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NanoTrak Autoalignment Controller
Fig. 3.9 CRT displays and actuator adjustments
3.6.2
Using an External Power Meter
Power meters are available that may give greater sensitivity and accuracy than the
integral power meter of the NanoTrak. The output of the detector should be connected
to the power meter, and the power meter O/P connected to the ‘SIG IN’ connector on
the rear panel of the NanoTrak. The input defaults to a range of 1 V, although this can
be changed to 2V, 5V or 10 V from the Settings panel – see Section 3.5.2.
Note
If the circle reaches the edge of the display, this means that the piezo
actuators cannot move far enough to reach the position of maximum
power. The horizontal and vertical actuators should be adjusted to bring
the circle away from the edge of the screen – see Fig. 3.9.
If the circle tends to drift, increase the scan circle diameter, if the circle
tends to oscillate, decrease the scan circle diameter.
Note
Use only an external power meter which gives a true analog output and
does not introduce any phase shift into the system. Some power meters
give a smoothed output only suitable for driving a chart recorder.
Decrease horizontal actuator
Decrease vertical actuator
Increase horizontal actuator
Increase vertical actuator
