Chapter 2. Performing Measurements
6. In the range chosen determine the contact resonance frequency of the cantilever
(
,
…). For that:
AFAM
n
f
1
AFAM
n
f
2
a. Turn on the feedback (
button is pressed in).
b. Open the instrument block scheme with the
Scheme
button in the Additional
Operations Panel. Supply voltage from the generator to the ultrasound transducer
by turning the key to
Ex6
position (Fig. 2-6).
Fig. 2-6
c. In the control panel of
Resonance
tab make the following changes (Fig. 2-7):
-
In
Generator Output
drop-down box select
Ex6
(Fig. 2-7).
At this the generator
output voltage is applied to the transducer.
Fig. 2-7
-
Set the gain factor of the lock-in amplifier equal to
10
(Fig. 2-8) since the
response in AFAM is much smaller than in the semicontact technique.
Fig. 2-8
d. Click
Run
button to plot the frequency response of cantilever oscillation amplitude
(
Mag
signal).
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