Functions - Stanford Research Systems SR865 Operation Manual

Chapter 3

Functions

[Auto Phase]
[Auto Phase] adjusts the reference phase shift so that the measured signal phase is 0°.
This is done by subtracting the measured value of θ from the reference phase shift. It will
take several time constants for the outputs to reach their new values during which time θ
will move towards 0°. Do not press [Auto Phase] again until the outputs have stabilized.
When the measurement is noisy or if the outputs are changing, Auto Phase may not result
in a zero phase.
[Auto Range]
[Auto Range] will adjust the Input Range so that the input signal does not overload the
input amplifier and that there is sufficient gain to drive the A/D converter. Remember
that the signal input is both the signal at f
largest component of the signal will determine the resulting input range.
When the input is at very low frequency, [Auto Range] may not function well. In this
case it is better to watch the signal strength indicators and change the input range
manually.
[Auto Scale]
[Auto Scale] will adjust the Sensitivity so that the displays and outputs of X, Y and R are
optimized. This results in numeric and bar graph displays with the best resolution
possible.
Note that the Sensitivity will affect analog outputs proportional to X, Y and R.
not use [Auto Scale] if changes to the analog output scales cannot be tolerated in the
experiment.
[Save Recall]
Press [Save Recall] to display the Save/Recall screen.
plus noise which may be much larger. The
ref
SR865 DSP Lock-in Amplifier
Operation 85
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