments until the SP vs Distance plot
is as horizontal as possible. Hold down the Shift and Ctrl keys while
pressing the Up arrow on the keyboard to increment the amount by
0.001. The traces will probably be noisy, but make them as
horizontal as possible. This adjustment has the largest effect on the
output of the SP servo and typically has a value of less than 0.05.
The servo values should now be optimized.
11 Stop the Spectroscopy.
12 On the Lock-in 2 tab select the From Servo check box.