JEOL JSPM-5200 Instructions Manual page 113

５ MEASUREMENT OPERATION
Adjust the Offset slider o
voltage becomes 0 V (so that the waveform of the bias voltage can be generated
with 0 V as the center line).
3.
Click on the Retract Off button and set the cantilever to an approach state.
Monitor Z/20 using oscilloscope CH1 and confirm that the Z voltage is in the
vicinity of 0 V. If the Z voltage is extremely far either above or below 0 V, adjust it.
4.
Select 1 or 2 from the Loop Gain box of the SPM Parame
5.
Move the Offset slider button to the plus side, and click on th
button in the Lock-in Amplifier window to make an automatic phase
adjustment.
6.
Confirm that the reading of the analog meter on the lock-in amplifier changes
toward the plus direction when you drag the Offset slider button in the KFM
window to the plus side (the bias voltage changes to the plus side).
7.
Click on the Retract On button to retract the tip from the specimen; check the
KFM Feedba
window to MIN.
5-50
f the KFM window so that the DC component of the bias
Judge whether or not automatic phase adju
To do this, click on the +90 butt
reading of the lock-in amplifier analog meter changes from 0 → negative → 0
→ positive each time the phase is changed 90 ° by clicking on the +90 button,
phase adjustment is normal. Stop clicking on the button when the analog meter
registers positive. If it does not indicate 0 when the phase is +90°, or +270°,
carry out the automatic phase adjustment again.
This polarity results from the fact that the automatic phase adjustment was
performed after changing the bias voltage to the plus side. If the polarity is
reversed, click on the +90 button twice to rotate the phase by 180 ° .
ck on check box; then set Time Constant in
If the lock-in amplifier meter needle swings beyond the scale (or in the case of
Model 5110, the OVLD LED lights up), lower its sensitivity using the Lock-In
Ampli fier window.
stment has been properly carried out.
on in the Lock-in-Amplifier window. If the
the Lock-in-Amplifier
ters window.
e Auto Configure
TMPM5200-2