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1 – 4
1.5 Phase sensitive detector
12. Turn the SENSITIVITY knob counterclockwise 2 clicks, to
10 mV. Verify the meter displays less than 20% deviation. Re-
peat trimming frequency and depth with the INPUT FILTER
knob to minimize the meter deflection. The meter should be
less than 10% deviation.
13. Turn SENSITIVITY 3 clicks clockwise, back to 100 mV. Press
[Mode] to return the output to Lock-In mode.
14. Press the [Type] button twice, to select Band Pass. The meter
should be near 100% deviation.
15. Perform an auto-phase adjustment by pressing the [Phase] but-
ton within the AUTO block. After a brief delay, the REFER-
ENCE display should show near 180 deg, and the panel meter
should show 100% deviation.
16. Press the [Type] button again to select High Pass filter. The
panel meter should move near 0 deflection.
17. Perform another auto-phase adjustment by pressing [Phase] in
the AUTO block. After the pause, the phase should show a
value near 90 deg, and the meter should return to near 100%
deflection.
18. Press the [Type] button again to select Low Pass filter. The
meter should swing to near 100% deflection.
19. Perform another auto-phase adjustment by pressing [Phase] in
the AUTO block. After the pause, the phase should show a
value near 270 deg, and the meter should return to near 100%
deflection.
This section walks you through a demonstration of how the phase
sensitive detector (square wave mixer) operates. You will need an
oscilloscope to view the output waveforms.
A BNC cable should connect the Reference Output (Ref. Out) to the
A I signal input. Connect the OUTPUT BNC to the oscilloscope.
1. Restore
default
REFERENCE if necessary to display "deFLt", and then
press [Recall] again.
2. Change the reference frequency from 1.000 kHz to 100 Hz by
turning the Range knob counterclockwise one click. Turn
the large REFERENCE knob counterclockwise to set the fre-
quency to 47 Hz.
settings
by
pressing
SR124 Analog Lock-In Amplifier
Getting Started
[Recall];
turn
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